WTNT42 KNHC 252029
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST WED AUG 25 2010
 
THE FIFTH TROPICAL STORM OF THE SEASON...TROPICAL STORM EARL...HAS
FORMED IN THE EASTERN ATLANTIC...ONE WEEK EARLIER THAN CLIMATOLOGY.
HIGH RESOLUTION SATELLITE IMAGES SHOW THAT THE CIRCULATION HAS
CONTINUE TO GROW AND THE CONVECTION...BOTH IN CLUSTERS AND CURVED
BANDS HAS CONTINUE TO BECOME BETTER ORGANIZED. T-NUMBERS FROM TAFB
AND SAB HAVE REACHED 3.0 AND 2.5 ON THE DVORAK SCALE INDICATING
THAT THE WINDS HAVE INCREASED TO AT LEAST 35 KNOTS. MOST OF THE
GLOBAL MODELS AS WELL AS SHIPS GUIDANCE DEPICT AN ENVIRONMENT OF
RELATIVELY LOW SHEAR ACROSS THE TROPICAL ATLANTIC. THE LOW SHEAR
COMBINED WITH UNUSUALLY WARM OCEAN WOULD FAVOR A GRADUAL
STRENGTHENING. THE OFFICIAL FORECAST CALLS FOR EARL TO BECOME A
HURRICANE IN ABOUT TWO DAYS.
 
THE BEST ESTIMATE OF THE INITIAL MOTION IS 275/14 KNOTS. MOST OF THE
GLOBAL MODELS SHOW A PERSISTENT SUBTROPICAL RIDGE EXTENDING
FROM AFRICA TO NEAR 60 DEGREES WEST. THIS STEERING PATTERN WILL
LIKELY KEEP THE CYCLONE ON A GENERAL WESTWARD TRACK FOR THE NEXT 3
TO 4 DAYS. A GRADUAL TURN MORE TO THE WEST-NORTHWEST IS FORECAST AT
THE END OF THE FORECAST PERIOD AS THE CYCLONE REACHES THE WESTERN
EDGE OF THE SUBTROPICAL RIDGE.  THE OFFICIAL FIVE DAY FORECAST
POSITION WAS ADJUSTED SOUTHWARD A LITTLE BIT...AND IS BASICALLY ON
TOP OF THE GFS AND THE ECMWF LOCATION FOR THAT TIME PERIOD. THIS WAS
BASED ON THE REMARKABLY GOOD AGREEMENT OF THESE TWO RELIABLE MODELS
IN FIVE DAYS. ALTHOUGH MOST OF THE GUIDANCE HAS SHIFTED SOUTHWARD A
LITTLE BIT...THE CORE OF THE CYCLONE IS STILL FORECAST TO PASS TO
THE NORTH OF THE LEEWARD ISLANDS. LETS SEE WHAT HAPPENS IN THE
NEXT MODEL CYCLE. 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      25/2100Z 14.4N  32.2W    35 KT
 12HR VT     26/0600Z 14.6N  34.6W    40 KT
 24HR VT     26/1800Z 15.0N  38.0W    45 KT
 36HR VT     27/0600Z 15.5N  41.0W    55 KT
 48HR VT     27/1800Z 16.0N  44.0W    65 KT
 72HR VT     28/1800Z 17.0N  50.0W    75 KT
 96HR VT     29/1800Z 18.0N  55.0W    80 KT
120HR VT     30/1800Z 20.0N  60.0W    80 KT
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 260241
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST WED AUG 25 2010
 
THE OVERALL ORGANIZATION OF EARL HAS CHANGED LITTLE THIS EVENING.
INFRARED SATELLITE IMAGERY SHOWS SEVERAL CURVED BANDS OF
THUNDERSTORMS OVER THE NORTHERN SEMICIRCLE OF THE CYCLONE.  THE
INITIAL INTENSITY REMAINS 35 KT AND IS IN AGREEMENT WITH THE 
LATEST SATELLITE ESTIMATES. THE ENVIRONMENT AHEAD OF EARL APPEARS
CONDUCIVE FOR GRADUAL STRENGTHENING.  BOTH THE STATISTICAL AND
DYNAMICAL MODELS INTENSIFY THE CYCLONE INTO A HURRICANE WITHIN A
COUPLE OF DAYS. THE LATEST ITERATIONS OF THE GFDL AND HWRF MODELS
SHOW HIGHER WIND SPEEDS AT DAYS 4 AND 5 THAN BEFORE.  THE
INTENSITY FORECAST IS UNCHANGED FROM THE PREVIOUS NHC ADVISORY
THROUGH 72 HOURS...BUT IS ADJUSTED A LITTLE HIGHER THEREAFTER TO 
BE MORE IN LINE WITH THE INTENSITY CONSENSUS...ICON.

SINCE THE CENTER HAS BEEN DIFFICULT TO DISCERN IN INFRARED
IMAGERY...THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 275/14.  EARL
IS EXPECTED TO CONTINUE WESTWARD TO THE SOUTH OF A SUBTROPICAL
RIDGE DURING THE NEXT 2-3 DAYS.  A TURN TOWARD THE WEST-NORTHWEST
IS EXPECTED AROUND DAY 4 AS THE CYCLONE NEARS THE WESTERN PORTION
OF THE RIDGE.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS
SCENARIO THROUGH 72 HOURS AND THE OFFICIAL FORECAST IS IN THE
MIDDLE OF THE GUIDANCE ENVELOPE THROUGH THAT TIME.  THEREAFTER...
THERE IS MORE SPREAD IN THE GUIDANCE WITH THE UKMET...NOGAPS...AND
GFDN SHOWING AN EARLIER TURN TOWARD THE WEST-NORTHWEST.  FOR NOW...
THE OFFICIAL FORECAST WILL REMAIN ON THE SOUTHERN SIDE OF THE
GUIDANCE ENVELOPE AT DAYS 4 AND 5...CLOSER TO THE USUALLY
RELIABLE ECMWF...GFS...AND GFDL MODELS.
        
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/0300Z 14.7N  33.6W    35 KT
 12HR VT     26/1200Z 15.0N  35.9W    40 KT
 24HR VT     27/0000Z 15.5N  39.1W    45 KT
 36HR VT     27/1200Z 16.0N  42.3W    55 KT
 48HR VT     28/0000Z 16.4N  45.4W    65 KT
 72HR VT     29/0000Z 17.4N  51.3W    75 KT
 96HR VT     30/0000Z 19.0N  56.5W    85 KT
120HR VT     31/0000Z 21.5N  60.5W    90 KT
 
$$
FORECASTER BROWN
 

WTNT42 KNHC 260848
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST THU AUG 26 2010
 
CONVENTIONAL SATELLITE IMAGERY INDICATES THAT THE SPIRAL BANDS
AROUND EARL HAVE BECOME BETTER ORGANIZED THIS MORNING...
PARTICULARLY OVER THE WESTERN PORTION OF THE CYCLONE. THE CYCLONE
STRUCTURE...HOWEVER...IS STILL A BIT ELONGATED ALONG A SOUTHWEST TO
NORTHEAST AXIS. DVORAK SATELLITE CURRENT INTENSITY ESTIMATES FROM
TAFB AND SAB ARE 45 AND 35 KT..RESPECTIVELY.  USING A BLEND OF THE
TWO...THE INITIAL INTENSITY IS INCREASED TO 40 KT. THE OCEAN IS
WARM AND THE SHEAR IS LOW...CREATING AN ENVIRONMENT CONDUCIVE FOR
STRENGTHENING DURING THE ENTIRE FORECAST PERIOD. IN FACT...THE
LGEM...HWRF...AND SHIPS MODELS ALL SHOW THE CYCLONE BECOMING A
HURRICANE IN 2 DAYS. THE OFFICIAL FORECAST FOLLOWS SUIT AND ALSO
BRINGS EARL TO CATEGORY TWO INTENSITY BY DAY 5.
 
THE CENTER OF EARL HAS BEEN RATHER DIFFICULT TO LOCATE THIS MORNING.
A 2315 UTC ASCAT OVERPASS INDICATED AN ELONGATED CENTER NEAR THE
CONVECTION OVER THE SOUTHERN PORTION OF THE SYSTEM...WELL TO
THE SOUTH OF THE PREVIOUS ADVISORY POSITION.  HOWEVER...A SUBSEQUENT
AMSU-B MICROWAVE PASS AT 2318 UTC AND A RECENT 0430 UTC TRMM IMAGE
SUGGESTED THE CENTER IS LOCATED TO THE NORTHEAST OF THE
AFOREMENTIONED ASCAT PASS...MUCH CLOSER TO THE PREVIOUS BEST TRACK. 
FOR THIS ADVISORY...AND BASED ON THESE DATA...CONTINUITY WILL BE
MAINTAINED AND THE INITIAL POSITION IS BE NEAR THE NORTHERN
CLUSTER OF DEEP CONVECTION AND CLOSE TO THE TRMM FIX.  IF THE
CIRCULATION CENTER DOES REFORM FARTHER SOUTH...THE FORECAST TRACK
WILL HAVE TO BE ADJUSTED SOUTH...OR TO THE LEFT OF THIS ADVISORY
PACKAGE.
 
EARL IS MOVING TOWARD THE WEST-NORTHWEST...AN ESTIMATED 285 DEGREES
AT 13 KT. THE TROPICAL STORM IS EMBEDDED WITHIN THE DEEP TROPICAL
ATLANTIC TRADE WIND FLOW AND SHOULD CONTINUE ON THIS GENERAL TRACK
OVER THE NEXT 48 TO 72 HOURS. AFTERWARD...A TURN TOWARD THE
WEST-NORTHWEST IS EXPECTED AS THE CYCLONE BEGINS TO MOVE TOWARD A
BREAK IN THE SUBTROPICAL RIDGE. WITH THE EXCEPTION OF NOGAPS AND
THE NAVY GFDN...WHICH ARE BOTH INDICATING AN EARLIER TURN TOWARD
THE NORTHWEST...THE DYNAMICAL MODELS ARE TIGHTLY CLUSTERED THROUGH
DAY 5. THE NHC FORECAST TRACK IS BASED ON THE TVCN MODEL CONSENSUS
AND IS CLOSE TO THE ECMWF AND GFS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/0900Z 15.2N  34.8W    40 KT
 12HR VT     26/1800Z 15.7N  37.2W    45 KT
 24HR VT     27/0600Z 16.4N  40.3W    50 KT
 36HR VT     27/1800Z 16.6N  43.7W    60 KT
 48HR VT     28/0600Z 16.7N  47.0W    70 KT
 72HR VT     29/0600Z 17.9N  52.3W    80 KT
 96HR VT     30/0600Z 20.0N  57.0W    90 KT
120HR VT     31/0600Z 22.5N  60.0W    95 KT
 
$$
FORECASTER ROBERTS/BRENNAN
 

WTNT42 KNHC 261459
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST THU AUG 26 2010
 
VISIBLE AND MICROWAVE SATELLITE IMAGERY INDICATE EARL HAS NOT BECOME
ANY BETTER ORGANIZED SINCE THE LAST ADVISORY. IN FACT...THE INNER
CORE CONVECTION HAS ERODED DUE TO DRY AIR ENTRAINMENT NOTED IN
CONVENTIONAL WATER VAPOR IMAGERY AND IN A 0735Z SSMI WATER VAPOR
IMAGE. THE INITIAL INTENSITY WILL REMAIN 40 KT FOR THIS ADVISORY
BASED ON A BLEND OF SATELLITE INTENSITY ESTIMATES OF 45 KT AND 35
KT FROM TAFB AND SAB...RESPECTIVELY.
 
THE CENTER OF EARL HAS BEEN REPOSITIONED ABOUT 30 NMI SOUTH OF THE
PREVIOUS ADVISORY AND FORECAST TRACK BASED ON A BLEND OF VISIBLE
AND MICROWAVE FIXES. THE INITIAL MOTION ESTIMATE IS A 24-HOUR
AVERAGE OF 275/15...AFTER SMOOTHING THROUGH ALL THE WIGGLES AND
WOBBLES IN THE FIXES. THE OFFICIAL FORECAST TRACK WAS SHIFTED SOUTH
OF THE PREVIOUS ADVISORY DUE IN PART TO THE MORE SOUTHWARD INITIAL
POSITION. OTHERWISE...THERE REMAINS NO SIGNIFICANT CHANGE TO THE
PREVIOUS TRACK REASONING. EARL IS EXPECTED TO MOVE STEADILY WEST TO
WEST-NORTHWESTWARD FOR THE NEXT 72 HOURS AND THEN GRADUALLY TURN
NORTHWESTWARD AND SLOW DOWN AS THE CYCLONE APPROACHES A WEAKNESS IN
THE SUBTROPICAL RIDGE BETWEEN BERMUDA AND THE LEEWARD ISLANDS. THIS
WEAKNESS IN THE STEERING FLOW IS THE COMBINED EFFECTS OF HURRICANE
DANIELLE AND A MID-LATITUDE TROUGH FORECAST TO CAPTURE AND LIFT OUT
THAT HURRICANE TO THE NORTHEAST. IF DANIELLE RECURVES FASTER THAN
CURRENTLY EXPECTED...WHICH THE UKMET AND ECMWF ARE HINTING AT...
THEN THE RIDGE TO THE NORTH OF EARL COULD BUILD BACK IN SOONER AND
KEEP EARL ON A SLOWER WEST-NORTHWESTWARD TRACK THAN INDICATED BY
THE OFFICIAL FORECAST TRACK. THE ADVISORY TRACK LIES ALONG THE
NORTHERN EDGE OF THE TIGHTLY PACKED MODEL GUIDANCE SUITE AND
SIMILAR TO THE SPEED OF THE CONSENSUS MODEL...TVCN.
 
ALL OF THE MODELS INDICATE THAT THE VERTICAL SHEAR SHOULD REMAIN
QUITE LOW THROUGH 72 HOURS OR SO...WHICH WOULD FAVOR SIGNIFICANT
INTENSIFICATION. HOWEVER...THE DRY MID-LEVEL ENVIRONMENT THAT EARL
IS FORECAST TO MOVE THROUGH DURING THAT TIME IS EXPECTED TO RESULT
IN A SLOWER THAN NORMAL RATE OF INTENSIFICATION. HOWEVER...BY DAYS
4 AND 5...EARL IS FORECAST TO MOVE INTO THE SOUTHWESTERLY PERIPHERY
OF SYNOPTIC-SCALE 200 MB ANTICYCLONE...WHICH GENERALLY FAVORS
DEVELOPMENT DUE TO ENHANCED OUTFLOW TO THE NORTH AND SOUTH OF THE
CYCLONE. IT IS POSSIBLE THAT EARL COULD REACH MAJOR HURRICANE
STRENGTH BY THAT TIME...AS INDICATED BY THE HWRF MODEL. THE
OFFICIAL INTENSITY FORECAST IS A BLEND OF THE VARIOUS INTENSITY
MODELS.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/1500Z 14.9N  37.1W    40 KT
 12HR VT     27/0000Z 15.4N  39.4W    45 KT
 24HR VT     27/1200Z 15.7N  42.6W    50 KT
 36HR VT     28/0000Z 16.1N  46.0W    55 KT
 48HR VT     28/1200Z 16.5N  49.1W    65 KT
 72HR VT     29/1200Z 17.8N  54.4W    75 KT
 96HR VT     30/1200Z 20.0N  58.5W    85 KT
120HR VT     31/1200Z 22.5N  61.0W    95 KT
 
$$
FORECASTER STEWART
 

WTNT42 KNHC 262055
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST THU AUG 26 2010
 
INNER-CORE CONVECTION REMAINS SHALLOW AND LOOSELY ORGANIZED...BUT
THE OVERALL CLOUD PATTERN AND STRUCTURE HAS IMPROVED AND BECOME
MORE CIRCULAR IN VISIBLE IMAGERY. AN 1150Z ASCAT PASS EARLIER THIS
MORNING INDICATED EARL POSSESSED A LARGE SWATH OF 34-KT WINDS MORE
THAN 90 NMI NORTH OF THE CENTER...WHICH WOULD SUPPORT HIGHER
NEAR-SURFACE WINDS GIVEN THE LOW BIAS OF ASCAT WINDS. THE INITIAL
INTENSITY WILL REMAIN 40 KT FOR THIS ADVISORY BASED ON A BLEND OF
SATELLITE CURRENT INTENSITY ESTIMATES OF 45 KT AND 35 KT FROM TAFB
AND SAB...RESPECTIVELY..AND THE AFOREMENTIONED ASCAT WINDS. EARL
ALSO PASSED JUST NORTH OF PIRATA BUOY 13008 AROUND 1800Z...WHICH
REPORTED A PRESSURE OF 1003 MB. THIS PRESSURE VALUE WOULD ALSO
SUPPORT AN INTENSITY OF ABOUT 40 KT.
 
EARL REMAINS ON TRACK WITH AN INITIAL MOTION ESTIMATE OF 280/16. THE
OFFICIAL FORECAST TRACK REMAINS UNCHANGED THROUGH 48 HOURS AS THE
STRONG SUBTROPICAL RIDGE TO THE NORTH REMAINS IN PLACE. BY 72
HOURS...EARL IS FORECAST TO APPROACH A WEAKNESS IN THE RIDGE AXIS
INDUCED BY DANIELLE AND A MID-LATITUDE TROUGH THAT IS FORECAST TO
HELP RECURVE THAT HURRICANE TO THE NORTHEAST. AS EARL APPROACHES
THE WEAKNESS IN THE RIDGE...IT IS EXPECTED TO GRADUALLY SLOW DOWN
AND TURN MORE TOWARD THE NORTHWEST. THE 12Z GFS AND ECMWF MODELS
ARE NOW FORECASTING DANIELLE TO RECURVE TO THE NORTHEAST FASTER
THAN PREVIOUSLY EXPECTED...WHICH ALSO ALLOWS THE SUBTROPICAL RIDGE
BETWEEN EARL AND DANIELLE TO BUILD BACK IN TO THE NORTH OF EARL.
THIS DEVELOPING FLOW PATTERN WOULD FORCE EARL MORE WESTWARD THAN
NORTHWARD AT A SLOWER FORWARD SPEED BY DAYS 4 AND 5. THE OFFICIAL
FORECAST TRACK IS JUST AN UPDATE OF THE PREVIOUS TRACK THROUGH 72
HOURS...AND THEN A LITTLE TO THE LEFT OF THE PREVIOUS ADVISORY
AFTER THAT. THE FORECAST REMAINS ON THE NORTHERN OR RIGHT EDGE OF
THE GUIDANCE ENVELOPE IN THE EVENT THE CIRCULATION CENTER
REDEVELOPS FARTHER NORTH WITHIN THE BROAD CONVECTIVE CLOUD MASS.
 
ALTHOUGH THE MODELS CONTINUE TO FORECAST LOW VERTICAL SHEAR ACROSS
EARL THROUGH THE NEXT 24-36 HOURS...THE CYCLONE STILL HAS TO
TRAVERSE THROUGH AN ENVIRONMENT OF DRY MID-LEVEL AIR. BY 48
HOURS...SOME OF THE NORTHERLY OUTFLOW ON THE EAST SIDE OF HURRICANE
DANIELLE IS EXPECTED TO CREATE SOME MODEST NORTHERLY SHEAR ACROSS
EARL...WHICH MAY INHIBIT THE DEVELOPMENT PROCESS. HOWEVER...BY DAYS
4 AND 5...THE UPPER-LEVEL FLOW PATTERN IS FORECAST TO BECOME MORE
FAVORABLE FOR DEVELOPMENT AS EARL MOVES INTO THE SOUTHWEST
PERIPHERY OF A LARGE SYNOPTIC-SCALE 200 MB ANTICYCLONE...WHICH
SHOULD ACT TO ENHANCE THE OUTFLOW TO THE NORTH AND SOUTH OF THE
CYCLONE. THE GFDL AND HWRF MODELS ARE ALSO INDICATING DEVELOPMENT
OF THIS FAVORABLE OUTFLOW PATTERN AND STRENGTHEN EARL TO CATEGORY 4
INTENSITY BY 120 HOURS. THE OFFICIAL INTENSITY FORECAST IS A LITTLE
LOWER THAN THE SHIPS AND LGEM MODELS THROUGH 72 HOURS AND THEN
HIGHER AT DAYS 4 AND 5...BUT NOT AS HIGH AS THE GFDL/HWRF MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/2100Z 15.2N  38.8W    40 KT
 12HR VT     27/0600Z 15.6N  41.2W    45 KT
 24HR VT     27/1800Z 15.9N  44.4W    55 KT
 36HR VT     28/0600Z 16.3N  47.7W    60 KT
 48HR VT     28/1800Z 16.7N  50.8W    65 KT
 72HR VT     29/1800Z 18.2N  55.9W    75 KT
 96HR VT     30/1800Z 20.6N  60.0W    85 KT
120HR VT     31/1800Z 23.0N  62.5W   100 KT
 
$$
FORECASTER STEWART
 

WTNT42 KNHC 270232
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST THU AUG 26 2010
 

AFTER LOSING MOST OF ITS DEEP CONVECTION DURING THE AFTERNOON...EARL
HAS DEVELOPED NEW THUNDERSTORM CELLS AROUND THE LARGE AND
WELL-DEFINED CIRCULATION TONIGHT. T-NUMBERS HAVE NOT CHANGED AND
STILL SUPPORT AN INITIAL INTENSITY OF 40 KNOTS. EARL IS MOVING
TOWARD A WARMER OCEAN AND WILL LIKELY CONTINUE UNDER RELATIVELY
LIGHT SHEAR FOR THE NEXT SEVERAL DAYS. GLOBAL MODELS INDICATE THAT
EARL WILL DEVELOP A DEEP CIRCULATION SURROUNDED BY A LARGE
UPPER-LEVEL OUTFLOW. THIS NORMALLY IS AN INDICATION OF
STRENGTHENING AND IN FACT...BOTH THE HWRF AND GFDL MODELS DEVELOP
EARL INTO AN INTENSE HURRICANE BY THE END OF THE FORECAST PERIOD.
ON THIS BASIS...THE OFFICIAL FORECAST CALLS FOR EARL TO BECOME A
HURRICANE IN A COUPLE OF DAYS WITH ADDITIONAL INTENSIFICATION
THEREAFTER.
 
ALTHOUGH THERE IS A LARGE CIRCULATION...THE CENTER IS DIFFICULT TO
LOCATE. USING ENHANCED SATELLITE IMAGERY AND MICROWAVE DATA...THE
BEST ESTIMATE OF THE INITIAL MOTION IS 280 DEGREES AT 15 KNOTS.
EARL IS TRAPPED SOUTH OF A STRONG SUBTROPICAL RIDGE EXTENDING FROM
AFRICA WESTWARD TO NEAR 60 DEGREES WEST. THIS PATTERN WILL KEEP THE
CYCLONE ON A GENERAL WESTWARD TRACK FOR THE NEXT 3 DAYS OR SO. EARL
SHOULD THEN BEGIN TO TURN MORE TO THE WEST-NORTHWEST AND NORTHWEST
AS IT APPROACHES 60W WHERE THERE IS A PERSISTENT WEAKNESS IN THE
SUBTROPICAL RIDGE. MOST OF THE TRACK MODELS ARE IN REMARKABLY GOOD
AGREEMENT AND THE OFFICIAL FORECAST IS IN THE MIDDLE OF THE GUIDANCE
ENVELOPE...BUT BIASED TO THE RELIABLE GFS AND ECMWF MODELS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/0300Z 15.5N  40.2W    40 KT
 12HR VT     27/1200Z 16.0N  42.8W    40 KT
 24HR VT     28/0000Z 16.3N  46.0W    45 KT
 36HR VT     28/1200Z 16.5N  49.3W    55 KT
 48HR VT     29/0000Z 16.7N  52.5W    65 KT
 72HR VT     30/0000Z 18.5N  58.0W    75 KT
 96HR VT     31/0000Z 21.0N  62.0W    85 KT
120HR VT     01/0000Z 24.0N  65.0W   100 KT
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 270839
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST FRI AUG 27 2010
 
EARL HAS GENERALLY CHANGED LITTLE IN ORGANIZATION DURING THE LAST
SEVERAL HOURS. DEEP CONVECTION THAT REFORMED AROUND 00 UTC HAS
PERSISTED IN BROAD CURVED BANDS MAINLY TO THE WEST OF THE ESTIMATED
LOW-LEVEL CENTER POSITION. SATELLITE INTENSITY ESTIMATES ARE 45 KT
AND 35 KT FROM TAFB AND SAB...RESPECTIVELY...AND THE INITIAL
INTENSITY WILL BE HELD AT 40 KT.  THE ATMOSPHERIC AND OCEANIC
ENVIRONMENTS APPEAR FAVORABLE FOR INTENSIFICATION...AND INDEED ALL
OF THE INTENSITY MODELS SHOW EARL STRENGTHENING THROUGHOUT THE
FORECAST PERIOD. THIS IS REFLECTED IN THE NHC OFFICIAL FORECAST
WHICH BRINGS EARL TO HURRICANE STRENGTH WITHIN 2 DAYS AND SHOWS
ADDITIONAL STRENGTHENING THEREAFTER. 
 
EARL CONTINUES TO MOVE ON A CONSISTENT WESTWARD PATH AND THE INITIAL
MOTION ESTIMATE IS 275/15. A GENERAL WESTWARD MOTION IS FORECAST TO
CONTINUE OVER THE NEXT COUPLE OF DAYS AS THE CYCLONE REMAINS
STEERED BY A NARROW MID-LEVEL RIDGE CENTERED ALONG 25N. EARL IS
EXPECTED TO APPROACH A BREAK IN THE RIDGE...WHICH WILL BE ENHANCED
BY HURRICANE DANIELLE...IN ABOUT 3 DAYS AND THAT SHOULD INDUCE A
TURN TO THE WEST-NORTHWEST TO NORTHWEST WITH A DECREASE IN FORWARD
SPEED. THE TRACK MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED FOR MUCH
OF THE PERIOD AND THE NHC OFFICIAL TRACK FORECAST IS ESSENTIALLY
AN UPDATE OF THE PREVIOUS ONE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/0900Z 15.9N  41.6W    40 KT
 12HR VT     27/1800Z 16.2N  44.2W    45 KT
 24HR VT     28/0600Z 16.4N  47.4W    50 KT
 36HR VT     28/1800Z 16.6N  50.7W    55 KT
 48HR VT     29/0600Z 17.2N  53.9W    65 KT
 72HR VT     30/0600Z 19.0N  59.0W    75 KT
 96HR VT     31/0600Z 21.5N  62.5W    85 KT
120HR VT     01/0600Z 24.5N  65.0W   100 KT
 
$$
FORECASTER CANGIALOSI
 

WTNT42 KNHC 271431
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST FRI AUG 27 2010
 
THE OVERALL PATTERN HAS NOT CHANGED MUCH DURING THE PAST SEVERAL
HOURS. EARL CONTINUES TO HAVE A LARGE CIRCULATION...MODERATE BANDS
OF DEEP CONVECTION AND FAIR OUTFLOW. DVORAK SATELLITE ESTIMATES
STILL SUPPORT AN INITIAL INTENSITY OF 40 KNOTS. THE OCEAN AND THE
ATMOSPHERE APPEAR TO BE FAVORABLE FOR INTENSIFICATION...AND THIS IS
REFLECTED IN THE INTENSITY GUIDANCE WHICH ARE ALL SHOWING
STRENGTHENING. IN FACT...BOTH GFDL AND HWRF ARE AGGRESSIVE IN
MAKING EARL AN INTENSE HURRICANE IN 5 DAYS.  ACCORDINGLY...THE
OFFICIAL FORECAST SHOWS EARL BECOMING A MAJOR HURRICANE BY THE END
OF THE FORECAST PERIOD.
 
EARL IS MOVING TOWARD THE WEST OR 270 DEGREES AT 15 KNOTS EMBEDDED
WITHIN THE EASTERLY FLOW AROUND THE SOUTH SIDE OF A NARROW
SUBTROPICAL RIDGE.  THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR
THE NEXT DAY OR TWO. THEREAFTER...THE CYCLONE WILL BEGIN TO
APPROACH A WEAKNESS IN THE SUBTROPICAL RIDGE AND SHOULD BEGIN TO
TURN MORE TO THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN
FORWARD SPEED. THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST FOR
THE FIRST 48 HOURS SINCE THE STEERING CURRENTS ARE WELL
ESTABLISHED. ONCE THE CYCLONE BEGINS TO APPROACH 60 DEGREES WEST...
THE TRACK MODELS ARE IN LESS AGREEMENT AND THERE IS LESS CONFIDENCE
IN THE FORECAST. THE OFFICIAL FORECAST IS IN BETWEEN THE GFS AND
THE ECMWF AND IS A LITTLE BIT SOUTH OF THE PREVIOUS ONE.
 
A DEVIATION TO THE SOUTH OF THE CURRENT FORECAST TRACK COULD BRING
EARL INTO THE NORTHERN LEEWARD ISLANDS. WITH THE WEEKEND
COMING...RESIDENTS IN THESE ISLANDS SHOULD CLOSELY MONITOR THE
PROGRESS OF EARL.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/1500Z 15.7N  43.6W    40 KT
 12HR VT     28/0000Z 15.8N  45.8W    45 KT
 24HR VT     28/1200Z 16.3N  49.5W    50 KT
 36HR VT     29/0000Z 16.8N  53.0W    60 KT
 48HR VT     29/1200Z 17.5N  56.0W    70 KT
 72HR VT     30/1200Z 18.8N  60.5W    80 KT
 96HR VT     31/1200Z 21.5N  64.0W    90 KT
120HR VT     01/1200Z 25.0N  67.0W   100 KT
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 272030
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST FRI AUG 27 2010
 
EARL CONTINUES TO HAVE A LARGE CIRCULATION AND THE ASSOCIATED DEEP
CONVECTION HAS BEEN PULSATING DURING THE PAST SEVERAL HOURS.
CURRENTLY...VISIBLE SATELLITE IMAGES SHOW SEVERAL CONVECTIVE
CYCLONICALLY CURVED BANDS DEVELOPING ON ITS WESTERN SEMICIRCLE. AN
EARLIER ASCAT PASS AS WELL AS THE LATEST SATELLITE ESTIMATES
INDICATE THAT THE INITIAL INTENSITY REMAINS AT 40 KNOTS. GIVEN THE
CURRENT POORLY ORGANIZED PATTERN...NO SIGNIFICANT CHANGE IS
ANTICIPATED TONIGHT. HOWEVER...EARL WILL BE MOVING SOON OVER AN
EVEN WARMER OCEAN AND UNDER AN UPPER-LEVEL ENVIRONMENT MORE
FAVORABLE FOR STRENGTHENING. THE OFFICIAL FORECAST CALLS FOR EARL
TO BECOME A HURRICANE BY SUNDAY AND BECOME AN INTENSE ONE BY DAY
FIVE. THIS IS CONSISTENT WITH GUIDANCE WHICH HAS BEEN CONSISTENTLY
FORECASTING INTENSIFICATION.

ALTHOUGH THE CIRCULATION IS LARGE THE CENTER HAS BEEN DIFFICULT TO
LOCATE. IT APPEARS THAT I WAS EITHER SLOW THIS MORNING OR EARL HAS
ACCELERATED A LITTLE BIT. THE BEST ESTIMATE OF THE INITIAL MOTION
IS 270 DEGREES OR WESTWARD AT 17 KNOTS.  EARL IS EXPECTED TO BE
STEERED BY THE EASTERLY FLOW SOUTH OF A SUBTROPICAL RIDGE FOR THE
NEXT DAY OR SO. THEREAFTER...THE CYCLONE WILL REACH THE WESTERN
EDGE OF THE SUBTROPICAL RIDGE AND SHOULD BEGIN TO TURN MORE TO THE
WEST-NORTHWEST AND NORTHWEST. I FEEL A LITTLE MORE CERTAIN WITH THE
NORTHWESTWARD TURN IN THIS FORECAST SINCE ALL TRACK GUIDANCE
UNANIMOUSLY BEGIN TO MOVE EARL ON A MORE WEST-NORTHWESTERLY COURSE
BY 48 HOURS. HOWEVER...A DEVIATION TO THE SOUTH OF THE CURRENT
FORECAST TRACK COULD BRING EARL INTO THE NORTHERN LEEWARD ISLANDS.
WITH THE WEEKEND COMING...RESIDENTS IN THESE ISLANDS SHOULD MONITOR
THE  PROGRESS OF EARL. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/2100Z 15.8N  46.0W    40 KT
 12HR VT     28/0600Z 15.9N  48.7W    40 KT
 24HR VT     28/1800Z 16.3N  52.2W    50 KT
 36HR VT     29/0600Z 17.0N  55.5W    60 KT
 48HR VT     29/1800Z 17.5N  58.0W    70 KT
 72HR VT     30/1800Z 19.5N  62.2W    80 KT
 96HR VT     31/1800Z 23.0N  65.0W    90 KT
120HR VT     01/1800Z 27.0N  68.0W   100 KT
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 280255
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST FRI AUG 27 2010
 
SATELLITE IMAGES INDICATE THAT CONVECTION HAS INCREASED IN THE
WESTERN SEMICIRCLE OF EARL.  BANDING FEATURES ARE BECOMING BETTER
DEFINED...AND A THUNDERSTORM CLUSTER IS LOCATED NEAR OR JUST
SOUTHWEST OF THE CENTER.  SATELLITE ESTIMATES ARE A CONSENSUS 45 KT
FROM TAFB/SAB...AND THAT WILL BE THE INITIAL INTENSITY.  THE CLOUD
PATTERN SUGGESTS THAT NORTHEASTERLY SHEAR HAS INCREASED DURING THE
PAST SEVERAL HOURS...AND GLOBAL MODELS SUGGEST THIS SHEAR WILL
CONTINUE FOR THE NEXT DAY OR SO.  THERE IS ALSO EVIDENCE THAT SOME
DRIER AIR IS LURKING NEAR THE CYCLONE.  THUS THE INTENSITY FORECAST
WILL BE A BIT BELOW MOST OF THE MODEL GUIDANCE FOR THE FIRST 36
HOURS.  THEREAFTER...EARL WILL BE MOVING CLOSER TO THE CENTER OF A
LARGE UPPER-LEVEL ANTICYCLONE NORTHEAST OF THE LESSER ANTILLES. 
THIS PATTERN IS QUITE FAVORABLE FOR INTENSIFICATION...ESPECIALLY
CONSIDERING THE 29C PLUS SSTS IN THE PATH OF THE HURRICANE.  THE
GFDL/GFDN RESPOND TO THESE CONDITIONS BY FORECASTING EARL TO BECOME
A CATEGORY 4 HURRICANE IN THE LONG-RANGE.  WHILE THE NEW NHC
FORECAST WILL NOT BE THAT AGGRESSIVE...IT IS INCREASED FROM THE
PREVIOUS ONE AND IS CLOSE TO A BLEND OF THE ABOVE DYNAMICAL
GUIDANCE AND THE LGEM MODEL.

A SERIES OF MICROWAVE PASSES SUGGESTS THE CENTER REMAINS A BIT
ELONGATED...THUS CONFIDENCE IN MY INITIAL MOTION OF 275/18 IS LOWER
THAN AVERAGE.  A STRONG RIDGE BETWEEN EARL AND DANIELLE IS EXPECTED
TO KEEP THE TROPICAL STORM MOVING GENERALLY WESTWARD FOR THE NEXT
DAY OR SO.  AFTER THAT TIME...EARL WILL REACH THE WESTERN PERIPHERY
OF THE RIDGE AND IS EXPECTED TO TURN TOWARD THE WEST-NORTHWEST. 
ALTHOUGH ALL OF THE GUIDANCE SHOWS THE CENTER NORTHEAST OF THE
LEEWARD ISLANDS...THERE REMAINS SOME UNCERTAINTY ON HOW CLOSE EARL
WILL COME.  THE GFS HAS THE STRONGEST RIDGE IN THE GLOBAL MODELS
AND MOVES THE CYCLONE CLOSER TO THE LEEWARD ISLANDS THAN MOST OF
THE OTHER GUIDANCE.  AT THIS POINT...IT IS PRUDENT NOT TO MAKE ANY
CHANGES IN THE TRACK FORECAST IN THE FIRST COUPLE OF DAYS...
ESPECIALLY SINCE THE CYCLONE HAS MOVED FASTER TOWARDS THE WEST THAN
PREVIOUSLY FORECAST.  THE NHC FORECAST REMAINS ON THE LEFT EDGE OF
THE GUIDANCE ENVELOPE THROUGH THE FIRST THREE DAYS...THEN IS JUST
LEFT OF THE MODEL CONSENSUS AT THE END.  
 
RESIDENTS IN THE LESSER ANTILLES SHOULD CLOSELY MONITOR THE PROGRESS
OF EARL THROUGHOUT THE WEEKEND.  WATCHES MAY BE REQUIRED AS EARLY
AS SATURDAY MORNING.  
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/0300Z 16.0N  47.9W    45 KT
 12HR VT     28/1200Z 16.2N  50.7W    50 KT
 24HR VT     29/0000Z 16.6N  54.0W    55 KT
 36HR VT     29/1200Z 17.3N  56.8W    65 KT
 48HR VT     30/0000Z 18.1N  59.1W    80 KT
 72HR VT     31/0000Z 20.5N  63.0W   100 KT
 96HR VT     01/0000Z 24.5N  66.0W   110 KT
120HR VT     02/0000Z 29.0N  68.5W   105 KT
 
$$
FORECASTER BLAKE
 

WTNT42 KNHC 280857
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST SAT AUG 28 2010
 
EARL HAS BECOME BETTER ORGANIZED THIS MORNING. THE CLOUD PATTERN
CONSISTS OF A CENTRAL DENSE OVERCAST WITH CLOUD TOPS TO -80 C AND A
LARGE CURVED BAND OVER THE WESTERN SEMICIRCLE OF THE STORM. THE
CIRRUS OUTFLOW HAS IMPROVED TO THE SOUTH AND WEST OF THE CENTER BUT
REMAINS RESTRICTED OVER THE EASTERN SEMICIRCLE. DVORAK
CLASSIFICATIONS ARE 45 KT AND 55 KT FROM TAFB AND SAB...
RESPECTIVELY.  ON THIS BASIS...THE INITIAL INTENSITY IS INCREASED TO
50 KT FOR THIS ADVISORY.
 
A 0413 UTC TRMM OVERPASS INDICATED THAT THE LOW-LEVEL CENTER OF EARL
WAS LOCATED A LITTLE TO THE SOUTH OF THE PREVIOUS ESTIMATES.  USING
A COMBINATION OF THIS OVERPASS AND SATELLITE FIXES YIELDS AN
INITIAL MOTION OF 270/18.  A MID-LEVEL RIDGE LOCATED OVER THE
SUBTROPICAL CENTRAL ATLANTIC IS EXPECTED TO KEEP EARL ON A RATHER
QUICK WESTWARD TO WEST-NORTHWESTWARD COURSE FOR THE NEXT DAY OR
TWO.  THEREAFTER...THE CYCLONE IS EXPECTED TO NEAR A BREAK IN THE
RIDGE...AND THAT SHOULD CAUSE A TURN TO THE NORTHWEST. WHILE THE
GLOBAL MODELS AGREE ON THE GENERAL EVOLUTION OF THE LARGE SCALE
PATTERN...THERE ARE CONSIDERABLE DIFFERENCES ON THE DETAILS OF THE
TIMING...LOCATION AND SHARPNESS OF THE TURN.  THE OFFICIAL FORECAST
IS NUDGED A LITTLE TO THE LEFT OF THE PREVIOUS ONE TO ACCOUNT FOR
THE INITIAL POSITION AND MOTION AND TRENDS TOWARD THE MULTI-MODEL
CONSENSUS. 
 
ALL OF THE INTENSITY GUIDANCE SHOWS ADDITIONAL INTENSIFICATION
DURING THE NEXT FEW DAYS...AS EARL MOVES OVER EVEN WARMER WATERS AND
INTO A MORE FAVORABLE UPPER-LEVEL WIND ENVIRONMENT. THE OFFICIAL
FORECAST IS ADJUSTED UPWARD FOR THE FIRST COUPLE OF DAYS AND NOW
BRINGS EARL TO HURRICANE STRENGTH IN 24 HOURS AND TO MAJOR
HURRICANE STATUS IN 3 DAYS.  BEYOND 72 HOURS...SOUTHWESTERLY SHEAR
IS EXPECTED TO INCREASE...WHICH SHOULD HALT INTENSIFICATION AND
POSSIBLY INDUCE GRADUAL WEAKENING.  THIS IS REFLECTED IN THE 
OFFICIAL FORECAST...WHICH IS IN BEST AGREEMENT WITH THE INTENSITY
MODEL CONSENSUS.

THE FORECAST NECESSITATES THE ISSUANCE OF TROPICAL STORM WATCHES FOR
PORTIONS OF THE NORTHERN LEEWARD ISLANDS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/0900Z 15.7N  50.1W    50 KT
 12HR VT     28/1800Z 16.0N  52.7W    60 KT
 24HR VT     29/0600Z 16.5N  55.7W    65 KT
 36HR VT     29/1800Z 17.2N  58.3W    75 KT
 48HR VT     30/0600Z 18.2N  60.5W    85 KT
 72HR VT     31/0600Z 20.8N  64.2W   100 KT
 96HR VT     01/0600Z 24.5N  67.5W   110 KT
120HR VT     02/0600Z 29.5N  69.5W   100 KT
 
$$
FORECASTER CANGIALOSI/BRENNAN
 

WTNT42 KNHC 281436
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST SAT AUG 28 2010
 
ALTHOUGH THE CIRCULATION CONTINUES TO BE LARGE AND VIGOROUS AND THE
AMOUNT OF DEEP CONVECTION HAS INCREASED SINCE YESTERDAY...VISIBLE
IMAGES INDICATE THAT CENTER HAS BECOME EXPOSED AND IS LOCATED ON
THE NORTHWESTERN SIDE OF THE DEEP CONVECTION. THIS HAS RESULTED
FROM SOME MODEST NORTHERLY SHEAR CAUSED BY THE OUTFLOW OF LARGER
HURRICANE DANIELLE. ALTHOUGH THE CYCLONE IS LESS ORGANIZED THAN
EARLIER TODAY...T-NUMBERS HAVE NOT CHANGED MUCH AND THE INITIAL
INTENSITY IS KEPT AT 50 KNOTS...BUT THE INTENSITY COULD BE LOWER. 
THE CURRENT NORTHERLY SHEAR IS EXPECTED TO ABATE SOON AS DANIELLE
MOVES NORTHWARD AND...IN FACT...MOST OF THE GLOBAL MODELS SHOW THE
UPPER-LEVEL FLOW BECOMING MORE FAVORABLE FOR INTENSIFICATION BY
SUNDAY.  THIS FLOW PATTERN...IN COMBINATION WITH A WARM OCEAN ALONG
THE TRACK...WOULD RESULT IN INTENSIFICATION. EARL IS FORECAST TO
BECOME A HURRICANE BY SUNDAY WITH A STEADY INTENSIFICATION
THEREAFTER.
 
EARL IS MOVING TOWARD THE WEST OR 275 DEGREES AT ABOUT 16 OR 17
KNOTS STEERED BY THE FLOW TO THE SOUTH OF A SUBTROPICAL RIDGE.
HOWEVER...IN A DAY OR SO...EARL WILL BE APPROACHING THE WESTERN
EDGE OF THE RIDGE AND THE CYCLONE SHOULD BEGIN TO TURN MORE TO THE
WEST-NORTHWEST AND NORTHWEST. THE TRACK MODELS DIVERGE BEYOND 48
HOURS BUT ONCE AGAIN...THE OFFICIAL FORECAST AND THE GUIDANCE
ENVELOPE HAVE SHIFTED A LITTLE BIT SOUTHWARD AND WESTWARD.
NEVERTHELESS...THE EXPECTED STEERING PATTERN STILL FAVORS A
GRADUAL TURN TO THE WEST-NORTHWEST DURING THE NEXT DAY OR TWO. AT
THIS TIME...IT IS NOT NECESSARY TO CHANGE THE TROPICAL STORM WATCH
FOR THE NORTHERN LEEWARD ISLANDS BUT A DEVIATION OF THE TRACK TO
THE WEST WOULD REQUIRE ADDITIONAL WATCHES OR WARNINGS.
 
A NOAA-P3 AIRCRAFT RESEARCH MISSION WILL PROBABLY CHECK THE SYSTEM
LATER TODAY WHILE A NOAA GULFSTREAM JET SAMPLES THE ENVIRONMENT.
THE FIRST AIR FORCE RECONNAISSANCE AIRCRAFT INTO EARL IS SCHEDULED
FOR EARLY SUNDAY.
 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/1500Z 16.0N  51.8W    50 KT
 12HR VT     29/0000Z 16.1N  54.3W    55 KT
 24HR VT     29/1200Z 17.0N  57.5W    65 KT
 36HR VT     30/0000Z 17.8N  60.0W    75 KT
 48HR VT     30/1200Z 18.7N  62.0W    85 KT
 72HR VT     31/1200Z 21.5N  66.0W    95 KT
 96HR VT     01/1200Z 25.0N  69.0W   100 KT
120HR VT     02/1200Z 30.0N  71.0W   100 KT
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 282042
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST SAT AUG 28 2010
 
THE CENTER BECAME EXPOSED EARLIER TODAY BUT IT APPEARS THAT THE
SHEAR HAS BEGUN TO RELAX AND THE CENTER IS NOW TUCKED INTO THE
CONVECTION ONCE AGAIN. EARL HAS MAINTAINED A LARGE VIGOROUS
CIRCULATION AND ITS UPPER-LEVEL OUTFLOW IS MAINLY TO THE SOUTH AND
WEST DUE TO THE STILL PREVAILING NORTHERLY SHEAR. T-NUMBERS
THIS AFTERNOON SUPPORT AN INITIAL INTENSITY OF 50 KNOTS. SINCE THE
NORTHERLY SHEAR IS EXPECTED TO ABATE...AND BECAUSE THERE IS PLENTY
OF VERY WARM WATERS ALONG
THE TRACK...THE OFFICIAL FORECAST CALLS FOR INTENSIFICATION WITH A
SIMILAR TREND INDICATED BY THE LGEM MODEL...AND MAKES EARL AN
INTENSE HURRICANE IN ABOUT 3 DAYS.

EARL HAS INCREASED ITS FORWARD SPEED AND IS NOW MOVING TOWARD THE
WEST OR 280 DEGREES AT 20 KNOTS. HOWEVER SOON...THE CYCLONE WILL BE
APPROACHING THE WESTERN EDGE OF THE SUBTROPICAL RIDGE AND BEGIN TO
TURN MORE TO THE WEST-NORTHWEST WITH A DECREASE IN FORWARD SPEED. 
THIS IS CONSISTENT WITH THE TRACK MODELS WHICH ARE IN GOOD
AGREEMENT. DUE TO AN INITIAL MOTION WHICH HAS BEEN A LITTLE MORE TO
THE WEST THAN INDICATED BY TRACK MODELS...THE OFFICIAL FORECAST
LIES ON THE SOUTHERN SIDE OF THE GUIDANCE ENVELOPE...PRIMARILY
DURING THE NEXT FIRST 24 TO 36 HOURS. GUIDANCE ALSO INDICATES A
SIGNIFICANT DECREASE IN FORWARD SPEED AS EARL MOVES NEAR OR OVER
THE NORTHERN LEEWARD ISLANDS...AND SO DOES THE OFFICIAL FORECAST. 
 
A NOAA-P3 AIRCRAFT RESEARCH MISSION IS EN ROUTE TO CHECK EARL AND
WILL LIKELY GIVE US A BETTER MEASUREMENT OF THE INTENSITY AND THE
WIND RADII.
  
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/2100Z 16.5N  54.2W    50 KT
 12HR VT     29/0600Z 17.0N  57.0W    55 KT
 24HR VT     29/1800Z 17.5N  59.5W    65 KT
 36HR VT     30/0600Z 18.3N  61.8W    75 KT
 48HR VT     30/1800Z 19.0N  63.5W    85 KT
 72HR VT     31/1800Z 21.0N  67.0W   100 KT
 96HR VT     01/1800Z 25.0N  70.5W   100 KT
120HR VT     02/1800Z 30.5N  72.5W   100 KT
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 290314
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST SAT AUG 28 2010
 
A NOAA HURRICANE HUNTER FLYING A RESEARCH MISSION INTO EARL REPORTED
FLIGHT-LEVEL AND SFMR WINDS SUPPORTING A INITIAL INTENSITY OF 55
KT.  THIS IS IN GOOD AGREEMENT WITH SATELLITE INTENSITY ESTIMATES
FROM TAFB AND SAB OF 55 KT...AND A CIMSS AMSU ESTIMATE OF 56 KT.
THE AIRCRAFT DATA SUGGEST THE CENTRAL PRESSURE IS NEAR 989 MB.
WHILE EARL IS STILL SHOWING SIGNS OF NORTHEASTERLY VERTICAL WIND
SHEAR...THE CONVECTION HAS INCREASED IN BOTH COVERAGE AND
ORGANIZATION DURING THE PAST SEVERAL HOURS.
 
THE INITIAL MOTION IS 280/17.  EARL IS APPROACHING THE END OF A
LOW/MID-LEVEL RIDGE SEPARATING IT FROM HURRICANE DANIELLE...WITH
WATER VAPOR IMAGERY SHOWING AN UPPER-LEVEL TROUGH JUST NORTH OF
CUBA AND HISPANIOLA.  THE LARGE-SCALE MODELS FORECAST A LOW-LEVEL
RIDGE TO BUILD TO THE NORTH OF EARL DURING THE NEXT 48-72 HR...
WHILE THE TROUGH REMAINS NEARLY STATIONARY AND POSSIBLY
STRENGTHENS.  THE LOW-LEVEL RIDGE WILL STEER EARL GENERALLY TOWARD
THE WEST-NORTHWEST OR WEST WITH SOME DECREASE IN FORWARD
SPEED...WITH THE UPPER TROUGH TRYING TO TURN IT NORTHWARD AS IT
APPROACHES.  OVERALL...THIS PATTERN EVOLUTION SHOULD CAUSE EARL TO
MOVE GENERALLY WEST-NORTHWESTWARD FOR 48 HR OR SO...FOLLOWED BY A
GRADUAL TURN TO THE NORTHWEST AND NORTH AS THE TROUGH EXERTS A
GREATER INFLUENCE.  THE NEW FORECAST TRACK IS SHIFTED A LITTLE
SOUTH OF THE PREVIOUS TRACK DURING THE FIRST 12 HR BASED ON THE
INITIAL POSITION AND MOTION.  AFTER THAT...IT LIES A LITTLE TO LEFT
OF THE CENTER OF THE GUIDANCE ENVELOPE BETWEEN THE CONSENSUS MODELS
AND THE GFDL.  THE NEW TRACK IS SIMILAR TO...BUT A LITTLE SOUTH
OF...THE PREVIOUS TRACK.

THE CURRENT NORTHEASTERLY SHEAR SHOULD GRADUALLY DIMINISH OVER THE
NEXT 24 HR AND ALLOW EARL TO STRENGTHEN.  THE INTENSITY GUIDANCE IS
IN GOOD AGREEMENT THAT EARL SHOULD BECOME A MAJOR HURRICANE BY 72
HR...IF NOT SOONER...AND THIS IS REFLECTED IN THE NHC FORECAST. 
THE INTENSITY FORECAST IS MORE PROBLEMATIC AFTER 72 HR...AS THERE
ARE DISAGREEMENTS IN THE LARGE-SCALE MODELS ON HOW MUCH SHEAR EARL
WILL ENCOUNTER AS IT APPROACHES THE UPPER-LEVEL TROUGH.  THE GFS
AND ECMWF FORECAST LIGHT ENOUGH SHEAR TO ALLOW EARL TO MAINTAIN ITS
STRENGTH...WHILE THE UKMET FORECASTS STRONG ENOUGH UPPER-LEVEL
WINDS TO CAUSE EARL TO SHEAR APART.  AT THIS TIME...THE INTENSITY
FORECAST COMPROMISES BETWEEN THESE EXTREMES WITH SLOW WEAKENING
AFTER 96 HR.
 
THE INITIAL AND FORECAST WIND RADII HAVE BEEN SIGNIFICANTLY REVISED
BASED ON THE AIRCRAFT DATA.
 
THE NEW FORECAST TRACK REQUIRES HURRICANE WARNINGS TO BE ISSUED FOR
PORTIONS OF THE NORTHERN LEEWARD ISLANDS AT THIS TIME.  ADDITIONAL
WARNINGS WILL BE REQUIRED ON SUNDAY. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/0300Z 16.6N  55.4W    55 KT
 12HR VT     29/1200Z 17.0N  57.5W    60 KT
 24HR VT     30/0000Z 17.5N  60.0W    70 KT
 36HR VT     30/1200Z 18.1N  62.0W    80 KT
 48HR VT     31/0000Z 19.0N  63.9W    90 KT
 72HR VT     01/0000Z 22.0N  68.0W   100 KT
 96HR VT     02/0000Z 25.0N  71.0W   105 KT
120HR VT     03/0000Z 31.0N  72.5W   100 KT
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 290842
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST SUN AUG 29 2010
 
DEEP CONVECTION HAS DECREASED NEAR THE ESTIMATED CENTER OF EARL OVER
THE PAST FEW HOURS...AND THE COLDEST CLOUD TOPS ARE NOW LOCATED IN
A LARGE BAND TO THE SOUTHWEST OF THE CENTER.  EARL APPEARS TO BE
EXPERIENCING SOME NORTHERLY SHEAR ASSOCIATED WITH THE OUTFLOW FROM
HURRICANE DANIELLE...AND THE OUTFLOW IS RESTRICTED IN THE NORTHERN
SEMICIRCLE.  THE INITIAL INTENSITY IS HELD AT 55 KT IN AGREEMENT
WITH DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB.  

THE SHEAR WILL BE DECREASING SOON AS DANIELLE CONTINUES MOVING
AWAY...AND EARL SHOULD BE IN AN ENVIRONMENT THAT WILL
SUPPORT STEADY STRENGTHENING THROUGH THE PERIOD.  MOST OF THE
GUIDANCE SUGGESTS EARL WILL BECOME A HURRICANE IN 12 TO 24 HOURS
...AND REACH MAJOR HURRICANE STRENGTH IN 72 TO 96 HOURS.  THE NHC 
INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND CLOSE TO THE
ICON CONSENSUS. 

THE CENTER HAS BEEN DIFFICULT TO LOCATE ON INFRARED IMAGERY
OVERNIGHT...SO THE INITIAL MOTION ESTIMATE OF 280/16 IS LARGELY
BASED ON CONTINUITY.  EARL WILL SOON REACH THE SOUTHWESTERN
EDGE OF THE SUBTROPICAL RIDGE CENTERED ALONG 25N...WHICH SHOULD
RESULT IN A TURN TOWARD THE WEST-NORTHWEST AND A DECREASE IN
FORWARD SPEED OVER THE NEXT 24 TO 36 HOURS.  BEYOND THAT TIME...A
BREAK DEVELOPS IN THE SUBTROPICAL RIDGE ALONG 65 TO 70W AS THE
LARGE UPPER TROUGH INTERACTING WITH DANIELLE LIFTS OUT TO THE
NORTHEAST.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT IN SHOWING EARL
TURNING NORTHWESTWARD INTO THIS WEAKNESS IN 2 OR 3 DAYS...AND THEN
ACCELERATING NORTHWARD...ALTHOUGH THERE IS SOME SPREAD IN THE
FORWARD SPEED AT DAYS 4 AND 5.  THE OFFICIAL NHC FORECAST IS
SIMILAR TO THE PREVIOUS PACKAGE THROUGH THE FIRST 48 HOURS...AND IS
FASTER LATE IN THE PERIOD IN AGREEMENT WITH THE MULTI-MODEL
CONSENSUS.  

ON THE FORECAST TRACK...EARL WILL MOVE VERY CLOSE TO THE NORTHERN
LEEWARD ISLANDS IN THE NEXT 24 TO 36 HOURS.  CONDITIONS WILL BEGIN
TO DETERIORATE IN THOSE AREAS LATER TODAY AND TONIGHT. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/0900Z 16.9N  56.9W    55 KT
 12HR VT     29/1800Z 17.3N  59.1W    65 KT
 24HR VT     30/0600Z 17.9N  61.4W    70 KT
 36HR VT     30/1800Z 18.7N  63.6W    80 KT
 48HR VT     31/0600Z 19.9N  65.4W    90 KT
 72HR VT     01/0600Z 23.5N  69.0W   100 KT
 96HR VT     02/0600Z 29.0N  72.0W   105 KT
120HR VT     03/0600Z 34.5N  72.0W   105 KT
 
$$
FORECASTER BRENNAN
 

WTNT42 KNHC 290314
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST SAT AUG 28 2010

A NOAA HURRICANE HUNTER FLYING A RESEARCH MISSION INTO EARL REPORTED
FLIGHT-LEVEL AND SFMR WINDS SUPPORTING A INITIAL INTENSITY OF 55
KT.  THIS IS IN GOOD AGREEMENT WITH SATELLITE INTENSITY ESTIMATES
FROM TAFB AND SAB OF 55 KT...AND A CIMSS AMSU ESTIMATE OF 56 KT.
THE AIRCRAFT DATA SUGGEST THE CENTRAL PRESSURE IS NEAR 989 MB.
WHILE EARL IS STILL SHOWING SIGNS OF NORTHEASTERLY VERTICAL WIND
SHEAR...THE CONVECTION HAS INCREASED IN BOTH COVERAGE AND
ORGANIZATION DURING THE PAST SEVERAL HOURS.

THE INITIAL MOTION IS 280/17.  EARL IS APPROACHING THE END OF A
LOW/MID-LEVEL RIDGE SEPARATING IT FROM HURRICANE DANIELLE...WITH
WATER VAPOR IMAGERY SHOWING AN UPPER-LEVEL TROUGH JUST NORTH OF
CUBA AND HISPANIOLA.  THE LARGE-SCALE MODELS FORECAST A LOW-LEVEL
RIDGE TO BUILD TO THE NORTH OF EARL DURING THE NEXT 48-72 HR...
WHILE THE TROUGH REMAINS NEARLY STATIONARY AND POSSIBLY
STRENGTHENS.  THE LOW-LEVEL RIDGE WILL STEER EARL GENERALLY TOWARD
THE WEST-NORTHWEST OR WEST WITH SOME DECREASE IN FORWARD
SPEED...WITH THE UPPER TROUGH TRYING TO TURN IT NORTHWARD AS IT
APPROACHES.  OVERALL...THIS PATTERN EVOLUTION SHOULD CAUSE EARL TO
MOVE GENERALLY WEST-NORTHWESTWARD FOR 48 HR OR SO...FOLLOWED BY A
GRADUAL TURN TO THE NORTHWEST AND NORTH AS THE TROUGH EXERTS A
GREATER INFLUENCE.  THE NEW FORECAST TRACK IS SHIFTED A LITTLE
SOUTH OF THE PREVIOUS TRACK DURING THE FIRST 12 HR BASED ON THE
INITIAL POSITION AND MOTION.  AFTER THAT...IT LIES A LITTLE TO LEFT
OF THE CENTER OF THE GUIDANCE ENVELOPE BETWEEN THE CONSENSUS MODELS
AND THE GFDL.  THE NEW TRACK IS SIMILAR TO...BUT A LITTLE SOUTH
OF...THE PREVIOUS TRACK.

THE CURRENT NORTHEASTERLY SHEAR SHOULD GRADUALLY DIMINISH OVER THE
NEXT 24 HR AND ALLOW EARL TO STRENGTHEN.  THE INTENSITY GUIDANCE IS
IN GOOD AGREEMENT THAT EARL SHOULD BECOME A MAJOR HURRICANE BY 72
HR...IF NOT SOONER...AND THIS IS REFLECTED IN THE NHC FORECAST.
THE INTENSITY FORECAST IS MORE PROBLEMATIC AFTER 72 HR...AS THERE
ARE DISAGREEMENTS IN THE LARGE-SCALE MODELS ON HOW MUCH SHEAR EARL
WILL ENCOUNTER AS IT APPROACHES THE UPPER-LEVEL TROUGH.  THE GFS
AND ECMWF FORECAST LIGHT ENOUGH SHEAR TO ALLOW EARL TO MAINTAIN ITS
STRENGTH...WHILE THE UKMET FORECASTS STRONG ENOUGH UPPER-LEVEL
WINDS TO CAUSE EARL TO SHEAR APART.  AT THIS TIME...THE INTENSITY
FORECAST COMPROMISES BETWEEN THESE EXTREMES WITH SLOW WEAKENING
AFTER 96 HR.

THE INITIAL AND FORECAST WIND RADII HAVE BEEN SIGNIFICANTLY REVISED
BASED ON THE AIRCRAFT DATA.

THE NEW FORECAST TRACK REQUIRES HURRICANE WARNINGS TO BE ISSUED FOR
PORTIONS OF THE NORTHERN LEEWARD ISLANDS AT THIS TIME.  ADDITIONAL
WARNINGS WILL BE REQUIRED ON SUNDAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL      29/0300Z 16.6N  55.4W    55 KT
12HR VT     29/1200Z 17.0N  57.5W    60 KT
24HR VT     30/0000Z 17.5N  60.0W    70 KT
36HR VT     30/1200Z 18.1N  62.0W    80 KT
48HR VT     31/0000Z 19.0N  63.9W    90 KT
72HR VT     01/0000Z 22.0N  68.0W   100 KT
96HR VT     02/0000Z 25.0N  71.0W   105 KT
120HR VT     03/0000Z 31.0N  72.5W   100 KT

$$
FORECASTER BEVEN




WTNT42 KNHC 290842
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST SUN AUG 29 2010

DEEP CONVECTION HAS DECREASED NEAR THE ESTIMATED CENTER OF EARL OVER
THE PAST FEW HOURS...AND THE COLDEST CLOUD TOPS ARE NOW LOCATED IN
A LARGE BAND TO THE SOUTHWEST OF THE CENTER.  EARL APPEARS TO BE
EXPERIENCING SOME NORTHERLY SHEAR ASSOCIATED WITH THE OUTFLOW FROM
HURRICANE DANIELLE...AND THE OUTFLOW IS RESTRICTED IN THE NORTHERN
SEMICIRCLE.  THE INITIAL INTENSITY IS HELD AT 55 KT IN AGREEMENT
WITH DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB.

THE SHEAR WILL BE DECREASING SOON AS DANIELLE CONTINUES MOVING
AWAY...AND EARL SHOULD BE IN AN ENVIRONMENT THAT WILL
SUPPORT STEADY STRENGTHENING THROUGH THE PERIOD.  MOST OF THE
GUIDANCE SUGGESTS EARL WILL BECOME A HURRICANE IN 12 TO 24 HOURS
...AND REACH MAJOR HURRICANE STRENGTH IN 72 TO 96 HOURS.  THE NHC
INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND CLOSE TO THE
ICON CONSENSUS.

THE CENTER HAS BEEN DIFFICULT TO LOCATE ON INFRARED IMAGERY
OVERNIGHT...SO THE INITIAL MOTION ESTIMATE OF 280/16 IS LARGELY
BASED ON CONTINUITY.  EARL WILL SOON REACH THE SOUTHWESTERN
EDGE OF THE SUBTROPICAL RIDGE CENTERED ALONG 25N...WHICH SHOULD
RESULT IN A TURN TOWARD THE WEST-NORTHWEST AND A DECREASE IN
FORWARD SPEED OVER THE NEXT 24 TO 36 HOURS.  BEYOND THAT TIME...A
BREAK DEVELOPS IN THE SUBTROPICAL RIDGE ALONG 65 TO 70W AS THE
LARGE UPPER TROUGH INTERACTING WITH DANIELLE LIFTS OUT TO THE
NORTHEAST.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT IN SHOWING EARL
TURNING NORTHWESTWARD INTO THIS WEAKNESS IN 2 OR 3 DAYS...AND THEN
ACCELERATING NORTHWARD...ALTHOUGH THERE IS SOME SPREAD IN THE
FORWARD SPEED AT DAYS 4 AND 5.  THE OFFICIAL NHC FORECAST IS
SIMILAR TO THE PREVIOUS PACKAGE THROUGH THE FIRST 48 HOURS...AND IS
FASTER LATE IN THE PERIOD IN AGREEMENT WITH THE MULTI-MODEL
CONSENSUS.

ON THE FORECAST TRACK...EARL WILL MOVE VERY CLOSE TO THE NORTHERN
LEEWARD ISLANDS IN THE NEXT 24 TO 36 HOURS.  CONDITIONS WILL BEGIN
TO DETERIORATE IN THOSE AREAS LATER TODAY AND TONIGHT.

FORECAST POSITIONS AND MAX WINDS

INITIAL      29/0900Z 16.9N  56.9W    55 KT
12HR VT     29/1800Z 17.3N  59.1W    65 KT
24HR VT     30/0600Z 17.9N  61.4W    70 KT
36HR VT     30/1800Z 18.7N  63.6W    80 KT
48HR VT     31/0600Z 19.9N  65.4W    90 KT
72HR VT     01/0600Z 23.5N  69.0W   100 KT
96HR VT     02/0600Z 29.0N  72.0W   105 KT
120HR VT     03/0600Z 34.5N  72.0W   105 KT

$$
FORECASTER BRENNAN




WTNT42 KNHC 291457
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST SUN AUG 29 2010
 
EARL HAS BECOME MUCH BETTER ORGANIZED IN SATELLITE IMAGERY WITH
SEVERAL BANDS OF THUNDERSTORMS WRAPPING AROUND THE CENTER AND A
DEVELOPING CDO.  AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
FOUND 850 MB FLIGHT-LEVEL WINDS OF 81 KT AND SFMR SURFACE WINDS OF
64 KT EARLIER THIS MORNING.  THESE MEASUREMENTS SUPPORTED THE
EARLIER UPGRADE TO HURRICANE STATUS. 
 
NORTHEASTERLY SHEAR SHOULD CONTINUE TO DECREASE TODAY...AND THE
UPPER-LEVEL ENVIRONMENT APPEARS QUITE FAVORABLE FOR INTENSIFICATION
DURING THE NEXT FEW DAYS.  THE SHIPS...LGEM...AND GFDL MODELS
SUPPORT STEADY STRENGTHENING...AND THE OFFICIAL FORECAST IS NEAR
THE HIGH END OF THE GUIDANCE THROUGH 36 HOURS...PREDICTING THAT
EARL WILL ATTAIN MAJOR HURRICANE DURING THAT TIME.  THEREAFTER...
THE NHC FORECAST IS CLOSE TO A BLEND OF THE MORE AGGRESSIVE GFDL
AND THE LOWER SHIPS/LGEM MODELS.
 
THE HURRICANE IS STILL MOVING WESTWARD OR 280/15 KT.  EARL IS
EXPECTED TO TURN WEST-NORTHWESTWARD AND SLOW DOWN AS IT APPROACHES
THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE DURING THE NEXT DAY
OR SO. THE HURRICANE IS FORECAST TO TURN NORTHWESTWARD IN 2-3 DAYS
AS IT ROUNDS THE RIDGE. LATE IN THE FORECAST PERIOD...A TROUGH IS
FORECAST TO MOVE ACROSS THE GREAT LAKES....WHICH SHOULD RESULT IN 
A NORTHWARD MOTION.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT...BUT
THE GLOBAL MODELS ARE MUCH FASTER THAN THE REGIONAL HURRICANE
MODELS AT DAYS 4 AND 5.  THE NHC TRACK IS ALONG THE SOUTHERN SIDE
OF THE GUIDANCE ENVELOPE FOR THE FIRST 36 HOURS AND LEANS TOWARD
THE FASTER SOLUTION OF THE GLOBAL MODELS AT DAYS 4 AND 5. 

PERSONS IN THE LEEWARD ISLANDS SHOULD REMEMBER THAT THE HURRICANE IS
NOT A POINT SINCE HAZARDS EXTEND WELL AWAY FROM THE CENTER. 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/1500Z 17.2N  58.4W    65 KT
 12HR VT     30/0000Z 17.6N  60.4W    75 KT
 24HR VT     30/1200Z 18.5N  62.7W    90 KT
 36HR VT     31/0000Z 19.6N  64.5W   100 KT
 48HR VT     31/1200Z 21.1N  66.3W   105 KT
 72HR VT     01/1200Z 25.2N  69.8W   110 KT
 96HR VT     02/1200Z 31.0N  72.0W   110 KT
120HR VT     03/1200Z 37.0N  71.5W   100 KT
 
$$
FORECASTER BROWN/BERG
 

WTNT42 KNHC 292052
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST SUN AUG 29 2010
 
THE SATELLITE APPEARANCE OF EARL HAS CONTINUED TO IMPROVE THROUGHOUT
THE DAY.  SEVERAL CURVED BANDS OF THUNDERSTORMS ARE SEEN SURROUNDING
A CENTRAL DENSE OVERCAST FEATURE.  THERE ARE NO HINTS OF AN EYE IN
VISIBLE IMAGERY...HOWEVER AN EYE IS APPARENT IN RECENT RADAR
IMAGERY FROM GUADELOUPE AND WAS ALSO REPORTED BY THE AIRCRAFT A
FEW HOURS AGO.  ALTHOUGH THE PLANE DID NOT FIND HIGHER FLIGHT-LEVEL
OR SFMR WINDS THAN IT DID THIS MORNING...THE MINIMUM PRESSURE
REPORTED WAS LOWER ON EACH SUCCESSIVE FIX AND WAS DOWN TO 978 MB.
BASED ON SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY ESTIMATES...
AND THE INCREASED ORGANIZATION ON SATELLITE IMAGES...THE ADVISORY
INTENSITY HAS BEEN INCREASED TO 75 KT.  A NOAA P-3 AIRCRAFT ON A
RESEARCH MISSION SHOULD BE IN EARL SHORTLY...FOLLOWED BY THE NEXT
AIR FORCE C-130 MISSION BETWEEN 0000 AND 0600 UTC.
 
THE CENTER FIXES FROM THE AIRCRAFT FLIGHT TODAY YIELD AN INITIAL
MOTION OF ABOUT 285/12...A LITTLE SLOWER THAN BEFORE.  THE FORECAST
REASONING REMAINS UNCHANGED FROM THE PREVIOUS ADVISORY.  EARL IS
EXPECTED TO BE STEERED AROUND THE WESTERN PERIPHERY OF THE
SUBTROPICAL RIDGE DURING THE NEXT COUPLE OF DAYS.  THE HURRICANE
SHOULD TURN NORTHWESTWARD IN 36-48 HOURS.  EARL IS FORECAST TO TURN
NORTHWARD...THEN NORTHEASTWARD AHEAD OF A TROUGH THAT MOVES INTO
GREAT LAKES REGION IN 4-5 DAYS.  THE TRACK GUIDANCE GENERALLY AGREES
WITH THIS SCENARIO...BUT THERE ARE SOME LARGE DIFFERENCES IN
THE FORWARD SPEED OF EARL AT DAYS 4 AND 5.  THE GLOBAL MODELS REMAIN
FASTER THAN THE GFDL/HWRF AND THE OFFICIAL CONTINUES TO BE FASTER
THAN THE DYNAMICAL MODEL CONSENSUS AFTER 72 HOURS.
 
THE GLOBAL MODELS SHOW A RATHER FAVORABLE UPPER-LEVEL ENVIRONMENT
FOR STRENGTHENING DURING THE NEXT COUPLE OF DAYS AS AN UPPER-LEVEL
ANTICYCLONE BUILDS OVER THE SYSTEM.  THE SHIPS...LGEM...AND GFDL
MODELS SHOW EARL REACHING MAJOR HURRICANE STRENGTH IN A DAY OR SO
AND THE OFFICIAL FORECAST FOLLOWS SUIT.  LATE IN THE FORECAST
PERIOD...THE HURRICANE IS EXPECTED TO BEGIN TO WEAKEN AS IT MOVES
OVER COOLER SSTS AND INTO AN AREA OF INCREASING SOUTHWESTERLY
SHEAR.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/2100Z 17.6N  59.5W    75 KT
 12HR VT     30/0600Z 18.0N  61.3W    90 KT
 24HR VT     30/1800Z 18.9N  63.3W   100 KT
 36HR VT     31/0600Z 20.3N  65.1W   110 KT
 48HR VT     31/1800Z 22.1N  66.9W   115 KT
 72HR VT     01/1800Z 27.3N  70.2W   115 KT
 96HR VT     02/1800Z 33.5N  71.5W   105 KT
120HR VT     03/1800Z 40.0N  68.0W    90 KT
 
$$
FORECASTER BROWN/BERG
 

WTNT42 KNHC 300236
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST SUN AUG 29 2010
 
EARL HAS STRENGTHENED OVER THE PAST FEW HOURS.  THE AIR FORCE
HURRICANE HUNTERS RECENTLY FOUND AN SFMR-MEASURED SURFACE WIND
SPEED OF 83 KT JUST SOUTHEAST OF THE CENTER.  MAXIMUM FLIGHT-LEVEL
WINDS FROM THE AIRCRAFT WERE 93 KT...WHICH ADJUSTS TO 84 KT AT THE
SURFACE USING THE STANDARD REDUCTION FACTOR.  BASED ON THESE
OBSERVATIONS...THE CURRENT INTENSITY IS SET TO 85 KT.  IMAGES FROM
THE GUADELOUPE AND ST. MARTIN RADARS SHOW A BANDING-TYPE EYE ABOUT
30 N MI IN DIAMETER WHILE THE RECONNAISSANCE OBSERVATIONS INDICATED
THAT THE EYE WAS OPEN OVER THE NORTHWEST QUADRANT.  WATER VAPOR
IMAGERY SHOWS THAT THE UPPER-LEVEL OUTFLOW IS BEING IMPEDED OVER
THE NORTHEAST QUADRANT...BUT IS WELL ESTABLISHED OVER THE REMAINDER
OF THE CIRCULATION.  A BROAD UPPER-LEVEL TROUGH IS CURRENTLY
SITUATED TO THE NORTHWEST OF EARL.  GLOBAL MODELS ARE IN GOOD
AGREEMENT THAT THIS TROUGH WILL SHIFT WESTWARD AND WEAKEN.  THIS
SHOULD CREATE A ENVIRONMENT CONDUCIVE FOR INTENSIFICATION AND THE
OFFICIAL FORECAST...LIKE THE PREVIOUS ONE...SHOWS EARL BECOMING A
MAJOR HURRICANE OVER THE NEXT DAY OR SO.  THE NHC WIND SPEED
FORECAST IS ABOVE THE INTENSITY MODEL CONSENSUS BUT BELOW THE
LATEST GFDL HURRICANE MODEL GUIDANCE.
 
INITIAL MOTION...285/13...IS ABOUT THE SAME AS IN THE PREVIOUS
ADVISORY.  A GRADUAL TURN TO THE NORTHWEST IS LIKELY TO TAKE PLACE
IN 24 TO 36 HOURS AS THE HURRICANE ENCOUNTERS THE WESTERN PERIPHERY
OF A MID-TROPOSPHERIC ANTICYCLONE.  BY DAYS 3 TO 4...THE HEADING
AND FORWARD SPEED OF EARL ARE DEPENDENT ON THE DETAILS OF THE
EVOLUTION OF A 500 MB TROUGH MOVING THROUGH THE GREAT LAKES.  THE
GFS AND ECMWF SHOW THIS TROUGH AMPLIFYING MORE THAN THE OTHER
DYNAMICAL MODELS AND MOVE EARL SIGNIFICANTLY FASTER TO THE
NORTH-NORTHEAST WITH A SHARPER EASTWARD TURN THAN THE OTHER
GUIDANCE.  THE OFFICIAL TRACK FORECAST IS NOT QUITE AS FAST AS THE
GFS AND ECMWF...BUT IS CLOSE TO THE MULTI-MODEL CONSENSUS.
 
THE FORECAST WIND RADII HAVE BEEN EXPANDED A LITTLE BASED ON
DYNAMICAL...MAINLY GLOBAL MODEL...GUIDANCE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/0300Z 17.9N  61.1W    85 KT
 12HR VT     30/1200Z 18.5N  62.7W    90 KT
 24HR VT     31/0000Z 19.6N  64.6W   100 KT
 36HR VT     31/1200Z 21.1N  66.4W   110 KT
 48HR VT     01/0000Z 22.8N  68.2W   115 KT
 72HR VT     02/0000Z 27.5N  71.5W   115 KT
 96HR VT     03/0000Z 34.0N  72.0W   100 KT
120HR VT     04/0000Z 40.0N  67.0W    85 KT
 
$$
FORECASTER PASCH
 

WTNT42 KNHC 300845
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST MON AUG 30 2010
 
SINCE THE AIRCRAFT DEPARTED JUST PRIOR TO 0600 UTC...AN EYE HAS BEEN
OCCASIONALLY APPARENT IN INFRARED IMAGERY...AND HAS BECOME 
BETTER DEFINED WITH A DIAMETER OF ABOUT 25 NM ON THE ST. MAARTEN
RADAR.  THE AIRCRAFT MEASURED A FLIGHT LEVEL MAXIMUM WIND OF 97 KT
AT 0510 UTC...AND 0600 UTC DVORAK INTENSITY ESTIMATES WERE 90 KT
FROM TAFB AND SAB.  BASED ON THESE DATA...THE INITIAL INTENSITY IS
SET TO 90 KT FOR THIS ADVISORY.  THE OUTFLOW IS IMPROVING IN THE
NORTHEASTERN QUADRANT AND IS GOOD ELSEWHERE...AND THE OVERALL
ENVIRONMENT SHOULD SUPPORT STEADY INTENSIFICATION THROUGH THE NEXT
36 TO 48 HOURS.  THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS
ONE...AND SHOWS EARL REACHING MAJOR HURRICANE STATUS IN THE NEXT 12
TO 24 HOURS...FOLLOWED BY A BROAD PEAK IN INTENSITY BETWEEN 36 AND
72 HOURS.  AFTER THAT TIME...EARL SHOULD BEGIN TO WEAKEN AS IT
MOVES OVER COOLER WATERS AND ENCOUNTERS HIGHER VERTICAL WIND SHEAR. 
THE OFFICIAL FORECAST IS A BLEND OF THE SHIPS MODEL AND THE GFDL.
 
BASED ON AIRCRAFT AND SATELLITE FIXES...THE INITIAL MOTION ESTIMATE
REMAINS 285/13.  EARL WILL GRADUALLY TURN TOWARD THE NORTHWEST IN
THE NEXT DAY OR SO AS IT MOVES AROUND THE SOUTHWESTERN EDGE OF THE
SUBTROPICAL RIDGE CENTERED ALONG 25N.  THE TRACK MODEL GUIDANCE IS
IN GOOD AGREEMENT ON THIS SCENARIO AND THE OFFICIAL FORECAST IS
NEAR THE MIDDLE OF THE TIGHTLY CLUSTERED GUIDANCE ENVELOPE THROUGH
24 HOURS.  AFTER THAT TIME MOST OF THE TRACK GUIDANCE HAS SHIFTED
FARTHER WEST...ESPECIALLY AT 72 HOURS AND BEYOND...AS EARL TURNS
NORTH-NORTHWESTWARD AND INTERACTS WITH A MID-LATITUDE TROUGH MOVING
FROM THE GREAT LAKES INTO THE NORTHEASTERN U.S.  GIVEN THE LARGE
SHIFT IN THE MODELS...THE OFFICIAL FORECAST HAS BEEN ADJUSTED TO
THE LEFT...OR WEST...BUT STILL LIES ON THE EASTERN EDGE OF THE
GUIDANCE SUITE.
 
THIS IS A GOOD TIME TO REMIND EVERYONE THAT NHC AVERAGE TRACK
FORECAST ERRORS ARE 200 TO 300 MILES AT DAYS 4 AND 5.  GIVEN THIS
UNCERTAINTY...IT IS TOO SOON TO DETERMINE WHAT...IF ANY...PARTS OF
THE U.S. EAST COAST MIGHT SEE DIRECT IMPACTS FROM EARL LATER THIS
WEEK.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/0900Z 18.3N  62.4W    90 KT
 12HR VT     30/1800Z 19.1N  64.0W    95 KT
 24HR VT     31/0600Z 20.3N  66.0W   105 KT
 36HR VT     31/1800Z 21.9N  67.8W   115 KT
 48HR VT     01/0600Z 24.0N  69.6W   115 KT
 72HR VT     02/0600Z 29.5N  73.0W   115 KT
 96HR VT     03/0600Z 35.5N  72.5W   100 KT
120HR VT     04/0600Z 42.0N  65.5W    85 KT
 
$$
FORECASTER BRENNAN
 

WTNT42 KNHC 301450
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST MON AUG 30 2010
 
THE EYE OF EARL HAS BECOME BETTER DEFINED IN VISIBLE SATELLITE
IMAGERY THIS MORNING AND IS WELL-DEFINED IN RADAR IMAGERY FROM BOTH
SAN JUAN AND ST. MAARTEN. AN AIR FORCE HURRICANE HUNTER AIRCRAFT
MEASURED 700 MB FLIGHT-LEVEL WINDS OF 111 KT IN THE NORTHEAST
EYEWALL AROUND 1200 UTC. THE AIRCRAFT HAS NOT SAMPLED THE
NORTHEASTERN QUADRANT AGAIN...BUT FOUND 90 KT SFMR WINDS IN THE
NORTHWEST EYEWALL AND A MINIMUM PRESSURE OF 960 MB. THIS SUPPORTS
INCREASING THE INITIAL INTENSITY TO 105 KT...CATEGORY THREE ON THE
SAFFIR-SIMPSON HURRICANE WIND SCALE. THE LOW SHEAR AND WARM WATER
ENVIRONMENT AHEAD OF EARL APPEARS CONDUCIVE FOR ADDITIONAL
STRENGTHENING DURING THE NEXT FEW DAYS.  THIS SUPPORTS KEEPING EARL
AT MAJOR HURRICANE STRENGTH DURING THAT TIME...ALTHOUGH EYEWALL
CYCLES COULD INDUCE SOME FLUCTUATIONS IN INTENSITY.  THE OFFICIAL
FORECAST IS AT THE UPPER END OF THE INTENSITY GUIDANCE. LATE IN THE
FORECAST PERIOD INCREASING SHEAR AND COOLER SSTS SHOULD INDUCE
WEAKENING.
 
THE INITIAL MOTION REMAINS 285/13.  EARL IS EXPECTED TO TURN TOWARD
THE NORTHWEST WITHIN THE NEXT DAY OR SO AS IT MOVES AROUND THE
WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE DURING THE NEXT COUPLE OF
DAYS. AFTER THAT TIME...EARL IS FORECAST TO TURN NORTHWARD...THEN
NORTHEASTWARD AHEAD OF A MID-LATITUDE TROUGH THAT MOVES ACROSS THE
GREAT LAKES AND INTO THE NORTHEAST UNITED STATES IN 4-5 DAYS.  THE
TRACK GUIDANCE HAS SHIFTED WESTWARD AGAIN AND THE OFFICIAL FORECAST
HAS BEEN ADJUSTED IN THAT DIRECTION.  THE UPDATED TRACK FORECAST IS
NEAR THE MIDDLE OF THE TIGHTLY CLUSTERED GUIDANCE.
 
THIS IS A GOOD TIME TO REMIND EVERYONE THAT NHC AVERAGE TRACK
FORECAST ERRORS ARE 200 TO 300 MILES AT DAYS 4 AND 5.  GIVEN THIS
UNCERTAINTY...IT IS TOO SOON TO DETERMINE WHAT PORTION OF THE U.S.
EAST COAST MIGHT SEE DIRECT IMPACTS FROM EARL.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/1500Z 18.7N  63.6W   105 KT
 12HR VT     31/0000Z 19.5N  65.1W   115 KT
 24HR VT     31/1200Z 21.0N  67.0W   125 KT
 36HR VT     01/0000Z 22.8N  68.7W   125 KT
 48HR VT     01/1200Z 25.2N  70.6W   120 KT
 72HR VT     02/1200Z 31.0N  73.5W   110 KT
 96HR VT     03/1200Z 37.5N  71.5W   100 KT
120HR VT     04/1200Z 45.5N  63.0W    75 KT...INLAND
 
$$
FORECASTER BROWN/BERG
 

WTNT42 KNHC 291457
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST SUN AUG 29 2010

EARL HAS BECOME MUCH BETTER ORGANIZED IN SATELLITE IMAGERY WITH
SEVERAL BANDS OF THUNDERSTORMS WRAPPING AROUND THE CENTER AND A
DEVELOPING CDO.  AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
FOUND 850 MB FLIGHT-LEVEL WINDS OF 81 KT AND SFMR SURFACE WINDS OF
64 KT EARLIER THIS MORNING.  THESE MEASUREMENTS SUPPORTED THE
EARLIER UPGRADE TO HURRICANE STATUS.

NORTHEASTERLY SHEAR SHOULD CONTINUE TO DECREASE TODAY...AND THE
UPPER-LEVEL ENVIRONMENT APPEARS QUITE FAVORABLE FOR INTENSIFICATION
DURING THE NEXT FEW DAYS.  THE SHIPS...LGEM...AND GFDL MODELS
SUPPORT STEADY STRENGTHENING...AND THE OFFICIAL FORECAST IS NEAR
THE HIGH END OF THE GUIDANCE THROUGH 36 HOURS...PREDICTING THAT
EARL WILL ATTAIN MAJOR HURRICANE DURING THAT TIME.  THEREAFTER...
THE NHC FORECAST IS CLOSE TO A BLEND OF THE MORE AGGRESSIVE GFDL
AND THE LOWER SHIPS/LGEM MODELS.

THE HURRICANE IS STILL MOVING WESTWARD OR 280/15 KT.  EARL IS
EXPECTED TO TURN WEST-NORTHWESTWARD AND SLOW DOWN AS IT APPROACHES
THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE DURING THE NEXT DAY
OR SO. THE HURRICANE IS FORECAST TO TURN NORTHWESTWARD IN 2-3 DAYS
AS IT ROUNDS THE RIDGE. LATE IN THE FORECAST PERIOD...A TROUGH IS
FORECAST TO MOVE ACROSS THE GREAT LAKES....WHICH SHOULD RESULT IN
A NORTHWARD MOTION.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT...BUT
THE GLOBAL MODELS ARE MUCH FASTER THAN THE REGIONAL HURRICANE
MODELS AT DAYS 4 AND 5.  THE NHC TRACK IS ALONG THE SOUTHERN SIDE
OF THE GUIDANCE ENVELOPE FOR THE FIRST 36 HOURS AND LEANS TOWARD
THE FASTER SOLUTION OF THE GLOBAL MODELS AT DAYS 4 AND 5.

PERSONS IN THE LEEWARD ISLANDS SHOULD REMEMBER THAT THE HURRICANE IS
NOT A POINT SINCE HAZARDS EXTEND WELL AWAY FROM THE CENTER.


FORECAST POSITIONS AND MAX WINDS

INITIAL      29/1500Z 17.2N  58.4W    65 KT
12HR VT     30/0000Z 17.6N  60.4W    75 KT
24HR VT     30/1200Z 18.5N  62.7W    90 KT
36HR VT     31/0000Z 19.6N  64.5W   100 KT
48HR VT     31/1200Z 21.1N  66.3W   105 KT
72HR VT     01/1200Z 25.2N  69.8W   110 KT
96HR VT     02/1200Z 31.0N  72.0W   110 KT
120HR VT     03/1200Z 37.0N  71.5W   100 KT

$$
FORECASTER BROWN/BERG




WTNT42 KNHC 292052
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST SUN AUG 29 2010

THE SATELLITE APPEARANCE OF EARL HAS CONTINUED TO IMPROVE THROUGHOUT
THE DAY.  SEVERAL CURVED BANDS OF THUNDERSTORMS ARE SEEN SURROUNDING
A CENTRAL DENSE OVERCAST FEATURE.  THERE ARE NO HINTS OF AN EYE IN
VISIBLE IMAGERY...HOWEVER AN EYE IS APPARENT IN RECENT RADAR
IMAGERY FROM GUADELOUPE AND WAS ALSO REPORTED BY THE AIRCRAFT A
FEW HOURS AGO.  ALTHOUGH THE PLANE DID NOT FIND HIGHER FLIGHT-LEVEL
OR SFMR WINDS THAN IT DID THIS MORNING...THE MINIMUM PRESSURE
REPORTED WAS LOWER ON EACH SUCCESSIVE FIX AND WAS DOWN TO 978 MB.
BASED ON SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY ESTIMATES...
AND THE INCREASED ORGANIZATION ON SATELLITE IMAGES...THE ADVISORY
INTENSITY HAS BEEN INCREASED TO 75 KT.  A NOAA P-3 AIRCRAFT ON A
RESEARCH MISSION SHOULD BE IN EARL SHORTLY...FOLLOWED BY THE NEXT
AIR FORCE C-130 MISSION BETWEEN 0000 AND 0600 UTC.

THE CENTER FIXES FROM THE AIRCRAFT FLIGHT TODAY YIELD AN INITIAL
MOTION OF ABOUT 285/12...A LITTLE SLOWER THAN BEFORE.  THE FORECAST
REASONING REMAINS UNCHANGED FROM THE PREVIOUS ADVISORY.  EARL IS
EXPECTED TO BE STEERED AROUND THE WESTERN PERIPHERY OF THE
SUBTROPICAL RIDGE DURING THE NEXT COUPLE OF DAYS.  THE HURRICANE
SHOULD TURN NORTHWESTWARD IN 36-48 HOURS.  EARL IS FORECAST TO TURN
NORTHWARD...THEN NORTHEASTWARD AHEAD OF A TROUGH THAT MOVES INTO
GREAT LAKES REGION IN 4-5 DAYS.  THE TRACK GUIDANCE GENERALLY AGREES
WITH THIS SCENARIO...BUT THERE ARE SOME LARGE DIFFERENCES IN
THE FORWARD SPEED OF EARL AT DAYS 4 AND 5.  THE GLOBAL MODELS REMAIN
FASTER THAN THE GFDL/HWRF AND THE OFFICIAL CONTINUES TO BE FASTER
THAN THE DYNAMICAL MODEL CONSENSUS AFTER 72 HOURS.

THE GLOBAL MODELS SHOW A RATHER FAVORABLE UPPER-LEVEL ENVIRONMENT
FOR STRENGTHENING DURING THE NEXT COUPLE OF DAYS AS AN UPPER-LEVEL
ANTICYCLONE BUILDS OVER THE SYSTEM.  THE SHIPS...LGEM...AND GFDL
MODELS SHOW EARL REACHING MAJOR HURRICANE STRENGTH IN A DAY OR SO
AND THE OFFICIAL FORECAST FOLLOWS SUIT.  LATE IN THE FORECAST
PERIOD...THE HURRICANE IS EXPECTED TO BEGIN TO WEAKEN AS IT MOVES
OVER COOLER SSTS AND INTO AN AREA OF INCREASING SOUTHWESTERLY
SHEAR.


FORECAST POSITIONS AND MAX WINDS

INITIAL      29/2100Z 17.6N  59.5W    75 KT
12HR VT     30/0600Z 18.0N  61.3W    90 KT
24HR VT     30/1800Z 18.9N  63.3W   100 KT
36HR VT     31/0600Z 20.3N  65.1W   110 KT
48HR VT     31/1800Z 22.1N  66.9W   115 KT
72HR VT     01/1800Z 27.3N  70.2W   115 KT
96HR VT     02/1800Z 33.5N  71.5W   105 KT
120HR VT     03/1800Z 40.0N  68.0W    90 KT

$$
FORECASTER BROWN/BERG




WTNT42 KNHC 300236
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST SUN AUG 29 2010

EARL HAS STRENGTHENED OVER THE PAST FEW HOURS.  THE AIR FORCE
HURRICANE HUNTERS RECENTLY FOUND AN SFMR-MEASURED SURFACE WIND
SPEED OF 83 KT JUST SOUTHEAST OF THE CENTER.  MAXIMUM FLIGHT-LEVEL
WINDS FROM THE AIRCRAFT WERE 93 KT...WHICH ADJUSTS TO 84 KT AT THE
SURFACE USING THE STANDARD REDUCTION FACTOR.  BASED ON THESE
OBSERVATIONS...THE CURRENT INTENSITY IS SET TO 85 KT.  IMAGES FROM
THE GUADELOUPE AND ST. MARTIN RADARS SHOW A BANDING-TYPE EYE ABOUT
30 N MI IN DIAMETER WHILE THE RECONNAISSANCE OBSERVATIONS INDICATED
THAT THE EYE WAS OPEN OVER THE NORTHWEST QUADRANT.  WATER VAPOR
IMAGERY SHOWS THAT THE UPPER-LEVEL OUTFLOW IS BEING IMPEDED OVER
THE NORTHEAST QUADRANT...BUT IS WELL ESTABLISHED OVER THE REMAINDER
OF THE CIRCULATION.  A BROAD UPPER-LEVEL TROUGH IS CURRENTLY
SITUATED TO THE NORTHWEST OF EARL.  GLOBAL MODELS ARE IN GOOD
AGREEMENT THAT THIS TROUGH WILL SHIFT WESTWARD AND WEAKEN.  THIS
SHOULD CREATE A ENVIRONMENT CONDUCIVE FOR INTENSIFICATION AND THE
OFFICIAL FORECAST...LIKE THE PREVIOUS ONE...SHOWS EARL BECOMING A
MAJOR HURRICANE OVER THE NEXT DAY OR SO.  THE NHC WIND SPEED
FORECAST IS ABOVE THE INTENSITY MODEL CONSENSUS BUT BELOW THE
LATEST GFDL HURRICANE MODEL GUIDANCE.

INITIAL MOTION...285/13...IS ABOUT THE SAME AS IN THE PREVIOUS
ADVISORY.  A GRADUAL TURN TO THE NORTHWEST IS LIKELY TO TAKE PLACE
IN 24 TO 36 HOURS AS THE HURRICANE ENCOUNTERS THE WESTERN PERIPHERY
OF A MID-TROPOSPHERIC ANTICYCLONE.  BY DAYS 3 TO 4...THE HEADING
AND FORWARD SPEED OF EARL ARE DEPENDENT ON THE DETAILS OF THE
EVOLUTION OF A 500 MB TROUGH MOVING THROUGH THE GREAT LAKES.  THE
GFS AND ECMWF SHOW THIS TROUGH AMPLIFYING MORE THAN THE OTHER
DYNAMICAL MODELS AND MOVE EARL SIGNIFICANTLY FASTER TO THE
NORTH-NORTHEAST WITH A SHARPER EASTWARD TURN THAN THE OTHER
GUIDANCE.  THE OFFICIAL TRACK FORECAST IS NOT QUITE AS FAST AS THE
GFS AND ECMWF...BUT IS CLOSE TO THE MULTI-MODEL CONSENSUS.

THE FORECAST WIND RADII HAVE BEEN EXPANDED A LITTLE BASED ON
DYNAMICAL...MAINLY GLOBAL MODEL...GUIDANCE.

FORECAST POSITIONS AND MAX WINDS

INITIAL      30/0300Z 17.9N  61.1W    85 KT
12HR VT     30/1200Z 18.5N  62.7W    90 KT
24HR VT     31/0000Z 19.6N  64.6W   100 KT
36HR VT     31/1200Z 21.1N  66.4W   110 KT
48HR VT     01/0000Z 22.8N  68.2W   115 KT
72HR VT     02/0000Z 27.5N  71.5W   115 KT
96HR VT     03/0000Z 34.0N  72.0W   100 KT
120HR VT     04/0000Z 40.0N  67.0W    85 KT

$$
FORECASTER PASCH



000

WTNT42 KNHC 300845
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST MON AUG 30 2010

SINCE THE AIRCRAFT DEPARTED JUST PRIOR TO 0600 UTC...AN EYE HAS BEEN
OCCASIONALLY APPARENT IN INFRARED IMAGERY...AND HAS BECOME
BETTER DEFINED WITH A DIAMETER OF ABOUT 25 NM ON THE ST. MAARTEN
RADAR.  THE AIRCRAFT MEASURED A FLIGHT LEVEL MAXIMUM WIND OF 97 KT
AT 0510 UTC...AND 0600 UTC DVORAK INTENSITY ESTIMATES WERE 90 KT
FROM TAFB AND SAB.  BASED ON THESE DATA...THE INITIAL INTENSITY IS
SET TO 90 KT FOR THIS ADVISORY.  THE OUTFLOW IS IMPROVING IN THE
NORTHEASTERN QUADRANT AND IS GOOD ELSEWHERE...AND THE OVERALL
ENVIRONMENT SHOULD SUPPORT STEADY INTENSIFICATION THROUGH THE NEXT
36 TO 48 HOURS.  THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS
ONE...AND SHOWS EARL REACHING MAJOR HURRICANE STATUS IN THE NEXT 12
TO 24 HOURS...FOLLOWED BY A BROAD PEAK IN INTENSITY BETWEEN 36 AND
72 HOURS.  AFTER THAT TIME...EARL SHOULD BEGIN TO WEAKEN AS IT
MOVES OVER COOLER WATERS AND ENCOUNTERS HIGHER VERTICAL WIND SHEAR.
THE OFFICIAL FORECAST IS A BLEND OF THE SHIPS MODEL AND THE GFDL.

BASED ON AIRCRAFT AND SATELLITE FIXES...THE INITIAL MOTION ESTIMATE
REMAINS 285/13.  EARL WILL GRADUALLY TURN TOWARD THE NORTHWEST IN
THE NEXT DAY OR SO AS IT MOVES AROUND THE SOUTHWESTERN EDGE OF THE
SUBTROPICAL RIDGE CENTERED ALONG 25N.  THE TRACK MODEL GUIDANCE IS
IN GOOD AGREEMENT ON THIS SCENARIO AND THE OFFICIAL FORECAST IS
NEAR THE MIDDLE OF THE TIGHTLY CLUSTERED GUIDANCE ENVELOPE THROUGH
24 HOURS.  AFTER THAT TIME MOST OF THE TRACK GUIDANCE HAS SHIFTED
FARTHER WEST...ESPECIALLY AT 72 HOURS AND BEYOND...AS EARL TURNS
NORTH-NORTHWESTWARD AND INTERACTS WITH A MID-LATITUDE TROUGH MOVING
FROM THE GREAT LAKES INTO THE NORTHEASTERN U.S.  GIVEN THE LARGE
SHIFT IN THE MODELS...THE OFFICIAL FORECAST HAS BEEN ADJUSTED TO
THE LEFT...OR WEST...BUT STILL LIES ON THE EASTERN EDGE OF THE
GUIDANCE SUITE.

THIS IS A GOOD TIME TO REMIND EVERYONE THAT NHC AVERAGE TRACK
FORECAST ERRORS ARE 200 TO 300 MILES AT DAYS 4 AND 5.  GIVEN THIS
UNCERTAINTY...IT IS TOO SOON TO DETERMINE WHAT...IF ANY...PARTS OF
THE U.S. EAST COAST MIGHT SEE DIRECT IMPACTS FROM EARL LATER THIS
WEEK.

FORECAST POSITIONS AND MAX WINDS

INITIAL      30/0900Z 18.3N  62.4W    90 KT
12HR VT     30/1800Z 19.1N  64.0W    95 KT
24HR VT     31/0600Z 20.3N  66.0W   105 KT
36HR VT     31/1800Z 21.9N  67.8W   115 KT
48HR VT     01/0600Z 24.0N  69.6W   115 KT
72HR VT     02/0600Z 29.5N  73.0W   115 KT
96HR VT     03/0600Z 35.5N  72.5W   100 KT
120HR VT     04/0600Z 42.0N  65.5W    85 KT

$$
FORECASTER BRENNAN




WTNT42 KNHC 301450
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST MON AUG 30 2010

THE EYE OF EARL HAS BECOME BETTER DEFINED IN VISIBLE SATELLITE
IMAGERY THIS MORNING AND IS WELL-DEFINED IN RADAR IMAGERY FROM BOTH
SAN JUAN AND ST. MAARTEN. AN AIR FORCE HURRICANE HUNTER AIRCRAFT
MEASURED 700 MB FLIGHT-LEVEL WINDS OF 111 KT IN THE NORTHEAST
EYEWALL AROUND 1200 UTC. THE AIRCRAFT HAS NOT SAMPLED THE
NORTHEASTERN QUADRANT AGAIN...BUT FOUND 90 KT SFMR WINDS IN THE
NORTHWEST EYEWALL AND A MINIMUM PRESSURE OF 960 MB. THIS SUPPORTS
INCREASING THE INITIAL INTENSITY TO 105 KT...CATEGORY THREE ON THE
SAFFIR-SIMPSON HURRICANE WIND SCALE. THE LOW SHEAR AND WARM WATER
ENVIRONMENT AHEAD OF EARL APPEARS CONDUCIVE FOR ADDITIONAL
STRENGTHENING DURING THE NEXT FEW DAYS.  THIS SUPPORTS KEEPING EARL
AT MAJOR HURRICANE STRENGTH DURING THAT TIME...ALTHOUGH EYEWALL
CYCLES COULD INDUCE SOME FLUCTUATIONS IN INTENSITY.  THE OFFICIAL
FORECAST IS AT THE UPPER END OF THE INTENSITY GUIDANCE. LATE IN THE
FORECAST PERIOD INCREASING SHEAR AND COOLER SSTS SHOULD INDUCE
WEAKENING.

THE INITIAL MOTION REMAINS 285/13.  EARL IS EXPECTED TO TURN TOWARD
THE NORTHWEST WITHIN THE NEXT DAY OR SO AS IT MOVES AROUND THE
WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE DURING THE NEXT COUPLE OF
DAYS. AFTER THAT TIME...EARL IS FORECAST TO TURN NORTHWARD...THEN
NORTHEASTWARD AHEAD OF A MID-LATITUDE TROUGH THAT MOVES ACROSS THE
GREAT LAKES AND INTO THE NORTHEAST UNITED STATES IN 4-5 DAYS.  THE
TRACK GUIDANCE HAS SHIFTED WESTWARD AGAIN AND THE OFFICIAL FORECAST
HAS BEEN ADJUSTED IN THAT DIRECTION.  THE UPDATED TRACK FORECAST IS
NEAR THE MIDDLE OF THE TIGHTLY CLUSTERED GUIDANCE.

THIS IS A GOOD TIME TO REMIND EVERYONE THAT NHC AVERAGE TRACK
FORECAST ERRORS ARE 200 TO 300 MILES AT DAYS 4 AND 5.  GIVEN THIS
UNCERTAINTY...IT IS TOO SOON TO DETERMINE WHAT PORTION OF THE U.S.
EAST COAST MIGHT SEE DIRECT IMPACTS FROM EARL.


FORECAST POSITIONS AND MAX WINDS

INITIAL      30/1500Z 18.7N  63.6W   105 KT
12HR VT     31/0000Z 19.5N  65.1W   115 KT
24HR VT     31/1200Z 21.0N  67.0W   125 KT
36HR VT     01/0000Z 22.8N  68.7W   125 KT
48HR VT     01/1200Z 25.2N  70.6W   120 KT
72HR VT     02/1200Z 31.0N  73.5W   110 KT
96HR VT     03/1200Z 37.5N  71.5W   100 KT
120HR VT     04/1200Z 45.5N  63.0W    75 KT...INLAND

$$
FORECASTER BROWN/BERG




WTNT42 KNHC 302047
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST MON AUG 30 2010
 
THE RECONNAISSANCE AIRCRAFT MEASURED 116 KT FLIGHT-LEVEL WINDS AND
108 KT SFMR SURFACE WINDS SHORTLY AFTER 1500 UTC.  THIS WAS THE
BASIS FOR THE EARLIER INCREASE IN INTENSITY.  SINCE THAT TIME...THE
PRESSURE HAS CONTINUED TO DROP AND WAS DOWN TO 955 MB ON THE LAST
DROPSONDE RELEASED IN THE EYE AROUND 1700 UTC.  SINCE THE AIRCRAFT
DEPARTED EARL...THE EYE HAS CONTINUED TO CLEAR AND IS SURROUNDED BY
CLOUD TOPS TO -70 DEGREES CELSIUS OR COLDER.  OBJECTIVE SATELLITE
INTENSITY ESTIMATES HAVE INCREASED TO JUST ABOVE 6.0 ON THE DVORAK
SCALE AND SUPPORT AN INITIAL INTENSITY OF 115 KT...CATEGORY FOUR ON
THE SAFFIR-SIMPSON HURRICANE WIND SCALE.
 
EARL IS EXPECTED TO REMAIN IN A LOW SHEAR ENVIRONMENT AND OVER WARM
WATER DURING THE NEXT FEW DAYS AND SOME ADDITIONAL STRENGTHENING IS
LIKELY IN THE SHORT TERM.  THEREAFTER...EYEWALL CYCLES WILL LIKELY
INDUCE SOME FLUCTUATIONS IN INTENSITY...WHICH ARE DIFFICULT TO
PREDICT.  THE NHC FORECAST IS AGAIN NEAR THE HIGH END OF THE
INTENSITY GUIDANCE. AT DAYS 4 AND 5...THE HURRICANE IS FORECAST TO
MOVE OVER COOLER WATER AND INTO AN AREA OF INCREASING SHEAR WHICH
SHOULD RESULT IN WEAKENING.
 
THE INITIAL MOTION IS 290/13.  THE FORECAST REASONING REMAINS
UNCHANGED AS EARL IS EXPECTED TO TURN NORTHWESTWARD IN ABOUT 24
HOURS AROUND THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE. THE
TRACK GUIDANCE HAS SHIFTED NOTICEABLY WESTWARD DURING THE FIRST
48 HOURS...WITH THE GFS AND ECMWF ON THE EASTERN EDGE OF THE
ENVELOPE.  THE OFFICIAL FORECAST HAS BEEN ADJUSTED WESTWARD...
PRIMARILY THROUGH 72 HOURS...AND LIES BETWEEN THE GFS/ECMWF AND THE
MULTI-MODEL CONSENSUS.
  
THIS IS A GOOD TIME TO REMIND EVERYONE THAT NHC AVERAGE TRACK
FORECAST ERRORS ARE 200 TO 300 MILES AT DAYS 4 AND 5.  GIVEN THIS
UNCERTAINTY...IT IS TOO SOON TO DETERMINE WHAT PORTION OF THE U.S.
EAST COAST MIGHT SEE DIRECT IMPACTS FROM EARL.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/2100Z 19.3N  64.7W   115 KT
 12HR VT     31/0600Z 20.2N  66.3W   125 KT
 24HR VT     31/1800Z 21.7N  68.1W   130 KT
 36HR VT     01/0600Z 23.4N  70.1W   130 KT
 48HR VT     01/1800Z 25.8N  72.1W   125 KT
 72HR VT     02/1800Z 31.6N  74.7W   115 KT
 96HR VT     03/1800Z 38.0N  71.0W    95 KT
120HR VT     04/1800Z 45.5N  63.0W    70 KT...INLAND
 
$$
FORECASTER BROWN
 

WTNT42 KNHC 310250
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST MON AUG 30 2010
 
THE INTENSITY OF EARL APPEARS TO HAVE LEVELED OFF FOR THE TIME
BEING.  DROPSONDE MEASUREMENTS FROM THE AIR FORCE RESERVE HURRICANE
HUNTERS INDICATE LITTLE CHANGE IN CENTRAL PRESSURE OVER THE PAST
FEW HOURS.  THERE WAS ALSO AN UNFLAGGED SFMR-MEASURED SURFACE WIND
OF 111 KT.  THE CURRENT INTENSITY IS HELD AT 115 KT FOR THIS
ADVISORY.  WSR-88D RADAR DATA FROM SAN JUAN SUGGEST THAT A
CONCENTRIC EYEWALL OR CONVECTIVE RING MAY BE FORMING.  THIS WOULD
AT LEAST TEMPORARILY HALT FURTHER INTENSIFICATION.  WATER VAPOR
IMAGERY CONTINUES TO DEPICT A BROAD UPPER-LEVEL TROUGH TO THE
NORTHWEST OF THE HURRICANE.  GLOBAL MODELS FORECAST AN UPPER-LEVEL
LOW TO CUT OFF FROM THE TROUGH AND MOVE SOUTHWARD...WHICH IS AN
UPPER-LEVEL FLOW EVOLUTION THAT IS USUALLY CONDUCIVE FOR
STRENGTHENING.  HOWEVER THE GFS PREDICTS AROUND 18-20 KT OF
SOUTH-SOUTHWESTERLY VERTICAL SHEAR OVER EARL IN 24-48 HOURS.  THE
OFFICIAL INTENSITY FORECAST HAS BACKED OFF SOME FROM THE PREVIOUS
ONE...AND SHOWS ONLY SLIGHT STRENGTHENING OVER THE NEXT DAY OR SO. 
ALSO...SOME OSCILLATIONS IN INTENSIYY DUE TO EYEWALL REPLACEMENTS
OR OTHER INNER-CORE CONVECTIVE PROCESSES ARE ALSO POSSIBLE.
 
THERE HAVE BEEN SOME WOBBLES IN THE TRACK OF EARL BUT THE MEAN
MOTION HAS BEEN ABOUT 300/12 OVER THE PAST 6 HOURS.  A GRADUAL TURN
TOWARD THE NORTHWEST IS LIKELY IN 12 TO 24 HOURS AS EARL MOVES
AROUND THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE.  BY DAY
3...A GENERALLY NORTHWARD TRACK IS EXPECTED AS THE HURRICANE MOVES
ALONG THE WESTERN SIDE OF THE RIDGE.  A STRONG MID-TROPOSPHERIC
TROUGH MOVING THROUGH THE GREAT LAKES SHOULD PROVIDE AN EASTWARD
COMPONENT OF STEERING BY DAY 4...AND EARL IS LIKELY TO ACCELERATE
NORTH-NORTHEASTWARD AHEAD OF THE TROUGH NEAR THE END OF THE
FORECAST PERIOD.   THE TRACK GUIDANCE SUITE IS IN RATHER CLOSE
AGREEMENT UP TO 72 HOURS...BUT BECOMES MORE DIVERGENT AFTER THAT
FORECAST TIME.  THE OFFICIAL TRACK FORECAST IS...ONCE AGAIN...
SHIFTED SLIGHTLY WESTWARD FROM THE PREVIOUS ONE AND IS VERY CLOSE
TO THE MULTI-MODEL CONSENSUS.

INTERESTS FROM THE CAROLINAS NORTHWARD TO NEW ENGLAND SHOULD MONITOR
THE PROGRESS OF EARL.  THERE IS STILL CONSIDERABLE UNCERTAINTY AS
TO HOW CLOSE THE HURRICANE WILL COME TO THE U.S. EAST COAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/0300Z 19.9N  65.8W   115 KT
 12HR VT     31/1200Z 20.9N  67.2W   120 KT
 24HR VT     01/0000Z 22.6N  69.2W   120 KT
 36HR VT     01/1200Z 24.6N  71.4W   120 KT
 48HR VT     02/0000Z 26.9N  73.4W   120 KT
 72HR VT     03/0000Z 32.5N  75.0W   110 KT
 96HR VT     04/0000Z 38.5N  70.5W    90 KT
120HR VT     05/0000Z 46.0N  62.0W    60 KT
 
$$
FORECASTER PASCH
 

WTNT42 KNHC 310902
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM AST TUE AUG 31 2010

AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT EARLIER REPORTED
700 MB FLIGHT-LEVEL WINDS OF 124 KT...AND ESTIMATED SURFACE WINDS
OF 112 KT FROM THE SFMR.  THE PLANE ALSO REPORTED A CENTRAL
PRESSURE OF 931 MB.  BASED ON THIS...THE INITIAL INTENSITY IS SET
AT 115 KT.  SINCE THE PLANE LEFT...A TRMM OVERPASS AND DATA FROM
THE SAN JUAN WSR-88D RADAR INDICATE THAT EARL HAS STARTED AN
EYEWALL REPLACEMENT CYCLE.  ANOTHER HURRICANE HUNTER AIRCRAFT WILL
ARRIVE IN EARL NEAR 12Z TO DETERMINE IF IT HAS PEAKED IN INTENSITY
FOR NOW.
 
THE INITIAL MOTION IS A WOBBLY 295/11.  THERE IS LITTLE CHANGE TO
THE TRACK FORECAST PHILOSOPHY FROM THE PREVIOUS ADVISORY.  EARL
SHOULD MOVE GENERALLY NORTHWESTWARD FOR THE NEXT 48 HR OR SO ON THE
SOUTHWESTERN SIDE OF THE SUBTROPICAL RIDGE.  AFTER THAT...THE
HURRICANE SHOULD TURN NORTHWARD AROUND THE WESTERN END OF THE
RIDGE...FOLLOWED BY A TURN TO THE NORTH-NORTHEAST AND ACCELERATION
ON THE EAST SIDE OF A STRONG DEEP-LAYER TROUGH MOVING INTO THE
NORTHEASTERN UNITED STATES.  THE TRACK GUIDANCE IS TIGHTLY
CLUSTERED FOR THE FIRST 72 HR...WITH SOME SPREAD IN THE TRACK
DIRECTIONS BETWEEN THE LEFT-MOST HWRF AND THE RIGHT-MOST GFS
ENSEMBLE MEAN THEREAFTER.  THE NEW FORECAST TRACK IS AN UPDATE OF
THE PREVIOUS TRACK AND LIES JUST LEFT OF THE CENTER OF THE GUIDANCE
ENVELOPE.

THE INTENSITY FORECAST IS A LITTLE PROBLEMATIC.  THE GFDL AND GFDN
MODELS SUGGEST THAT EARL COULD STRENGTHEN DURING THE NEXT 24 HR OR
SO...AND THIS COULD OCCUR IF THE HURRICANE COMPLETES THE EYEWALL
REPLACEMENT QUICKLY ENOUGH.  ON THE OTHER HAND...EARL IS FORECAST
TO BE IN AN ENVIRONMENT OF MODERATE SOUTHWESTERLY VERTICAL WIND
SHEAR...AND WATER VAPOR IMAGERY SHOWS VERY DRY MID/UPPER-LEVEL AIR
APPROACHING THE HURRICANE FROM THE NORTH.  THESE FACTORS COULD
PREVENT ADDITIONAL STRENGTHENING.  THE INTENSITY FORECAST WILL
FOLLOW THE GFDL/GFDN SCENARIO WITH A LITTLE MORE STRENGTHENING
DURING THE NEXT 12-24 HR...BASED ON THE HURRICANE COMPLETING THE
EYEWALL REPLACEMENT AND THE DRY AIR NOT REACHING THE HURRICANE
CORE.  THE FORECAST TRACK TAKES EARL OVER COLDER SEA SURFACE
TEMPERATURES AND INTO INCREASING SHEAR AFTER 72 HR...WHICH SHOULD
CAUSE STEADY WEAKENING AND EVENTUAL EXTRATROPICAL TRANSITION.  
 
INTERESTS FROM THE CAROLINAS NORTHWARD TO NEW ENGLAND SHOULD MONITOR
THE PROGRESS OF EARL.  THERE IS STILL CONSIDERABLE UNCERTAINTY AS
TO HOW CLOSE THE HURRICANE WILL COME TO THE U.S. EAST COAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/0900Z 20.5N  66.7W   115 KT
 12HR VT     31/1800Z 21.4N  68.2W   120 KT
 24HR VT     01/0600Z 23.3N  70.3W   120 KT
 36HR VT     01/1800Z 25.5N  72.3W   120 KT
 48HR VT     02/0600Z 28.0N  73.8W   115 KT
 72HR VT     03/0600Z 33.5N  74.5W   105 KT
 96HR VT     04/0600Z 40.0N  69.5W    85 KT
120HR VT     05/0600Z 48.0N  60.5W    60 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 311457
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST TUE AUG 31 2010
 
THE EYE HAS BECOME OBSCURED ON VISIBLE IMAGES AND THIS IS REFLECTED
IN A DECREASE IN THE DVORAK NUMBERS AND IN AN INCREASE IN THE
PRESSURE TO 939 MB. THIS APPARENT WEAKENING IS MOST LIKELY RELATED
TO AN ONGOING EYEWALL REPLACEMENT CYCLE AS INDICATED BY THE DOUBLE
EYE STRUCTURE OBSERVED ON MICROWAVE DATA AT 1035 UTC. HOWEVER...AN
AVERAGE OF THE FLIGHT-LEVEL WINDS AND SFMR DATA FROM THE AIR FORCE
RECONNAISSANCE PLANE STILL SUPPORTS AN INITIAL INTENSITY OF 115
KNOTS. NO CHANGE IN INTENSITY IS EXPECTED TODAY BUT THERE IS A
CHANCE FOR EARL TO STRENGTHEN A LITTLE DURING THE NEXT 24 HOURS IF
THE OUTER EYEWALL SHRINKS. DESPITE THE FLUCTUATIONS IN INTENSITY...
EARL MOST LIKELY WILL RETAIN CATEGORY FOUR STATUS FOR THE NEXT 48
HOURS. A GRADUAL WEAKENING SHOULD BEGIN THEREAFTER AS THE SHEAR
INCREASES.
 
EARL HAS CONTINUED TO WOBBLE DURING THE PAST FEW HOURS BUT THE
AVERAGE MOTION IS TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 12
KNOTS. EARL HAS BEEN STEERED BY THE FLOW AROUND A SUBTROPICAL RIDGE
EXTENDING FROM THE EASTERN UNITED STATES EASTWARD ACROSS THE
ATLANTIC. THIS PATTERN WILL KEEP EARL ON A GENERAL WEST-NORTHWEST
TO NORTHWEST TRACK DURING THE NEXT 24 TO 48 HOURS. THEREAFTER...THE
SUBTROPICAL RIDGE WILL MOVE EAST AND EARL WILL LIKELY TURN NORTH AND
NORTHEAST BETWEEN THE RIDGE AND MID-LEVEL TROUGH OVER THE EASTERN
UNITED STATES. THIS IS THE SCENARIO PROVIDED BY MOST OF THE
DYNAMICAL MODELS. THE OFFICIAL FORECAST HAS SHIFTED A LITTLE TO THE
WEST BEFORE 48 HOURS AND IS ON THE WESTERN EDGE OF THE GUIDANCE
ENVELOPE.
 
GIVEN THE TRACK AND THE LARGE AREA OF TROPICAL STORM FORCE WINDS...A
HURRICANE WATCH WILL LIKELY BE REQUIRED FOR A PORTION OF THE
MID-ATLANTIC COAST LATER TODAY. INTERESTS FROM THE CAROLINAS
NORTHWARD TO NEW ENGLAND SHOULD MONITOR THE PROGRESS OF EARL.
THERE IS STILL CONSIDERABLE UNCERTAINTY AS TO HOW CLOSE THE
HURRICANE WILL COME TO THE U.S. EAST COAST.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/1500Z 21.2N  67.9W   115 KT
 12HR VT     01/0000Z 22.3N  69.7W   115 KT
 24HR VT     01/1200Z 24.8N  71.7W   120 KT
 36HR VT     02/0000Z 27.3N  73.5W   115 KT
 48HR VT     02/1200Z 30.5N  75.0W   115 KT
 72HR VT     03/1200Z 36.5N  73.0W   100 KT
 96HR VT     04/1200Z 43.5N  66.0W    80 KT
120HR VT     05/1200Z 52.5N  57.0W    55 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 312043
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM AST TUE AUG 31 2010
 
ALTHOUGH THE SATELLITE PRESENTATION IS NOT AS IMPRESSIVE AS IT WAS
EARLIER...A RECONNAISSANCE PLANE AROUND 1700 UTC REPORTED A MINIMUM
PRESSURE OF 940 MB AND MAXIMUM FLIGHT-LEVEL WINDS OF 128 KNOTS.
THESE DATA SUPPORT AN INITIAL INTENSITY OF 115 KNOTS.
CURRENTLY...THERE IS SOME SOUTHWESTERLY SHEAR DISRUPTING THE
UPPER-LEVEL OUTFLOW OVER THE WESTERN SEMICIRCLE OF EARL.  THIS SHEAR
IS CAUSED BY A WEAK UPPER-LOW OR TROUGH OVER THE EASTERN BAHAMAS AS
OBSERVED ON WATER VAPOR IMAGES.  HOWEVER...MODELS WEAKEN THE UPPER
LOW AS EARL MOVES AROUND IT...RESULTING IN A MORE FAVORABLE
ENVIRONMENT. EARL IS EXPECTED TO MAINTAIN ITS CATEGORY FOUR
INTENSITY FOR THE NEXT DAY OR TWO.
 
EARL HAS BEGUN TO MOVE TOWARD THE NORTHWEST OR 305 DEGREES AT 12 OR
13 KNOTS DURING THE PAST FEW HOURS. THE SUBTROPICAL HIGH THAT IS
STEERING EARL TOWARD THE WEST-NORTHWEST OR NORTHWEST IS FORECAST TO
GRADUALLY SHIFT EASTWARD AS A BROAD TROUGH BECOMES ESTABLISHED OVER
THE EASTERN UNITED STATES. THIS PATTERN WILL FORCE EARL ON A MORE
NORTHWESTERLY AND NORTHERLY TRACK FOR THE NEXT DAY OR TWO.
THEREAFTER...EARL WILL REACH THE BASE OF THE MID-LATITUDE WESTERLIES
AND WILL LIKELY TURN SHARPLY TO THE NORTHEAST WITH AN INCREASE IN
FORWARD SPEED.  THIS IS THE SOLUTION UNANIMOUSLY PROVIDED BY TRACK
GUIDANCE.  ONCE AGAIN THE OFFICIAL FORECAST HAS BEEN SHIFTED A FEW
MILES TO THE WEST BEFORE 48 HOURS FOLLOWING THE TRENDS OF THE ECMWF
AND THE GFS.

GIVEN THE LARGE AREA OF TROPICAL STORM FORCE WINDS ASSOCIATED WITH
EARL...AND THE NEW DEFINITION OF WATCHES AND WARNINGS...A HURRICANE
AND TROPICAL STORM WATCH HAS BEEN ISSUED FOR A PORTION OF THE MID-
ATLANTIC COAST.

INTERESTS FROM VIRGINIA NORTHWARD TO NEW ENGLAND SHOULD MONITOR THE
PROGRESS OF EARL. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/2100Z 22.0N  68.8W   115 KT
 12HR VT     01/0600Z 23.3N  70.5W   115 KT
 24HR VT     01/1800Z 25.6N  72.8W   115 KT
 36HR VT     02/0600Z 28.0N  74.5W   115 KT
 48HR VT     02/1800Z 31.0N  75.5W   115 KT
 72HR VT     03/1800Z 36.0N  73.5W    95 KT
 96HR VT     04/1800Z 44.0N  65.0W    75 KT
120HR VT     05/1800Z 56.0N  55.0W    50 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 010248
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  27
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM AST TUE AUG 31 2010

EARL REMAINS A WELL-ORGANIZED HURRICANE ON SATELLITE IMAGES.  AN EYE
OF ABOUT 20 N MI IN DIAMETER IS EVIDENT ON THE INFRARED IMAGES...
AND THE UPPER-LEVEL OUTFLOW IS WELL-DEFINED OVER ALL BUT THE
SOUTHWEST PART OF THE CIRCULATION...AS CONFIRMED BY SURVELLIANCE
DATA FROM THE NOAA G-IV JET THIS EVENING.  THE INITIAL INTENSITY IS
KEPT AT 115 KT BASED ON A DVORAK ESTIMATE FROM TAFB.  THERE IS
CURRENTLY ABOUT 20 KT OF SOUTHWESTERLY SHEAR OVER EARL AS DEPICTED
BY UW-CIMSS ANALYSES.  THIS SHEAR SHOULD LESSEN AS AN UPPER-LEVEL
TROUGH...JUST TO THE WEST AND NORTHWEST OF THE HURRICANE...IS
PREDICTED BY THE GLOBAL MODELS TO SHIFT WESTWARD OVER THE NEXT DAY
OR SO.  THIS EVOLUTION OF THE UPPER-LEVEL ENVIRONMENT SHOULD ALLOW
EARL TO MORE OR LESS MAINTAIN ITS INTENSITY FOR ABOUT THE NEXT 36
HOURS.  THE NHC INTENSITY FORECAST IS ONLY A LITTLE ABOVE THE
STATISTICAL/DYNAMICAL LGEM GUIDANCE AND A LITTLE BELOW THE GFDL
HURRICANE MODEL GUIDANCE.  BY DAY 4...GLOBAL MODELS SHOW EARL
BECOME EMBEDDED WITHIN A BAROCLINIC ZONE WITH WELL-DEFINED THERMAL
ADVECTION SO EXTRATROPICAL TRANSITION SHOULD HAVE OCCURRED BY THAT
TIME.

THE TRACK HAS BEEN WOBBLING AS IS TYPICAL OF INTENSE HURRICANES BUT
THE MEAN MOTION OVER THE PAST 6 HOURS IS ABOUT 310/13.  THERE HAS
BEEN LITTLE CHANGE TO THE NHC FORECAST TRACK OR REASONING.  EARL IS
EXPECTED TO GRADUALLY TURN TO THE RIGHT AS IT MOVES AROUND THE
WESTERN PERIPHERY OF A MID-LEVEL SUBTROPICAL ANTICYCLONE FOR THE
NEXT COUPLE OF DAYS.  AFTERWARDS...A VIGOROUS MID-LATITUDE TROUGH
AT 500 MB WILL APPROACH THE EAST COAST AND SHOULD CAUSE THE
HURRICANE TO TURN TOWARD THE NORTH-NORTHEAST.  OF COURSE...THE
TIMING OF THIS TURN IS CRITICAL IN DETERMINING HOW CLOSE THE CENTER
WILL COME TO THE U.S. EAST COAST.  ONE SHOULD NOT FOCUS ON THE
EXACT FORECAST TRACK BECAUSE OF FORECAST UNCERTAINTY...AND ALSO
BECAUSE EARL IS A LARGE HURRICANE AND SIGNIFICANT IMPACTS CAN BE
WELL REMOVED FROM THE CENTER.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/0300Z 23.0N  69.9W   115 KT
 12HR VT     01/1200Z 24.5N  71.6W   115 KT
 24HR VT     02/0000Z 27.0N  73.5W   115 KT
 36HR VT     02/1200Z 29.8N  75.0W   115 KT
 48HR VT     03/0000Z 32.7N  75.2W   110 KT
 72HR VT     04/0000Z 39.0N  70.5W    90 KT
 96HR VT     05/0000Z 47.0N  62.0W    75 KT...POST-TROP/EXTRATROP
120HR VT     06/0000Z 56.0N  58.0W    50 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER PASCH/KIMBERLAIN
 

WTNT42 KNHC 010903
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM EDT WED SEP 01 2010
 
THE EYE OF EARL HAS BECOME LESS DISTINCT IN SATELLITE IMAGERY DURING
THE PAST FEW HOURS...AND THE EYEWALL CLOUD TOPS HAVE WARMED A
LITTLE.  AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT REPORTED A
CENTRAL PRESSURE OF 941 MB...WHICH IS LITTLE CHANGED FROM EARLIER. 
HOWEVER...THE MAXIMUM FLIGHT-LEVEL WINDS WERE 116 KT...WHICH WAS
LOWER THAN THE PREVIOUS MISSION...AND SURFACE WIND ESTIMATES FROM
THE SFMR WERE UNDER 100 KT.  THE INITIAL INTENSITY IS DECREASED TO
110 KT...AND THIS COULD BE A LITTLE GENEROUS.

EARL IS MOVING 310-315 DEGREES AT ABOUT 14 KT.  FOR THE NEXT 36 OR
SO...THE HURRICANE SHOULD CONTINUE TO MOVE GENERALLY NORTHWESTWARD
ON THE SOUTHWESTERN SIDE OF A LOW/MID-LEVEL RIDGE OVER THE CENTRAL
ATLANTIC.  AFTER THAT...EARL IS EXPECTED TO TURN NORTHWARD AND THEN
NORTH-NORTHEASTWARD AS IT ROUNDS THE END OF THE RIDGE AND ENTERS
THE WESTERLIES ASSOCIATED WITH A DEEP-LAYER TROUGH MOVING INTO THE
NORTHEASTERN UNITED STATES.  THE TRACK GUIDANCE IS IN GOOD
AGREEMENT WITH THIS SCENARIO.  HOWEVER...THERE ARE SOME SMALL
DIFFERENCE IN THE MODEL GUIDANCE THAT COULD HAVE LARGE IMPLICATIONS
IN TERMS OF IMPACTS.  THE GFDN...NOGAPS...AND UKMET FORECAST THE
CENTER TO PASS NEAR OR OVER THE NORTH CAROLINA COAST AND NEW
ENGLAND.  THE OTHER MODELS ARE FARTHER TO THE EAST...KEEPING THE
CENTER OFFSHORE.  THROUGH 48 HR...THE NEW FORECAST TRACK IS SIMILAR
TO THE PREVIOUS TRACK...KEEPS THE CENTER OFF THE NORTH CAROLINA
COAST...AND LIES JUST WEST OF THE CENTER OF THE GUIDANCE ENVELOPE. 
AFTER 48 HR...THE GUIDANCE ENVELOPE HAS SHIFTED A LITTLE TO THE
WEST...AND THE NEW FORECAST TRACK DOES LIKEWISE TO BE IN THE CENTER
OF THE ENVELOPE.  THIS PART OF THE TRACK IS CLOSER TO THE NEW
ENGLAND STATES THAN THE PREVIOUS FORECAST.

THE INTENSITY FORECAST IS A CONUNDRUM.  ON THE FAVORABLE SIDE...THE
HURRICANE IS OVER VERY WARM SEA SURFACE TEMPERATURES...HAS GOOD
CIRRUS OUTFLOW IN ALL DIRECTIONS EXCEPT TO THE SOUTH...AND HAS A
GOOD CONVECTIVE STRUCTURE.  ON THE NEGATIVE SIDE...EARL IS
EXPERIENCING 15-20 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR...AND
WATER VAPOR IMAGERY SHOWS A TONGUE OF MID/UPPER-LEVEL DRY AIR
WRAPPED MORE THAN HALFWAY AROUND THE CYCLONE.  SOME SHEAR IS LIKELY
TO CONTINUE FOR THE NEXT 36-48 HR...AND NONE OF THE INTENSITY
GUIDANCE CALLS FOR MUCH STRENGTHENING AT THIS TIME.  BASED ON
THIS...THE NHC INTENSITY FORECAST CALLS FOR LITTLE CHANGE IN
STRENGTH FOR 36 HR...FOLLOWED BY WEAKENING AS EARL ENCOUNTERS
COOLER SEA SURFACE TEMPERATURES AND INCREASING SHEAR.  EARL IS
EXPECTED TO BECOME EXTRATROPICAL BY 96 HR.  
 
HURRICANE WARNINGS WILL LIKELY BE REQUIRED FOR PORTIONS OF THE NORTH
CAROLINA COAST LATER THIS MORNING.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/0900Z 24.0N  71.2W   110 KT
 12HR VT     01/1800Z 25.8N  72.9W   110 KT
 24HR VT     02/0600Z 28.5N  74.6W   110 KT
 36HR VT     02/1800Z 31.3N  75.2W   110 KT
 48HR VT     03/0600Z 34.6N  74.4W   105 KT
 72HR VT     04/0600Z 42.0N  68.0W    85 KT
 96HR VT     05/0600Z 50.0N  61.5W    60 KT...POST-TROP/EXTRATROP
120HR VT     06/0600Z 57.0N  58.0W    45 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 011455
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  29
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM EDT WED SEP 01 2010
 

VISIBLE SATELLITE IMAGES THIS MORNING SHOW THAT EARL HAS A DISTINCT
EYE SURROUNDED BY MODERATE TO STRONG CONVECTION. A BLEND BETWEEN
SATELLITE INTENSITY ESTIMATES AND DATA FROM A NOAA RECONNAISSANCE
PLANE SUGGEST THAT WINDS ARE STILL 110 KNOTS.  GIVEN THE CURRENT
SATELLITE PRESENTATION...WHICH SHOWS A DECREASE IN THE SHEAR SINCE
YESTERDAY AND THE WARM OCEAN ALONG THE TRACK OF EARL...THERE IS A
POSSIBILITY THAT THE HURRICANE COULD REGAIN SOME INTENSITY.
HOWEVER...MOST OF THE GUIDANCE WITH THE EXCEPTION OF THE GFDL MODEL 
SHOWS A STEADY STATE OR GRADUAL WEAKENING DURING THE NEXT DAY OR
TWO...AND THIS TREND IS FOLLOWED IN THE OFFICIAL FORECAST. AFTER
48 HOURS...EARL SHOULD BEGIN TO MOVE OVER COOLER WATERS AND
ENCOUNTER INCREASING SHEAR RESULTING IN WEAKENING. BY DAY 5 THE
HURRICANE SHOULD HAVE BEEN ABSORBED BY A LARGE EXTRATROPICAL
CYCLONE WELL NORTH OF CANADA.      

SATELLITE AND RECONNAISSANCE AIRCRAFT FIXES INDICATE THAT THE
INITIAL MOTION IS TOWARD THE NORTHWEST OR 320 DEGREES AT 15 KNOTS.
THE SUBTROPICAL RIDGE THAT HAS BEEN STEERING EARL TOWARD THE
NORTHWEST IS ALREADY SHIFTING EASTWARD...AND LATER TODAY...EARL
SHOULD BE ON THE WESTERN SIDE OF THE RIDGE TURNING GRADUALLY
NORTHWARD. IN 36 HOURS OR SO...THE HURRICANE WILL ENCOUNTER THE
BASE OF THE MID-LATITUDE WESTERLIES AND SHOULD BEGIN TO RECURVE OR
TURN TO THE NORTHEAST WITH AN INCREASING FORWARD SPEED. THIS IS THE
SOLUTION UNANIMOUSLY PROVIDED BY TRACK MODELS...WHICH HAVE EARL
PASSING TO THE EAST BUT NOT FAR FROM THE OUTER BANKS OF NORTH
CAROLINA BETWEEN 36 AND 48 HOURS. ONLY A SMALL WESTWARD DEVIATION
TO THE TRACK TO THE WEST WOULD BRING THE CORE OF THE HURRICANE 
TO THE COAST.

GIVEN THE FORECAST TRACK AND THE LARGE WIND RADII ASSOCIATED WITH A
EARL...A HURRICANE WARNING WAS REQUIRED FOR A PORTION OF THE NORTH
CAROLINA COAST.  
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/1500Z 25.1N  72.1W   110 KT
 12HR VT     02/0000Z 27.0N  73.7W   110 KT
 24HR VT     02/1200Z 29.8N  75.0W   110 KT
 36HR VT     03/0000Z 32.8N  75.2W   110 KT
 48HR VT     03/1200Z 36.0N  73.6W   100 KT
 72HR VT     04/1200Z 44.0N  66.0W    70 KT
 96HR VT     05/1200Z 55.0N  60.0W    50 KT...POST-TROP/EXTRATROP
120HR VT     06/1200Z...ABSORBED BY A LARGER EXTRATROPICAL CYCLONE
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 012051
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM EDT WED SEP 01 2010
 
VISIBLE SATELLITE IMAGES INDICATE THAT THE EYE HAS BECOME VERY
DISTINCT...WITH OJECTIVE T-NUMBERS OSCILLATING AROUND 6.0 FOR THE
PAST FEW HOURS. AN AIR FORCE PLANE MEASURED FLIGHT-LEVEL WINDS OF
138 KNOTS AND A MINIMUM PRESSURE OF 941 MB IN THE LAST FIX.
HOWEVER...SFMR MEASUREMENTS WERE A LITTLE LOWER. A COMPROMISE OF
THESE DATA SUPPORTS AN INITIAL INTENSITY OF 115 KNOTS.
HOWEVER...EARL COULD FLUCTUATE IN INTENSITY DURING THE NEXT 12 TO
24 HOURS BUT SHOULD BEGIN TO GRADUALLY WEAKEN AS IT REACHES
COOLER WATERS AND MOVES INTO HIGHER SHEAR BEYOND 36 HOURS. BY DAY 5
THE HURRICANE SHOULD HAVE BEEN ABSORBED BY A LARGE EXTRATROPICAL
CYCLONE WELL NORTH OF CANADA.
 
SATELLITE AND RECONNAISSANCE AIRCRAFT FIXES INDICATE THAT EARL
HAS BEEN MOVING RELENTLESSLY TOWARD THE NORTHWEST OR 310 DEGREES
AT 15 KNOTS. THE HURRICANE IS ABOUT TO REACH THE WESTERN EDGE OF
THE SUBTROPICAL RIDGE AND SHOULD BEGIN TO TURN MORE TO THE
NORTH-NORTHWEST AND NORTH LATER TONIGHT AND THURSDAY. IN ABOUT 36
HOURS OR SO...THE HURRICANE WILL ENCOUNTER THE BASE OF THE
MID-LATITUDE WESTERLIES AND SHOULD BEGIN TO RECURVE OR TURN TO THE
NORTHEAST WITH AN INCREASING FORWARD SPEED. THIS IS THE SOLUTION
CONSISTENTLY PROVIDED BY TRACK MODELS...WHICH HAVE EARL PASSING TO
THE EAST BUT NOT FAR FROM THE OUTER BANKS OF NORTH CAROLINA ON
THURSDAY NIGHT. ONLY A SMALL WESTWARD DEVIATION OF THE TRACK TO THE
WEST WOULD BRING THE CORE OF THE HURRICANE TO THE COAST.
 
GIVEN THE FORECAST TRACK...THE LARGE SIZE OF THE WIND FIELD...AND
THE EXPECTED INCREASE IN FORWARD SPEED WATCHES AND WATCHES HAVE
BEEN EXTENDED NORTHWARD ALONG THE EAST COAST OF THE UNITED STATES.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/2100Z 26.3N  73.3W   115 KT
 12HR VT     02/0600Z 28.4N  74.7W   115 KT
 24HR VT     02/1800Z 31.7N  75.4W   110 KT
 36HR VT     03/0600Z 35.1N  74.7W   100 KT
 48HR VT     03/1800Z 38.5N  72.2W    90 KT
 72HR VT     04/1800Z 46.5N  63.5W    60 KT
 96HR VT     05/1800Z 58.0N  57.0W    40 KT...POST-TROP/EXTRATROP
120HR VT     06/1800Z...DISSIPATED
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 020259
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  31
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM EDT WED SEP 01 2010
 
ENHANCED INFRARED SATELLITE IMAGERY SHOWS THAT THE EYE OF EARL HAS
BECOME MORE WELL-DEFINED AND THE CLOUD TOPS IN THE EYEWALL HAVE
COOLED.  A NOAA HURRICANE HUNTER AIRCRAFT INVESTIGATING THE
HURRICANE FOUND THAT THE CENTRAL PRESSURE HAS FALLEN
SIGNIFICANTLY...AND THEY MEASURED WINDS TO 137 KT JUST NORTH OF THE
CENTER AT A FLIGHT LEVEL JUST BELOW 7000 FT.  REDUCING THIS WIND
SPEED FROM THE AIRCRAFT FLIGHT LEVEL TO THE SURFACE YIELDS ABOUT
120 KT...AND THAT WILL BE THE ADVISORY INTENSITY.  SOME
FLUCTUATIONS IN INTENSITY DUE TO INNER CORE CHANGES ARE LIKELY ON
THURSDAY.  EARL SHOULD REMAIN IN A LOW-SHEAR ENVIRONMENT FOR ABOUT
ANOTHER 24 HOURS...THEREFORE GRADUAL WEAKENING SHOULD COMMENCE IN A
DAY OR SO.  HOWEVER...EARL IS LIKELY TO MAINTAIN MAJOR HURRICANE
STATUS WHEN IT IS NEAREST TO...OR POSSIBLY OVER...THE OUTER BANKS.
THE OFFICIAL INTENSITY FORECAST IS RATHER CLOSE TO THE LATEST
STATISTICAL/DYNAMICAL MODEL GUIDANCE.
 
THE EYE OF THE HURRICANE WOBBLED NORTHWARD A COUPLE OF HOURS
AGO...HOWEVER THE MEAN MOTION APPEARS TO BE ABOUT 330/16. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST TRACK OR
SYNOPTIC REASONING FROM THE PREVIOUS ADVISORY PACKAGE...ALTHOUGH
THE MULTI-MODEL CONSENSUS FORECAST HAS NUDGED EASTWARD ABOUT 20 N
MI ON THIS CYCLE. EARL IS EXPECTED TO GRADUALLY TURN TOWARD THE
NORTH AND SLIGHTLY EAST OF NORTH AS IT MOVES ALONG THE WESTERN
PERIPHERY OF THE SUBTROPICAL RIDGE FOR THE NEXT DAY OR SO.
THEREAFTER...A STRONG 500 MB TROUGH MOVING THROUGH THE GREAT LAKES
SHOULD CAUSE THE HURRICANE TO TURN TOWARD THE NORTH-NORTHEAST AND
ACCELERATE.  ONE SHOULD NOT FOCUS ON THE EXACT FORECAST TRACK OF
THIS LARGE AND INTENSE HURRICANE.  SIGNIFICANT IMPACTS ARE LIKELY
TO BE FELT WELL AWAY FROM THE CENTER. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/0300Z 27.8N  73.8W   120 KT
 12HR VT     02/1200Z 30.0N  75.1W   120 KT
 24HR VT     03/0000Z 33.2N  75.2W   110 KT
 36HR VT     03/1200Z 36.5N  73.7W   100 KT
 48HR VT     04/0000Z 40.0N  70.7W    85 KT
 72HR VT     05/0000Z 48.5N  61.5W    55 KT...POST-TROP/EXTRATROP
 96HR VT     06/0000Z 57.0N  57.0W    40 KT...POST-TROP/EXTRATROP
120HR VT     07/0000Z...DISSIPATED
 
$$
FORECASTER PASCH
 

WTNT42 KNHC 020907
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  32
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM EDT THU SEP 02 2010

AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT REPORTED 140 KT WINDS
AT 700 MB IN THE NORTHEASTERN EYEWALL.  AN EYE DROPSONDE REPORTED A
SURFACE PRESSURE OF 929 MB WITH A WIND OF 25 KT...SUGGESTING A
CENTRAL PRESSURE NEAR 928 MB.  BASED ON THIS...THE INITIAL
INTENSITY IS INCREASED TO 125 KT.  EARL IS LIKELY NEAR PEAK
INTENSITY AT THIS TIME...AS THE EYEWALL CONVECTION IS BECOMING A
LITTLE LESS ORGANIZED IN SATELLITE IMAGERY.

THE INITIAL MOTION IS 330/16.  THERE IS LITTLE CHANGE TO EITHER THE
FORECAST PHILOSOPHY OF THE TRACK FORECAST FOR THE FIRST 48 HR. 
EARL SHOULD TURN NORTHWARD AND NORTH-NORTHEASTWARD AS IT ROUNDS THE
END OF THE SUBTROPICAL RIDGE AND ENTERS THE WESTERLIES.  THE TRACK
MODEL GUIDANCE IS TIGHTLY CLUSTERED AROUND THIS SOLUTION...AND THE
NEW TRACK IS DOWN THE MIDDLE OF THE CLUSTER.  AFTER 48 HR...THE
GUIDANCE HAS SHIFTED TO THE LEFT DUE TO CHANGES IN THE INTERACTION
OF EARL WITH A STRONG WESTERLY TROUGH DURING EXTRATROPICAL
TRANSITION.  THE 48-72 HR TRACK HAS BEEN SHIFTED TO THE LEFT...BUT
STILL LIES ON THE RIGHT SIDE OF THE GUIDANCE ENVELOPE.

THE INTENSITY GUIDANCE SUGGESTS EARL SHOULD MAINTAIN ITS CURRENT
INTENSITY FOR 12 HR OR SO.  AFTER THAT...INCREASING VERTICAL WIND
SHEAR AND MOTION OVER DECREASING SEA SURFACE TEMPERATURES SHOULD
CAUSE STEADY WEAKENING.  EXTRATROPICAL TRANSITION SHOULD BEGIN AT
ABOUT 48 HR AND BE COMPLETE BY 72 HR...WITH THE REMNANTS OF EARL
BEING ABSORBED INTO A LARGER BAROCLINIC LOW BY 96 HR.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/0900Z 29.3N  74.7W   125 KT
 12HR VT     02/1800Z 31.7N  75.3W   125 KT
 24HR VT     03/0600Z 34.8N  74.6W   115 KT
 36HR VT     03/1800Z 38.1N  72.6W   100 KT
 48HR VT     04/0600Z 41.6N  69.2W    85 KT
 72HR VT     05/0600Z 50.5N  62.5W    50 KT...POST-TROP/EXTRATROP
 96HR VT     06/0600Z...ABSORBED BY EXTRATROPICAL LOW
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 021456
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  33
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM EDT THU SEP 02 2010

THERE HAS BEEN NO SIGNIFICANT CHANGES IN THE STRUCTURE OF EARL
DURING THE PAST FEW HOURS.  HOWEVER..MICROWAVE INAGERY SUGGEST THAT
AN EYEWALL REPLACEMENT COULD OCCUR SOON...IN WHICH CASE THE WIND
FIELD WOULD BECOME LARGER.  THE HURRICANE CONTINUES WITH A DISTINCT
EYE SURROUNDED BY DEEP CONVECTION.  SATELLITE INTENSITY ESTIMATES
AND DATA FROM A RECONNAISSANCE AIRCRAFT A FEW HOURS AGO INDICATE
THAT THE INITIAL INTENSITY IS 120 KNOTS.  EARL PROBABLY HAS ALREADY
REACHED ITS PEAK INTENSITY AND IT SHOULD SOON BEGIN TO WEAKEN
GRADUALLY AS THE SHEAR INCREASES. THE HURRICANE SHOULD WEAKEN EVEN
FASTER AFTER 36 HOURS...AS IT MOVES OVER A COLDER OCEAN.  EARL
SHOULD BECOME EXTRATROPICAL BY 72 HOURS AND DISSIPATE THEREAFTER AS
IT BECOMES ABSORBED BY A MUCH LARGER EXTRATROPICAL CYCLONE. 

AS ANTICIPATED...EARL HAS BEGUN TO MOVE NORTHWARD OR 355 DEGREES AT
16 KNOTS.  SINCE THE STEERING PATTERN HAS NOT CHANGED...EARL IS
FORECAST TO CONTINUE NORTHWARD TODAY. IN ABOUT 24 HOURS...THE
HURRICANE SHOULD BE ENCOUNTERING THE BASE OF THE MID-LATITUDE
WESTERLIES AND EARL SHOULD THEN TURN MORE TOWARD THE NORTH-NORTHEAST
AND NORTHEAST WITH AN INCREASE IN FORWARD SPEED.  THIS SHARP TURN
HAS BEEN CONSISTENTLY INDICATED FOR THE PAST COUPLE OF DAYS IN THE
OFFICIAL FORECAST AND BY THE TIGHTLY CLUSTERED TRACK GUIDANCE.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/1500Z 30.9N  74.8W   120 KT
 12HR VT     03/0000Z 33.5N  75.0W   115 KT
 24HR VT     03/1200Z 36.5N  73.5W   100 KT
 36HR VT     04/0000Z 40.0N  70.8W    85 KT
 48HR VT     04/1200Z 44.0N  67.0W    65 KT
 72HR VT     05/1200Z 53.5N  62.0W    40 KT...POST-TROP/EXTRATROP
 96HR VT     06/1200Z...ABSORBED BY A LARGE EXTRATROPICAL LOW
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 022039
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  34
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM EDT THU SEP 02 2010
 
DATA FROM A RECONNAISSANCE PLANE INDICATE THAT EARL HAS WEAKENED A
LITTLE BIT THIS AFTERNOON.  THE CENTRAL PRESSURE ROSE TO 947
MB...AND A BLEND OF THE SFMR MEASUREMENTS AND FLIGHT-LEVEL WINDS
SUGGEST THAT THE INITIAL INTENSITY HAS DECREASED TO 100 KNOTS. EARL
SHOULD CONTINUE TO WEAKEN GRADUALLY AS THE SHEAR INCREASES AND THE
HURRICANE SHOULD WEAKEN EVEN FASTER AFTER 24 HOURS AS IT MOVES OVER
A COLDER OCEAN.  AFTER CROSSING CANADA IN 48 HOURS...EARL SHOULD
BECOME POST-TROPICAL/EXTRATROPICAL AND THEN DISSIPATE AS IT IS
ABSORBED BY A MUCH LARGER EXTRATROPICAL CYCLONE.
 
SATELLITE AND RECONNAISSANCE FIXES SHOW...AS ANTICIPATED...THAT EARL
HAS TURNED NORTHWARD AND IS MOVING 360 DEGREES AT 16 KNOTS. THE
STEERING PATTERN CONTROLLING THE MOTION OF EARL...AND THE
CONSISTENCY IN TRACK GUIDANCE...HAVE BEEN ADEQUATELY DESCRIBED IN
PREVIOUS DISCUSSIONS. EARL IS ABOUT TO BECOME EMBEDDED IN THE
MID-LATITUDE FLOW AND IT IS READY TO GRADUALLY TURN TO THE
NORTH-NORTHEAST AND NORTHEAST WITH AN INCREASE IN FORWARD SPEED. 

ALTHOUGH THE MAXIMUM WINDS IN THE CORE HAVE DECREASED...EARL
CONTINUES TO BE A LARGE AND POWERFUL HURRICANE. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/2100Z 32.5N  75.2W   100 KT
 12HR VT     03/0600Z 34.8N  74.8W    95 KT
 24HR VT     03/1800Z 38.0N  72.7W    85 KT
 36HR VT     04/0600Z 41.7N  69.0W    75 KT
 48HR VT     04/1800Z 46.5N  64.5W    50 KT...POST-TROP/EXTRATROP
 72HR VT     05/1800Z...DISSIPATED
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 030241
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  35
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM EDT THU SEP 02 2010
 
DATA FROM AIRCRAFT RECONNAISSANCE THIS EVENING SHOW THAT EARL HAS
CONTINUED TO SLOWLY WEAKEN...AS THE PRESSURE HAS RISEN TO 951 MB.
THE MAXIMUM FLIGHT LEVEL WIND WAS 111 KT...HOWEVER THE HIGHEST
SURFACE WIND MEASURED RECENTLY BY THE SFMR WAS 84 KT...AND DROPSONDE
DATA ARE CONSISTENT WITH SURFACE WINDS IN THE 80 TO 90 KT RANGE.
BASED ON A BLEND OF THESE DATA...THE INITIAL INTENSITY IS SET TO 90
KT FOR THIS ADVISORY.  THE AIRCRAFT DATA ALONG WITH MICROWAVE
IMAGERY SHOW THAT THE OLD INNER EYEWALL HAS DISSIPATED...AND A
LARGER 50 N MI WIDE EYE IS NOW REPORTED BY THE AIRCRAFT AND VISIBLE
IN RADAR IMAGERY FROM MOREHEAD CITY.  SOUTHWESTERLY SHEAR OF 15 TO
20 KNOTS IS CURRENTLY ANALYZED OVER THE CYCLONE BY UW-CIMSS AND THE
SHIPS MODEL...AND OUTFLOW IS NOW RESTRICTED IN THE SOUTHWEST
QUADRANT. EARL SHOULD CONTINUE TO SLOWLY WEAKEN AS IT MOVES
NORTHWARD OVER COOLER WATERS AND SHEAR INCREASES.  MODEL FIELDS AND
CYCLONE PHASE SPACE DIAGRAMS SHOW EARL BECOMING EXTRATROPICAL BY 48
HOURS...AND BEING ABSORBED BY A LARGER EXTRATROPICAL CYCLONE BY 72
HOURS.  THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED DOWNWARD
SLIGHTLY IN AGREEMENT WITH THE ICON CONSENSUS.
 
SATELLITE AND RECONNAISSANCE FIXES SHOW THAT EARL HAS TURNED TOWARD
THE NORTH-NORTHEAST...AND THE INITIAL MOTION ESTIMATE IS 015/15. 
THE TRACK MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED AND SHOWS AN
INCREASE IN FORWARD SPEED AND A TURN TOWARD THE NORTHEAST IN THE
NEXT 24 TO 36 HOURS AS EARL IS CAPTURED BY A LARGE MID- TO UPPER-
LEVEL TROUGH MOVING INTO EASTERN NORTH AMERICA.  BASED ON THE
INITIAL POSITION AND MOTION...THE TRACK FORECAST HAS BEEN ADJUSTED
A LITTLE TO THE EAST OF THE PREVIOUS PACKAGE...BUT LIES ON THE LEFT
SIDE OF THE GUIDANCE SUITE.  LATER FORECASTS MAY BE ADJUSTED FARTHER
EASTWARD IF THE CURRENT MOTION TO THE EAST OF DUE NORTH CONTINUES.
 
ALTHOUGH THE MAXIMUM WINDS IN THE CORE HAVE DECREASED...EARL
CONTINUES TO BE A LARGE HURRICANE AND AIRCRAFT DATA SHOW THAT THE
WIND FIELD HAS EXPANDED SOMEWHAT IN THE WESTERN SEMICIRCLE.  EARL
IS EXPECTED TO PRODUCE TROPICAL-STORM-FORCE WINDS OVER A LARGE
PORTION OF THE MID-ATLANTIC AND NEW ENGLAND COASTS...AND NEW
TROPICAL STORM WARNINGS HAVE BEEN ISSUED FOR PORTIONS OF THE COAST
OF MASSACHUSETTS AND MAINE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/0300Z 33.8N  74.4W    90 KT
 12HR VT     03/1200Z 36.2N  73.7W    85 KT
 24HR VT     04/0000Z 39.5N  70.7W    80 KT
 36HR VT     04/1200Z 43.9N  66.5W    70 KT
 48HR VT     05/0000Z 48.4N  61.5W    50 KT...POST-TROP/EXTRATROP
 72HR VT     06/0000Z...DISSIPATED
 
$$
FORECASTER BRENNAN
 

WTNT42 KNHC 030911
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  36
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM EDT FRI SEP 03 2010

EARL CONTINUES TO SLOWLY WEAKEN...WITH THE EYE BECOMING INDISTINCT
IN BOTH SATELLITE AND RADAR DATA.  AN AIR FORCE RESERVE HURRICANE
HUNTER REPORTED A CENTRAL PRESSURE OF 955 MB AT ABOUT 05Z.  THE
MAXIMUM 700 MB FLIGHT-LEVEL WINDS AT 03Z WERE 118 KT...WHILE THE
MAXIMUM SFMR WINDS NEAR THAT TIME WERE 83 KT.  A BLEND OF THESE
DATA IS USED FOR THE INITIAL INTENSITY OF 90 KT.  EARL SHOULD
CONTINUE TO WEAKEN THROUGH 36 HR DUE TO INCREASING VERTICAL WIND
SHEAR AND COOLER SEA SURFACE TEMPERATURES.  HOWEVER...IT IS STILL
FORECAST TO BE A HURRICANE AS IT PASSES NEAR OR OVER SOUTHEASTERN
NEW ENGLAND AND NOVA SCOTIA.  THE CYCLONE IS FORECAST TO BECOME
EXTRATROPICAL BY 48 HR...AND TO BE ABSORBED BY A LARGER
EXTRATROPICAL LOW BY 72 HR.

THE INITIAL MOTION IS 015-020 AT ABOUT 16 KT.  ALL GUIDANCE AGREES
THAT EARL SHOULD TURN NORTHEASTWARD AND ACCELERATE DURING THE NEXT
12-24 HOURS...AND THE NHC FORECAST FOLLOWS THIS SCENARIO.  A TURN
MORE TO THE NORTH-NORTHEAST IS POSSIBLE AFTER 36 HR AS EARL
UNDERGOES EXTRATROPICAL TRANSITION.  THE NEW FORECAST TRACK IS DOWN
THE MIDDLE OF THE GUIDANCE ENVELOPE AND IS SIMILAR TO THE PREVIOUS
FORECAST.  IT SHOULD BE NOTED THAT THE UKMET CONTINUES TO FORECAST
EARL TO MAKE LANDFALL NEAR CAPE COD...AND ANY MOTION TO THE LEFT OF
THE FORECAST TRACK COULD ALLOW THIS TO HAPPEN.
 
ALTHOUGH THE MAXIMUM WINDS IN THE CORE ARE DECREASING...EARL
CONTINUES TO BE A LARGE HURRICANE WITH THE WIND RADII EXPANDED IN
THE SOUTHEASTERN QUADRANT BASED ON ASCAT DATA.  THE CYCLONE IS
EXPECTED TO PRODUCE TROPICAL-STORM-FORCE WINDS OVER A LARGE PORTION
OF THE MID-ATLANTIC AND NEW ENGLAND COASTS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/0900Z 35.3N  74.0W    90 KT
 12HR VT     03/1800Z 37.8N  72.4W    85 KT
 24HR VT     04/0600Z 41.6N  68.9W    75 KT
 36HR VT     04/1800Z 45.9N  64.3W    55 KT
 48HR VT     05/0600Z 50.7N  60.0W    45 KT...POST-TROP/EXTRATROP
 72HR VT     06/0600Z...DISSIPATED
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 031459
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  37
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM EDT FRI SEP 03 2010
 

SATELLITE IMAGES AND DATA FROM AN AIR FORCE RECONNAISSANCE PLANE
INDICATE THAT EARL HAS CONTINUED TO WEAKEN. THE INITIAL INTENSITY
HAS BEEN REDUCED TO 75 KNOTS. THE HURRICANE IS ALREADY MOVING OVER
INCREASINGLY COOLER WATERS AND A CONTINUED WEAKENING IS
ANTICIPATED. HOWEVER...EARL IS FORECAST TO PASS NEAR CAPE COD AS A
HURRICANE WITH A LARGE AREA OF TROPICAL STORM FORCE WINDS WHICH
SHOULD AFFECT A LARGE PORTION OF THE MID-ATLANTIC AND NEW ENGLAND
COASTS. EARL SHOULD REACH CANADA AS A STRONG TROPICAL STORM AND
THEN BECOME EXTRATROPICAL IN ABOUT 36 HOURS.

EARL IS MOVING TOWARD THE NORTH-NORTHEAST OR 030 DEGREES AT 18
KNOTS. THE HURRICANE HAS ALREADY RECURVED WHILE EMBEDDED IN THE
SOUTHWESTERLY FLOW AHEAD OF AN APPROACHING MID-LATITUDE TROUGH.
EARL SHOULD CONTINUE ON THIS GENERAL TRACK WITH AN INCREASE IN
FORWARD SPEED UNTIL DISSIPATION IN A FEW DAYS.  
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/1500Z 36.8N  73.1W    75 KT
 12HR VT     04/0000Z 39.7N  70.8W    70 KT
 24HR VT     04/1200Z 43.8N  66.5W    60 KT
 36HR VT     05/0000Z 49.0N  62.0W    45 KT...POST-TROP/EXTRATROP
 48HR VT     05/1200Z 52.0N  56.5W    45 KT...POST-TROP/EXTRATROP
 72HR VT     06/1200Z...DISSIPATED
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 032037
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  38
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM EDT FRI SEP 03 2010
 
EARL HAS BEEN MOVING OVER COOLER WATER AND WEAKENING. BASED ON THE
SATELLITE PRESENTATION AND EARLIER RECONNAISSANCE DATA...THE INITIAL
INTENSITY HAS BEEN LOWERED TO 70 KNOTS. ALTHOUGH CONTINUED
WEAKENING IS ANTICIPATED...EARL IS FORECAST TO PASS NEAR CAPE COD
AS A HURRICANE WITH A LARGE AREA OF TROPICAL STORM FORCE WINDS.
THESE WINDS WILL LIKELY AFFECT A LARGE PORTION OF THE MID-ATLANTIC
AND NEW ENGLAND COASTS. EARL IS EXPECTED TO REACH CANADA AS A
STRONG TROPICAL STORM AND THEN BECOME EXTRATROPICAL IN ABOUT 36
HOURS.
 
EARL IS STILL MOVING TOWARD THE NORTH-NORTHEAST OR 030 DEGREES AT 18
KNOTS...BUT IT SHOULD SOON INCREASE ITS FORWARD SPEED. THE HURRICANE
HAS ALREADY RECURVED WHILE EMBEDDED IN THE SOUTHWESTERLY FLOW AHEAD
OF AN APPROACHING MID-LATITUDE TROUGH. EARL SHOULD CONTINUE ON THIS
GENERAL TRACK WITH AN INCREASE IN FORWARD SPEED UNTIL DISSIPATION
IN 36 TO 48 HOURS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/2100Z 38.2N  71.8W    70 KT
 12HR VT     04/0600Z 41.2N  69.2W    60 KT
 24HR VT     04/1800Z 46.5N  64.0W    50 KT
 36HR VT     05/0600Z 51.5N  59.0W    40 KT...POST-TROP/EXTRATROP
 48HR VT     05/1800Z...ABSORBED BY A LARGE EXTRATROPICAL LOW
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 040239
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  39
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM EDT FRI SEP 03 2010
 
EARL HAS CONTINUED TO SLOWLY WEAKEN THIS EVENING.  WHILE THE
CENTRAL PRESSURE REMAINS 958 MB...AIRCRAFT DATA SUGGEST THAT EARL
IS NOW BELOW HURRICANE STRENGTH.  THE INITIAL INTENSITY OF 60 KT IS
BASED ON A BLEND OF PEAK SFMR VALUES OF AROUND 55 KT AND A 700-MB
FLIGHT LEVEL WIND MAXIMUM OF 67 KT JUST PRIOR TO 0000 UTC.  THE
DEEP CONVECTION WITH EARL IS INCREASINGLY LIMITED TO THE NORTHERN
SEMICIRCLE OF THE CIRCULATION...DUE TO SOUTHERLY WIND SHEAR OF
15-20 KT AND DRY AIR ADVECTION SOUTH OF THE CENTER.  EARL WILL BE
CROSSING THE NORTHERN WALL OF THE GULF STREAM SOON...AND COLD WATER
AND INCREASING SHEAR SHOULD RESULT IN CONTINUED WEAKENING UNTIL
EXTRATROPICAL TRANSITION BEGINS.  GLOBAL MODEL FIELDS AND PHASE
SPACE DIAGRAMS SUGGEST THAT EARL WILL BE UNDERGOING EXTRATROPICAL
TRANSITION BY 24 HOURS...WITH THE TRANSITION COMPLETE IN 36 HOURS.
 
THE INITIAL MOTION ESTIMATE IS TOWARD THE NORTHEAST...OR 035 DEGREES
AT 22 KNOTS.  EARL SHOULD CONTINUE TO ACCELERATE AHEAD OF A LARGE
MID- TO UPPER-LEVEL TROUGH MOVING EASTWARD FROM THE GREAT LAKES
INTO SOUTHEASTERN CANADA OVER THE NEXT COUPLE OF DAYS.  BEYOND THAT
TIME...MUCH OF THE GLOBAL MODEL GUIDANCE NOW SUGGESTS THAT EARL WILL
TURN NORTHWARD AND THEN NORTHWESTWARD AS A DISTINCT CYCLONE THROUGH
72 HOURS BEFORE DISSIPATING OR BEING ABSORBED.  THE EXTRATROPICAL
PORTION OF THE TRACK IS BASED ON COORDINATION WITH THE OCEAN
PREDICTION CENTER.
 
EARL REMAINS A LARGE TROPICAL CYCLONE...AND WILL BRING HIGH WINDS
AND RAINFALL TO MUCH OF COASTAL NEW ENGLAND AND THE CANADIAN
MARITIMES OVERNIGHT TONIGHT AND SATURDAY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/0300Z 40.0N  69.7W    60 KT
 12HR VT     04/1200Z 43.1N  66.6W    55 KT
 24HR VT     05/0000Z 48.2N  61.6W    45 KT...POST-TROPICAL
 36HR VT     05/1200Z 52.5N  56.5W    45 KT...POST-TROP/EXTRATROP
 48HR VT     06/0000Z 55.5N  54.0W    40 KT...POST-TROP/EXTRATROP
 72HR VT     07/0000Z 57.0N  57.0W    40 KT...POST-TROP/EXTRATROP
 96HR VT     08/0000Z...DISSIPATED
 
$$
FORECASTER BRENNAN
 

WTNT42 KNHC 040856
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  40
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 AM EDT SAT SEP 04 2010
 
BOTH DOPPLER RADAR AND SATELLITE IMAGERY INDICATE THAT DURING THE
PAST FEW HOURS EARL HAS DEVELOPED A RING OF SHALLOW TO MODERATE
CONVECTION AROUND THE CENTER...WHICH RESEMBLES AN EYEWALL. BASED ON
THE LAST RECON DATA...LITTLE CHANGE NOTED IN THE OVERALL STRUCTURE
OF THE CYCLONE...AND THE FASTER FORWARD SPEED...THE INITIAL
INTENSITY WILL REMAIN AT 60 KT FOR THIS ADVISORY.

THE INITIAL MOTION ESTIMATE IS 045/26. THERE IS NO SIGNIFICANT
CHANGE TO THE PREVIOUS FORECAST TRACK AND INTENSITY REASONINGS.
EARL IS EMBEDDED WITHIN SOUTHWESTERLY FLOW AHEAD OF A DEEP LAYER
TROUGH THAT IS MOVING EASTWARD ACROSS THE GREAT LAKES AREA AND INTO
THE NORTHEASTERN UNITED STATES. THE CYCLONE IS FORECAST TO CONTINUE
MOVING NORTHEASTWARD AND SLOWLY WEAKEN AS IT MOVES OVER MUCH COOLER
WATER AND INTERACTS WITH THE CANADIAN MARITIMES LANDMASSES.
HOWEVER...EARL IS STILL EXPECTED TO REMAIN A VERY LARGE AND STRONG
EXTRATROPICAL LOW PRESSURE SYSTEM AFTER IT PASSES NORTH OF NOVA
SCOTIA LATER TODAY. THE OFFICIAL FORECAST TRACK IS A LITTLE TO THE
RIGHT OF THE PREVIOUS ADVISORY TRACK...AND IS CLOSE TO THE MODEL
CONSENSUS. THE EXTRATROPICAL PORTION OF THE TRACK IS BASED ON
COORDINATION WITH THE NOAA OCEAN PREDICTION CENTER.
 
EARL REMAINS A LARGE TROPICAL CYCLONE...AND WILL BRING HIGH WINDS
AND RAINFALL TO EASTERN NEW ENGLAND THIS MORNING...AND TO THE
CANADIAN MARITIMES THIS AFTERNOON AND EVENING.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/0900Z 41.7N  67.1W    60 KT
 12HR VT     04/1800Z 45.4N  63.3W    55 KT...INLAND
 24HR VT     05/0600Z 50.1N  58.8W    45 KT...POST-TROP/EXTRATROP
 36HR VT     05/1800Z 54.0N  55.0W    45 KT...POST-TROP/EXTRATROP
 48HR VT     06/0600Z 56.0N  53.5W    40 KT...POST-TROP/EXTRATROP
 72HR VT     07/0600Z 56.5N  55.0W    35 KT...POST-TROP/EXTRATROP
 96HR VT     08/0600Z...DISSIPATED
 
$$
FORECASTER STEWART
 

WTNT42 KNHC 041449
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  41
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM EDT SAT SEP 04 2010
 
EARL HAS MAINTAINED SOME CIRCULAR CONVECTIVE STRUCTURE ON SATELLITE
IMAGERY INDICATING THAT IT IS STILL A TROPICAL CYCLONE.
HOWEVER...MOST THE RAIN SHIELD HAS BEGUN TO SHIFT TOWARD THE
NORTHWESTERN PORTION OF THE CIRCULATION...AND THE WIND FIELD IS
EXPANDING ON THE SOUTH SIDE. THIS SUGGESTS THAT EARL IS GRADUALLY
BEGINNING TO ACQUIRE SOME EXTRATROPICAL CHARACTERISTICS.  BEST
ESTIMATE OF THE INITIAL INTENSITY IS 60 KNOTS...BASED ON
SURROUNDING SURFACE DATA. EARL IS EXPECTED TO BECOME EXTRATROPICAL
IN ABOUT 24 HOURS AND SHOULD CONTINUE AS A LARGE EXTRATROPICAL
CYCLONE FOR 2 TO 3 DAYS.
 
EARL HAS CONTINUED TO INCREASE ITS FORWARD SPEED AND IS NOW MOVING
TOWARD THE NORTHEAST OF 035 DEGREES AT 30 KNOTS.  THIS GENERAL
TRACK WITH A DECREASE IN FORWARD SPEED IS EXPECTED DURING THE NEXT
DAY OR SO.
 

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/1500Z 44.3N  64.5W    60 KT
 12HR VT     05/0000Z 48.0N  60.7W    50 KT...OVER WATER
 24HR VT     05/1200Z 52.5N  56.0W    45 KT...POST-TROP/EXTRATROP
 36HR VT     06/0000Z 55.5N  53.5W    40 KT...POST-TROP/EXTRATROP
 48HR VT     06/1200Z 57.0N  54.0W    40 KT...POST-TROP/EXTRATROP
 72HR VT     07/1200Z 56.0N  53.0W    40 KT...POST-TROP/EXTRATROP
 96HR VT     08/1200Z...ABSORBED
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 042033
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  42
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM EDT SAT SEP 04 2010
 
LARGE TROPICAL CYCLONE EARL HAS BEEN MOVING TOWARD THE
NORTH-NORTHEAST AT ABOUT 35 KNOTS PRODUCING SUSTAINED TROPICAL
STORM FORCE WINDS OVER MUCH OF THE CANADIAN MARITIMES. THE
CYCLONE IS BECOMING A LITTLE BIT ASYMMETRIC AND THE WIND FIELD IS
EXPANDING...BUT THERE IS PLENTY OF ORGANIZED CONVECTION NEAR THE
CENTER FOR SUCH A HIGH LATITUDE CYCLONE. THIS MEANS THAT EARL STILL
IS RETAINING ITS TROPICAL CHARACTERISTICS.  THE CYCLONE IS FORECAST
TO MOVE OVER THE COLD WATERS OF THE GULF OF SAINT LAWRENCE AND
BECOME POST-TROPICAL LATER TONIGHT.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/2100Z 47.5N  62.2W    60 KT
 12HR VT     05/0600Z 52.0N  58.5W    45 KT...POST-TROP/EXTRATROP
 24HR VT     05/1800Z 55.0N  55.0W    40 KT...POST-TROP/EXTRATROP
 36HR VT     06/0600Z 55.7N  51.0W    40 KT...POST-TROP/EXTRATROP
 48HR VT     06/1800Z 57.0N  51.0W    35 KT...POST-TROP/EXTRATROP
 72HR VT     07/1800Z...DISSIPATED
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 050235
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER  43
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 PM EDT SAT SEP 04 2010
 
OVER THE PAST FEW HOURS THE WIND FIELD OF EARL HAS BECOME
INCREASINGLY ELONGATED AND THE STRONGEST WINDS ARE NOW WELL REMOVED
FROM THE CENTER.  DRY AIR ASSOCIATED WITH THE LARGE UPPER TROUGH
INTERACTING WITH EARL HAS BEEN ENTRAINED THROUGH THE SOUTHERN
SEMICIRCLE OF THE CYCLONE.  ALSO...THE EASTERN PORTION OF EARL/S
CIRCULATION IS NOW INVOLVED WITH A FRONTAL ZONE.  BASED ON ALL
OF THIS...EARL IS NOW DECLARED POST-TROPICAL...AND THIS WILL BE THE
LAST NHC ADVISORY ON EARL.  THE INITIAL INTENSITY IS HELD AT 55 KT
BASED ON SURFACE OBSERVATIONS.  WEAKENING IS EXPECTED AS EARL
COMPLETES THE EXTRATROPICAL TRANSITION PROCESS.
 
THE FORWARD SPEED HAS CONTINUED TO INCREASE...AND IS NOW 030/40.
THE GLOBAL MODELS ARE IN RELATIVELY GOOD AGREEMENT ON THE TRACK OF
POST-TROPICAL EARL NORTHEASTWARD ACROSS LABRADOR AND INTO THE
ATLANTIC OVER THE NEXT DAY OR SO.  EARL WILL THEN MOVE SLOWLY
NORTHWARD AND NORTHWESTWARD FOR A COUPLE OF DAYS AS IT BECOMES A
VERTICALLY STACKED COLD CORE CYCLONE BEFORE ACCELERATING EASTWARD
ACROSS THE NORTH ATLANTIC AND DISSIPATING IN 4 OR 5 DAYS. THE
OFFICIAL FORECAST IS BASED ON A BLEND OF THE GFS AND ECMWF.
 
EARL IS STILL PRODUCING TROPICAL STORM CONDITIONS OVER PORTIONS OF
ATLANTIC CANADA.  FOR FURTHER INFORMATION ON POST-TROPICAL EARL IN
CANADA...SEE PRODUCTS FROM ENVIRONMENT CANADA.
 
ADDITIONAL INFORMATION ON POST-TROPICAL EARL CAN BE FOUND IN HIGH
SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/0300Z 50.7N  59.2W    55 KT...POST-TROPICAL 
 12HR VT     05/1200Z 52.9N  55.4W    40 KT...POST-TROP/EXTRATROP
 24HR VT     06/0000Z 55.0N  52.0W    35 KT...POST-TROP/EXTRATROP
 36HR VT     06/1200Z 57.0N  53.0W    35 KT...POST-TROP/EXTRATROP
 48HR VT     07/0000Z 57.0N  55.0W    35 KT...POST-TROP/EXTRATROP
 72HR VT     08/0000Z 54.0N  50.0W    35 KT...POST-TROP/EXTRATROP
 96HR VT     09/0000Z 52.0N  36.0W    25 KT...POST-TROP/EXTRATROP
120HR VT     10/0000Z...DISSIPATED
 
$$
FORECASTER BRENNAN
 

