WTNT42 KNHC 130248
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST SUN SEP 12 2010
 
INFRARED AND MICROWAVE SATELLITE IMAGERY SHOW THAT THE CENTER OF
THE CYCLONE IS LOCATED NEAR THE EASTERN EDGE OF A CURVED BAND OF
CONVECTION THAT WRAPS AROUND THE WESTERN SEMICIRCLE OF THE SYSTEM.
SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE 35 KT FROM TAFB AND 30 KT
FROM SAB.  OBJECTIVE DVORAK ESTIMATES FROM UW/CIMMS ARE SLIGHTLY
HIGHER.  A BLEND OF THESE ESTIMATES SUPPORT AN UPGRADE OF THE
DEPRESSION TO A 35-KT TROPICAL STORM...THE TENTH OF THE 2010 
ATLANTIC HURRICANE SEASON.
 
THE EASTERLY SHEAR IS EXPECTED TO WEAKEN DURING THE NEXT 12 HOURS
AND IS FORECAST TO REMAIN LIGHT OVER THE NEXT COUPLE OF DAYS.
DURING THAT TIME JULIA WILL BE TRAVERSING WARM WATER AND AS A
RESULT...STEADY STRENGTHENING IS ANTICIPATED.  THE SHIPS...LGEM...
AND GFDL MODELS ALL BRING JULIA TO HURRICANE STATUS WITHIN TWO DAYS
AND THE NHC FORECAST IS IN GOOD AGREEMENT.  THEREAFTER...JULIA WILL
BE MOVING OVER SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND INTO AN
AREA OF INCREASING SOUTHWESTERLY SHEAR TO THE EAST OF AN
UPPER-LEVEL LOW/TROUGH BETWEEN 30W AND 40W.  IT IS A BIT SURPRISING
GIVEN THESE NEGATIVE FACTORS THAT THE INTENSITY GUIDANCE SHOWS
LITTLE...IF ANY...WEAKENING.  BECAUSE OF THAT...THE OFFICIAL
FORECAST WILL KEEP JULIA AT 65 KT AT DAYS 3-5 FOR NOW.
 
THE CENTER OF JULIA WAS RELOCATED A LITTLE EAST OF THE PREVIOUS
ADVISORY POSITION BASED ON THE EARLIER MICROWAVE DATA.  THE INITIAL
MOTION ESTIMATE IS 285/10.  THE TRACK FORECAST REASONING REMAINS
THE SAME AS THE PREVIOUS ADVISORY.  JULIA IS FORECAST TO MOVE
WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A MID-LEVEL
RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN ATLANTIC. 
IN A COUPLE OF DAYS...THE CYCLONE IS FORECAST TO TURN NORTHWESTWARD
TOWARD A WEAKNESS IN THE RIDGE.  MOST OF THE GUIDANCE INDICATES A
TURN BACK TOWARD THE WEST-NORTHWEST LATE IN THE PERIOD AS JULIA
MOVES AROUND THE NORTH SIDE OF AN UPPER-LEVEL LOW THAT CUTS OFF
NEAR 40W.  THE OFFICIAL FORECAST TRACK IS GOOD AGREEMENT WITH THE
PREVIOUS ADVISORY AND A BLEND OF THE LATEST RUNS OF THE GFS...
UKMET...GFDL...HWRF...AND ECMWF MODELS.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/0300Z 13.5N  23.5W    35 KT
 12HR VT     13/1200Z 14.0N  25.3W    45 KT
 24HR VT     14/0000Z 14.9N  27.6W    50 KT
 36HR VT     14/1200Z 15.9N  29.5W    55 KT
 48HR VT     15/0000Z 17.1N  31.1W    65 KT
 72HR VT     16/0000Z 20.9N  35.1W    65 KT
 96HR VT     17/0000Z 24.5N  41.0W    65 KT
120HR VT     18/0000Z 27.5N  46.5W    65 KT
 
$$
FORECASTER BROWN
 

WTNT42 KNHC 130837
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST MON SEP 13 2010
 
THERE HAS NOT BEEN MUCH CHANGE TO THE OVERALL ORGANIZATION OF THE
CLOUD PATTERN OF JULIA.  MOST OF THE BANDING FEATURES ARE OVER THE
WESTERN SEMICIRCLE OF THE CIRCULATION WITH PERHAPS A SLIGHT
INCREASE IN DEEP CONVECTION NEAR THE CENTER.  DVORAK INTENSITY
ESTIMATES FROM BOTH SAB AND TAFB ARE 35 KT...SO THE WIND SPEED IS
UNCHANGED FROM THE PREVIOUS ADVISORY.  VERTICAL SHEAR IS EXPECTED
TO BE WEAK FOR THE NEXT DAY OR TWO AS JULIA MOVES AWAY FROM AN AREA
OF STRONG UPPER-LEVEL EASTERLIES ASSOCIATED WITH A RIDGE OVER WEST
AFRICA.  LATER IN THE FORECAST PERIOD THE TROPICAL CYCLONE COULD
EXPERIENCE A SIGNIFICANT INCREASE IN SHEAR DUE TO THE INFLUENCE OF
AN UPPER-LEVEL TROUGH OVER THE EASTERN SUBTROPICAL ATLANTIC...WHICH
WOULD LIMIT INTENSIFICATION.  THERE IS THE POSSIBILITY THAT A
CYCLONE WILL CUT OFF FROM THE TROUGH AND BECOME SITUATED TO THE
SOUTH OR SOUTHWEST OF JULIA.  THIS SCENARIO COULD RESULT IN LESS
SHEAR AND ALLOW MORE STRENGTHENING NEAR THE END OF THE PERIOD.
HOWEVER...THE GFS INPUT TO THE SHIPS AND LGEM MODELS SHOWS 25 TO 35
KT OF SHEAR AT 96-120 HOURS.  GIVEN THE UNCERTAINTIES THE OFFICIAL
FORECAST...LIKE THE PREVIOUS ONE...SHOWS NO CHANGE IN STRENGTH
BEYOND 48 HOURS.  THIS IS CLOSE TO THE INTENSITY MODEL CONSENSUS
THROUGH 48 HOURS AND IS SIMILAR TO THE LGEM GUIDANCE FOR DAYS 3 TO
5.
 
LATEST CENTER FIXES ARE A BIT TO THE NORTH OF THE PREVIOUS TRACK.
THIS MAY BE THE RESULT OF SOME REFORMATION OR MERELY BECAUSE THE
CENTER HAS BEEN DIFFICULT TO LOCATE.  AFTER SOME ADJUSTMENTS...THE
INITIAL MOTION IS ESTIMATED TO BE 300/11.  NOTWITHSTANDING THE
SLIGHT NORTHWARD ADJUSTMENT...THE TRACK FORECAST REASONING REMAINS
ESSENTIALLY THE SAME AS IN THE PREVIOUS ADVISORY.  JULIA IS EXPECTED
TO MOVE WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A
MID-LEVEL RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN
ATLANTIC.  IN ABOUT 48 HOURS...A WEAKNESS IN THE RIDGE SHOULD CAUSE
THE TROPICAL CYCLONE TO TURN NORTHWESTWARD.  THERE IS A FAIR AMOUNT
OF SPREAD IN THE MODEL FORECAST TRACKS FOR DAYS 3 TO 5....AND THE
OFFICIAL FORECAST IS BASICALLY DOWN THE MIDDLE OF THE SUITE.  THIS
IS CLOSE TO BUT A TAD SLOWER THAN THE MODEL CONSENSUS DURING THE
LATTER HALF OF THE FORECAST PERIOD...AND ALSO A LITTLE NORTH OF THE
PREVIOUS NHC FORECAST TRACK DUE TO THE NORTHWARD RELOCATION.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/0900Z 14.4N  24.6W    35 KT
 12HR VT     13/1800Z 15.1N  26.2W    45 KT
 24HR VT     14/0600Z 16.2N  28.2W    50 KT
 36HR VT     14/1800Z 17.5N  30.1W    55 KT
 48HR VT     15/0600Z 19.0N  31.9W    65 KT
 72HR VT     16/0600Z 22.5N  36.0W    65 KT
 96HR VT     17/0600Z 25.5N  41.0W    65 KT
120HR VT     18/0600Z 28.5N  46.5W    65 KT
 
$$
FORECASTER PASCH
 

WTNT42 KNHC 131453
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST MON SEP 13 2010

METEOSAT-9 IMAGERY AND A 0938 UTC SSMIS MICROWAVE OVERPASS INDICATE
LITTLE CHANGE IN THE CLOUD PATTERN DURING THE PAST 6 HOURS. THE
MAJORITY OF THE CONVECTIVE BANDING IS SITUATED OVER THE WESTERN
PORTION OF THE CYCLONE...WHERE THE UPPER-LEVEL OUTFLOW IS THE MOST
IMPRESSIVE.  DVORAK TECHNIQUE INTENSITY ESTIMATES FROM BOTH TAFB
AND SAB ARE T2.5...35 KT...AND THIS IS THE INITIAL INTENSITY.

THE DYNAMICAL MODELS AND THE SHIPS MODEL SUGGEST THAT THE
UPPER-LEVEL WIND PATTERN SHOULD REMAIN CONDUCIVE FOR STRENGTHENING
DURING THE NEXT 48 HOURS.  BEYOND THAT TIME...JULIA COULD BE
IMPACTED BY A SUBSTANTIAL INCREASE IN WESTERLY SHEAR DUE TO AN
AMPLIFYING UPPER-LEVEL TROUGH OVER THE EASTERN SUBTROPICAL
ATLANTIC...WHICH SHOULD HINDER FURTHER INTENSIFICATION. THE NHC
INTENSITY FORECAST REFLECTS THIS SCENARIO BY MAINTAINING JULIA AS A
LOW-END HURRICANE THROUGH 96 HOURS.  AFTERWARD...THE SHIPS...
LGEM...AND THE LARGE-SCALE MODELS ALL SUGGEST THAT THE UPPER-LEVEL
OUTFLOW ASSOCIATED WITH HURRICANE IGOR WILL CREATE MODERATE TO
STRONG NORTHEASTERLY SHEAR OVER JULIA. THIS INCREASE IN SHEAR
AROUND DAY 5 IS REFLECTED IN THE OFFICIAL FORECAST...WHICH SHOWS
JULIA WEAKENING INTO A TROPICAL STORM. 

BASED ON A NUMBER OF MICROWAVE FIXES...THE INITIAL MOTION IS
ESTIMATED TO BE WEST-NORTHWESTWARD...295/12...A LITTLE LEFT OF THE
PREVIOUS ADVISORY.  THE DYNAMICAL MODELS ARE IN GOOD AGREEMENT
THROUGH DAY 5 WITH A NORTHWESTWARD TURN IN 36 HOURS IN RESPONSE TO
A MID- TO UPPER-LEVEL CUT-OFF LOW LOCATED TO THE NORTHWEST OF
JULIA. BEYOND THIS TIME...THE EASTERN EXTENT OF THE SUBTROPICAL
RIDGE GRADUALLY BUILDS NORTHEAST OF THE CYCLONE AS THE CUT-OFF LOW
WEAKENS AND DISSIPATES.  THIS SHOULD ALLOW JULIA TO MAINTAIN A
GENERAL NORTHWESTWARD MOTION THROUGH DAY 5.  THE OFFICIAL FORECAST
FAVORS THE TVCN MULTI-MODEL CONSENSUS AND LIES BETWEEN THE GFS AND
ECMWF GLOBAL MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/1500Z 14.9N  26.1W    35 KT
 12HR VT     14/0000Z 15.6N  27.6W    45 KT
 24HR VT     14/1200Z 16.7N  29.6W    55 KT
 36HR VT     15/0000Z 18.1N  31.4W    60 KT
 48HR VT     15/1200Z 19.6N  33.2W    65 KT
 72HR VT     16/1200Z 22.8N  37.7W    65 KT
 96HR VT     17/1200Z 25.5N  43.0W    65 KT
120HR VT     18/1200Z 28.5N  47.5W    60 KT
 
$$
FORECASTER ROBERTS/BRENNAN
 

WTNT42 KNHC 132039
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST MON SEP 13 2010

SATELLITE IMAGERY SHOWS THAT JULIA HAS BECOME BETTER ORGANIZED THIS
AFTERNOON...AS THE EASTERLY SHEAR APPEARS TO HAVE DIMINISHED A BIT. 
BANDING CONTINUES TO IMPROVE OVER THE WESTERN SEMICIRCLE AND A
SMALL IRREGULAR CENTRAL DENSE OVERCAST FEATURE IS DEVELOPING OVER
THE CENTER. THE INITIAL INTENSITY OF 45 KT IS BASED ON A BLEND OF
DVORAK ESTIMATES OF 35 AND 45 KT FROM TAFB AND SAB...RESPECTIVELY
...AND A UW-CIMSS ADT ESTIMATE OF 53 KT USING THE SHEAR PATTERN.

THE LARGE-SCALE MODELS...THE LGEM...AND THE SHIPS MODEL CONTINUE TO
SHOW AN UPPER-LEVEL WIND ENVIRONMENT CONDUCIVE FOR STRENGTHENING
DURING THE NEXT 36 TO 48 HOURS.  AFTER THAT TIME...THE CYCLONE
SHOULD FEEL THE AFFECTS OF INCREASING WESTERLY SHEAR DUE TO AN
AMPLIFYING MID- TO UPPER-LEVEL TROUGH OVER THE EASTERN SUBTROPICAL
ATLANTIC...WHICH SHOULD CURTAIL FURTHER INTENSIFICATION. THE NHC
INTENSITY FORECAST CALLS FOR JULIA TO BECOME A HURRICANE IN 24
HOURS AND THEN BASICALLY MAINTAIN THIS INTENSITY THROUGH DAY 4. 
AFTERWARD...THE DYNAMICAL MODELS ALL SUGGEST THAT THE UPPER-LEVEL
OUTFLOW ASSOCIATED WITH LARGER HURRICANE IGOR WILL PRODUCE MODERATE
TO STRONG NORTHEASTERLY SHEAR OVER JULIA.  THIS INCREASE IN SHEAR
IS REFLECTED IN THE NHC FORECAST...WHICH SHOWS JULIA WEAKENING
TO A TROPICAL STORM AT DAY 5.
 
THE INITIAL MOTION IS BASICALLY THE SAME AS THE PREVIOUS ADVISORY
AND IS ESTIMATED TO BE WEST-NORTHWESTWARD...OR 295/12.  THE GFS...
GFS ENSEMBLE MEAN...HWRF...AND THE GFDL ARE NOW INDICATING MORE
OF A NORTHWESTWARD MOTION DURING THE 24 TO 36 HOUR PERIOD DUE TO A
DEVELOPING MID- TO UPPER-LEVEL CUT-OFF LOW LOCATED NORTH-NORTHWEST
OF JULIA.  HOWEVER...THE NOGAPS...ECMWF...AND UKMET SHOW A
CONTINUED WEST-NORTHWESTWARD TRACK...WHICH APPEARS TO BE DUE TO A
SHALLOWER VERTICAL STRUCTURE OF THE CYCLONE.  THROUGH THE REMAINDER
OF THE FORECAST PERIOD...THE EASTERN EXTENT OF THE SUBTROPICAL
RIDGE GRADUALLY BUILDS NORTHEAST OF THE JULIA AS THE AFOREMENTIONED
CUT-OFF LOW WEAKENS AND DISSIPATES.  THIS SHOULD ALLOW JULIA TO
MAINTAIN A GENERAL NORTHWESTWARD MOTION.  THE OFFICIAL FORECAST IS
BASED ON THE TVCN CONSENSUS MODEL AND IS WEIGHTED MORE TOWARD THE
MODELS THAT INDICATE A TURN TOWARD THE NORTHWEST AROUND 36 HOURS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/2100Z 15.3N  27.5W    45 KT
 12HR VT     14/0600Z 16.0N  29.0W    50 KT
 24HR VT     14/1800Z 17.3N  30.8W    65 KT
 36HR VT     15/0600Z 18.8N  32.4W    65 KT
 48HR VT     15/1800Z 20.5N  34.4W    70 KT
 72HR VT     16/1800Z 23.8N  39.7W    70 KT
 96HR VT     17/1800Z 27.0N  46.0W    65 KT
120HR VT     18/1800Z 30.0N  49.5W    55 KT
 
$$
FORECASTER ROBERTS/BRENNAN
 

WTNT42 KNHC 140255
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST MON SEP 13 2010

A RECENT AMSU MICROWAVE PASS SHOWS IMPROVED BANDING OVER THE WESTERN
SEMICIRCLE AND THAT THE DEEP CONVECTION IS NOW WRAPPING AROUND THE
SOUTHERN PORTION OF THE CIRCULATION.  DESPITE THE IMPROVED
PRESENTATION...DVORAK ESTIMATES FROM SAB AND TAFB REMAIN 45 KT...SO
THE INITIAL INTENSITY IS MAINTAINED FOR NOW.  THIS IS ALSO
SUPPORTED BY A 2324 UTC ASCAT PASS THAT SHOWED SEVERAL 35-40 KT
WIND VECTORS OVER THE NORTHEAST QUADRANT.
 
THE INITIAL MOTION ESTIMATE IS 295/11 KT.  JULIA IS FORECAST TO TURN
NORTHWESTWARD IN ABOUT 12-24 HOURS AS IT MOVES BETWEEN THE WESTERN
PERIPHERY OF A MID-LEVEL RIDGE AND AN AMPLIFYING MID- TO
UPPER-LEVEL TROUGH OVER THE EASTERN ATLANTIC.  THEREAFTER JULIA IS
EXPECTED TO MOVE IN A DIRECTION BETWEEN WEST-NORTHWEST AND NORTHWEST
AS A MID-LEVEL RIDGE STRENGTHS TO THE NORTH AND NORTHEAST OF THE
CYCLONE.  THE TRACK GUIDANCE IS IN GENERAL AGREEMENT ON THIS
SCENARIO...BUT THERE IS SOME SIGNIFICANT SPREAD ON WHEN THE
NORTHWESTWARD TURN WILL OCCUR.  THE GFS/GFDL ARE ALONG THE EASTERN
EDGE OF THE GUIDANCE...WHILE THE UKMET AND NOGAPS ARE ALONG THE
WESTERN SIDE.  THE OFFICIAL FORECAST LIES BETWEEN THE TVCN
CONSENSUS AND THE GFS/GFDL SOLUTIONS...AND IS CLOSE TO THE PREVIOUS
NHC ADVISORY.

JULIA WILL BE OVER WARM WATER AND IN A LOW SHEAR ENVIRONMENT DURING
THE NEXT DAY OR SO.  THE SHIPS/LGEM GUIDANCE BRING THE CYCLONE TO
HURRICANE STRENGTH WITHIN THAT TIME AND SO DOES THE OFFICIAL
FORECAST.  THEREAFTER...INCREASING SOUTHWESTERLY SHEAR AND SLIGHTLY
COOLER SEA SURFACE TEMPERATURES ARE LIKELY TO HALT ANY ADDITIONAL
INTENSIFICATION.  AFTER 72 HOURS...THE GLOBAL MODELS SUGGEST THAT
STRONG UPPER-LEVEL NORTHEASTERLY WINDS ASSOCIATED WITH THE OUTFLOW
FROM IGOR WILL BEGIN TO IMPINGE UPON JULIA.  AS A RESULT...
WEAKENING IS ANTICIPATED AT DAYS 4 AND 5. 

THE WIND RADII WERE ADJUSTED OUTWARD BASED ON THE ASCAT DATA.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      14/0300Z 15.6N  28.0W    45 KT
 12HR VT     14/1200Z 16.3N  29.4W    55 KT
 24HR VT     15/0000Z 17.5N  31.1W    65 KT
 36HR VT     15/1200Z 19.1N  32.7W    70 KT
 48HR VT     16/0000Z 21.1N  35.1W    70 KT
 72HR VT     17/0000Z 24.3N  40.9W    65 KT
 96HR VT     18/0000Z 27.5N  46.5W    55 KT
120HR VT     19/0000Z 31.5N  50.0W    50 KT
 
$$
FORECASTER BROWN
 

WTNT42 KNHC 140837
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST TUE SEP 14 2010
 
JULIA HAS STRENGTHENED THIS MORNING.  A RAGGED EYE FEATURE HAS
OCCASIONALLY BEEN EVIDENT IN GEOSTATIONARY SATELLITE IMAGES DURING
THE PAST FEW HOURS AND THE CONVECTIVE BANDING HAS BECOME BETTER
ORGANIZED...ESPECIALLY OVER THE SOUTHERN SEMICIRCLE.  DVORAK
CLASSIFICATIONS FROM TAFB AND SAB WERE 65 KT...AND THE CIMSS ADT
ESTIMATES ARE ALSO NEAR THAT VALUE.  ON THIS BASIS...JULIA IS
UPGRADED TO A HURRICANE WITH THE INITIAL WIND SPEED SET AT 65 KT.

SOME ADDITIONAL STRENGTHENING APPEARS LIKELY DURING THE NEXT DAY OR
SO AS UNANIMOUSLY SHOWN BY THE MODEL GUIDANCE.  HOWEVER...SEA
SURFACE TEMPERATURES COOL BELOW 27 C ALONG THE FORECAST TRACK IN 24
TO 48 HOURS...AND THAT SHOULD LIMIT INTENSIFICATION DURING THAT
TIME PERIOD.  ALTHOUGH JULIA IS EXPECTED TO TRACK OVER WARMER
WATERS BEYOND A FEW DAYS...STRONG NORTH TO NORTHEASTERLY SHEAR...
ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR...SHOULD INDUCE
WEAKENING BY THAT TIME.  THE OFFICIAL FORECAST IS ADJUSTED UPWARD
DURING THE FIRST FEW DAYS AND THEN FALLS IN LINE WITH THE PREVIOUS
FORECAST BY THE END OF THE PERIOD...AND IS IN GOOD AGREEMENT WITH
THE STATISTICAL-DYNAMICAL GUIDANCE.
 
THE INITIAL MOTION ESTIMATE IS 295/10.  A MID- TO UPPER-LEVEL TROUGH
OVER THE EASTERN ATLANTIC IS EXPECTED TO CAUSE JULIA TO TURN
NORTHWESTWARD LATER TODAY AND CONTINUE IN THAT DIRECTION FOR THE
NEXT 24 TO 48 HOURS.  THEREAFTER...THE GLOBAL MODELS ARE IN
AGREEMENT IN SHOWING A SUBTROPICAL RIDGE TO STRENGTHEN NORTH OF
JULIA.  THIS PATTERN SHOULD CAUSE THE CYCLONE TO TURN BACK TO THE
WEST-NORTHWEST FOR A COUPLE OF DAYS.  BY THE END OF THE FORECAST
PERIOD...JULIA IS EXPECTED TO MOVE NORTHWESTWARD OR
NORTH-NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF THE RIDGE.  THE
OFFICIAL FORECAST IS ADJUSTED SLIGHTLY TO THE WEST IN THE 3 TO 5
DAY RANGE...TRENDING TOWARD THE MULTI-MODEL CONSENSUS. 
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      14/0900Z 16.1N  29.0W    65 KT
 12HR VT     14/1800Z 16.8N  30.1W    70 KT
 24HR VT     15/0600Z 18.1N  31.7W    80 KT
 36HR VT     15/1800Z 19.7N  33.6W    80 KT
 48HR VT     16/0600Z 21.5N  36.1W    75 KT
 72HR VT     17/0600Z 24.5N  42.5W    70 KT
 96HR VT     18/0600Z 27.5N  48.5W    60 KT
120HR VT     19/0600Z 32.0N  51.0W    50 KT
 
$$
FORECASTER CANGIALOSI
 

WTNT42 KNHC 141444
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST TUE SEP 14 2010
 
SATELLITE IMAGES INDICATE THAT JULIA IS STILL STRENGTHENING. A 0920
UTC SSM/IS OVERPASS SHOWED A WELL-DEFINED EYEWALL SURROUNDED BY TWO
PROMINENT BANDS...WHILE CONVENTIONAL IMAGERY SHOWS THE APPEARANCE
OF A WELL-DEVELOPED CENTRAL DENSE OVERCAST AND A BANDING-TYPE EYE.
SUBJECTIVE DVORAK T-NUMBERS AT 1200 UTC ARE 4.0 AND 5.0 FROM TAFB
AND SAB...RESPECTIVELY. THE INITIAL INTENSITY IS RAISED TO 75
KT...BASED UPON A BLEND OF THESE ESTIMATES.
 
WHILE SOME ADDITIONAL INTENSIFICATION IS POSSIBLE DURING THE NEXT 12
TO 24 HOURS...WATER VAPOR IMAGERY SHOWS A MID- TO UPPER-LEVEL
TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF HURRICANE IGOR...
LOCATED A FEW HUNDRED MILES NORTHWEST OF JULIA. GLOBAL MODELS
SUGGEST THAT THIS FEATURE SHOULD BEGIN TO IMPART WESTERLY SHEAR
OVER THE CYCLONE AFTER ABOUT 24 HOURS...AT ABOUT THE TIME JULIA
BEGINS TO PASS OVER MARGINAL SEA SURFACE TEMPERATURES. WATERS
SHOULD BEGIN TO WARM AGAIN ALONG THE FORECAST TRACK IN A FEW
DAYS...BUT MODEL GUIDANCE SHOWS A STRONG SURGE OF NORTHERLY FLOW
ASSOCIATED THE OUTFLOW OF IGOR THAT COULD NEGATIVELY IMPACT JULIA
AFTER 72 HOURS. IN FACT...SHIPS MODEL OUTPUT INDICATES THE
POTENTIAL FOR 30-40 KT OF NORTHERLY SHEAR. ALTHOUGH NO SIGNIFICANT
CHANGES WERE MADE TO THE OFFICIAL INTENSITY FORECAST...JULIA
COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR MATERIALIZES.
 
THE INITIAL MOTION ESTIMATE IS 295/09...INDICATING THAT JULIA HAS
RECENTLY SLOWED A BIT. THERE IS AN UNUSUAL AMOUNT OF SPREAD IN THE
SHORT-TERM TRACK FORECAST. THE GFS/HWRF/GFDL SHOW JULIA TURNING
TOWARD THE NORTHWEST DURING THE NEXT DAY OR SO AS IT INTERACTS WITH
AN EXTENSION OF A MID- TO UPPER-LEVEL CYCLONE LOCATED OVER THE
NORTHEAST ATLANTIC. THE UKMET/ECMWF FAVOR A WEST-NORTHWEST COURSE
AS A RESULT OF MORE SUBTROPICAL RIDGING. FROM ABOUT 36-72 HR...
THERE IS BETTER AGREEMENT IN THE MODEL GUIDANCE OF SUBTROPICAL
RIDGING BUILDING NORTH OF JULIA AND HENCE A MORE WEST-NORTHWESTERLY
COURSE WITH AN INCREASE IN FORWARD SPEED. AFTER 72 HR...GLOBAL
MODELS SHOW JULIA TURNING NORTH-NORTHWESTWARD AS IT APPROACHES THE
WESTERN END OF THE SUBTROPICAL RIDGE AND THE LARGE HURRICANE IGOR
OVER THE CENTRAL ATLANTIC. THE OFFICIAL NHC FORECAST TRACK IS
NUDGED A BIT TO THE RIGHT...LYING NEAR A CONSENSUS THAT EXCLUDES
THE UKMET.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      14/1500Z 16.2N  29.5W    75 KT
 12HR VT     15/0000Z 17.2N  30.8W    85 KT
 24HR VT     15/1200Z 18.7N  32.4W    80 KT
 36HR VT     16/0000Z 20.3N  34.5W    75 KT
 48HR VT     16/1200Z 22.2N  37.7W    70 KT
 72HR VT     17/1200Z 24.7N  44.3W    70 KT
 96HR VT     18/1200Z 28.0N  49.0W    60 KT
120HR VT     19/1200Z 32.5N  50.5W    50 KT
 
$$
FORECASTER KIMBERLAIN
 

WTNT42 KNHC 142036
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST TUE SEP 14 2010
 
THE CLOUD PATTERN ASSOCIATED WITH JULIA HAS BECOME SOMEWHAT
ASYMMETRIC DURING THE PAST SEVERAL HOURS...WITH A LARGE MASS OF
DEEP CONVECTION HAVING FORMED SOUTHWEST OF THE CENTER. THE
EYE THAT WAS VISIBLE EARLIER IS ALSO NO LONGER AS EVIDENT. THE
OUTFLOW HAS BECOME A BIT RESTRICTED TO THE WEST...INDICATIVE OF
SOME UPPER-LEVEL WESTERLY FLOW ALREADY IMPINGING UPON THE CYCLONE.
DVORAK CI NUMBERS AT 1800 UTC ARE UNCHANGED FROM 1200 UTC...WHILE
THE 3-HOURLY AVERAGED ADT VALUE IS AT 4.6. THE INITIAL INTENSITY IS
HELD AT 75 KT FOR THIS ADVISORY IN AGREEMENT WITH SATELLITE
ESTIMATES.
 
RECENT FIXES INDICATE THAT JULIA HAS SLOWED A BIT FURTHER...AND THE
INITIAL MOTION ESTIMATE IS 295/08.  WITH THE EXCEPTION OF THE
UKMET...THE TRACK MODEL GUIDANCE IS IN BETTER AGREEMENT THIS CYCLE
CONCERNING THE SHORT-TERM TRACK FORECAST.  JULIA IS EXPECTED TO
MOVE ON A GENERAL NORTHWESTERLY COURSE DURING THE NEXT 24 HOURS AS
IT INTERACTS WITH A MID- TO UPPER-LEVEL TROUGH EXTENDING
SOUTHWESTWARD FROM A CYCLONE OVER THE NORTHEAST ATLANTIC.
FROM 24-72 HOURS...GLOBAL MODELS INDICATE THAT JULIA SHOULD TURN
WEST-NORTHWESTWARD WITH SOME INCREASE IN FORWARD SPEED UNDER THE
INFLUENCE OF A BUILDING SUBTROPICAL RIDGE TO THE NORTH.  BEYOND THAT
TIME...JULIA IS FORECAST TO TURN NORTH-NORTHWESTWARD AND THEN
NORTHWARD ONCE IT REACHES THE WESTERN PERIPHERY OF THE SUBTROPICAL
RIDGE. THE OFFICIAL NHC TRACK FORECAST IS NUDGED TO THE RIGHT AGAIN
USING A MODEL CONSENSUS THAT EXCLUDES THE UKMET BUT HAS SHIFTED A
BIT TO THE LEFT LATE IN THE PERIOD...FOLLOWING THE TREND IN THE
GUIDANCE.
 
WATER VAPOR IMAGERY SUGGESTS THAT WESTERLY SHEAR ASSOCIATED WITH A
MID- TO UPPER-LEVEL TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF
HURRICANE IGOR...MAY ALREADY BE NEGATIVELY IMPACTING JULIA.  SHIPS
MODEL OUTPUT INDICATES SOME INCREASE IN THIS SHEAR DURING THE NEXT
COUPLE OF DAYS AT THE SAME TIME JULIA TRAVERSES MARGINAL SEA
SURFACE TEMPERATURES.  ALTHOUGH THE CYCLONE IS FORECAST TO MOVE
OVER WARMER WATERS AGAIN LATER IN THE FORECAST PERIOD...GLOBAL
MODELS SHOW A STRONG SURGE OF NORTHERLY FLOW ASSOCIATED WITH THE
OUTFLOW FROM HURRICANE IGOR ADVERSELY AFFECTING JULIA.  ALTHOUGH
FEW CHANGES WERE MADE TO THE OFFICIAL NHC INTENSITY FORECAST...
JULIA COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR
MATERIALIZES.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      14/2100Z 16.7N  30.2W    75 KT
 12HR VT     15/0600Z 17.8N  31.4W    80 KT
 24HR VT     15/1800Z 19.5N  33.1W    80 KT
 36HR VT     16/0600Z 21.3N  35.7W    75 KT
 48HR VT     16/1800Z 22.8N  39.1W    70 KT
 72HR VT     17/1800Z 25.0N  46.0W    70 KT
 96HR VT     18/1800Z 29.1N  50.5W    60 KT
120HR VT     19/1800Z 33.0N  51.0W    50 KT
 
$$
FORECASTER KIMBERLAIN
 

WTNT42 KNHC 150237
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST TUE SEP 14 2010
 
JULIA HAS AGAIN DEVELOPED A SMALL EYE...AND INTENSE DEEP CONVECTION
HAS BEEN WRAPPING AROUND THAT FEATURE OVER THE PAST FEW HOURS. 
DVORAK CURRENT INTENSITY ESTIMATES ARE A UNANIMOUS 5.0 FROM TAFB...
SAB...AND THE OBJECTIVE ADT...SO THE INITIAL INTENSITY IS RAISED TO
90 KT.  MICROWAVE IMAGES INDICATE THAT JULIA HAS A WELL-DEFINED
CENTER ALTHOUGH THE SATELLITE PRESENTATION IS NOW A LITTLE
ELONGATED AND OUTFLOW IS RESTRICTED OVER THE WESTERN SIDE OF THE
HURRICANE...LIKELY DUE TO SHEAR PRODUCED BY AN UPPER-LEVEL TROUGH
TO ITS NORTHWEST.  EVEN THOUGH THE SHEAR IS ALREADY PRESENT...IT
MAY NOT BE STRONG ENOUGH YET TO LIMIT INTENSIFICATION...AND THE
OFFICIAL FORECAST INDICATES VERY LITTLE CHANGE IN INTENSITY FOR THE
NEXT 24-36 HOURS.  THIS FOLLOWS THE TREND SHOWN IN THE STATISTICAL
GUIDANCE.  AFTER 36 HOURS...VERTICAL SHEAR IS EXPECTED TO INCREASE
DRASTICALLY AS JULIA MOVES AROUND THE NORTHERN EDGE OF A MID- TO
UPPER-LEVEL LOW...AND THEN BEGINS TO FEEL THE INFLUENCE OF
UPPER-LEVEL OUTFLOW FROM HURRICANE IGOR.  THE OFFICIAL FORECAST IS
JUST A LITTLE HIGHER THAN THE PREVIOUS ONE DUE TO THE RECENT
INTENSIFICATION...AND IT STILL SHOWS WEAKENING TO A TROPICAL STORM
BY DAY 5.

THE INITIAL POSITION HAS BEEN ADJUSTED A LITTLE TO THE SOUTH BASED
ON RECENT MICROWAVE IMAGERY...BUT THE MOTION IS STILL ESTIMATED AT
295/8.  JULIA IS EXPECTED TO TURN TO THE NORTHWEST SHORTLY...BUT IT
SHOULD TURN BACK TO THE WEST-NORTHWEST WITHIN 36 HOURS AS IT GETS
STEERED BETWEEN THE NORTHERN EDGE OF THE UPPER LOW AND A BLOCKING
RIDGE TO THE NORTH.  BY DAY 4...JULIA WILL HAVE REACHED THE
SOUTHWESTERN PERIPHERY OF THE RIDGE AND THE SOUTHERLY FLOW TO THE
EAST OF IGOR...AND IT SHOULD TURN SHARPLY NORTHWEST THEN TO THE
NORTH BY DAY 5.  THE TRACK GUIDANCE IS TIGHTLY-CLUSTERED THROUGH
DAY 4 BUT THEN WIDENS ON DAY 5 WITH THE ECMWF TAKING A MORE
WESTERLY COURSE.  THE OFFICIAL FORECAST IS LOCATED JUST TO THE WEST
OF THE CONSENSUS TVCN ON DAY 5 OUT OF RESPECT FOR THE ECMWF. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/0300Z 16.7N  30.9W    90 KT
 12HR VT     15/1200Z 17.8N  32.1W    95 KT
 24HR VT     16/0000Z 19.4N  34.2W    90 KT
 36HR VT     16/1200Z 21.0N  37.3W    85 KT
 48HR VT     17/0000Z 22.4N  40.8W    80 KT
 72HR VT     18/0000Z 25.0N  47.0W    75 KT
 96HR VT     19/0000Z 29.0N  51.0W    65 KT
120HR VT     20/0000Z 33.0N  51.0W    50 KT
 
$$
FORECASTER BERG
 

WTNT42 KNHC 150532
TCDAT2
HURRICANE JULIA SPECIAL DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1230 AM AST WED SEP 15 2010

ENHANCED INFRARED SATELLITE IMAGES INDICATE THAT JULIA HAS RAPIDLY
STRENGTHENED DURING THE LAST FEW HOURS WITH THE EYE NOW MORE
DISTINCT AND CIRCULAR AND THE LARGER CIRCULATION LESS ELONGATED
THAN IT WAS EARLIER. CLOUD TOPS COLDER THAN -75 C NOW SURROUND THE
EYE.  A SPECIAL CLASSIFICATION FROM TAFB GAVE A DVORAK T-NUMBER OF
6.0 OR 115 KT AND OBJECTIVE DVORAK ESTIMATES FROM UW-CIMSS ARE
CLOSER TO 100 OR 105 KT.  BASED ON THESE ESTIMATES...THE NEW
INITIAL INTENSITY IS SET AT 110 KT.  SINCE THE ENVIRONMENT HAS
OBVIOUSLY BECOME MORE FAVORABLE FOR STRENGTHENING...AT LEAST IN THE
SHORT TERM...THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED
UPWARD FOR THE FIRST COUPLE OF DAYS TO ACCOUNT FOR THESE CHANGES.
   
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/0530Z 16.9N  31.3W   110 KT
 12HR VT     15/1200Z 17.8N  32.1W   120 KT
 24HR VT     16/0000Z 19.4N  34.2W   120 KT
 36HR VT     16/1200Z 21.0N  37.3W   110 KT
 48HR VT     17/0000Z 22.4N  40.8W    90 KT
 72HR VT     18/0000Z 25.0N  47.0W    75 KT
 96HR VT     19/0000Z 29.0N  51.0W    65 KT
120HR VT     20/0000Z 33.0N  51.0W    50 KT
 
$$
FORECASTER CANGIALOSI/PASCH
 

WTNT42 KNHC 150859
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST WED SEP 15 2010

A RAPID STRENGTHENING EPISODE WAS NOTED A FEW HOURS AGO.  THIS WAS
MOSTLY UNEXPECTED...AND REMINDS US OF OUR LIMITED UNDERSTANDING OF
TROPICAL CYCLONE INTENSITY CHANGE.  JULIA IS STILL STRENGTHENING...
BUT AT A SIGNIFICANTLY SLOWER RATE THAN WAS OBSERVED LAST EVENING
AND EARLIER THIS MORNING.  ALTHOUGH THE EYE HAS NOT WARMED
MUCH...THE CONVECTIVE BANDING AROUND THE EYE HAS BECOME BETTER
ORGANIZED.  SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 115
KT...AND THAT WILL BE THE INITIAL WIND SPEED FOR THIS ADVISORY...
MAKING JULIA A CATEGORY FOUR HURRICANE.  JULIA COULD STRENGTHEN A
LITTLE MORE TODAY AS IT REMAINS OVER RELATIVELY WARM WATER AND IN A
MODERATE WIND SHEAR ENVIRONMENT.  HOWEVER...MUCH OF THE INTENSITY
GUIDANCE SHOWS GRADUAL WEAKENING BEYOND 12 TO 24 HOURS AS JULIA
MOVES OVER COOLER WATER AND THEN INTO STRONG NORTHERLY SHEAR
ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR.  THE NHC OFFICIAL
INTENSITY FORECAST IS A LITTLE HIGHER THAN THE PREVIOUS
ADVISORY...AND IS ABOVE ALL OF THE MODELS FOR THE FIRST FEW DAYS AS
NONE OF THE GUIDANCE ANTICIPATED THE OBSERVED STRENGTHENING OF
JULIA.
 
THE HURRICANE HAS NOW TURNED TO THE NORTHWEST...WITH A 12-HOUR
INITIAL MOTION ESTIMATE OF 305/9.  A CONTINUED NORTHWESTWARD MOTION
IS EXPECTED FOR THE NEXT DAY OR SO AS JULIA NEARS A MID- TO
UPPER-LEVEL TROUGH OVER THE EASTERN ATLANTIC.  HOWEVER...A TURN
BACK TO THE WEST-NORTHWEST IS FORECAST IN ABOUT 36 HOURS AS THE
HURRICANE IS STEERED BETWEEN AN UPPER-LEVEL LOW AND A STRENGTHENING
SUBTROPICAL RIDGE.  JULIA IS EXPECTED TO APPROACH THE WESTERN
PERIPHERY OF THE RIDGE IN 3 TO 4 DAYS ALLOWING THE SYSTEM TO TURN
NORTHWARD AND POSSIBLY NORTH-NORTHEASTWARD BY DAY 5.  THE OFFICIAL
TRACK FORECAST IS ADJUSTED SLIGHTLY TO THE RIGHT AND IS A LITTLE
FASTER THAN THE PREVIOUS ONE TO COME INTO BETTER AGREEMENT WITH THE
NEW GUIDANCE SUITE. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/0900Z 17.3N  31.8W   115 KT
 12HR VT     15/1800Z 18.6N  33.2W   120 KT
 24HR VT     16/0600Z 20.4N  35.9W   120 KT
 36HR VT     16/1800Z 22.2N  39.3W   105 KT
 48HR VT     17/0600Z 23.4N  42.6W    95 KT
 72HR VT     18/0600Z 26.3N  48.1W    80 KT
 96HR VT     19/0600Z 30.0N  50.5W    65 KT
120HR VT     20/0600Z 34.0N  49.5W    50 KT
 
$$
FORECASTER CANGIALOSI
 

WTNT42 KNHC 151454
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1100 AM AST WED SEP 15 2010
 
RAPID INTENSIFICATION OCCURRED DURING THE OVERNIGHT HOURS WITH
JULIA WHEN THE HURRICANE REACHED CATEGORY FOUR STRENGTH. THIS
STRENGTHENING APPPEARS TO HAVE LEVELED OFF THIS MORNING...AS
OUTFLOW FROM HURRICANE IGOR COMBINED WITH A NEARBY UPPER LEVEL LOW
IS PRODUCING SOUTHERLY SHEAR OVER JULIA.  THIS LEVELING OF ITS
INTENSITY ALSO SHOWS UP WITH THE T NUMBERS FROM BOTH SAB AND
TAFB...WHICH HOVER AND DROP SLIGHTLY AROUND/BETWEEN 5 AND 6.
HOWEVER JULIA MAINTAINS A SOLID CENTRAL DENSE OVERCAST/CORE AND
CLEAR EYE STRUCTURE WITH IMPRESSIVE CLOUD TOP ENHANCEMENT... THUS
INITIAL INTENSITY WILL REMAIN AT 115 KTS. JULIA IS EXPECTED TO
MAINTAIN THIS STRENGTH OVER THE NEXT 24 HRS BEFORE BEGINNING TO
WEAKEN AS THE SYSTEM INTERACTS WITH MARGINAL AND COOLER SST VALUES.  

THE FORECAST SCENARIO HAS NOT BUDGED MUCH BUT THERE REMAINS RATHER
LARGE SPREAD WITHIN THE GLOBAL AND DYNAMICAL GUIDANCE IN THE EARLY
MEDIUM RANGE PERIOD. FOR THE NEXT 60 TO 72 HRS...JULIA IS EXPECTED
TO MOVE AROUND 15 KTS OR GREATER OFF TO THE NORTHWEST OR
WEST-NORTHWEST AS A BUILDING MID-LEVEL RIDGE BUILDS OVER THE EAST
CENTRAL ATLANTIC.  AFTER 72 HRS...JULIA FORWARD MOTION SLOWS AS A
NORTHERN STREAM RIDGE BUILDS TO ITS NORTH EAST OF NEWFOUNDLAND
WHICH KEEPS THE STORM FROM ACCELERATING INTO THE MAIN BAND OF THE
WESTERLIES.  THE OFFICIAL TRACK FORECAST MAINTAINED A TIGHT
CORRELATION TO THE MODEL CONSENSUS AND KEPT GOOD CONTINUITY.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/1500Z 18.2N  32.7W   115 KT
 12HR VT     16/0000Z 19.5N  34.4W   115 KT
 24HR VT     16/1200Z 21.3N  37.5W   115 KT
 36HR VT     17/0000Z 22.9N  41.0W   105 KT
 48HR VT     17/1200Z 24.3N  44.2W    95 KT
 72HR VT     18/1200Z 27.5N  49.0W    80 KT
 96HR VT     19/1200Z 31.5N  50.0W    65 KT
120HR VT     20/1200Z 35.0N  47.5W    50 KT
 
$$
FORECASTER MUSHER
 

WTNT42 KNHC 152044
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST WED SEP 15 2010
 
THE EYE OF JULIA HAS BEEN APPARENT INTERMITTENTLY IN INFRARED
SATELLITE IMAGERY THIS AFTERNOON.  A 1912 UTC SSMIS MICROWAVE
OVERPASS INDICATES THAT THERE IS SOME TILT TO THE CIRCULATION WITH
THE LOW-LEVEL CENTER LOCATED A LITTLE TO THE SOUTH OF THE MID- TO
UPPER-LEVEL EYE...DUE TO SOUTH-SOUTHWESTERLY SHEAR.  JULIA HAS
LIKELY PEAKED IN INTENSITY.  THE INITIAL INTENSITY IS LOWERED TO
110 KT...BASED ON A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK DATA
T-NUMBERS THAT HAVE DECREASED SLIGHTLY.  THE CYCLONE WILL BE MOVING
INTO A LESS FAVORABLE ENVIRONMENT WITH MODERATE SOUTHERLY SHEAR AND
SLIGHTLY COOLER SSTS DURING THE NEXT DAY OR SO. THIS SHOULD RESULT
IN GRADUAL WEAKENING.  AFTER 48 HOURS...THE GLOBAL MODELS SHOW JULIA
MOVING INTO AN AREA OF INCREASING NORTHEASTERLY UPPER-LEVEL WINDS
ASSOCIATED WITH THE OUTFLOW FROM HURRICANE IGOR. A FASTER RATE OF
WEAKENING IS INDICATED BY THE INTENSITY GUIDANCE AND IN THE
OFFICIAL FORECAST AT THAT TIME. THE NHC FORECAST IS CLOSE TO THE
INTENSITY CONSENSUS AT DAYS 3-5...BUT IS HIGHER THAN THE SHIPS
GUIDANCE WHICH WEAKENS THE JULIA VERY RAPIDLY AFTER 72 HOURS.
 
THE INITIAL MOTION ESTIMATE IS 315/11. JULIA IS FORECAST TO MOVE
NORTHWESTWARD AROUND AN UPPER-LEVEL LOW TO ITS SOUTHWEST DURING THE
NEXT 12-24 HOURS.  DURING THIS TIME...THE FORWARD SPEED OF JULIA IS
FORECAST TO INCREASE.  BETWEEN 24 AND 72 HOURS...THE HURRICANE WILL
BE STEERED IN A WEST-NORTHWEST TO NORTHWEST DIRECTION AROUND THE
WESTERN PERIPHERY OF A MID-LEVEL RIDGE CENTERED BETWEEN JULIA AND
THE AZORES ISLANDS.  THEREAFTER...JULIA SHOULD TURN
NORTHWARD...THEN NORTHEASTWARD BETWEEN THE NORTHWEST SIDE OF THE
RIDGE AND HURRICANE IGOR TO THE WEST.  THE TRACK GUIDANCE IS IN A
LITTLE BETTER AGREEMENT FOR THIS CYCLE.  THE NEW NHC TRACK FORECAST
HAS BEEN ADJUSTED SOMEWHAT NORTHWARD AND LIES NEAR THE MIDDLE OF
THE MODEL ENVELOPE.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/2100Z 19.2N  33.5W   110 KT
 12HR VT     16/0600Z 20.6N  35.5W   105 KT
 24HR VT     16/1800Z 22.6N  38.9W   100 KT
 36HR VT     17/0600Z 24.3N  42.4W    95 KT
 48HR VT     17/1800Z 26.0N  45.5W    85 KT
 72HR VT     18/1800Z 30.0N  49.6W    75 KT
 96HR VT     19/1800Z 34.0N  49.0W    60 KT
120HR VT     20/1800Z 36.0N  45.0W    45 KT
 
$$
FORECASTER BROWN
 

WTNT42 KNHC 160255
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST WED SEP 15 2010
 
JULIA IS COMING UNDER INCREASING INFLUENCE OF SOUTHERLY SHEAR...AND
RECENT MICROWAVE IMAGES INDICATE THAT THE LOW-LEVEL CENTER AND THE
MID-LEVEL EYE ARE DISPLACED FROM ONE ANOTHER.  SATELLITE INTENSITY
ESTIMATES ARE NOW T5.0/5.5 FROM TAFB...T4.0/5.0 FROM SAB...AND
T5.3/5.7 FROM THE UW-CIMSS ADT.  THE INITIAL INTENSITY IS LOWERED
TO 100 KT FOR THIS ADVISORY...BUT IT IS POSSIBLE THAT JULIA COULD
BE WEAKER THAN THAT.  JULIA IS LOCATED VERY NEAR A DEVELOPING
CLOSED UPPER-LEVEL LOW...AND STRONG SHEAR IS EXPECTED TO CONTINUE
OVER THE HURRICANE DURING THE FORECAST PERIOD.  THE OFFICIAL
FORECAST INDICATES GRADUAL WEAKENING DURING THE NEXT 48-72 HOURS
AND IS IN LINE WITH THE INTENSITY CONSENSUS.  JULIA SHOULD WEAKEN
TO A TROPICAL STORM BY DAYS 4 AND 5...BUT THE FORECAST IS A LITTLE
ABOVE THE INTENSITY CONSENSUS AT THAT TIME SINCE THE SHIPS
MODEL...FOR SOME UNKNOWN REASON...SHOWS THE SYSTEM DISSIPATED BY
DAY 5.  THIS SEEMS UNREASONABLE SINCE THE GFS STILL SHOWS AN INTACT
AREA OF LOW PRESSURE.

THE HURRICANE IS STARTING TO ACCELERATE AND IS NOW MOVING AT 315/14. 
ADDITIONAL ACCELERATION IS EXPECTED OVER THE NEXT 24 HOURS AS JULIA
IS STEERED BETWEEN A MID-LEVEL HIGH TO ITS NORTHEAST AND THE
UPPER-LEVEL LOW TO ITS SOUTHWEST...ALMOST LIKE A SLING-SHOT AFFECT. 
JULIA WILL THEN BE STEERED NORTH-NORTHWEST AND THEN NORTH FROM
48-72 HOURS AS IT REACHES THE WESTERN SIDE OF THE RIDGE AND THE
EASTERN SIDE OF THE LARGE CIRCULATION ASSOCIATED WITH IGOR.  THE
RECURVATURE TO THE NORTHEAST IS ANTICIPATED BY DAY 5 AS JULIA GETS
EMBEDDED WITHIN THE MID-LATITUDE WESTERLY FLOW.  THE OFFICIAL TRACK
FORECAST IS VERY CLOSE TO THE PREVIOUS FORECAST...AND LIES JUST TO
THE WEST OF THE MODEL CONSENSUS.  JUST LIKE IN THE CASE WITH
IGOR...THE ECMWF MODEL LIES AT THE WESTERN SIDE OF THE GUIDANCE
ENVELOPE AND CANNOT BE IGNORED. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      16/0300Z 20.2N  34.6W   100 KT
 12HR VT     16/1200Z 21.7N  36.9W    90 KT
 24HR VT     17/0000Z 23.6N  40.4W    85 KT
 36HR VT     17/1200Z 25.3N  43.8W    80 KT
 48HR VT     18/0000Z 27.0N  46.5W    75 KT
 72HR VT     19/0000Z 31.5N  49.5W    65 KT
 96HR VT     20/0000Z 35.0N  48.0W    50 KT
120HR VT     21/0000Z 36.5N  43.5W    40 KT
 
$$
FORECASTER BERG
 

WTNT42 KNHC 160903
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST THU SEP 16 2010
 
THE SATELLITE PRESENTATION OF JULIA HAS CONTINUED TO DETERIORATE
OVER THE PAST FEW HOURS.  MOST OF THE DEEP CONVECTION IS DISPLACED
NORTH OF THE ESTIMATED CENTER POSITION...AND CLOUD TOPS HAVE
CONTINUED TO WARM.  JULIA IS CURRENTLY SITUATED OVER WATERS OF
26-27C...AND THE MID- TO UPPER-LEVEL TROUGH/LOW BETWEEN JULIA AND
HURRICANE IGOR IS IMPARTING 20 TO 30 KT OF SOUTHWESTERLY SHEAR OVER
JULIA ACCORDING TO THE UW-CIMSS SHEAR ANALYSIS.  BASED ON A BLEND
OF SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES THE INITIAL
INTENSITY IS LOWERED TO 90 KT FOR THIS ADVISORY.  WHILE THE SHIPS
MODEL OUTPUT SHOWS THE SHEAR DECREASING TO LESS THAN 20 KT FROM 12
TO 24 HOURS...JULIA WILL REMAIN OVER MARGINAL SSTS THROUGH THAT
TIME.  THEN BY 36 HOURS OR SO...WHEN JULIA TEMPORARILY MOVES BACK
OVER WARMER WATERS...THE SHEAR INCREASES TO AROUND 30 KT AND
REMAINS HIGH FOR THE REST OF THE PERIOD.  THIS SCENARIO SHOULD
RESULT IN A GRADUAL WEAKENING FOR THE FIRST 48 HOURS...WITH MORE
RAPID WEAKENING TOWARD THE END OF THE PERIOD.  THE OFFICIAL FORECAST
REFLECT THIS AND FOLLOWS A BLEND OF THE LGEM AND SHIPS MODELS
THROUGH 48 HOURS...AND IS CLOSEST TO THE LGEM THEREAFTER. 
 
WITH A LACK OF MICROWAVE IMAGERY OVER THE PAST FEW HOURS...THE
INITIAL MOTION ESTIMATE OF 310/16 IS BASED LARGELY ON CONTINUITY
AND THE ASSUMPTION THAT THE LOW-LEVEL CENTER REMAINS DISPLACED SOUTH
AND EAST OF THE DEEP CONVECTION.  THE TRACK FORECAST REASONING
REMAINS UNCHANGED FROM THE PREVIOUS PACKAGE.  JULIA IS CURRENTLY
BEING STEERED NORTHWESTWARD BY THE UPPER-LEVEL LOW TO ITS SOUTHWEST
AND A LARGE MID-LEVEL RIDGE TO ITS EAST...AND THIS WILL CONTINUE
FOR THE NEXT DAY OR SO. THEN...AS JULIA MOVES AWAY FROM THE
UPPER-LOW...THE CYCLONE WILL MOVE AROUND THE WESTERN PERIPHERY OF
THE RIDGE AND TURN EAST-NORTHEASTWARD BY THE END OF THE PERIOD AS
IT COMES UNDER THE INFLUENCE OF THE MID-LATITUDE WESTERLIES.  SOME
DIFFERENCES REMAIN IN HOW SHARPLY JULIA MOVES AROUND THE RIDGE...
WITH THE UKMET SHOWING A SHARPER TURN...WHILE THE ECMWF AND HWRF
SHOW A WIDER TURN.  THE OFFICIAL FORECAST HAS BEEN ADJUSTED TOWARD
THE TVCN MULTI-MODEL CONSENSUS...AND IS CLOSE TO THE GFS FOR
THE FIRST 72 HOURS...WHICH REPRESENTS A COMPROMISE BETWEEN THE
ECMWF AND UKMET. THE NEW NHC FORECAST IS ALSO FASTER THAN THE
PREVIOUS PACKAGE DURING THE FIRST 24 HOURS...ACCOUNTING FOR THE
OBSERVED ACCELERATION OF JULIA.   
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      16/0900Z 21.2N  36.2W    90 KT
 12HR VT     16/1800Z 22.8N  38.8W    85 KT
 24HR VT     17/0600Z 24.6N  42.4W    80 KT
 36HR VT     17/1800Z 26.4N  45.5W    75 KT
 48HR VT     18/0600Z 28.3N  47.7W    70 KT
 72HR VT     19/0600Z 32.5N  49.5W    65 KT
 96HR VT     20/0600Z 35.0N  46.5W    50 KT
120HR VT     21/0600Z 36.0N  42.5W    40 KT
 
$$
FORECASTER BRENNAN
 

WTNT42 KNHC 161457
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST THU SEP 16 2010
 
SATELLITE IMAGERY CONTINUES TO INDICATE WARMING OF THE CLOUD TOPS IN
THE RATHER RAGGED LOOKING CENTRAL DENSE OVERCAST. A 1001Z AMSU
MICROWAVE OVERPASS INDICATED A 25-30 NMI DIAMETER EYE THAT WAS OPEN
IN THE SOUTHEAST QUADRANT. WATER VAPOR IMAGERY ALSO SHOWS A LARGE
SLUG OF DRY AIR BEING ENTRAINED INTO THE EASTERN SEMICIRCLE...WHICH
LIKELY EXPLAINS THE EROSION OF THE EASTERN EYEWALL NOTED IN THE
AMSU IMAGERY. DESPITE THE AFOREMENTIONED NEGATIVE FACTORS...JULIA
HAS MAINTAINED GOOD OUTFLOW TO THE WEST AND NORTH OF THE CYCLONE.

THE INITIAL MOTION ESTIMATE HAS INCREASED SHARPLY TO 300/22. JULIA
IS EXPECTED TO MOVE TO THE WEST-NORTHWEST AND THEN NORTHWEST
FOR THE NEXT 36-48 HOURS AS THE HURRICANE ROUNDS THE SOUTHERN
PERIPHERY OF A LARGE SUBTROPICAL RIDGE SITUATED TO ITS NORTH AND
NORTHEAST. AFTER THAT...SIGNIFICANT VERTICAL WIND SHEAR MAY WEAKEN
THE CYCLONE AND CAUSE IT TO BECOME MORE SHALLOW...AND THEN BE
STEERED MORE NORTHWARD SIMILAR TO THE ECMWF AND GFDL MODELS...BUT
NOT AS FAR NORTH AND WEST AS THE SHALLOW BAM MODEL. THE OFFICIAL
TRACK FORECAST HAS BEEN NUDGED TO THE LEFT OF THE PREVIOUS ADVISORY
THROUGH 72 HOURS...AND IS SIMILAR TO THE MULTI-MODEL CONSENSUS.

DRY AIR AND COOLER SSTS SHOULD CONTINUE THE RECENT WEAKENING
TREND...ESPECIALLY AFTER 24 HOURS. BY 36-48 HOURS...ALL OF THE
GLOBAL MODELS INDICATE THAT JULIA WILL BE MOVING INTO A REGION OF
STRONG UPPER-LEVEL SHEAR CAUSED BY THE PRONOUNCED NORTHERLY OUTFLOW
EMANATING FROM THE MAJOR HURRICANE IGOR LOCATED TO ITS WEST. WITH
JULIA MOVING INTO 50-70 KT OF 200 MB WINDS...IT WILL BE HARD FOR
JULIA TO SURVIVE AS A TROPICAL CYCLONE AS INDICATED BY THE GLOBAL
MODELS AND GFDL/HWRF MODELS. THE OFFICIAL INTENSITY FORECAST SHOWS
A FASTER WEAKENING TREND THAN THE PREVIOUS ADVISORY...BUT NOT AS
FAST AS THE SHIPS MODEL...WHICH DISSIPATES JULIA BY 120 HOURS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      16/1500Z 22.4N  38.6W    85 KT
 12HR VT     17/0000Z 23.7N  41.2W    75 KT
 24HR VT     17/1200Z 25.5N  44.6W    65 KT
 36HR VT     18/0000Z 27.3N  47.3W    55 KT
 48HR VT     18/1200Z 29.3N  49.1W    45 KT
 72HR VT     19/1200Z 33.2N  49.6W    35 KT
 96HR VT     20/1200Z 35.8N  46.3W    35 KT
120HR VT     21/1200Z 38.0N  42.0W    35 KT
 
$$
FORECASTER STEWART
 

WTNT42 KNHC 162040
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST THU SEP 16 2010
 
VERTICAL SHEAR APPEARS TO HAVE ABATED FOR THE MOMENT...WITH A 1533
UTC AMSR-E MICROWAVE PASS SHOWING THAT THE LOW- AND MID-LEVEL
CENTERS ARE JUST ABOUT VERTICALLY STACKED.  HOWEVER...CONVECTIVE
TOPS HAVE WARMED...AND SATELLITE CURRENT INTENSITY ESTIMATES ARE
NOW 77 KT FROM TAFB...65 KT FROM SAB...AND 65 KT AND 80 KT FROM TWO
VERSIONS OF THE UW-CIMSS ADT.  THE INITIAL INTENSITY IS THEREFORE
LOWERED TO 75 KT FOR THIS ADVISORY.
 
JULIA HAS AN INITIAL MOTION OF 295/22 KT.  THERE HAS BEEN A
SIGNIFICANT WESTWARD SHIFT IN NEARLY ALL THE TRACK GUIDANCE ON THIS
CYCLE...POSSIBLY DUE TO A STRONGER-THAN-EXPECTED MID-LEVEL HIGH TO
THE NORTH AND NORTHEAST OF THE HURRICANE.  CONSEQUENTLY...THE NEW
OFFICIAL FORECAST HAS BEEN SHIFTED WESTWARD ABOUT HALFWAY BETWEEN
OFCI AND THE MODEL CONSENSUS TVCN.  SEVERAL MODELS...ESPECIALLY THE
UKMET AND ECMWF...ARE EVEN FARTHER WEST THAN THIS TRACK SO IT IS
POSSIBLE THAT ADDITIONAL SHIFTS COULD BE REQUIRED IN THE NEXT FEW
ADVISORY PACKAGES.  GLOBAL MODEL FIELDS INDICATE THAT AFTER JULIA
MOVES NORTHWARD AROUND THE RIDGE...IT SHOULD TURN TOWARD THE
NORTHEAST AND DISSIPATE IN THE STRONG SOUTHWESTERLY FLOW TO THE 
EAST OF IGOR IN ABOUT 120 HOURS.
 
WITH THE WESTWARD SHIFT IN THE FORECAST TRACK...JULIA APPEARS TO
HAVE A BETTER CHANCE TO MAINTAIN SOME OF ITS INTENSITY OVER THE
NEXT COUPLE OF DAYS.  THE HURRICANE WILL BE BATTLING THE STRONG
UPPER-LEVEL OUTFLOW OF IGOR DURING THE NEXT 36 HOURS OR SO...BUT
AFTER THAT THE GLOBAL MODELS SUGGEST THAT JULIA COULD SNEAK
UNDERNEATH THE UPPER-LEVEL ANTICYCLONE PARTIALLY GENERATED BY IGOR.
THE SHEAR COULD RELAX JUST ENOUGH DURING THAT TIME AND CAUSE MORE
MODEST WEAKENING...SO THE NEW INTENSITY FORECAST IS A LITTLE BIT
HIGHER THAN THE PREVIOUS ONE FROM 36-72 HOURS.  INCIDENTALLY... THE
NEW FORECAST IS STILL LOWER THAN INDICATED BY THE LGEM...THE
DYNAMICAL MODELS...AND THE INTENSITY CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      16/2100Z 23.1N  41.1W    75 KT
 12HR VT     17/0600Z 24.2N  43.9W    65 KT
 24HR VT     17/1800Z 26.0N  47.1W    65 KT
 36HR VT     18/0600Z 27.9N  49.6W    60 KT
 48HR VT     18/1800Z 30.1N  51.0W    55 KT
 72HR VT     19/1800Z 34.0N  50.5W    45 KT
 96HR VT     20/1800Z 37.0N  47.0W    35 KT
120HR VT     21/1800Z...DISSIPATED
 
$$
FORECASTER BERG
 

WTNT42 KNHC 170248
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST THU SEP 16 2010
 
THE EYE OF JULIA BECAME BETTER DEFINED IN INFRARED SATELLITE IMAGES
FOR A PERIOD OF TIME THIS EVENING. HOWEVER...THE AREA OF COLD
CLOUDS TOPS ASSOCIATED WITH THE HURRICANE HAS DECREASED IN SIZE.
THE LATEST DVORAK INTENSITY ESTIMATES SUPPORT AN INITIAL INTENSITY
OF 70 KT.  THE GLOBAL MODELS AND WATER VAPOR IMAGERY SHOW THAT
JULIA WILL BE ENTERING AN AREA OF STRONG NORTHWESTERLY UPPER-LEVEL
WINDS ASSOCIATED WITH THE OUTFLOW FROM HURRICANE IGOR VERY SHORTLY.
THE SHIPS GUIDANCE INDICATES 30-40 KT WIND SHEAR DURING THE NEXT
DAY OR SO.  DURING THIS TIME JULIA IS EXPECTED TO WEAKEN
SIGNIFICANTLY AND THE NEW INTENSITY FORECAST IS A LITTLE LOWER THAN
THE PREVIOUS ADVISORY THROUGH 36 HOURS.  IF JULIA SURVIVES THE
STRONG SHEAR...THE GLOBAL MODELS SUGGEST THAT THE UPPER-LEVEL
ENVIRONMENT COULD IMPROVE BETWEEN 36-72 HOURS.  DURING THAT TIME
ONLY GRADUAL WEAKENING IS SHOWN. IN 4-5 DAYS...JULIA IS EXPECTED TO
DISSIPATE IN THE STRONG SOUTHWESTERLY FLOW TO THE EAST OF IGOR. THE
OFFICIAL INTENSITY FORECAST IS IN BEST AGREEMENT WITH THE SHIPS
INTENSITY GUIDANCE.

JULIA CONTINUES TO MOVE QUICKLY WEST-NORTHWESTWARD WITH AN INITIAL
MOTION OF 290/21 KT.  THE FORECAST TRACK REASONING REMAINS UNCHANGED
AS JULIA WILL BE MOVING AROUND THE WESTERN PORTION OF A MID-LEVEL
RIDGE CENTERED SOUTHWEST OF THE AZORES.  THE TRACK GUIDANCE HAS
AGAIN SHIFTED WESTWARD AND THE OFFICIAL FORECAST FOLLOWS SUIT. THE
NEW FORECAST LIES BETWEEN THE GFS...WHICH IS ALONG THE EAST EDGE OF
THE GUIDANCE...AND THE TVCN CONSENSUS.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/0300Z 23.5N  42.9W    70 KT
 12HR VT     17/1200Z 24.6N  45.7W    60 KT
 24HR VT     18/0000Z 26.3N  48.8W    55 KT
 36HR VT     18/1200Z 28.6N  50.8W    50 KT
 48HR VT     19/0000Z 31.0N  52.0W    45 KT
 72HR VT     20/0000Z 35.0N  50.5W    40 KT
 96HR VT     21/0000Z 39.0N  46.5W    35 KT
120HR VT     22/0000Z...DISSIPATED
 
$$
FORECASTER BROWN
 

WTNT42 KNHC 170847
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST FRI SEP 17 2010
 
UP UNTIL THE LAST HOUR...JULIA HAD EXHIBITED A SMALL BUT WELL-
DEFINED EYE WITH A SOLID EYEWALL. SUBJECTIVE DVORAK CLASSIFICATIONS
ARE 77 KT...WITH ADT VALUES USING AN EYE PATTERN SUPPORTING
ANYWHERE FROM 75-85 KT. GIVEN THAT THE EYE HAS BECOME OBSCURED...
THE INITIAL WINDS ARE ONLY INCREASED TO THE LOWER END OF THOSE
ESTIMATES...75 KT. THE HURRICANE IS IN A SMALL LOW SHEAR ENVIRONMENT
TO THE NORTH OF AN UPPER LOW. HOWEVER...JULIA IS ABOUT TO ENCOUNTER
AN UPPER-LEVEL JET...PART OF THE OUTFLOW FROM IGOR...WHICH SHOULD
INDUCE SIGNIFICANT SHEAR AND A FAIR AMOUNT OF WEAKENING. JULIA
SHOULD MOVE AWAY FROM THE MAIN JET CORE IN TWO TO THREE DAYS...
CAUSING THE SHEAR TO MODERATE SOMEWHAT...BUT SLOW WEAKENING IS
STILL EXPECTED.  BY THE END OF THE FORECAST PERIOD...VERY STRONG
SHEAR IS FORECAST TO OCCUR...WHICH SHOULD CAUSE RAPID DISSIPATION.
THE NEW NHC INTENSITY FORECAST IS CLOSE TO THE PREVIOUS ONE AND THE
SHIPS MODEL...BUT BELOW MOST OF THE REST OF THE GUIDANCE.
 
JULIA CONTINUES TO MOVE 290/21.  THE HURRICANE APPEARS TO BE
LEAVING THE INFLUENCE OF A MID- TO UPPER-LEVEL LOW TO THE SOUTHEAST
...AND BECOMING MOSTLY STEERED BY A RIDGE OVER THE EASTERN ATLANTIC
OCEAN.  JULIA SHOULD GRADUALLY GAIN LATITUDE AND EVENTUALLY TURN TO
THE NORTH AND NORTHEAST AROUND THE WESTERN PORTION OF THE RIDGE. 
THE TRACK GUIDANCE CONTINUES TO SHIFT WESTWARD...PERHAPS DUE TO THE
FAST WEST-NORTHWESTWARD MOTION AND UNFORESEEN IMPACTS OF THE MID-
TO UPPER-LEVEL LOW.  THE NHC FORECAST IS SHIFTED WESTWARD AGAIN
...AND LIES BETWEEN THE GFS ENSEMBLE AND THE MULTI-MODEL CONSENSUS.   
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/0900Z 23.8N  45.1W    75 KT
 12HR VT     17/1800Z 25.0N  47.6W    65 KT
 24HR VT     18/0600Z 27.2N  50.2W    55 KT
 36HR VT     18/1800Z 29.7N  51.9W    50 KT
 48HR VT     19/0600Z 32.4N  52.4W    45 KT
 72HR VT     20/0600Z 36.0N  49.5W    40 KT
 96HR VT     21/0600Z 40.0N  44.5W    35 KT
120HR VT     22/0600Z...DISSIPATED
 
$$
FORECASTER BLAKE
 

WTNT42 KNHC 171436
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST FRI SEP 17 2010

JULIA IS MAINTAINING A CENTRAL DENSE OVERCAST FEATURE THAT IS
DISPLACED SLIGHTLY TO THE SOUTH-SOUTHEAST OF THE CENTER.  USING A
BLEND OF DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB GIVES 75 KT
FOR THE CURRENT INTENSITY.  THE SYSTEM IS LIKELY TO EXPERIENCE
INCREASING NORTHERLY TO NORTHWESTERLY SHEAR ASSOCIATED WITH THE
MASSIVE UPPER-LEVEL OUTFLOW PATTERN OF HURRICANE IGOR.  GIVEN THE
HIGH AMOUNT OF SHEAR EXPECTED TO IMPACT JULIA...THE OFFICIAL
INTENSITY FORECAST SHOWS A SOMEWHAT FASTER RATE OF WEAKENING THAN
INDICATED BY THE STATISTICAL-DYNAMICAL GUIDANCE MODELS LGEM AND
SHIPS.  DISSIPATION IS LIKELY BY THE END OF THE FORECAST PERIOD AS
MOST OF THE DYNAMICAL MODELS DEPICT JULIA BECOMING ABSORBED WITHIN
THE MUCH LARGER CIRCULATION OF IGOR.

LATEST CENTER FIXES SHOW THAT THE INITIAL MOTION HAS SLOWED SOMEWHAT
AND IS NOW 285/17.  THE HURRICANE HAS MOVED UNEXPECTEDLY FAR TO THE
WEST...LIKELY BECAUSE THE STEERING EFFECTS OF AN UPPER-LEVEL CYCLONE
TO THE SOUTH WERE MORE PRONOUNCED THAN EARLIER ANTICIPATED. 
NONETHELESS...JULIA IS FORECAST TO MOVE AROUND THE WESTERN PERIPHERY
OF A MID-LEVEL SUBTROPICAL ANTICYCLONE OVER THE NEXT 2 TO 4 DAYS. 
THE OFFICIAL FORECAST TRACK IS ESSENTIALLY AN UPDATE OF THE
PREVIOUS ONE AND IS CLOSE TO THE MULTI-MODEL CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/1500Z 24.2N  46.7W    75 KT
 12HR VT     18/0000Z 25.8N  48.8W    70 KT
 24HR VT     18/1200Z 28.3N  51.1W    65 KT
 36HR VT     19/0000Z 30.9N  52.1W    60 KT
 48HR VT     19/1200Z 33.2N  51.7W    50 KT
 72HR VT     20/1200Z 36.4N  48.5W    40 KT
 96HR VT     21/1200Z 40.0N  44.0W    30 KT
120HR VT     22/1200Z...DISSIPATED
 
$$
FORECASTER PASCH
 

WTNT42 KNHC 172053
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST FRI SEP 17 2010
 
JULIA HAS BEEN EXPERIENCING MODERATE NORTHERLY SHEAR...AND
AT TIMES IT APPEARS THAT THE LOW-LEVEL CENTER IS BEGINNING TO
BECOME EXPOSED.  USING A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK
T-NUMBERS LEADS TO A CURRENT INTENSITY ESTIMATE OF 65 KT.  THE
SHEAR...WHICH IS PRIMARILY ASSOCIATED WITH THE MASSIVE OUTFLOW
PATTERN OF HURRICANE IGOR...IS NOT LIKELY TO RELENT.  IN FACT...
THE DYNAMICAL GUIDANCE SUGGESTS THAT THE SHEAR WILL BECOME STRONGER. 
THE OFFICIAL INTENSITY FORECAST SHOWS STEADY WEAKENING AND IS BASED
ON A COMBINATION OF THE STATISTICAL-DYNAMICAL SHIPS AND LGEM
MODELS. BY THE END OF THE FORECAST PERIOD...GLOBAL MODELS INDICATE
THAT JULIA WILL BECOME ABSORBED BY THE MUCH LARGER CIRCULATION OF
POST-TROPICAL IGOR.

THE INITIAL MOTION IS ABOUT 300/18.  THE FORECAST REASONING IS
ESSENTIALLY UNCHANGED.  JULIA IS EXPECTED TO MOVE AROUND A
MID-LEVEL SUBTROPICAL HIGH FOR THE NEXT FEW DAYS...BEFORE GETTING
PULLED INTO THE CIRCULATION OF IGOR.  THUS...THE NHC TRACK FORECAST
SHOWS A GRADUAL TURN TOWARD THE NORTHWEST...NORTH...AND NORTH-
NORTHEAST.  THIS IS JUST A LITTLE TO THE WEST OF THE PREVIOUS
OFFICIAL TRACK AND GENERALLY TO THE RIGHT OF THE MULTI-MODEL
CONSENSUS TVCN.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/2100Z 25.2N  48.2W    65 KT
 12HR VT     18/0600Z 26.9N  50.0W    60 KT
 24HR VT     18/1800Z 29.6N  51.8W    55 KT
 36HR VT     19/0600Z 32.5N  52.3W    50 KT
 48HR VT     19/1800Z 34.8N  51.2W    45 KT
 72HR VT     20/1800Z 38.2N  47.2W    35 KT
 96HR VT     21/1800Z 43.0N  43.0W    25 KT
120HR VT     22/1800Z...DISSIPATED
 
$$
FORECASTER PASCH
 

WTNT42 KNHC 180241
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST FRI SEP 17 2010
 
THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA
JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED
CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A
STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE EARL.  SUBSEQUENT
BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO
65 AND 60 KT RESPECTIVELY.  BASED ON THESE DATA...THE INITIAL
INTENSITY IS LOWERED TO 60 KT.  THE GLOBAL AND THE SHIPS MODELS ALL
SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR
PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY
FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE
AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING
ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR.
 
THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS
ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14.  THE
DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE
NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH
TO THE NORTHEAST OF JULIA.  THROUGH DAY 3...THE MODELS INDICATE
THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD
AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE
CENTRAL ATLANTIC.  AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT
WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR
EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS
ENSEMBLE MEANS.  THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS
ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS.
 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/0300Z 26.0N  49.2W    60 KT
 12HR VT     18/1200Z 28.1N  50.8W    55 KT
 24HR VT     19/0000Z 31.0N  52.1W    50 KT
 36HR VT     19/1200Z 33.5N  52.0W    45 KT
 48HR VT     20/0000Z 35.5N  50.6W    40 KT
 72HR VT     21/0000Z 39.0N  46.0W    30 KT
 96HR VT     22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW
 
$$
FORECASTER ROBERTS/AVILA
 

WTNT42 KNHC 180302
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  24...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST FRI SEP 17 2010
 
CORRECTED TO ADD IGOR

THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA
JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED
CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A
STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE IGOR.  SUBSEQUENT
BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO
65 AND 60 KT RESPECTIVELY.  BASED ON THESE DATA...THE INITIAL
INTENSITY IS LOWERED TO 60 KT.  THE GLOBAL AND THE SHIPS MODELS ALL
SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR
PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY
FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE
AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING
ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR.
 
THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS
ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14.  THE
DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE
NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH
TO THE NORTHEAST OF JULIA.  THROUGH DAY 3...THE MODELS INDICATE
THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD
AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE
CENTRAL ATLANTIC.  AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT
WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR
EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS
ENSEMBLE MEANS.  THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS
ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS.
 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/0300Z 26.0N  49.2W    60 KT
 12HR VT     18/1200Z 28.1N  50.8W    55 KT
 24HR VT     19/0000Z 31.0N  52.1W    50 KT
 36HR VT     19/1200Z 33.5N  52.0W    45 KT
 48HR VT     20/0000Z 35.5N  50.6W    40 KT
 72HR VT     21/0000Z 39.0N  46.0W    30 KT
 96HR VT     22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW
 
$$
FORECASTER ROBERTS/AVILA
 

WTNT42 KNHC 140837
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST TUE SEP 14 2010

JULIA HAS STRENGTHENED THIS MORNING.  A RAGGED EYE FEATURE HAS
OCCASIONALLY BEEN EVIDENT IN GEOSTATIONARY SATELLITE IMAGES DURING
THE PAST FEW HOURS AND THE CONVECTIVE BANDING HAS BECOME BETTER
ORGANIZED...ESPECIALLY OVER THE SOUTHERN SEMICIRCLE.  DVORAK
CLASSIFICATIONS FROM TAFB AND SAB WERE 65 KT...AND THE CIMSS ADT
ESTIMATES ARE ALSO NEAR THAT VALUE.  ON THIS BASIS...JULIA IS
UPGRADED TO A HURRICANE WITH THE INITIAL WIND SPEED SET AT 65 KT.

SOME ADDITIONAL STRENGTHENING APPEARS LIKELY DURING THE NEXT DAY OR
SO AS UNANIMOUSLY SHOWN BY THE MODEL GUIDANCE.  HOWEVER...SEA
SURFACE TEMPERATURES COOL BELOW 27 C ALONG THE FORECAST TRACK IN 24
TO 48 HOURS...AND THAT SHOULD LIMIT INTENSIFICATION DURING THAT
TIME PERIOD.  ALTHOUGH JULIA IS EXPECTED TO TRACK OVER WARMER
WATERS BEYOND A FEW DAYS...STRONG NORTH TO NORTHEASTERLY SHEAR...
ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR...SHOULD INDUCE
WEAKENING BY THAT TIME.  THE OFFICIAL FORECAST IS ADJUSTED UPWARD
DURING THE FIRST FEW DAYS AND THEN FALLS IN LINE WITH THE PREVIOUS
FORECAST BY THE END OF THE PERIOD...AND IS IN GOOD AGREEMENT WITH
THE STATISTICAL-DYNAMICAL GUIDANCE.

THE INITIAL MOTION ESTIMATE IS 295/10.  A MID- TO UPPER-LEVEL TROUGH
OVER THE EASTERN ATLANTIC IS EXPECTED TO CAUSE JULIA TO TURN
NORTHWESTWARD LATER TODAY AND CONTINUE IN THAT DIRECTION FOR THE
NEXT 24 TO 48 HOURS.  THEREAFTER...THE GLOBAL MODELS ARE IN
AGREEMENT IN SHOWING A SUBTROPICAL RIDGE TO STRENGTHEN NORTH OF
JULIA.  THIS PATTERN SHOULD CAUSE THE CYCLONE TO TURN BACK TO THE
WEST-NORTHWEST FOR A COUPLE OF DAYS.  BY THE END OF THE FORECAST
PERIOD...JULIA IS EXPECTED TO MOVE NORTHWESTWARD OR
NORTH-NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF THE RIDGE.  THE
OFFICIAL FORECAST IS ADJUSTED SLIGHTLY TO THE WEST IN THE 3 TO 5
DAY RANGE...TRENDING TOWARD THE MULTI-MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL      14/0900Z 16.1N  29.0W    65 KT
12HR VT     14/1800Z 16.8N  30.1W    70 KT
24HR VT     15/0600Z 18.1N  31.7W    80 KT
36HR VT     15/1800Z 19.7N  33.6W    80 KT
48HR VT     16/0600Z 21.5N  36.1W    75 KT
72HR VT     17/0600Z 24.5N  42.5W    70 KT
96HR VT     18/0600Z 27.5N  48.5W    60 KT
120HR VT     19/0600Z 32.0N  51.0W    50 KT

$$
FORECASTER CANGIALOSI




WTNT42 KNHC 141444
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST TUE SEP 14 2010

SATELLITE IMAGES INDICATE THAT JULIA IS STILL STRENGTHENING. A 0920
UTC SSM/IS OVERPASS SHOWED A WELL-DEFINED EYEWALL SURROUNDED BY TWO
PROMINENT BANDS...WHILE CONVENTIONAL IMAGERY SHOWS THE APPEARANCE
OF A WELL-DEVELOPED CENTRAL DENSE OVERCAST AND A BANDING-TYPE EYE.
SUBJECTIVE DVORAK T-NUMBERS AT 1200 UTC ARE 4.0 AND 5.0 FROM TAFB
AND SAB...RESPECTIVELY. THE INITIAL INTENSITY IS RAISED TO 75
KT...BASED UPON A BLEND OF THESE ESTIMATES.

WHILE SOME ADDITIONAL INTENSIFICATION IS POSSIBLE DURING THE NEXT 12
TO 24 HOURS...WATER VAPOR IMAGERY SHOWS A MID- TO UPPER-LEVEL
TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF HURRICANE IGOR...
LOCATED A FEW HUNDRED MILES NORTHWEST OF JULIA. GLOBAL MODELS
SUGGEST THAT THIS FEATURE SHOULD BEGIN TO IMPART WESTERLY SHEAR
OVER THE CYCLONE AFTER ABOUT 24 HOURS...AT ABOUT THE TIME JULIA
BEGINS TO PASS OVER MARGINAL SEA SURFACE TEMPERATURES. WATERS
SHOULD BEGIN TO WARM AGAIN ALONG THE FORECAST TRACK IN A FEW
DAYS...BUT MODEL GUIDANCE SHOWS A STRONG SURGE OF NORTHERLY FLOW
ASSOCIATED THE OUTFLOW OF IGOR THAT COULD NEGATIVELY IMPACT JULIA
AFTER 72 HOURS. IN FACT...SHIPS MODEL OUTPUT INDICATES THE
POTENTIAL FOR 30-40 KT OF NORTHERLY SHEAR. ALTHOUGH NO SIGNIFICANT
CHANGES WERE MADE TO THE OFFICIAL INTENSITY FORECAST...JULIA
COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR MATERIALIZES.

THE INITIAL MOTION ESTIMATE IS 295/09...INDICATING THAT JULIA HAS
RECENTLY SLOWED A BIT. THERE IS AN UNUSUAL AMOUNT OF SPREAD IN THE
SHORT-TERM TRACK FORECAST. THE GFS/HWRF/GFDL SHOW JULIA TURNING
TOWARD THE NORTHWEST DURING THE NEXT DAY OR SO AS IT INTERACTS WITH
AN EXTENSION OF A MID- TO UPPER-LEVEL CYCLONE LOCATED OVER THE
NORTHEAST ATLANTIC. THE UKMET/ECMWF FAVOR A WEST-NORTHWEST COURSE
AS A RESULT OF MORE SUBTROPICAL RIDGING. FROM ABOUT 36-72 HR...
THERE IS BETTER AGREEMENT IN THE MODEL GUIDANCE OF SUBTROPICAL
RIDGING BUILDING NORTH OF JULIA AND HENCE A MORE WEST-NORTHWESTERLY
COURSE WITH AN INCREASE IN FORWARD SPEED. AFTER 72 HR...GLOBAL
MODELS SHOW JULIA TURNING NORTH-NORTHWESTWARD AS IT APPROACHES THE
WESTERN END OF THE SUBTROPICAL RIDGE AND THE LARGE HURRICANE IGOR
OVER THE CENTRAL ATLANTIC. THE OFFICIAL NHC FORECAST TRACK IS
NUDGED A BIT TO THE RIGHT...LYING NEAR A CONSENSUS THAT EXCLUDES
THE UKMET.


FORECAST POSITIONS AND MAX WINDS

INITIAL      14/1500Z 16.2N  29.5W    75 KT
12HR VT     15/0000Z 17.2N  30.8W    85 KT
24HR VT     15/1200Z 18.7N  32.4W    80 KT
36HR VT     16/0000Z 20.3N  34.5W    75 KT
48HR VT     16/1200Z 22.2N  37.7W    70 KT
72HR VT     17/1200Z 24.7N  44.3W    70 KT
96HR VT     18/1200Z 28.0N  49.0W    60 KT
120HR VT     19/1200Z 32.5N  50.5W    50 KT

$$
FORECASTER KIMBERLAIN




WTNT42 KNHC 142036
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST TUE SEP 14 2010

THE CLOUD PATTERN ASSOCIATED WITH JULIA HAS BECOME SOMEWHAT
ASYMMETRIC DURING THE PAST SEVERAL HOURS...WITH A LARGE MASS OF
DEEP CONVECTION HAVING FORMED SOUTHWEST OF THE CENTER. THE
EYE THAT WAS VISIBLE EARLIER IS ALSO NO LONGER AS EVIDENT. THE
OUTFLOW HAS BECOME A BIT RESTRICTED TO THE WEST...INDICATIVE OF
SOME UPPER-LEVEL WESTERLY FLOW ALREADY IMPINGING UPON THE CYCLONE.
DVORAK CI NUMBERS AT 1800 UTC ARE UNCHANGED FROM 1200 UTC...WHILE
THE 3-HOURLY AVERAGED ADT VALUE IS AT 4.6. THE INITIAL INTENSITY IS
HELD AT 75 KT FOR THIS ADVISORY IN AGREEMENT WITH SATELLITE
ESTIMATES.

RECENT FIXES INDICATE THAT JULIA HAS SLOWED A BIT FURTHER...AND THE
INITIAL MOTION ESTIMATE IS 295/08.  WITH THE EXCEPTION OF THE
UKMET...THE TRACK MODEL GUIDANCE IS IN BETTER AGREEMENT THIS CYCLE
CONCERNING THE SHORT-TERM TRACK FORECAST.  JULIA IS EXPECTED TO
MOVE ON A GENERAL NORTHWESTERLY COURSE DURING THE NEXT 24 HOURS AS
IT INTERACTS WITH A MID- TO UPPER-LEVEL TROUGH EXTENDING
SOUTHWESTWARD FROM A CYCLONE OVER THE NORTHEAST ATLANTIC.
FROM 24-72 HOURS...GLOBAL MODELS INDICATE THAT JULIA SHOULD TURN
WEST-NORTHWESTWARD WITH SOME INCREASE IN FORWARD SPEED UNDER THE
INFLUENCE OF A BUILDING SUBTROPICAL RIDGE TO THE NORTH.  BEYOND THAT
TIME...JULIA IS FORECAST TO TURN NORTH-NORTHWESTWARD AND THEN
NORTHWARD ONCE IT REACHES THE WESTERN PERIPHERY OF THE SUBTROPICAL
RIDGE. THE OFFICIAL NHC TRACK FORECAST IS NUDGED TO THE RIGHT AGAIN
USING A MODEL CONSENSUS THAT EXCLUDES THE UKMET BUT HAS SHIFTED A
BIT TO THE LEFT LATE IN THE PERIOD...FOLLOWING THE TREND IN THE
GUIDANCE.

WATER VAPOR IMAGERY SUGGESTS THAT WESTERLY SHEAR ASSOCIATED WITH A
MID- TO UPPER-LEVEL TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF
HURRICANE IGOR...MAY ALREADY BE NEGATIVELY IMPACTING JULIA.  SHIPS
MODEL OUTPUT INDICATES SOME INCREASE IN THIS SHEAR DURING THE NEXT
COUPLE OF DAYS AT THE SAME TIME JULIA TRAVERSES MARGINAL SEA
SURFACE TEMPERATURES.  ALTHOUGH THE CYCLONE IS FORECAST TO MOVE
OVER WARMER WATERS AGAIN LATER IN THE FORECAST PERIOD...GLOBAL
MODELS SHOW A STRONG SURGE OF NORTHERLY FLOW ASSOCIATED WITH THE
OUTFLOW FROM HURRICANE IGOR ADVERSELY AFFECTING JULIA.  ALTHOUGH
FEW CHANGES WERE MADE TO THE OFFICIAL NHC INTENSITY FORECAST...
JULIA COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR
MATERIALIZES.


FORECAST POSITIONS AND MAX WINDS

INITIAL      14/2100Z 16.7N  30.2W    75 KT
12HR VT     15/0600Z 17.8N  31.4W    80 KT
24HR VT     15/1800Z 19.5N  33.1W    80 KT
36HR VT     16/0600Z 21.3N  35.7W    75 KT
48HR VT     16/1800Z 22.8N  39.1W    70 KT
72HR VT     17/1800Z 25.0N  46.0W    70 KT
96HR VT     18/1800Z 29.1N  50.5W    60 KT
120HR VT     19/1800Z 33.0N  51.0W    50 KT

$$
FORECASTER KIMBERLAIN



000

WTNT42 KNHC 150237
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST TUE SEP 14 2010

JULIA HAS AGAIN DEVELOPED A SMALL EYE...AND INTENSE DEEP CONVECTION
HAS BEEN WRAPPING AROUND THAT FEATURE OVER THE PAST FEW HOURS.
DVORAK CURRENT INTENSITY ESTIMATES ARE A UNANIMOUS 5.0 FROM TAFB...
SAB...AND THE OBJECTIVE ADT...SO THE INITIAL INTENSITY IS RAISED TO
90 KT.  MICROWAVE IMAGES INDICATE THAT JULIA HAS A WELL-DEFINED
CENTER ALTHOUGH THE SATELLITE PRESENTATION IS NOW A LITTLE
ELONGATED AND OUTFLOW IS RESTRICTED OVER THE WESTERN SIDE OF THE
HURRICANE...LIKELY DUE TO SHEAR PRODUCED BY AN UPPER-LEVEL TROUGH
TO ITS NORTHWEST.  EVEN THOUGH THE SHEAR IS ALREADY PRESENT...IT
MAY NOT BE STRONG ENOUGH YET TO LIMIT INTENSIFICATION...AND THE
OFFICIAL FORECAST INDICATES VERY LITTLE CHANGE IN INTENSITY FOR THE
NEXT 24-36 HOURS.  THIS FOLLOWS THE TREND SHOWN IN THE STATISTICAL
GUIDANCE.  AFTER 36 HOURS...VERTICAL SHEAR IS EXPECTED TO INCREASE
DRASTICALLY AS JULIA MOVES AROUND THE NORTHERN EDGE OF A MID- TO
UPPER-LEVEL LOW...AND THEN BEGINS TO FEEL THE INFLUENCE OF
UPPER-LEVEL OUTFLOW FROM HURRICANE IGOR.  THE OFFICIAL FORECAST IS
JUST A LITTLE HIGHER THAN THE PREVIOUS ONE DUE TO THE RECENT
INTENSIFICATION...AND IT STILL SHOWS WEAKENING TO A TROPICAL STORM
BY DAY 5.

THE INITIAL POSITION HAS BEEN ADJUSTED A LITTLE TO THE SOUTH BASED
ON RECENT MICROWAVE IMAGERY...BUT THE MOTION IS STILL ESTIMATED AT
295/8.  JULIA IS EXPECTED TO TURN TO THE NORTHWEST SHORTLY...BUT IT
SHOULD TURN BACK TO THE WEST-NORTHWEST WITHIN 36 HOURS AS IT GETS
STEERED BETWEEN THE NORTHERN EDGE OF THE UPPER LOW AND A BLOCKING
RIDGE TO THE NORTH.  BY DAY 4...JULIA WILL HAVE REACHED THE
SOUTHWESTERN PERIPHERY OF THE RIDGE AND THE SOUTHERLY FLOW TO THE
EAST OF IGOR...AND IT SHOULD TURN SHARPLY NORTHWEST THEN TO THE
NORTH BY DAY 5.  THE TRACK GUIDANCE IS TIGHTLY-CLUSTERED THROUGH
DAY 4 BUT THEN WIDENS ON DAY 5 WITH THE ECMWF TAKING A MORE
WESTERLY COURSE.  THE OFFICIAL FORECAST IS LOCATED JUST TO THE WEST
OF THE CONSENSUS TVCN ON DAY 5 OUT OF RESPECT FOR THE ECMWF.

FORECAST POSITIONS AND MAX WINDS

INITIAL      15/0300Z 16.7N  30.9W    90 KT
12HR VT     15/1200Z 17.8N  32.1W    95 KT
24HR VT     16/0000Z 19.4N  34.2W    90 KT
36HR VT     16/1200Z 21.0N  37.3W    85 KT
48HR VT     17/0000Z 22.4N  40.8W    80 KT
72HR VT     18/0000Z 25.0N  47.0W    75 KT
96HR VT     19/0000Z 29.0N  51.0W    65 KT
120HR VT     20/0000Z 33.0N  51.0W    50 KT

$$
FORECASTER BERG



000

WTNT42 KNHC 150532
TCDAT2
HURRICANE JULIA SPECIAL DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1230 AM AST WED SEP 15 2010

ENHANCED INFRARED SATELLITE IMAGES INDICATE THAT JULIA HAS RAPIDLY
STRENGTHENED DURING THE LAST FEW HOURS WITH THE EYE NOW MORE
DISTINCT AND CIRCULAR AND THE LARGER CIRCULATION LESS ELONGATED
THAN IT WAS EARLIER. CLOUD TOPS COLDER THAN -75 C NOW SURROUND THE
EYE.  A SPECIAL CLASSIFICATION FROM TAFB GAVE A DVORAK T-NUMBER OF
6.0 OR 115 KT AND OBJECTIVE DVORAK ESTIMATES FROM UW-CIMSS ARE
CLOSER TO 100 OR 105 KT.  BASED ON THESE ESTIMATES...THE NEW
INITIAL INTENSITY IS SET AT 110 KT.  SINCE THE ENVIRONMENT HAS
OBVIOUSLY BECOME MORE FAVORABLE FOR STRENGTHENING...AT LEAST IN THE
SHORT TERM...THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED
UPWARD FOR THE FIRST COUPLE OF DAYS TO ACCOUNT FOR THESE CHANGES.

FORECAST POSITIONS AND MAX WINDS

INITIAL      15/0530Z 16.9N  31.3W   110 KT
12HR VT     15/1200Z 17.8N  32.1W   120 KT
24HR VT     16/0000Z 19.4N  34.2W   120 KT
36HR VT     16/1200Z 21.0N  37.3W   110 KT
48HR VT     17/0000Z 22.4N  40.8W    90 KT
72HR VT     18/0000Z 25.0N  47.0W    75 KT
96HR VT     19/0000Z 29.0N  51.0W    65 KT
120HR VT     20/0000Z 33.0N  51.0W    50 KT

$$
FORECASTER CANGIALOSI/PASCH




WTNT42 KNHC 150859
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST WED SEP 15 2010

A RAPID STRENGTHENING EPISODE WAS NOTED A FEW HOURS AGO.  THIS WAS
MOSTLY UNEXPECTED...AND REMINDS US OF OUR LIMITED UNDERSTANDING OF
TROPICAL CYCLONE INTENSITY CHANGE.  JULIA IS STILL STRENGTHENING...
BUT AT A SIGNIFICANTLY SLOWER RATE THAN WAS OBSERVED LAST EVENING
AND EARLIER THIS MORNING.  ALTHOUGH THE EYE HAS NOT WARMED
MUCH...THE CONVECTIVE BANDING AROUND THE EYE HAS BECOME BETTER
ORGANIZED.  SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 115
KT...AND THAT WILL BE THE INITIAL WIND SPEED FOR THIS ADVISORY...
MAKING JULIA A CATEGORY FOUR HURRICANE.  JULIA COULD STRENGTHEN A
LITTLE MORE TODAY AS IT REMAINS OVER RELATIVELY WARM WATER AND IN A
MODERATE WIND SHEAR ENVIRONMENT.  HOWEVER...MUCH OF THE INTENSITY
GUIDANCE SHOWS GRADUAL WEAKENING BEYOND 12 TO 24 HOURS AS JULIA
MOVES OVER COOLER WATER AND THEN INTO STRONG NORTHERLY SHEAR
ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR.  THE NHC OFFICIAL
INTENSITY FORECAST IS A LITTLE HIGHER THAN THE PREVIOUS
ADVISORY...AND IS ABOVE ALL OF THE MODELS FOR THE FIRST FEW DAYS AS
NONE OF THE GUIDANCE ANTICIPATED THE OBSERVED STRENGTHENING OF
JULIA.

THE HURRICANE HAS NOW TURNED TO THE NORTHWEST...WITH A 12-HOUR
INITIAL MOTION ESTIMATE OF 305/9.  A CONTINUED NORTHWESTWARD MOTION
IS EXPECTED FOR THE NEXT DAY OR SO AS JULIA NEARS A MID- TO
UPPER-LEVEL TROUGH OVER THE EASTERN ATLANTIC.  HOWEVER...A TURN
BACK TO THE WEST-NORTHWEST IS FORECAST IN ABOUT 36 HOURS AS THE
HURRICANE IS STEERED BETWEEN AN UPPER-LEVEL LOW AND A STRENGTHENING
SUBTROPICAL RIDGE.  JULIA IS EXPECTED TO APPROACH THE WESTERN
PERIPHERY OF THE RIDGE IN 3 TO 4 DAYS ALLOWING THE SYSTEM TO TURN
NORTHWARD AND POSSIBLY NORTH-NORTHEASTWARD BY DAY 5.  THE OFFICIAL
TRACK FORECAST IS ADJUSTED SLIGHTLY TO THE RIGHT AND IS A LITTLE
FASTER THAN THE PREVIOUS ONE TO COME INTO BETTER AGREEMENT WITH THE
NEW GUIDANCE SUITE.

FORECAST POSITIONS AND MAX WINDS

INITIAL      15/0900Z 17.3N  31.8W   115 KT
12HR VT     15/1800Z 18.6N  33.2W   120 KT
24HR VT     16/0600Z 20.4N  35.9W   120 KT
36HR VT     16/1800Z 22.2N  39.3W   105 KT
48HR VT     17/0600Z 23.4N  42.6W    95 KT
72HR VT     18/0600Z 26.3N  48.1W    80 KT
96HR VT     19/0600Z 30.0N  50.5W    65 KT
120HR VT     20/0600Z 34.0N  49.5W    50 KT

$$
FORECASTER CANGIALOSI




WTNT42 KNHC 151454
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1100 AM AST WED SEP 15 2010

RAPID INTENSIFICATION OCCURRED DURING THE OVERNIGHT HOURS WITH
JULIA WHEN THE HURRICANE REACHED CATEGORY FOUR STRENGTH. THIS
STRENGTHENING APPPEARS TO HAVE LEVELED OFF THIS MORNING...AS
OUTFLOW FROM HURRICANE IGOR COMBINED WITH A NEARBY UPPER LEVEL LOW
IS PRODUCING SOUTHERLY SHEAR OVER JULIA.  THIS LEVELING OF ITS
INTENSITY ALSO SHOWS UP WITH THE T NUMBERS FROM BOTH SAB AND
TAFB...WHICH HOVER AND DROP SLIGHTLY AROUND/BETWEEN 5 AND 6.
HOWEVER JULIA MAINTAINS A SOLID CENTRAL DENSE OVERCAST/CORE AND
CLEAR EYE STRUCTURE WITH IMPRESSIVE CLOUD TOP ENHANCEMENT... THUS
INITIAL INTENSITY WILL REMAIN AT 115 KTS. JULIA IS EXPECTED TO
MAINTAIN THIS STRENGTH OVER THE NEXT 24 HRS BEFORE BEGINNING TO
WEAKEN AS THE SYSTEM INTERACTS WITH MARGINAL AND COOLER SST VALUES.

THE FORECAST SCENARIO HAS NOT BUDGED MUCH BUT THERE REMAINS RATHER
LARGE SPREAD WITHIN THE GLOBAL AND DYNAMICAL GUIDANCE IN THE EARLY
MEDIUM RANGE PERIOD. FOR THE NEXT 60 TO 72 HRS...JULIA IS EXPECTED
TO MOVE AROUND 15 KTS OR GREATER OFF TO THE NORTHWEST OR
WEST-NORTHWEST AS A BUILDING MID-LEVEL RIDGE BUILDS OVER THE EAST
CENTRAL ATLANTIC.  AFTER 72 HRS...JULIA FORWARD MOTION SLOWS AS A
NORTHERN STREAM RIDGE BUILDS TO ITS NORTH EAST OF NEWFOUNDLAND
WHICH KEEPS THE STORM FROM ACCELERATING INTO THE MAIN BAND OF THE
WESTERLIES.  THE OFFICIAL TRACK FORECAST MAINTAINED A TIGHT
CORRELATION TO THE MODEL CONSENSUS AND KEPT GOOD CONTINUITY.


FORECAST POSITIONS AND MAX WINDS

INITIAL      15/1500Z 18.2N  32.7W   115 KT
12HR VT     16/0000Z 19.5N  34.4W   115 KT
24HR VT     16/1200Z 21.3N  37.5W   115 KT
36HR VT     17/0000Z 22.9N  41.0W   105 KT
48HR VT     17/1200Z 24.3N  44.2W    95 KT
72HR VT     18/1200Z 27.5N  49.0W    80 KT
96HR VT     19/1200Z 31.5N  50.0W    65 KT
120HR VT     20/1200Z 35.0N  47.5W    50 KT

$$
FORECASTER MUSHER




WTNT42 KNHC 152044
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST WED SEP 15 2010

THE EYE OF JULIA HAS BEEN APPARENT INTERMITTENTLY IN INFRARED
SATELLITE IMAGERY THIS AFTERNOON.  A 1912 UTC SSMIS MICROWAVE
OVERPASS INDICATES THAT THERE IS SOME TILT TO THE CIRCULATION WITH
THE LOW-LEVEL CENTER LOCATED A LITTLE TO THE SOUTH OF THE MID- TO
UPPER-LEVEL EYE...DUE TO SOUTH-SOUTHWESTERLY SHEAR.  JULIA HAS
LIKELY PEAKED IN INTENSITY.  THE INITIAL INTENSITY IS LOWERED TO
110 KT...BASED ON A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK DATA
T-NUMBERS THAT HAVE DECREASED SLIGHTLY.  THE CYCLONE WILL BE MOVING
INTO A LESS FAVORABLE ENVIRONMENT WITH MODERATE SOUTHERLY SHEAR AND
SLIGHTLY COOLER SSTS DURING THE NEXT DAY OR SO. THIS SHOULD RESULT
IN GRADUAL WEAKENING.  AFTER 48 HOURS...THE GLOBAL MODELS SHOW JULIA
MOVING INTO AN AREA OF INCREASING NORTHEASTERLY UPPER-LEVEL WINDS
ASSOCIATED WITH THE OUTFLOW FROM HURRICANE IGOR. A FASTER RATE OF
WEAKENING IS INDICATED BY THE INTENSITY GUIDANCE AND IN THE
OFFICIAL FORECAST AT THAT TIME. THE NHC FORECAST IS CLOSE TO THE
INTENSITY CONSENSUS AT DAYS 3-5...BUT IS HIGHER THAN THE SHIPS
GUIDANCE WHICH WEAKENS THE JULIA VERY RAPIDLY AFTER 72 HOURS.

THE INITIAL MOTION ESTIMATE IS 315/11. JULIA IS FORECAST TO MOVE
NORTHWESTWARD AROUND AN UPPER-LEVEL LOW TO ITS SOUTHWEST DURING THE
NEXT 12-24 HOURS.  DURING THIS TIME...THE FORWARD SPEED OF JULIA IS
FORECAST TO INCREASE.  BETWEEN 24 AND 72 HOURS...THE HURRICANE WILL
BE STEERED IN A WEST-NORTHWEST TO NORTHWEST DIRECTION AROUND THE
WESTERN PERIPHERY OF A MID-LEVEL RIDGE CENTERED BETWEEN JULIA AND
THE AZORES ISLANDS.  THEREAFTER...JULIA SHOULD TURN
NORTHWARD...THEN NORTHEASTWARD BETWEEN THE NORTHWEST SIDE OF THE
RIDGE AND HURRICANE IGOR TO THE WEST.  THE TRACK GUIDANCE IS IN A
LITTLE BETTER AGREEMENT FOR THIS CYCLE.  THE NEW NHC TRACK FORECAST
HAS BEEN ADJUSTED SOMEWHAT NORTHWARD AND LIES NEAR THE MIDDLE OF
THE MODEL ENVELOPE.


FORECAST POSITIONS AND MAX WINDS

INITIAL      15/2100Z 19.2N  33.5W   110 KT
12HR VT     16/0600Z 20.6N  35.5W   105 KT
24HR VT     16/1800Z 22.6N  38.9W   100 KT
36HR VT     17/0600Z 24.3N  42.4W    95 KT
48HR VT     17/1800Z 26.0N  45.5W    85 KT
72HR VT     18/1800Z 30.0N  49.6W    75 KT
96HR VT     19/1800Z 34.0N  49.0W    60 KT
120HR VT     20/1800Z 36.0N  45.0W    45 KT

$$
FORECASTER BROWN




WTNT42 KNHC 160255
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST WED SEP 15 2010

JULIA IS COMING UNDER INCREASING INFLUENCE OF SOUTHERLY SHEAR...AND
RECENT MICROWAVE IMAGES INDICATE THAT THE LOW-LEVEL CENTER AND THE
MID-LEVEL EYE ARE DISPLACED FROM ONE ANOTHER.  SATELLITE INTENSITY
ESTIMATES ARE NOW T5.0/5.5 FROM TAFB...T4.0/5.0 FROM SAB...AND
T5.3/5.7 FROM THE UW-CIMSS ADT.  THE INITIAL INTENSITY IS LOWERED
TO 100 KT FOR THIS ADVISORY...BUT IT IS POSSIBLE THAT JULIA COULD
BE WEAKER THAN THAT.  JULIA IS LOCATED VERY NEAR A DEVELOPING
CLOSED UPPER-LEVEL LOW...AND STRONG SHEAR IS EXPECTED TO CONTINUE
OVER THE HURRICANE DURING THE FORECAST PERIOD.  THE OFFICIAL
FORECAST INDICATES GRADUAL WEAKENING DURING THE NEXT 48-72 HOURS
AND IS IN LINE WITH THE INTENSITY CONSENSUS.  JULIA SHOULD WEAKEN
TO A TROPICAL STORM BY DAYS 4 AND 5...BUT THE FORECAST IS A LITTLE
ABOVE THE INTENSITY CONSENSUS AT THAT TIME SINCE THE SHIPS
MODEL...FOR SOME UNKNOWN REASON...SHOWS THE SYSTEM DISSIPATED BY
DAY 5.  THIS SEEMS UNREASONABLE SINCE THE GFS STILL SHOWS AN INTACT
AREA OF LOW PRESSURE.

THE HURRICANE IS STARTING TO ACCELERATE AND IS NOW MOVING AT 315/14.
ADDITIONAL ACCELERATION IS EXPECTED OVER THE NEXT 24 HOURS AS JULIA
IS STEERED BETWEEN A MID-LEVEL HIGH TO ITS NORTHEAST AND THE
UPPER-LEVEL LOW TO ITS SOUTHWEST...ALMOST LIKE A SLING-SHOT AFFECT.
JULIA WILL THEN BE STEERED NORTH-NORTHWEST AND THEN NORTH FROM
48-72 HOURS AS IT REACHES THE WESTERN SIDE OF THE RIDGE AND THE
EASTERN SIDE OF THE LARGE CIRCULATION ASSOCIATED WITH IGOR.  THE
RECURVATURE TO THE NORTHEAST IS ANTICIPATED BY DAY 5 AS JULIA GETS
EMBEDDED WITHIN THE MID-LATITUDE WESTERLY FLOW.  THE OFFICIAL TRACK
FORECAST IS VERY CLOSE TO THE PREVIOUS FORECAST...AND LIES JUST TO
THE WEST OF THE MODEL CONSENSUS.  JUST LIKE IN THE CASE WITH
IGOR...THE ECMWF MODEL LIES AT THE WESTERN SIDE OF THE GUIDANCE
ENVELOPE AND CANNOT BE IGNORED.


FORECAST POSITIONS AND MAX WINDS

INITIAL      16/0300Z 20.2N  34.6W   100 KT
12HR VT     16/1200Z 21.7N  36.9W    90 KT
24HR VT     17/0000Z 23.6N  40.4W    85 KT
36HR VT     17/1200Z 25.3N  43.8W    80 KT
48HR VT     18/0000Z 27.0N  46.5W    75 KT
72HR VT     19/0000Z 31.5N  49.5W    65 KT
96HR VT     20/0000Z 35.0N  48.0W    50 KT
120HR VT     21/0000Z 36.5N  43.5W    40 KT

$$
FORECASTER BERG




WTNT42 KNHC 160903
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST THU SEP 16 2010

THE SATELLITE PRESENTATION OF JULIA HAS CONTINUED TO DETERIORATE
OVER THE PAST FEW HOURS.  MOST OF THE DEEP CONVECTION IS DISPLACED
NORTH OF THE ESTIMATED CENTER POSITION...AND CLOUD TOPS HAVE
CONTINUED TO WARM.  JULIA IS CURRENTLY SITUATED OVER WATERS OF
26-27C...AND THE MID- TO UPPER-LEVEL TROUGH/LOW BETWEEN JULIA AND
HURRICANE IGOR IS IMPARTING 20 TO 30 KT OF SOUTHWESTERLY SHEAR OVER
JULIA ACCORDING TO THE UW-CIMSS SHEAR ANALYSIS.  BASED ON A BLEND
OF SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES THE INITIAL
INTENSITY IS LOWERED TO 90 KT FOR THIS ADVISORY.  WHILE THE SHIPS
MODEL OUTPUT SHOWS THE SHEAR DECREASING TO LESS THAN 20 KT FROM 12
TO 24 HOURS...JULIA WILL REMAIN OVER MARGINAL SSTS THROUGH THAT
TIME.  THEN BY 36 HOURS OR SO...WHEN JULIA TEMPORARILY MOVES BACK
OVER WARMER WATERS...THE SHEAR INCREASES TO AROUND 30 KT AND
REMAINS HIGH FOR THE REST OF THE PERIOD.  THIS SCENARIO SHOULD
RESULT IN A GRADUAL WEAKENING FOR THE FIRST 48 HOURS...WITH MORE
RAPID WEAKENING TOWARD THE END OF THE PERIOD.  THE OFFICIAL FORECAST
REFLECT THIS AND FOLLOWS A BLEND OF THE LGEM AND SHIPS MODELS
THROUGH 48 HOURS...AND IS CLOSEST TO THE LGEM THEREAFTER.

WITH A LACK OF MICROWAVE IMAGERY OVER THE PAST FEW HOURS...THE
INITIAL MOTION ESTIMATE OF 310/16 IS BASED LARGELY ON CONTINUITY
AND THE ASSUMPTION THAT THE LOW-LEVEL CENTER REMAINS DISPLACED SOUTH
AND EAST OF THE DEEP CONVECTION.  THE TRACK FORECAST REASONING
REMAINS UNCHANGED FROM THE PREVIOUS PACKAGE.  JULIA IS CURRENTLY
BEING STEERED NORTHWESTWARD BY THE UPPER-LEVEL LOW TO ITS SOUTHWEST
AND A LARGE MID-LEVEL RIDGE TO ITS EAST...AND THIS WILL CONTINUE
FOR THE NEXT DAY OR SO. THEN...AS JULIA MOVES AWAY FROM THE
UPPER-LOW...THE CYCLONE WILL MOVE AROUND THE WESTERN PERIPHERY OF
THE RIDGE AND TURN EAST-NORTHEASTWARD BY THE END OF THE PERIOD AS
IT COMES UNDER THE INFLUENCE OF THE MID-LATITUDE WESTERLIES.  SOME
DIFFERENCES REMAIN IN HOW SHARPLY JULIA MOVES AROUND THE RIDGE...
WITH THE UKMET SHOWING A SHARPER TURN...WHILE THE ECMWF AND HWRF
SHOW A WIDER TURN.  THE OFFICIAL FORECAST HAS BEEN ADJUSTED TOWARD
THE TVCN MULTI-MODEL CONSENSUS...AND IS CLOSE TO THE GFS FOR
THE FIRST 72 HOURS...WHICH REPRESENTS A COMPROMISE BETWEEN THE
ECMWF AND UKMET. THE NEW NHC FORECAST IS ALSO FASTER THAN THE
PREVIOUS PACKAGE DURING THE FIRST 24 HOURS...ACCOUNTING FOR THE
OBSERVED ACCELERATION OF JULIA.

FORECAST POSITIONS AND MAX WINDS

INITIAL      16/0900Z 21.2N  36.2W    90 KT
12HR VT     16/1800Z 22.8N  38.8W    85 KT
24HR VT     17/0600Z 24.6N  42.4W    80 KT
36HR VT     17/1800Z 26.4N  45.5W    75 KT
48HR VT     18/0600Z 28.3N  47.7W    70 KT
72HR VT     19/0600Z 32.5N  49.5W    65 KT
96HR VT     20/0600Z 35.0N  46.5W    50 KT
120HR VT     21/0600Z 36.0N  42.5W    40 KT

$$
FORECASTER BRENNAN




WTNT42 KNHC 161457
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST THU SEP 16 2010

SATELLITE IMAGERY CONTINUES TO INDICATE WARMING OF THE CLOUD TOPS IN
THE RATHER RAGGED LOOKING CENTRAL DENSE OVERCAST. A 1001Z AMSU
MICROWAVE OVERPASS INDICATED A 25-30 NMI DIAMETER EYE THAT WAS OPEN
IN THE SOUTHEAST QUADRANT. WATER VAPOR IMAGERY ALSO SHOWS A LARGE
SLUG OF DRY AIR BEING ENTRAINED INTO THE EASTERN SEMICIRCLE...WHICH
LIKELY EXPLAINS THE EROSION OF THE EASTERN EYEWALL NOTED IN THE
AMSU IMAGERY. DESPITE THE AFOREMENTIONED NEGATIVE FACTORS...JULIA
HAS MAINTAINED GOOD OUTFLOW TO THE WEST AND NORTH OF THE CYCLONE.

THE INITIAL MOTION ESTIMATE HAS INCREASED SHARPLY TO 300/22. JULIA
IS EXPECTED TO MOVE TO THE WEST-NORTHWEST AND THEN NORTHWEST
FOR THE NEXT 36-48 HOURS AS THE HURRICANE ROUNDS THE SOUTHERN
PERIPHERY OF A LARGE SUBTROPICAL RIDGE SITUATED TO ITS NORTH AND
NORTHEAST. AFTER THAT...SIGNIFICANT VERTICAL WIND SHEAR MAY WEAKEN
THE CYCLONE AND CAUSE IT TO BECOME MORE SHALLOW...AND THEN BE
STEERED MORE NORTHWARD SIMILAR TO THE ECMWF AND GFDL MODELS...BUT
NOT AS FAR NORTH AND WEST AS THE SHALLOW BAM MODEL. THE OFFICIAL
TRACK FORECAST HAS BEEN NUDGED TO THE LEFT OF THE PREVIOUS ADVISORY
THROUGH 72 HOURS...AND IS SIMILAR TO THE MULTI-MODEL CONSENSUS.

DRY AIR AND COOLER SSTS SHOULD CONTINUE THE RECENT WEAKENING
TREND...ESPECIALLY AFTER 24 HOURS. BY 36-48 HOURS...ALL OF THE
GLOBAL MODELS INDICATE THAT JULIA WILL BE MOVING INTO A REGION OF
STRONG UPPER-LEVEL SHEAR CAUSED BY THE PRONOUNCED NORTHERLY OUTFLOW
EMANATING FROM THE MAJOR HURRICANE IGOR LOCATED TO ITS WEST. WITH
JULIA MOVING INTO 50-70 KT OF 200 MB WINDS...IT WILL BE HARD FOR
JULIA TO SURVIVE AS A TROPICAL CYCLONE AS INDICATED BY THE GLOBAL
MODELS AND GFDL/HWRF MODELS. THE OFFICIAL INTENSITY FORECAST SHOWS
A FASTER WEAKENING TREND THAN THE PREVIOUS ADVISORY...BUT NOT AS
FAST AS THE SHIPS MODEL...WHICH DISSIPATES JULIA BY 120 HOURS.


FORECAST POSITIONS AND MAX WINDS

INITIAL      16/1500Z 22.4N  38.6W    85 KT
12HR VT     17/0000Z 23.7N  41.2W    75 KT
24HR VT     17/1200Z 25.5N  44.6W    65 KT
36HR VT     18/0000Z 27.3N  47.3W    55 KT
48HR VT     18/1200Z 29.3N  49.1W    45 KT
72HR VT     19/1200Z 33.2N  49.6W    35 KT
96HR VT     20/1200Z 35.8N  46.3W    35 KT
120HR VT     21/1200Z 38.0N  42.0W    35 KT

$$
FORECASTER STEWART




WTNT42 KNHC 162040
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST THU SEP 16 2010

VERTICAL SHEAR APPEARS TO HAVE ABATED FOR THE MOMENT...WITH A 1533
UTC AMSR-E MICROWAVE PASS SHOWING THAT THE LOW- AND MID-LEVEL
CENTERS ARE JUST ABOUT VERTICALLY STACKED.  HOWEVER...CONVECTIVE
TOPS HAVE WARMED...AND SATELLITE CURRENT INTENSITY ESTIMATES ARE
NOW 77 KT FROM TAFB...65 KT FROM SAB...AND 65 KT AND 80 KT FROM TWO
VERSIONS OF THE UW-CIMSS ADT.  THE INITIAL INTENSITY IS THEREFORE
LOWERED TO 75 KT FOR THIS ADVISORY.

JULIA HAS AN INITIAL MOTION OF 295/22 KT.  THERE HAS BEEN A
SIGNIFICANT WESTWARD SHIFT IN NEARLY ALL THE TRACK GUIDANCE ON THIS
CYCLE...POSSIBLY DUE TO A STRONGER-THAN-EXPECTED MID-LEVEL HIGH TO
THE NORTH AND NORTHEAST OF THE HURRICANE.  CONSEQUENTLY...THE NEW
OFFICIAL FORECAST HAS BEEN SHIFTED WESTWARD ABOUT HALFWAY BETWEEN
OFCI AND THE MODEL CONSENSUS TVCN.  SEVERAL MODELS...ESPECIALLY THE
UKMET AND ECMWF...ARE EVEN FARTHER WEST THAN THIS TRACK SO IT IS
POSSIBLE THAT ADDITIONAL SHIFTS COULD BE REQUIRED IN THE NEXT FEW
ADVISORY PACKAGES.  GLOBAL MODEL FIELDS INDICATE THAT AFTER JULIA
MOVES NORTHWARD AROUND THE RIDGE...IT SHOULD TURN TOWARD THE
NORTHEAST AND DISSIPATE IN THE STRONG SOUTHWESTERLY FLOW TO THE
EAST OF IGOR IN ABOUT 120 HOURS.

WITH THE WESTWARD SHIFT IN THE FORECAST TRACK...JULIA APPEARS TO
HAVE A BETTER CHANCE TO MAINTAIN SOME OF ITS INTENSITY OVER THE
NEXT COUPLE OF DAYS.  THE HURRICANE WILL BE BATTLING THE STRONG
UPPER-LEVEL OUTFLOW OF IGOR DURING THE NEXT 36 HOURS OR SO...BUT
AFTER THAT THE GLOBAL MODELS SUGGEST THAT JULIA COULD SNEAK
UNDERNEATH THE UPPER-LEVEL ANTICYCLONE PARTIALLY GENERATED BY IGOR.
THE SHEAR COULD RELAX JUST ENOUGH DURING THAT TIME AND CAUSE MORE
MODEST WEAKENING...SO THE NEW INTENSITY FORECAST IS A LITTLE BIT
HIGHER THAN THE PREVIOUS ONE FROM 36-72 HOURS.  INCIDENTALLY... THE
NEW FORECAST IS STILL LOWER THAN INDICATED BY THE LGEM...THE
DYNAMICAL MODELS...AND THE INTENSITY CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL      16/2100Z 23.1N  41.1W    75 KT
12HR VT     17/0600Z 24.2N  43.9W    65 KT
24HR VT     17/1800Z 26.0N  47.1W    65 KT
36HR VT     18/0600Z 27.9N  49.6W    60 KT
48HR VT     18/1800Z 30.1N  51.0W    55 KT
72HR VT     19/1800Z 34.0N  50.5W    45 KT
96HR VT     20/1800Z 37.0N  47.0W    35 KT
120HR VT     21/1800Z...DISSIPATED

$$
FORECASTER BERG



000

WTNT42 KNHC 172053
TCDAT2
HURRICANE JULIA DISCUSSION NUMBER  23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST FRI SEP 17 2010

JULIA HAS BEEN EXPERIENCING MODERATE NORTHERLY SHEAR...AND
AT TIMES IT APPEARS THAT THE LOW-LEVEL CENTER IS BEGINNING TO
BECOME EXPOSED.  USING A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK
T-NUMBERS LEADS TO A CURRENT INTENSITY ESTIMATE OF 65 KT.  THE
SHEAR...WHICH IS PRIMARILY ASSOCIATED WITH THE MASSIVE OUTFLOW
PATTERN OF HURRICANE IGOR...IS NOT LIKELY TO RELENT.  IN FACT...
THE DYNAMICAL GUIDANCE SUGGESTS THAT THE SHEAR WILL BECOME STRONGER.
THE OFFICIAL INTENSITY FORECAST SHOWS STEADY WEAKENING AND IS BASED
ON A COMBINATION OF THE STATISTICAL-DYNAMICAL SHIPS AND LGEM
MODELS. BY THE END OF THE FORECAST PERIOD...GLOBAL MODELS INDICATE
THAT JULIA WILL BECOME ABSORBED BY THE MUCH LARGER CIRCULATION OF
POST-TROPICAL IGOR.

THE INITIAL MOTION IS ABOUT 300/18.  THE FORECAST REASONING IS
ESSENTIALLY UNCHANGED.  JULIA IS EXPECTED TO MOVE AROUND A
MID-LEVEL SUBTROPICAL HIGH FOR THE NEXT FEW DAYS...BEFORE GETTING
PULLED INTO THE CIRCULATION OF IGOR.  THUS...THE NHC TRACK FORECAST
SHOWS A GRADUAL TURN TOWARD THE NORTHWEST...NORTH...AND NORTH-
NORTHEAST.  THIS IS JUST A LITTLE TO THE WEST OF THE PREVIOUS
OFFICIAL TRACK AND GENERALLY TO THE RIGHT OF THE MULTI-MODEL
CONSENSUS TVCN.

FORECAST POSITIONS AND MAX WINDS

INITIAL      17/2100Z 25.2N  48.2W    65 KT
12HR VT     18/0600Z 26.9N  50.0W    60 KT
24HR VT     18/1800Z 29.6N  51.8W    55 KT
36HR VT     19/0600Z 32.5N  52.3W    50 KT
48HR VT     19/1800Z 34.8N  51.2W    45 KT
72HR VT     20/1800Z 38.2N  47.2W    35 KT
96HR VT     21/1800Z 43.0N  43.0W    25 KT
120HR VT     22/1800Z...DISSIPATED

$$
FORECASTER PASCH




WTNT42 KNHC 180241
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST FRI SEP 17 2010

THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA
JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED
CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A
STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE EARL.  SUBSEQUENT
BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO
65 AND 60 KT RESPECTIVELY.  BASED ON THESE DATA...THE INITIAL
INTENSITY IS LOWERED TO 60 KT.  THE GLOBAL AND THE SHIPS MODELS ALL
SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR
PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY
FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE
AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING
ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR.

THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS
ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14.  THE
DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE
NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH
TO THE NORTHEAST OF JULIA.  THROUGH DAY 3...THE MODELS INDICATE
THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD
AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE
CENTRAL ATLANTIC.  AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT
WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR
EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS
ENSEMBLE MEANS.  THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS
ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS.



FORECAST POSITIONS AND MAX WINDS

INITIAL      18/0300Z 26.0N  49.2W    60 KT
12HR VT     18/1200Z 28.1N  50.8W    55 KT
24HR VT     19/0000Z 31.0N  52.1W    50 KT
36HR VT     19/1200Z 33.5N  52.0W    45 KT
48HR VT     20/0000Z 35.5N  50.6W    40 KT
72HR VT     21/0000Z 39.0N  46.0W    30 KT
96HR VT     22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW

$$
FORECASTER ROBERTS/AVILA




WTNT42 KNHC 180302
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  24...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST FRI SEP 17 2010

CORRECTED TO ADD IGOR

THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA
JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED
CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A
STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE IGOR.  SUBSEQUENT
BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO
65 AND 60 KT RESPECTIVELY.  BASED ON THESE DATA...THE INITIAL
INTENSITY IS LOWERED TO 60 KT.  THE GLOBAL AND THE SHIPS MODELS ALL
SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR
PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY
FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE
AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING
ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR.

THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS
ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14.  THE
DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE
NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH
TO THE NORTHEAST OF JULIA.  THROUGH DAY 3...THE MODELS INDICATE
THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD
AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE
CENTRAL ATLANTIC.  AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT
WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR
EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS
ENSEMBLE MEANS.  THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS
ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS.



FORECAST POSITIONS AND MAX WINDS

INITIAL      18/0300Z 26.0N  49.2W    60 KT
12HR VT     18/1200Z 28.1N  50.8W    55 KT
24HR VT     19/0000Z 31.0N  52.1W    50 KT
36HR VT     19/1200Z 33.5N  52.0W    45 KT
48HR VT     20/0000Z 35.5N  50.6W    40 KT
72HR VT     21/0000Z 39.0N  46.0W    30 KT
96HR VT     22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW

$$
FORECASTER ROBERTS/AVILA




WTNT42 KNHC 180831
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST SAT SEP 18 2010

STRONG NORTHERLY SHEAR CONTINUES TO WEAKEN JULIA.  SATELLITE IMAGES
SHOW THAT THE CENTER OF THE STORM IS PARTIALLY EXPOSED ON THE
NORTHWESTERN EDGE OF A BURST OF CONVECTION.  DVORAK CLASSIFICATIONS
ARE DROPPING QUICKLY...AND A BLEND OF THE T/CI NUMBERS FROM
TAFB/SAB AND ADT VALUES FROM UW-CIMSS GIVES AN INITIAL WIND SPEED
OF 50 KT. A STEADY DECREASE IN STRENGTH IS LIKELY WITH THE STRONG
SHEAR EXPECTED TO PERSIST.  JULIA SHOULD BECOME A REMNANT LOW BY 72
HOURS...IF NOT SOONER BECAUSE OF EXPECTED COOL SSTS.  THE NHC
FORECAST IS CLOSE TO THE SHIPS MODEL...AND IS BELOW MOST OF THE
GUIDANCE.  THE REMNANT LOW IS EXPECTED TO BE ABSORBED BY IGOR IN
ABOUT 96 HRS.  

THE INITIAL MOTION CONTINUES TO BEND A LITTLE TO THE RIGHT AND IS
NOW 320/16.  THE MODEL GUIDANCE IS TIGHTLY CLUSTERED ON A
NORTHWESTWARD TRACK TODAY...WITH A NORTHWARD TURN TOMORROW AS JULIA
MOVES AROUND A SUBTROPICAL RIDGE.  MOST OF THE GUIDANCE SUGGESTS
THAT JULIA WILL STAY FAR ENOUGH AWAY FROM IGOR THAT THE LARGER
HURRICANE WILL NOT HAVE AN IMMEDIATE IMPACT ON THE TRACK OF JULIA. 
THE NHC FORECAST IS CLOSE TO THE PREVIOUS ONE...ON THE RIGHT EDGE
OF THE GUIDANCE ENVELOPE...AND NOT TOO FAR FROM THE GFS.  

THE WIND RADII HAVE BEEN ADJUSTED BASED ON AN EARLIER ASCAT PASS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/0900Z 27.4N  50.1W    50 KT
 12HR VT     18/1800Z 29.5N  51.5W    45 KT
 24HR VT     19/0600Z 32.3N  52.1W    40 KT
 36HR VT     19/1800Z 34.5N  51.3W    35 KT
 48HR VT     20/0600Z 36.0N  49.0W    30 KT
 72HR VT     21/0600Z 39.5N  44.0W    25 KT...POST-TROP/REMNT LOW
 96HR VT     22/0600Z...ABSORBED BY IGOR
 
$$
FORECASTER BLAKE
 

WTNT42 KNHC 181447
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST SAT SEP 18 2010
 
VISIBLE SATELLITE IMAGES INDICATE THAT STRONG NORTHERLY SHEAR HAS
DISPLACED DEEP CONVECTION ASSOCIATED WITH JULIA TO THE SOUTHEAST OF
THE NOW EXPOSED LOW-LEVEL CENTER.  AS A RESULT...DVORAK T-NUMBERS
ARE DECREASING AS QUICKLY AS CONSTRAINTS WILL ALLOW.  A BLEND OF
T/CI NUMBERS FROM TAFB/SAB REPRESENT THE BASIS FOR AN INITIAL
INTENSITY OF 45 KT FOR THIS ADVISORY.  THE PERSISTENCE OF STRONG
SHEAR ASSOCIATED WITH THE OUTFLOW OF IGOR AND PROGRESSIVELY COOLER
WATERS ALONG THE FORECAST TRACK SHOULD LEAD TO A CONTINUED
WEAKENING.  THE NHC OFFICIAL FORECAST IS NEAR THE STATISTICAL-
DYNAMICAL GUIDANCE...AND INDICATES JULIA BECOMING A REMNANT LOW IN
48 HOURS.  HOWEVER...JULIA COULD DEGENERATE INTO A REMNANT LOW
SOONER THAN CURRENTLY FORECAST.  ULTIMATELY...THE REMNANT
CIRCULATION OF JULIA COULD BE ABSORBED BY LARGE HURRICANE IGOR AS
IGOR UNDERGOES EXTRATROPICAL TRANSITION BEYOND 72 HOURS.

THE INITIAL MOTION ESTIMATE HAS SHIFTED A LITTLE MORE TO THE RIGHT
COMPARED TO BEFORE AND IS NOW 320/16.  THE MODEL GUIDANCE IS IN
GOOD AGREEMENT...SHOWING A TRACK BENDING TOWARD THE NORTH-NORTHWEST
LATER TODAY AND TURNING NORTHWARD TOMORROW AS JULIA MOVES AROUND A
SUBTROPICAL RIDGE TO THE EAST.  THE OFFICIAL NHC FORECAST IS NEAR
THE THE PREVIOUS ONE...CLOSE TO THE MIDDLE OF THE GUIDANCE ENVELOPE
BUT SLIGHTLY RIGHT OF THE MULTI-MODEL CONSENSUS.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/1500Z 28.9N  51.0W    45 KT
 12HR VT     19/0000Z 31.1N  51.9W    40 KT
 24HR VT     19/1200Z 33.5N  51.8W    35 KT
 36HR VT     20/0000Z 35.5N  50.3W    30 KT
 48HR VT     20/1200Z 37.0N  48.0W    25 KT...POST-TROP/REMNT LOW
 72HR VT     21/1200Z 40.5N  43.0W    20 KT...POST-TROP/REMNT LOW
 96HR VT     22/1200Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN
 

WTNT42 KNHC 182031
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  27
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST SAT SEP 18 2010

SATELLITE PICTURES INDICATE THAT THE CLOUD PATTERN ASSOCIATED WITH
JULIA HAS CHANGED LITTLE DURING THE LAST SEVERAL HOURS.  THE
CYCLONE CONTINUES TO EXPERIENCE STRONG NORTH-NORTHWESTERLY SHEAR...
AND THE LOW-LEVEL CENTER REMAINS EXPOSED EVEN THOUGH REPEATED
BURSTS OF NEW CONVECTION CONTINUE FORMING NEAR AND TO THE SOUTHEAST
OF IT. DESPITE ITS APPEARANCE...RECENT PRESSURE DATA FROM A NUMBER
OF DRIFTING BUOYS NEAR JULIA SUGGEST THAT THE CIRCULATION OF JULIA
HAS LIKELY RETAINED ITS VIGOR.  BASED UPON THESE OBSERVATIONS AND
DVORAK CI NUMBERS ARE 2.5 AND 3.5 AT 1800 UTC FROM TAFB AND
SAB...THE INTENSITY OF JULIA IS UNCHANGED AT 45 KT.  SHIPS MODEL
OUTPUT SHOWS NORTHERLY SHEAR ASSOCIATED WITH THE OUTFLOW FROM
HURRICANE IGOR INCREASING FURTHER DURING THE NEXT DAY OR TWO WHILE
JULIA MOVES OVER PROGRESSIVELY COOLER WATERS.  THE COMBINATION OF
THESE FACTORS SHOULD RESULT IN A CONTINUED WEAKENING. THE NHC
INTENSITY FORECAST IS IS SIMILAR TO THE PREVIOUS ONE AND IN LINE
WITH THE LATEST STATISTICAL-DYNAMICAL GUIDANCE.  JULIA IS FORECAST
TO BECOME A REMNANT LOW IN 48 HOURS...IF NOT SOONER.  THE REMNANT
CIRCULATION OF JULIA IS LIKELY TO BE ABSORBED BY LARGE HURRICANE
IGOR AS IGOR UNDERGOES EXTRATROPICAL IN ABOUT 72 HOURS.
 
THE TRACK OF JULIA CONTINUES BENDING TO THE RIGHT...WITH THE INITIAL
MOTION NOW ESTIMATED TO BE 330/17.  JULIA IS FORECAST TO TURN TOWARD
THE NORTH BY TONIGHT AND TOWARD THE NORTH-NORTHEAST AND THEN
NORTHEAST TOMORROW AS JULIA MOVES AROUND THE NORTHWEST SIDE OF A
SUBTROPICAL RIDGE TO THE SOUTHEAST.  WITH THE EXCEPTION OF THE
UKMET SOLUTION WHICH SEEMS LIKE AN OUTLIER...THE MODEL GUIDANCE IS
FAIRLY TIGHTLY CLUSTER AND IS IN GOOD AGREEMENT ON THIS SCENARIO.  
THE OFFICIAL NHC FORECAST CONTINUES TO BE NEAR THE THE PREVIOUS
ONE...AND IT CLOSE TO A MULTI-MODEL CONSENSUS THAT EXCLUDES THE
UKMET.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/2100Z 30.6N  51.8W    45 KT
 12HR VT     19/0600Z 32.6N  52.0W    40 KT
 24HR VT     19/1800Z 34.8N  51.2W    35 KT
 36HR VT     20/0600Z 36.4N  49.4W    30 KT
 48HR VT     20/1800Z 38.0N  47.4W    25 KT...POST-TROP/REMNT LOW
 72HR VT     21/1800Z 42.0N  43.0W    20 KT...POST-TROP/REMNT LOW
 96HR VT     22/1800Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN
 

WTNT42 KNHC 190233
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST SAT SEP 18 2010
 
JULIA HAS MOVED INTO A REGION OF WEAKER VERTICAL SHEAR DURING THE
PAST 6 HOURS AND VERY COLD TOPPED CONVECTION HAS DEVELOPED NEAR AND
SOUTHEAST OF THE LOW-LEVEL CENTER AS A RESULT. SATELLITE CURRENT
INTENSITY ESTIMATES ARE T3.5/55 KT FROM TAFB...T2.5/35 KT FROM
SAB...AND ADT VALUES OF T3.4/43 KT FROM UW-CIMSS...RESPECTIVELY.
GIVEN THE NEW DEVELOPMENT OF DEEP CONVECTION NEAR THE CENTER...THE
INITIAL INTENSITY REMAINS 45 KT...WHICH IS AN AVERAGE OF THE THREE
INTENSITY ESTIMATES.

JULIA HAS TURNED TOWARD THE NORTH AND IS NOW ESTIMATED TO BE MOVING
AT 360/12. JULIA EARLIER ACCELERATED NORTHWARD AT ABOUT 20 KT
DURING THE PERIOD WHEN IT POSSESSED NO DEEP CONVECTION NEAR THE
CENTER. HOWEVER...NOW THAT CONVECTION HAS REFORMED...THE
CIRCULATION HAS LIKELY DEEPENED IN THE VERTICAL AND WILL BE SUBJECT
TO A DEEPER AND SLOWER STEERING FLOW. THE NHC MODEL GUIDANCE IS IN
GENERAL AGREEMENT ON JULIA MOVING NORTHWARD FOR THE NEXT 12 HOURS
AND THEN NORTHEASTWARD AFTER THAT AS THE CYCLONE MOVES AROUND THE
WESTERN PERIPHERY OF A LARGE SUBTROPICAL RIDGE LOCATED TO ITS EAST.
BY 48 HOURS...A SEVERELY WEAKENED AND SHALLOW JULIA AT THAT TIME IS
EXPECTED TO GRADUALLY BECOME ABSORBED INTO THE EASTERN PORTION OF
THE VERY LARGE HURRICANE IGOR CIRCULATION. THE OFFICIAL FORECAST IS
A LITTLE TO THE LEFT OF THE PREVIOUS ADVISORY TRACK...AND IS
SIMILAR TO THE CONSENSUS MODELS...TVCN AND TVCC.

WEAKER VERTICAL SHEAR CONDITIONS THAT JULIA HAS BEEN EXPERIENCING
THE PAST 6 HOURS WILL BE SHORT-LIVED SINCE THE CYCLONE WILL BE
MOVING NORTHWARD INTO A REGION OF STRONG WESTERLY SHEAR OF 30-50 KT
EMANATING FROM THE MASSIVE OUTFLOW FROM HURRICANE IGOR IN 6-12
HOURS. BY 24 HOURS...JULIA WILL ALSO BE MOVING OVER SUB-26C
SSTS...WHICH WHEN COMBINED WITH THE INCREASING WESTERLY SHEAR...
SHOULD INDUCE RAPID WEAKENING. JULIA IS EXPECTED TO BECOME A
REMNANT LOW IN 36-48 HOURS...IF NOT SOONER. THE OFFICIAL INTENSITY
FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY...AND CLOSELY FOLLOWS
THE SHIPS/LGEM MODELS...WHICH DISSIPATE JULIA BY AROUND 48 HOURS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/0300Z 32.4N  51.9W    45 KT
 12HR VT     19/1200Z 34.3N  51.7W    40 KT
 24HR VT     20/0000Z 36.1N  50.4W    30 KT
 36HR VT     20/1200Z 37.6N  48.7W    25 KT
 48HR VT     21/0000Z 39.1N  46.9W    25 KT...POST-TROP/REMNT LOW
 72HR VT     22/0000Z 43.6N  41.8W    20 KT...POST-TROP/REMNT LOW
 96HR VT     23/0000Z...DISSIPATED
 
$$
FORECASTER STEWART
 

WTNT42 KNHC 190849
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  29
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST SUN SEP 19 2010
 
SOMEWHAT UNEXPECTEDLY...THE ASCAT PASS AT 0106Z OVER JULIA SHOWED 50
TO 55 KT WINDS AT THE SURFACE...WHICH SUGGESTS THAT THE CYCLONE WAS
AT LEAST 55 KT AROUND 0000Z GIVEN THE LOW BIAS OF THAT INSTRUMENT.
SINCE THEN...THE CONVECTION HAS WEAKENED AND THE CDO HAS BECOME
FRAGMENTED.  DVORAK INTENSITY ESTIMATES WERE 3.0...OR 45 KT...FROM
TAFB AND 2.5...OR 35 KT...FROM SAB.  THE INTENSITY WAS SET AT
50 KT AT THE SYNOPTIC TIME AND IS 45 KT FOR THIS ADVISORY.
 
THE MOTION OF JULIA IS 355 DEGREES AT 14 KT...WHICH IS FAIRLY WELL
KNOWN DUE TO AN 0506Z AQUA PASS THAT WAS JUST RECEIVED. THE CYCLONE
IS IN THE PROCESS OF RECURVING AROUND THE DEEP LAYER SUBTROPICAL
RIDGE TO ITS SOUTHEAST. A MODEST DECELERATION IS EXPECTED OVER THE
NEXT 36 HOURS AS JULIA TURNS TOWARD THE NORTHEAST. THE MODEL
GUIDANCE HAS SHIFTED SIGNIFICANTLY SOUTHEASTWARD AND THE TRACK
FORECAST IS A BLEND OF THE PREVIOUS ADVISORY AND THE FAIRLY
CLUSTERED MODEL CONSENSUS.
 
THE MODEST REINTENSIFICATION OF JULIA IS NOT LIKELY TO BE REPEATED. 
THE CYCLONE WILL BE MOVING OVER SUB-26C SSTS IN ABOUT A DAY WHILE
BEING BLUDGEONED BY ABOUT 50 KT UPPER TROPOSPHERIC NORTHWESTERLIES. 
GRADUAL DECAY IS EXPECTED OVER THE NEXT TWO DAYS...AFTER WHICH
JULIA SHOULD BE ABSORBED INTO THE VERY LARGE CIRCULATION OF IGOR. 
THE INTENSITY FORECAST IS NEARLY IDENTICAL TO THE PREVIOUS
ADVISORY...BUT BELOW THE INTENSITY MODEL CONSENSUS WHICH APPEARS TO
HOLD ON TO A ROBUST CYCLONE FOR TOO LONG.
 
THE AFOREMENTIONED ASCAT PASS ALLOWED FOR AN ADJUSTMENT TO THE WIND
RADII UTILIZED IN THIS ADVISORY.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/0900Z 33.6N  51.8W    45 KT
 12HR VT     19/1800Z 35.7N  51.2W    40 KT
 24HR VT     20/0600Z 36.8N  49.4W    30 KT
 36HR VT     20/1800Z 37.7N  47.5W    25 KT...POST-TROP/REMNT LOW
 48HR VT     21/0600Z 39.5N  45.5W    25 KT...POST-TROP/REMNT LOW
 72HR VT     22/0600Z...DISSIPATED
 
$$
FORECASTER LANDSEA/BRENNAN
 

WTNT42 KNHC 191458
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST SUN SEP 19 2010
 
JULIA HAS HAD ANOTHER BURST OF DEEP CONVECTION OVER THE PAST SEVERAL
HOURS...AND SATELLITE INTENSITY ESTIMATES REMAIN AT T3.0/45 KT FROM
BOTH TAFB AND SAB.  THE INITIAL INTENSITY IS KEPT AT 45 KT FOR THIS
ADVISORY...BUT IT APPEARS THAT THE STORM IS AGAIN RUNNING INTO
STRONG SHEAR ASSOCIATED WITH OUTFLOW FROM HURRICANE IGOR AND SHOULD
WEAKEN SOON.  THE SHIPS AND LGEM MODELS SHOW FASTER WEAKENING THAN
THE DYNAMICAL GUIDANCE...INCLUDING THE GLOBAL MODELS WHICH SHOULD
HAVE A BETTER REPRESENTATION OF THE MID-LATITUDE SYNOPTIC PRESSURE
PATTERN.  THE OFFICIAL FORECAST IS NEAR OR JUST BELOW THE INTENSITY
CONSENSUS...AND INDICATES JULIA WEAKENING TO A TROPICAL DEPRESSION
OR REMNANT LOW IN 36-48 HOURS.
 
BASED ON RECENT MICROWAVE DATA AND VISIBLE SATELLITE IMAGERY...THE
CENTER OF JULIA HAS BEEN RELOCATED TO THE SOUTH...AND THE INITIAL
MOTION HAS VEERED QUICKLY TO 065 DEGREES AT 13 KT.  JULIA IS
EXPECTED TO CONTINUE MOVING AROUND THE NORTHWESTERN AND NORTHERN
SIDE OF A MID-LEVEL HIGH OVER THE NEXT COUPLE OF DAYS.  WITH THE
ADJUSTED INITIAL POSITION BEING FARTHER SOUTH...THE NEW TRACK
FORECAST IS SHIFTED SIGNIFICANTLY TO THE SOUTH OF THE PREVIOUS
FORECAST AND LIES ALONG THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/1500Z 34.2N  50.3W    45 KT
 12HR VT     20/0000Z 34.9N  48.5W    35 KT
 24HR VT     20/1200Z 35.6N  46.5W    35 KT
 36HR VT     21/0000Z 36.2N  44.5W    30 KT...POST-TROP/REMNT LOW
 48HR VT     21/1200Z 37.5N  42.5W    25 KT...POST-TROP/REMNT LOW
 72HR VT     22/1200Z...DISSIPATED
 
$$
FORECASTER BERG
 

WTNT42 KNHC 191458
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST SUN SEP 19 2010
 
JULIA HAS HAD ANOTHER BURST OF DEEP CONVECTION OVER THE PAST SEVERAL
HOURS...AND SATELLITE INTENSITY ESTIMATES REMAIN AT T3.0/45 KT FROM
BOTH TAFB AND SAB.  THE INITIAL INTENSITY IS KEPT AT 45 KT FOR THIS
ADVISORY...BUT IT APPEARS THAT THE STORM IS AGAIN RUNNING INTO
STRONG SHEAR ASSOCIATED WITH OUTFLOW FROM HURRICANE IGOR AND SHOULD
WEAKEN SOON.  THE SHIPS AND LGEM MODELS SHOW FASTER WEAKENING THAN
THE DYNAMICAL GUIDANCE...INCLUDING THE GLOBAL MODELS WHICH SHOULD
HAVE A BETTER REPRESENTATION OF THE MID-LATITUDE SYNOPTIC PRESSURE
PATTERN.  THE OFFICIAL FORECAST IS NEAR OR JUST BELOW THE INTENSITY
CONSENSUS...AND INDICATES JULIA WEAKENING TO A TROPICAL DEPRESSION
OR REMNANT LOW IN 36-48 HOURS.
 
BASED ON RECENT MICROWAVE DATA AND VISIBLE SATELLITE IMAGERY...THE
CENTER OF JULIA HAS BEEN RELOCATED TO THE SOUTH...AND THE INITIAL
MOTION HAS VEERED QUICKLY TO 065 DEGREES AT 13 KT.  JULIA IS
EXPECTED TO CONTINUE MOVING AROUND THE NORTHWESTERN AND NORTHERN
SIDE OF A MID-LEVEL HIGH OVER THE NEXT COUPLE OF DAYS.  WITH THE
ADJUSTED INITIAL POSITION BEING FARTHER SOUTH...THE NEW TRACK
FORECAST IS SHIFTED SIGNIFICANTLY TO THE SOUTH OF THE PREVIOUS
FORECAST AND LIES ALONG THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/1500Z 34.2N  50.3W    45 KT
 12HR VT     20/0000Z 34.9N  48.5W    35 KT
 24HR VT     20/1200Z 35.6N  46.5W    35 KT
 36HR VT     21/0000Z 36.2N  44.5W    30 KT...POST-TROP/REMNT LOW
 48HR VT     21/1200Z 37.5N  42.5W    25 KT...POST-TROP/REMNT LOW
 72HR VT     22/1200Z...DISSIPATED
 
$$
FORECASTER BERG
 


WTNT42 KNHC 192033
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  31
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 PM AST SUN SEP 19 2010
 
SINCE THIS MORNING...THE CENTER OF JULIA HAS BECOME EXPOSED TO THE
NORTHWEST OF A SMALL AREA OF DEEP CONVECTION.  AMSU AND ASCAT
ESTIMATES FROM AROUND 1200 UTC SUPPORTED AN INTENSITY OF 45 KT...SO
THE INITIAL INTENSITY IS LOWERED TO 40 KT NOW THAT THE CYCLONE IS
MORE STRONGLY SHEARED.  THIS IS ALSO SUPPORTED BY DECREASING
T-NUMBERS.  THE STATISTICAL MODELS STILL SHOW QUICKER WEAKENING
THAN THE DYNAMICAL MODELS...AND THE OFFICIAL FORECAST REMAINS NEAR
THE INTENSITY CONSENSUS.  JULIA WILL BE BATTLING VERY STRONG
NORTHWESTERLY SHEAR...BUT IT SHOULD TAKE SOME TIME FOR THE
CIRCULATION TO SPIN DOWN.  THE CYCLONE IS EXPECTED TO BECOME A
REMNANT LOW IN ABOUT 36 HOURS AND THEN DISSIPATE WITHIN THE
SOUTHWESTERLY FLOW EAST OF IGOR IN 48 HOURS.
 
AFTER TAKING A SUDDEN AND QUICK JUMP TO THE EAST-NORTHEAST THIS
MORNING...JULIA HAS SETTLED ON A MOTION OF ABOUT 50 DEGREES AT 12
KT.  THE UKMET...GFDL...AND GFDN SEEM TO UNREALISTICALLY TURN JULIA
TOWARD THE NORTHWEST OR NORTH AFTER 24 HOURS...SO THE NHC TRACK
FORECAST IS BASED ON A BLEND OF THE OTHER MAJOR DYNAMICAL MODELS. 
THIS TRACK REMAINS ON THE SOUTHERN SIDE OF THE GUIDANCE ENVELOPE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/2100Z 34.8N  49.7W    40 KT
 12HR VT     20/0600Z 35.4N  48.4W    35 KT
 24HR VT     20/1800Z 36.3N  46.6W    35 KT
 36HR VT     21/0600Z 37.7N  44.4W    30 KT...POST-TROP/REMNT LOW
 48HR VT     21/1800Z...DISSIPATED
 
$$
FORECASTER BERG
 

WTNT42 KNHC 200234
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  32
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST SUN SEP 19 2010
 
JULIA CONTINUES TO WEAKEN THIS EVENING.  SATELLITE IMAGES INDICATE
THAT DEEP CONVECTION IS CONFINED TO A POORLY ORGANIZED BAND WELL
NORTHEAST OF THE ESTIMATED CENTER.  DVORAK DATA T-NUMBERS HAVE
DECREASED TO 2.0 FROM BOTH TAFB AND SAB.  THE INITIAL INTENSITY IS
SET TO 35 KT...USING A BLEND OF THE DVORAK DATA T AND CI NUMBERS. 
ADDITIONAL WEAKENING IS EXPECTED AS STRONG NORTHWESTERLY SHEAR
CONTINUES TO IMPACT THE CYCLONE.  JULIA IS NOW FORECAST TO BECOME A
REMNANT LOW IN 24 HOURS...AS IT IS ANTICIPATED TO BE OVER 25 C
WATERS BY THAT TIME...BUT THIS COULD OCCUR SOONER.

A 1958 UTC TRMM OVERPASS AND A 2307 UTC SSMIS OVERPASS HAVE BEEN
HELPFUL IN LOCATING THE LOW-LEVEL CENTER OF JULIA...WHICH IS VERY
NEAR THE PREVIOUS FORECAST TRACK.  THE INITIAL MOTION ESTIMATE IS
055/11...USING A BLEND OF SATELLITE FIXES AND THE AFOREMENTIONED
MICROWAVE DATA.  JULIA IS EXPECTED TO CONTINUE MOVING
EAST-NORTHEASTWARD TO NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF
A SUBTROPICAL RIDGE UNTIL DISSIPATION.  THE OFFICIAL TRACK FORECAST
IS AN UPDATE OF THE PREVIOUS ONE AND IN AGREEMENT WITH A CONSENSUS
OF THE GFS...ECMWF...NOGAPS...AND HWRF MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/0300Z 35.2N  48.7W    35 KT
 12HR VT     20/1200Z 35.8N  47.5W    30 KT
 24HR VT     21/0000Z 36.8N  45.7W    30 KT...POST-TROP/REMNT LOW
 36HR VT     21/1200Z 38.0N  43.7W    25 KT...POST-TROP/REMNT LOW
 48HR VT     22/0000Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI
 

WTNT42 KNHC 200234
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  32
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST SUN SEP 19 2010
 
JULIA CONTINUES TO WEAKEN THIS EVENING.  SATELLITE IMAGES INDICATE
THAT DEEP CONVECTION IS CONFINED TO A POORLY ORGANIZED BAND WELL
NORTHEAST OF THE ESTIMATED CENTER.  DVORAK DATA T-NUMBERS HAVE
DECREASED TO 2.0 FROM BOTH TAFB AND SAB.  THE INITIAL INTENSITY IS
SET TO 35 KT...USING A BLEND OF THE DVORAK DATA T AND CI NUMBERS. 
ADDITIONAL WEAKENING IS EXPECTED AS STRONG NORTHWESTERLY SHEAR
CONTINUES TO IMPACT THE CYCLONE.  JULIA IS NOW FORECAST TO BECOME A
REMNANT LOW IN 24 HOURS...AS IT IS ANTICIPATED TO BE OVER 25 C
WATERS BY THAT TIME...BUT THIS COULD OCCUR SOONER.

A 1958 UTC TRMM OVERPASS AND A 2307 UTC SSMIS OVERPASS HAVE BEEN
HELPFUL IN LOCATING THE LOW-LEVEL CENTER OF JULIA...WHICH IS VERY
NEAR THE PREVIOUS FORECAST TRACK.  THE INITIAL MOTION ESTIMATE IS
055/11...USING A BLEND OF SATELLITE FIXES AND THE AFOREMENTIONED
MICROWAVE DATA.  JULIA IS EXPECTED TO CONTINUE MOVING
EAST-NORTHEASTWARD TO NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF
A SUBTROPICAL RIDGE UNTIL DISSIPATION.  THE OFFICIAL TRACK FORECAST
IS AN UPDATE OF THE PREVIOUS ONE AND IN AGREEMENT WITH A CONSENSUS
OF THE GFS...ECMWF...NOGAPS...AND HWRF MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/0300Z 35.2N  48.7W    35 KT
 12HR VT     20/1200Z 35.8N  47.5W    30 KT
 24HR VT     21/0000Z 36.8N  45.7W    30 KT...POST-TROP/REMNT LOW
 36HR VT     21/1200Z 38.0N  43.7W    25 KT...POST-TROP/REMNT LOW
 48HR VT     22/0000Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI
 


WTNT42 KNHC 200842
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  33
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST MON SEP 20 2010
 
JULIA AGAIN PROVIDED A SURPRISE FOR A SECOND NIGHT IN A ROW WITH
STRONGER SURFACE WINDS MEASURED FROM THE ASCAT SCATTEROMETER THAN
WHAT WAS SUGGESTED FROM CONVENTIONAL SATELLITE IMAGERY USING THE
DVORAK TECHNIQUE.  THE 0046Z ASCAT PASS SHOWED MAXIMUM WINDS OF AT
LEAST 45 KT...DESPITE A FAIRLY DISHEVELED APPEARANCE TO THE DEEP
CONVECTION.  THE 0600Z TAFB AND SAB DATA-T DVORAK NUMBERS REMAIN AT
A 2.0...OR 30 KT.  THE INITIAL INTENSITY IS SET AT 40 KT...ASSUMING
SOME WEAKENING SINCE THE ASCAT PASS.

THE CENTER CONTINUES TO BE DISPLACED WEST OF THE LIMITED DEEP
CONVECTION DUE TO STRONG WESTERLY VERTICAL SHEAR INDUCED BY
EXTREMELY LARGE HURRICANE IGOR. THE INITIAL MOTION OF JULIA IS
ESTIMATED TO BE 65 DEGREES AT 8 KT...AND THE CYCLONE IS BEING
ADVECTED AROUND THE NORTHERN PERIPHERY OF THE DEEP LAYER
SUBTROPICAL RIDGE. THE CYCLONE SHOULD ACCELERATE SOME TOWARD THE
NORTH-NORTHEAST IN THE NEXT DAY OR SO. AROUND 36 HOURS...JULIA
SHOULD BECOME ABSORBED INTO THE CIRCULATION OF IGOR AS SHOWN BY
NEARLY ALL OF THE MODELS. HOWEVER...THE ECMWF MODEL KEEPS THE
CYCLONE FAR ENOUGH SOUTH OF IGOR TO PREVENT THE ABSORPTION.
INSTEAD...THE ECMWF MAINTAINS JULIA AS A SEPARATE CYCLONE FOR
SEVERAL MORE DAYS...THOUGH BECOMING EXTRATROPICAL ABOUT TWO DAYS
FROM NOW. THIS TRACK FORECAST GOES WITH THE CONSENSUS...MINUS THE
ECMWF...AND IS SLIGHTLY TO THE LEFT OF AND FASTER THAN THE PREVIOUS
ADVISORY.

AS JULIA SHOULD GRADUALLY ENCOUNTER SUB-26C WATER TEMPERATURES ALONG
WITH QUITE HOSTILE VERTICAL SHEAR...GRADUAL WEAKENING IS EXPECTED
FOR THE NEXT TWO DAYS UNTIL DISSIPATION.  THE INTENSITY FORECAST IS
BASED UPON THE MODEL CONSENSUS AND IS SLIGHTLY HIGHER THAN THE
PREVIOUS ADVISORY BECAUSE OF THE STRONGER INITIAL CYCLONE.

THE AFOREMENTIONED ASCAT PASS ALLOWED FOR AN ENLARGEMENT OF THE
TROPICAL STORM WIND RADII. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/0900Z 35.5N  47.9W    40 KT
 12HR VT     20/1800Z 36.1N  46.8W    35 KT
 24HR VT     21/0600Z 37.6N  45.3W    30 KT...POST-TROP/REMNT LOW
 36HR VT     21/1800Z 39.6N  43.5W    25 KT...POST-TROP/REMNT LOW
 48HR VT     22/0600Z...DISSIPATED
 
$$
FORECASTER LANDSEA/BRENNAN
 

WTNT42 KNHC 201439
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  34
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST MON SEP 20 2010
 
 
DEEP CONVECTION HAS BEEN SHEARED OFF TO THE EAST OF THE CENTER BY
THE OUTFLOW OF HURRICANE IGOR...WITH THE COLDEST TOPS NOW A COUPLE
OF HUNDRED MILES AWAY FROM THE CENTER.  THE ASCAT PASS FROM 0046Z
LAST NIGHT SHOWED THAT THE CIRCULATION WAS BECOMING ELONGATED EVEN
THEN...AND VISIBLE IMAGERY THIS MORNING SHOWS THAT JULIA IS LOSING
SOME DEFINITION AS IT BECOMES ENTANGLED WITH A FRONTAL TROUGH TO
THE EAST OF THE CYCLONE.  BASED ON THESE STRUCTURAL CHANGES...THIS
WILL BE THE LAST ADVISORY.
 
MORNING VISIBLE IMAGERY INDICATES THAT JULIA IS A LITTLE SOUTH OF
THE PREVIOUS TRACK...AND IS MOVING AT 090/8.  THE 00Z ECMWF HANDLED
THE OVERNIGHT MOTION OF JULIA BEST...WITH THE OTHER GUIDANCE WELL
TO THE LEFT AND SHOWING MORE OF AN INTERACTION WITH THE CIRCULATION
OF IGOR.  THE OFFICIAL FORECAST FOLLOWS THE ECMWF GUIDANCE WITH A
FORECAST MOTION SOUTH OF THE PREVIOUS FORECAST.
 
STRONG UPPER-LEVEL NORTHWESTERLY FLOW SHOULD KEEP THE SHEAR OVER
JULIA ELEVATED...AND GIVEN THE MARGINAL SEA SURFACE TEMPERATURES...
PREVENT THE SYSTEM FROM REDEVELOPING ORGANIZED DEEP CONVECTION.  IF
PRESENT TRENDS CONTINUE...THE CIRCULATION OF JULIA WILL BECOME
ILL-DEFINED WITHIN A FRONTAL TROUGH OVER THE NEXT DAY OR SO.  THAT
SCENARIO IS REFLECTED IN THE OFFICIAL FORECAST...ALTHOUGH IT IS
POSSIBLE THAT JULIA COULD REMAIN WELL-ENOUGH DEFINED TO LINGER AND
MOVE EASTWARD AS A REMNANT LOW FOR SEVERAL DAYS...AS SHOWN BY THE
ECMWF.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/1500Z 34.7N  46.4W    40 KT...POST-TROPICAL
 12HR VT     21/0000Z 34.9N  45.3W    35 KT...POST-TROPICAL
 24HR VT     21/1200Z 35.5N  43.0W    30 KT...POST-TROP/REMNT LOW
 36HR VT     22/0000Z...DISSIPATED
 
$$
FORECASTER FRANKLIN
 

WTNT42 KNHC 200842
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  33
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
500 AM AST MON SEP 20 2010
 
JULIA AGAIN PROVIDED A SURPRISE FOR A SECOND NIGHT IN A ROW WITH
STRONGER SURFACE WINDS MEASURED FROM THE ASCAT SCATTEROMETER THAN
WHAT WAS SUGGESTED FROM CONVENTIONAL SATELLITE IMAGERY USING THE
DVORAK TECHNIQUE.  THE 0046Z ASCAT PASS SHOWED MAXIMUM WINDS OF AT
LEAST 45 KT...DESPITE A FAIRLY DISHEVELED APPEARANCE TO THE DEEP
CONVECTION.  THE 0600Z TAFB AND SAB DATA-T DVORAK NUMBERS REMAIN AT
A 2.0...OR 30 KT.  THE INITIAL INTENSITY IS SET AT 40 KT...ASSUMING
SOME WEAKENING SINCE THE ASCAT PASS.

THE CENTER CONTINUES TO BE DISPLACED WEST OF THE LIMITED DEEP
CONVECTION DUE TO STRONG WESTERLY VERTICAL SHEAR INDUCED BY
EXTREMELY LARGE HURRICANE IGOR. THE INITIAL MOTION OF JULIA IS
ESTIMATED TO BE 65 DEGREES AT 8 KT...AND THE CYCLONE IS BEING
ADVECTED AROUND THE NORTHERN PERIPHERY OF THE DEEP LAYER
SUBTROPICAL RIDGE. THE CYCLONE SHOULD ACCELERATE SOME TOWARD THE
NORTH-NORTHEAST IN THE NEXT DAY OR SO. AROUND 36 HOURS...JULIA
SHOULD BECOME ABSORBED INTO THE CIRCULATION OF IGOR AS SHOWN BY
NEARLY ALL OF THE MODELS. HOWEVER...THE ECMWF MODEL KEEPS THE
CYCLONE FAR ENOUGH SOUTH OF IGOR TO PREVENT THE ABSORPTION.
INSTEAD...THE ECMWF MAINTAINS JULIA AS A SEPARATE CYCLONE FOR
SEVERAL MORE DAYS...THOUGH BECOMING EXTRATROPICAL ABOUT TWO DAYS
FROM NOW. THIS TRACK FORECAST GOES WITH THE CONSENSUS...MINUS THE
ECMWF...AND IS SLIGHTLY TO THE LEFT OF AND FASTER THAN THE PREVIOUS
ADVISORY.

AS JULIA SHOULD GRADUALLY ENCOUNTER SUB-26C WATER TEMPERATURES ALONG
WITH QUITE HOSTILE VERTICAL SHEAR...GRADUAL WEAKENING IS EXPECTED
FOR THE NEXT TWO DAYS UNTIL DISSIPATION.  THE INTENSITY FORECAST IS
BASED UPON THE MODEL CONSENSUS AND IS SLIGHTLY HIGHER THAN THE
PREVIOUS ADVISORY BECAUSE OF THE STRONGER INITIAL CYCLONE.

THE AFOREMENTIONED ASCAT PASS ALLOWED FOR AN ENLARGEMENT OF THE
TROPICAL STORM WIND RADII. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/0900Z 35.5N  47.9W    40 KT
 12HR VT     20/1800Z 36.1N  46.8W    35 KT
 24HR VT     21/0600Z 37.6N  45.3W    30 KT...POST-TROP/REMNT LOW
 36HR VT     21/1800Z 39.6N  43.5W    25 KT...POST-TROP/REMNT LOW
 48HR VT     22/0600Z...DISSIPATED
 
$$
FORECASTER LANDSEA/BRENNAN
 


WTNT42 KNHC 201439
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER  34
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 AM AST MON SEP 20 2010
 
 
DEEP CONVECTION HAS BEEN SHEARED OFF TO THE EAST OF THE CENTER BY
THE OUTFLOW OF HURRICANE IGOR...WITH THE COLDEST TOPS NOW A COUPLE
OF HUNDRED MILES AWAY FROM THE CENTER.  THE ASCAT PASS FROM 0046Z
LAST NIGHT SHOWED THAT THE CIRCULATION WAS BECOMING ELONGATED EVEN
THEN...AND VISIBLE IMAGERY THIS MORNING SHOWS THAT JULIA IS LOSING
SOME DEFINITION AS IT BECOMES ENTANGLED WITH A FRONTAL TROUGH TO
THE EAST OF THE CYCLONE.  BASED ON THESE STRUCTURAL CHANGES...THIS
WILL BE THE LAST ADVISORY.
 
MORNING VISIBLE IMAGERY INDICATES THAT JULIA IS A LITTLE SOUTH OF
THE PREVIOUS TRACK...AND IS MOVING AT 090/8.  THE 00Z ECMWF HANDLED
THE OVERNIGHT MOTION OF JULIA BEST...WITH THE OTHER GUIDANCE WELL
TO THE LEFT AND SHOWING MORE OF AN INTERACTION WITH THE CIRCULATION
OF IGOR.  THE OFFICIAL FORECAST FOLLOWS THE ECMWF GUIDANCE WITH A
FORECAST MOTION SOUTH OF THE PREVIOUS FORECAST.
 
STRONG UPPER-LEVEL NORTHWESTERLY FLOW SHOULD KEEP THE SHEAR OVER
JULIA ELEVATED...AND GIVEN THE MARGINAL SEA SURFACE TEMPERATURES...
PREVENT THE SYSTEM FROM REDEVELOPING ORGANIZED DEEP CONVECTION.  IF
PRESENT TRENDS CONTINUE...THE CIRCULATION OF JULIA WILL BECOME
ILL-DEFINED WITHIN A FRONTAL TROUGH OVER THE NEXT DAY OR SO.  THAT
SCENARIO IS REFLECTED IN THE OFFICIAL FORECAST...ALTHOUGH IT IS
POSSIBLE THAT JULIA COULD REMAIN WELL-ENOUGH DEFINED TO LINGER AND
MOVE EASTWARD AS A REMNANT LOW FOR SEVERAL DAYS...AS SHOWN BY THE
ECMWF.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/1500Z 34.7N  46.4W    40 KT...POST-TROPICAL
 12HR VT     21/0000Z 34.9N  45.3W    35 KT...POST-TROPICAL
 24HR VT     21/1200Z 35.5N  43.0W    30 KT...POST-TROP/REMNT LOW
 36HR VT     22/0000Z...DISSIPATED
 
$$
FORECASTER FRANKLIN
 


