WTNT44 KNHC 120231
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 PM AST TUE SEP 11 2012
 
SINCE THE PREVIOUS ADVISORY...DEEP CONVECTION HAS INCREASED OVER THE
CENTER OF THE CYCLONE AND A CURVED BAND OF CONVECTION HAS DEVELOPED
IN THE NORTHWEST QUADRANT. SATELLITE INTENSITY ESTIMATES ARE A
CONSENSUS T2.5/35 KT FROM TAFB...SAB...AND UW-CIMSS ADT.
THEREFORE...THE DEPRESSION HAS BEEN UPGRADED TO TROPICAL STORM
NADINE...THE FOURTEENTH NAMED STORM OF THE 2012 ATLANTIC SEASON.
 
THE INITIAL MOTION ESTIMATE IS 300/13 KT. NADINE MADE A SLIGHT JOG
TO THE WEST DURING THE PAST 6 HOURS...BUT THIS IS EXPECTED TO BE A
TRANSIENT MOTION DUE TO REFORMATION OF THE CENTER WITHIN THE LARGER
CYCLONIC ENVELOPE. NOW THAT CONVECTION HAS FORMED OVER THE
CENTER...THE VORTEX COLUMN SHOULD BECOME VERTICALLY DEEPER AND MORE
STABLE...RESULTING IN LESS WOBBLE IN THE TRACK MOTION. OTHERWISE...
THERE IS NO CHANGE TO THE PREVIOUS FORECAST TRACK OR REASONING. THE
NHC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH 72 HOURS ON
NADINE MOVING NORTHWESTWARD TOWARD A BREAK IN THE SUBTROPICAL RIDGE
ALONG ROUGHLY 55W LONGITUDE. AFTER THAT...THE MODELS DIVERGE
SIGNIFICANTLY ON HOW SOON AND HOW MUCH NADINE WILL INTERACT WITH AN
UPPER-LEVEL TROUGH/LOW FORECAST TO DEVELOP TO THE WEST OF THE
CYCLONE ON DAYS 3-5. GIVEN THE UNCERTAINTY IN THE EXACT LOCATION
AND STRENGTH OF DEVELOPMENT OF THE AFOREMENTIONED LOW...THE
OFFICIAL FORECAST TRACK INDICATES ONLY A DECREASE IN FORWARD SPEED
AND A GRADUAL TURN TOWARD THE EAST-NORTHEAST ON DAY 4...AND TOWARD
THE EAST ON DAY 5. THE OFFICIAL ADVISORY TRACK IS CLOSE TO THE
PREVIOUS TRACK AFTER 24 HOURS...AND IS SLIGHTLY TO THE RIGHT OF AND
SLOWER THAN THE CONSENSUS MODELS TVCN AND TV15.
 
THE LAST FEW VISIBLE IMAGES INDICATED NADINE HAD DEVELOPED A TIGHT
INNER-CORE CIRCULATION. NOW THAT DEEP CONVECTION AND A POSSIBLE CDO
FEATURE HAVE FORMED OVER THE WELL-DEFINED LOW-LEVEL CENTER...THE
POSSIBILITY OF RAPID INTENSIFICATION SOMETIME DURING THE NEXT 24-36
HOURS EXISTS OWING TO THE LOW VERTICAL SHEAR AND OTHER FAVORABLE
ENVIRONMENTAL CONDITIONS THAT ARE EXPECTED. LATE IN THE FORECAST
PERIOD...WESTERLY SHEAR AHEAD OF AN APPROACHING MID-LATITUDE TROUGH
IS EXPECTED TO INCREASE TO 20-25 KT...WHICH SHOULD BEGIN TO INDUCE
A SLOW WEAKENING TREND. THE OFFICIAL INTENSITY FORECAST IS SLIGHTLY
HIGHER THAN THE PREVIOUS ADVISORY...BUT IS NOT AS ROBUST AS THE
HWRF MODEL...WHICH MAKES NADINE A MAJOR HURRICANE BY 96 HOURS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0300Z 17.8N  45.2W   35 KT  40 MPH
 12H  12/1200Z 18.9N  46.9W   40 KT  45 MPH
 24H  13/0000Z 20.5N  49.2W   50 KT  60 MPH
 36H  13/1200Z 22.2N  51.2W   60 KT  70 MPH
 48H  14/0000Z 24.4N  53.0W   70 KT  80 MPH
 72H  15/0000Z 28.0N  53.8W   75 KT  85 MPH
 96H  16/0000Z 30.0N  51.9W   70 KT  80 MPH
120H  17/0000Z 31.5N  48.0W   65 KT  75 MPH
 
$$
FORECASTER STEWART
 

WTNT44 KNHC 120843
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST WED SEP 12 2012

NADINE CONTINUES TO BECOME BETTER ORGANIZED WITH THE FORMATION OF A
CENTRAL DENSE OVERCAST AND AN OUTER CONVECTIVE BAND IN THE
SOUTHEASTERN SEMICIRCLE. SATELLITE INTENSITY ESTIMATES ARE 45 KT
FROM SAB AND 35 KT FROM TAFB.  IN ADDITION...RECENT AUTOMATED
DVORAK INTENSITY ESTIMATES FROM CIMSS ARE NEAR 45 KT.  THE INITIAL
INTENSITY IS INCREASED TO 40 KT...AND THIS COULD BE A LITTLE
CONSERVATIVE.

THE INITIAL MOTION IS 300/15.  NADINE IS MOVING TOWARD A SIGNIFICANT
BREAK IN THE SUBTROPICAL RIDGE OVER THE CENTRAL NORTH ATLANTIC. 
THE GLOBAL MODELS FORECAST THIS BREAK TO BECOME EVEN MORE
PRONOUNCED BY 72 HR AS A DEEP-LAYER LOW PRESSURE SYSTEM FORMS NEAR
OR NORTH OF BERMUDA.  THIS EVOLUTION SHOULD STEER NADINE GENERALLY
NORTHWESTWARD FOR 36 HR OR SO...FOLLOWED BY A TURN TOWARD THE
NORTH.  THIS PART OF THE NEW FORECAST TRACK IS SIMILAR TO THE
PREVIOUS TRACK AND LIES JUST TO THE RIGHT OF THE CONSENSUS MODELS. 
AFTER 72 HR...THE SUBTROPICAL RIDGE IS FORECAST TO BUILD ALONG
20N...LEAVING NADINE IN WESTERLY OR SOUTHWESTERLY FLOW ON THE NORTH
SIDE OF THE RIDGE.  THE TRACK GUIDANCE BECOMES MORE DIVERGENT
DURING THIS PERIOD.  THE UKMET SHOWS NADINE GOING NORTHWARD AND
BECOMING ENTANGLED WITH THE DEEP-LAYER LOW...WHILE THE GFS SHOWS AN
EASTWARD MOTION.  THE OTHER DYNAMICAL MODELS ARE SPREAD BETWEEN
THESE EXTREMES.  THIS PORTION OF THE NEW FORECAST TRACK IS SHIFTED
A LITTLE NORTH OF THE PREVIOUS TRACK...BUT LIES TO THE SOUTH OF THE
CONSENSUS MODELS AND THE CENTER OF THE TRACK GUIDANCE ENVELOPE. 
OVERALL...THE NEW FORECAST TRACK IS IN BEST AGREEMENT WITH THE
FLORIDA STATE SUPERENSEMBLE.

NADINE IS CURRENTLY IN AN ENVIRONMENT OF LIGHT VERTICAL WIND SHEAR
WITH GOOD TO EXCELLENT CIRRUS OUTFLOW IN ALL DIRECTIONS.  THE
QUESTION IS HOW LONG WILL THE FAVORABLE CONDITIONS LAST?  THE SHIPS
MODEL FORECASTS WESTERLY SHEAR OF ABOUT 15 KT TO DEVELOP WITHIN 24
HR...ALTHOUGH THE SOURCE OF THIS IS NOT READILY APPARENT IN THE GFS
MODEL FIELDS.  THE SHIPS AND LGEM MODELS SHOW NADINE BECOMING A
HURRICANE IN 36-48 HR DESPITE THE SHEAR FORECAST...SO THE NEW
INTENSITY FORECAST DOES LIKEWISE.  THERE IS AN ALTERNATIVE SCENARIO
FOR THIS PORTION OF THE INTENSITY FORECAST...WHICH IS THE SHEAR
DOES NOT OCCUR AND NADINE RAPIDLY STRENGTHENS.  THIS IS SOMEWHAT
SUPPORTED BY THE RAPID INTENSIFICATION INDEX OF THE SHIPS MODEL...
WHICH SHOWS ABOUT A 40 PERCENT CHANCE OF RAPID INTENSIFICATION
DURING THE NEXT 24 HOURS.  REGARDLESS OF WHAT HAPPENS IN THE SHORT
TERM...FROM 72-120 HR NADINE IS LIKELY TO ENCOUNTER AT LEAST 20-25
KT OF WESTERLY SHEAR NORTH OF THE SUBTROPICAL RIDGE AXIS...WHICH
SHOULD STOP INTENSIFICATION AND START A WEAKENING TREND.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0900Z 18.6N  46.6W   40 KT  45 MPH
 12H  12/1800Z 19.7N  48.5W   50 KT  60 MPH
 24H  13/0600Z 21.4N  50.6W   60 KT  70 MPH
 36H  13/1800Z 23.3N  52.6W   65 KT  75 MPH
 48H  14/0600Z 25.4N  53.8W   70 KT  80 MPH
 72H  15/0600Z 29.0N  54.0W   75 KT  85 MPH
 96H  16/0600Z 31.0N  51.0W   70 KT  80 MPH
120H  17/0600Z 32.5N  46.5W   65 KT  75 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 121443
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 AM AST WED SEP 12 2012
 
THE SATELLITE PRESENTATION OF NADINE SHOWS A CONTINUED INCREASE IN
ORGANIZATION...WITH A DEVELOPING CENTRAL DENSE OVERCAST AND
CONVECTIVE BANDING FEATURES IN ALL QUADRANTS.  DVORAK INTENSITY
ESTIMATES ARE 55 KT FROM SAB AND 45 KT FROM TAFB.  USING A BLEND OF
THESE INTENSITY ESTIMATES...THE INITIAL INTENSITY IS SET TO 50 KT. 
ANIMATION OF WATER VAPOR IMAGERY SHOWS WEAK SHEAR OVER NADINE WITH
A WELL-DEFINED UPPER-LEVEL OUTFLOW PATTERN.  A BROAD TROUGH WELL TO
THE NORTHEAST OF THE STORM MAY BE ASSISTING THE OUTFLOW TO THE
NORTH AND EAST.  NADINE IS EXPECTED TO REMAIN IN A FAVORABLE UPPER-
LEVEL WIND ENVIRONMENT FOR THE NEXT COUPLE OF DAYS.  HOWEVER...FROM
72 HOURS AND BEYOND NADINE IS EXPECTED TO ENCOUNTER A BELT OF
STRONG WESTERLIES TO THE NORTH OF THE SUBTROPICAL RIDGE...AND THE
LGEM GUIDANCE SHOWS WESTERLY SHEAR INCREASING TO 25-30 KT DURING
THIS TIME FRAME.  THE NHC INTENSITY FORECAST IS IN REASONABLE
AGREEMENT WITH THE LATEST LGEM AND CONSENSUS MODEL GUIDANCE.  IT
SHOULD BE NOTED THAT THE SHIPS RI INDEX IS STILL SHOWING A
SIGNIFICANT PROBABILITY OF RAPID INTENSIFICATION DURING THE NEXT 24
HOURS...SO THE OFFICIAL INTENSITY FORECAST FOR THE NEXT DAY OR TWO
COULD BE CONSERVATIVE.

CENTER FIXES SHOW A MOTION BETWEEN WEST-NORTHWEST AND NORTHWEST...
AND THE CURRENT MOTION ESTIMATE IS 300/13.  NADINE CONTINUES TO
HEAD TOWARD A BREAK IN THE SUBTROPICAL RIDGE CAUSED BY A MID- TO
UPPER-LEVEL LOW TO ITS WEST.  THE OFFICIAL FORECAST IS SIMILAR TO
THE PREVIOUS ONE AND TAKES THE TROPICAL CYCLONE AROUND THE WESTERN
PERIPHERY OF A SUBTROPICAL ANTICYCLONE FOR THE NEXT 2-3 DAYS. 
NADINE IS EXPECTED TO MOVE INTO THE WESTERLIES BEYOND 72 HOURS...SO
THE OFFICIAL FORECAST SHOWS A TURN TOWARDS THE NORTHEAST AND
EAST-NORTHEAST DURING THE LATTER PART OF THE FORECAST PERIOD.  THE
CURRENT NHC TRACK LIES BETWEEN THE SLOWER ECMWF...AND ITS ENSEMBLE
MEAN...AND THE QUICKER 0600 UTC GFS SOLUTION.

THE WIND RADII HAVE BEEN ADJUSTED BASED ON A 1215 UTC ASCAT
OVERPASS...WHICH SAMPLED THE EASTERN SIDE OF THE CIRCULATION AND
REVEALED A LARGER TROPICAL CYCLONE THAN PREVIOUSLY ESTIMATED.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/1500Z 19.1N  47.6W   50 KT  60 MPH
 12H  13/0000Z 20.3N  49.2W   60 KT  70 MPH
 24H  13/1200Z 22.1N  51.3W   70 KT  80 MPH
 36H  14/0000Z 24.1N  52.9W   75 KT  85 MPH
 48H  14/1200Z 26.3N  53.8W   75 KT  85 MPH
 72H  15/1200Z 30.0N  52.5W   75 KT  85 MPH
 96H  16/1200Z 32.5N  49.0W   70 KT  80 MPH
120H  17/1200Z 34.5N  43.5W   65 KT  75 MPH
 
$$
FORECASTER ROTH/PASCH
 

WTNT44 KNHC 122032
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
500 PM AST WED SEP 12 2012
 
THE SYSTEM HAS BECOME A LITTLE MORE ASYMMETRIC...WITH A COMMA-TYPE
CLOUD APPEARANCE ON SATELLITE IMAGERY.  DRY AIR ROTATING AROUND THE
NORTHERN SIDE OF THE CYCLONE COULD BE ERODING CONVECTION OVER THE
WESTERN SEMICIRCLE.  HOWEVER...THE CENTRAL DENSE OVERCAST HAS
INCREASED SOMEWHAT IN SIZE AND DVORAK INTENSITY ESTIMATES ARE 55 KT
FROM BOTH AGENCIES.  ON THIS BASIS...THE ADVISORY INTENSITY HAS
BEEN INCREASED TO 55 KT.  CIRRUS CLOUD MOTIONS CONTINUE TO INDICATE
A WELL-DEFINED UPPER-TROPOSPHERIC OUTFLOW PATTERN...AND DYNAMICAL
GUIDANCE INDICATES THE VERTICAL WIND SHEAR SHOULD REMAIN MODERATE
FOR THE NEXT 36-48 HOURS.  LATER IN THE FORECAST PERIOD AS NADINE
MOVES NORTH OF 30N LATITUDE...THE GLOBAL MODELS SHOW A SIGNIFICANT
INCREASE IN THE UPPER-LEVEL WESTERLY FLOW NEAR AND OVER NADINE. 
THEREFORE...STRENGTHENING SHOULD BE LIMITED TO THE EARLY PART OF
THE FORECAST PERIOD AND A WEAKENING TREND SHOULD COMMENCE WITHIN A
COUPLE OF DAYS.  IT SHOULD BE NOTED THAT THE LGEM GUIDANCE SHOWS
MORE WEAKENING THAN THE OFFICIAL FORECAST DURING THE LATTER HALF OF
THE PERIOD.  WHILE THE 1200 UTC ECMWF SOLUTION SHOWS THE
POSSIBILITY OF EXTRATROPICAL TRANSITION AT THE END OF THE
PERIOD...THE MAJORITY OF THE 1200 UTC GLOBAL GUIDANCE DOES NOT. 
UNTIL THERE IS GREATER AGREEMENT AMONGST THE GLOBAL GUIDANCE...THIS
TRANSITION WILL NOT BE INDICATED IN THE OFFICIAL FORECAST.
 
THE HEADING OF THE STORM HAS SHIFTED SLIGHTLY TO THE RIGHT AND THE
MOTION IS NOW ABOUT 310/14.  THERE HAS BEEN LITTLE CHANGE TO THE
TRACK FORECAST PHILOSOPHY.  NADINE IS EXPECTED TO ROUND THE WESTERN
PERIPHERY OF A SUBTROPICAL RIDGE OVER THE EAST-CENTRAL ATLANTIC
WITHIN THE NEXT COUPLE DAYS.  THE CYCLONE SHOULD THEN TURN
EAST-NORTHEASTWARD TO EASTWARD AFTER MOVING NORTH OF THE RIDGE
AXIS.  THE GLOBAL MODEL TRACK GUIDANCE...IN PARTICULAR THE ECMWF..
HAS SHIFTED SOUTHWARD IN THE LATTER PART OF THE FORECAST PERIOD. 
THE 4- AND 5-DAY NHC TRACK HAS BEEN ADJUSTED SOUTH OF THE PREVIOUS
ONE...AND IS CLOSEST TO THE FLORIDA STATE UNIVERSITY SUPERENSEMBLE. 
THIS GUIDANCE HAS BEEN A STRONG PERFORMER FOR TRACK PREDICTION THIS
YEAR.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/2100Z 20.0N  48.9W   55 KT  65 MPH
 12H  13/0600Z 21.3N  50.4W   65 KT  75 MPH
 24H  13/1800Z 23.3N  52.3W   70 KT  80 MPH
 36H  14/0600Z 25.5N  53.8W   75 KT  85 MPH
 48H  14/1800Z 28.0N  54.0W   75 KT  85 MPH
 72H  15/1800Z 31.0N  51.0W   70 KT  80 MPH
 96H  16/1800Z 32.5N  46.0W   70 KT  80 MPH
120H  17/1800Z 33.0N  40.0W   65 KT  75 MPH
 
$$
FORECASTER ROTH/PASCH
 

WTNT44 KNHC 130243
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER   7
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 PM AST WED SEP 12 2012
 
THE OVERALL CONVECTIVE PATTERN HAS IMPROVED SINCE THE PREVIOUS
ADVISORY AND CONVECTIVE BANDING NOW WRAPS ALMOST COMPLETELY AROUND
THE CENTER. THE CDO HAS ALSO INCREASED IN SIZE AND TOPS HAVE COOLED
BELOW -80C NEAR THE CENTER...AND IN MOST OF THE NORTHEAST QUADRANT.
SATELLITE INTENSITY ESTIMATES WERE A CONSENSUS T3.5/55 KT AT 00Z...
BUT THE BANDING HAS CONTINUED TO INCREASE SINCE THEN. THE LATEST
UW-CIMSS ADT INTENSITY ESTIMATE IS T3.9/63 KT. HOWEVER...WITH NO
RECENT MICROWAVE DATA THAT WOULD BE USEFUL IN DETERMINING IF NADINE
HAS AN EYE UNDERNEATH THE COLD CLOUD CANOPY...THE INITIAL INTENSITY
IS BEING HELD JUST BELOW HURRICANE STRENGTH AT 60 KT.

THE INITIAL MOTION IS STILL NORTHWESTWARD...OR 305/14 KT. OTHER THAN
MINOR WOBBLES OVER THE PAST FEW HOURS...NADINE HAS BASICALLY BEEN
ON TRACK. FOR THE NEXT 72 HOURS OR SO...NADINE SHOULD CONTINUE TO
MOVE NORTHWESTWARD AND THEN NORTHWARD AROUND THE WESTERN PERIPHERY
OF A DEEP-LAYER SUBTROPICAL RIDGE THAT IS ORIENTED EAST-WEST ALONG
32-33N LATITUDE. AFTER THAT...THE CYCLONE IS FORECAST TO COME UNDER
THE INFLUENCE OF WESTERLY MID- TO UPPER-LEVEL FLOW ON THE EAST SIDE
OF AN EASTWARD-MOVING DEEP-LAYER TROUGH THAT IS CURRENTLY LOCATED
OFF THE EAST COAST OF NORTH AMERICA. OTHER THAN A SLIGHT SOUTHWARD
SHIFT IN THE FORECAST TRACK AT DAYS 4 AND 5...THE PREVIOUS ADVISORY
TRACK HAS REMAINED UNCHANGED. THE OFFICIAL FORECAST TRACK IS CLOSE
TO THE CONSENSUS MODELS TVCN AND TV15 THROUGH 72 HOURS...AND THEN
LIES WELL TO THE RIGHT OF THOSE MODELS DUE TO THE GFDL MODEL BEING
A SIGNIFICANT OUTLIER WITH ITS FAST NORTHWARD TRACK AT DAYS 4/5.
 
NADINE HAS BEEN STRENGTHENING OVER THE PAST 24 HOURS AT JUST BELOW
THE RATE OF RAPID INTENSIFICATION. THE CYCLONE POSSESSES AN
IMPRESSIVE OUTFLOW REGIME THAT SHOULD CONTINUE TO EXPAND AS NADINE
MOVES BETWEEN A LARGE UPPER-LEVEL LOW TO ITS NORTHEAST AND A
SMALLER LOW TO ITS WEST. THE COMBINATION OF A FAVORABLE OUTFLOW
PATTERN AND RELATIVELY LOW VERTICAL WIND SHEAR SHOULD ALLOW FOR
SOME ADDITIONAL INTENSIFICATION TO OCCUR FOR THE NEXT 24 HOURS OR
SO. AFTER THAT...HOWEVER...A SHARP INCREASE IN WESTERLY SHEAR IS
EXPECTED AHEAD OF THE AFOREMENTIONED DEEP-LAYER TROUGH APPROACHING
FROM THE WEST. THIS SHOULD RESULT IN A CAPPING OF THE INTENSITY BY
36 HOURS...AND POSSIBLY INDUCE SOME SLIGHT WEAKENING AT 48 HOURS
AND BEYOND. THE INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS
ADVISORY...AND LIES CLOSE TO THE INTENSITY CONSENSUS MODEL IVCN.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  13/0300Z 20.7N  50.1W   60 KT  70 MPH
 12H  13/1200Z 22.1N  51.5W   70 KT  80 MPH
 24H  14/0000Z 24.2N  53.2W   75 KT  85 MPH
 36H  14/1200Z 26.4N  54.0W   75 KT  85 MPH
 48H  15/0000Z 28.6N  53.8W   70 KT  80 MPH
 72H  16/0000Z 30.9N  50.2W   65 KT  75 MPH
 96H  17/0000Z 31.8N  44.5W   65 KT  75 MPH
120H  18/0000Z 32.9N  38.0W   65 KT  75 MPH
 
$$
FORECASTER STEWART
 

WTNT44 KNHC 130844
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST THU SEP 13 2012

THE OVERALL APPEARANCE OF NADINE IN INFRARED IMAGERY HAS CHANGED
LITTLE DURING THE PAST SEVERAL HOURS.  A RECENT AMSU IMAGE SHOWS A
MID-LEVEL EYE DISPLACED TO THE EAST-NORTHEAST OF OF THE APPARENT
LOW-LEVEL CENTER.  THIS MAY BE DUE TO 10-20 KT OF SOUTHWESTERLY
VERTICAL WIND SHEAR DIAGNOSED BY THE SHIPS MODEL AND ANALYSES FROM
CIMSS.  SATELLITE INTENSITY ESTIMATES ARE 55 KT FROM TAFB AND
SAB...AND A ASCAT OVERPASS RECEIVED JUST AFTER THE PREVIOUS
ADVISORY SUPPORTS WINDS OF AT LEAST 55-60 KT.  BASED ON THESE
DATA...THE INITIAL INTENSITY REMAINS 60 KT.  THE INITIAL WIND RADII
HAVE BEEN REVISED A LITTLE BASED ON THE ASCAT DATA.

THE INITIAL MOTION IS 305/14.  NADINE IS MOVING TOWARD A BREAK IN
THE SUBTROPICAL RIDGE...AND DURING THE NEXT 48 HR THE GUIDANCE IS
IN GOOD AGREEMENT THAT THE CYCLONE SHOULD RECURVE AROUND THE
WESTERN END OF THE RIDGE INTO THE WESTERLIES.  THIS PART OF THE
FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK.  AFTER 48 HR...THE
GUIDANCE BECOMES SERIOUSLY DIVERGENT.  THE GFDL FORECASTS A
NORTHWARD MOVEMENT TOWARD NEWFOUNDLAND...WHILE THE GFS AND ECMWF
FORECAST A GENERALLY EASTWARD MOTION.  THE OTHER DYNAMICAL AND
CONSENSUS MODELS ARE SPREAD BETWEEN THESE EXTREMES.  THIS SPREAD
SEEMS TO RESULT FROM HOW THE MODELS HANDLE THE INTERACTIONS BETWEEN
NADINE...A DEEP-LAYER LOW FORECAST TO BE TO ITS EAST...AND A
MID/UPPER-LEVEL TROUGH FORECAST TO BE IN THE WESTERLIES NEAR
NEWFOUNDLAND.  AT THIS TIME...IT IS NOT CLEAR WHICH OF THE MODELS
HAS THE BEST HANDLE ON THESE INTERACTIONS.  THEREFORE...THE
FORECAST TRACK IS NUDGED ONLY SLIGHTLY NORTHWARD...AND IT LIES NEAR
THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE IN BEST AGREEMENT WITH
THE GFS...ECMWF...AND FLORIDA STATE SUPERENSEMBLE.  ADDITIONAL
ADJUSTMENTS OF THIS PART OF THE TRACK MAY BE NECESSARY WHEN THE
MODELS COME INTO BETTER AGREEMENT.

THE WINDOW FOR NADINE TO STRENGTHEN MAY BE CLOSING.  IN ADDITION TO
THE CURRENT INCREASE IN SHEAR...WATER VAPOR IMAGERY SHOWS
MID/UPPER-LEVEL DRY AIR IMPINGING ON THE CYCLONE FROM THE
SOUTHWEST.  DESPITE THE LESS FAVORABLE ENVIRONMENT...MOST OF THE
INTENSITY GUIDANCE SHOWS SOME STRENGTHENING DURING THE NEXT 24
HR...AND THE NEW FORECAST CALLS FOR NADINE TO BECOME A HURRICANE
DURING THAT TIME.  AFTER 24 HR...THE DYNAMICAL MODELS ARE IN GOOD
AGREEMENT THAT NADINE WILL ENCOUNTER AT LEAST 20-30 KT OF WESTERLY
SHEAR...WHICH SHOULD CAUSE SOME WEAKENING.  THERE ARE HINTS THAT
THE SHEAR COULD SUBSIDE AFTER 72 HR...BUT DUE TO THE UNCERTAINTY OF
HOW NADINE WILL INTERACT WITH THE OTHER SYSTEMS IN THE WESTERLIES
THE FORECAST WILL NOT SHOW STRENGTHENING DURING THAT PERIOD.  THE
NEW FORECAST IS SIMILAR TO...BUT LESS INTENSE THAN...THE PREVIOUS
FORECAST USING A BLEND OF THE SHIPS...LGEM...AND INTENSITY
CONSENSUS MODELS. 

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  13/0900Z 21.5N  51.3W   60 KT  70 MPH
 12H  13/1800Z 23.1N  52.7W   65 KT  75 MPH
 24H  14/0600Z 25.4N  54.0W   70 KT  80 MPH
 36H  14/1800Z 27.6N  54.2W   70 KT  80 MPH
 48H  15/0600Z 29.3N  53.3W   65 KT  75 MPH
 72H  16/0600Z 31.5N  49.5W   60 KT  70 MPH
 96H  17/0600Z 32.5N  44.0W   60 KT  70 MPH
120H  18/0600Z 34.0N  38.0W   60 KT  70 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 131449
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1100 AM AST THU SEP 13 2012

BASED ON VISIBLE AND INFRARED SATELLITE IMAGERY...NADINE HAS NOT
BECOME SIGNIFICANTLY BETTER ORGANIZED THIS MORNING.  THERE IS
A GOOD CONCENTRATION OF DEEP CONVECTION IN A SMALL AREA NEAR THE
CENTER...BUT NADINE HAS YET TO DISPLAY ANY SIGN OF EYE FORMATION ON
GEOSTATIONARY IMAGES.  THE OVERALL CLOUD PATTERN REMAINS SOMEWHAT
ASYMMETRIC...WITH MORE DEEP CONVECTION OVER THE EASTERN SEMICIRCLE.
ARC CLOUDS HAVE BEEN NOTED EMANATING NORTHWARD FROM THE STORM...
SUGGESTING SOME INTRUSION OF MID-LEVEL DRY AIR.  DVORAK CURRENT
INTENSITY ESTIMATES FROM TAFB AND SAB REMAIN UNCHANGED FROM THE
PREVIOUS CYCLE...SO THE ADVISORY WIND SPEED IS HELD AT 60 KT.
 
ALTHOUGH THE CENTER IS NOT THAT EASY TO LOCATE...MOST RECENT
SATELLITE FIXES GIVE A MOTION ESTIMATE OF 315/14.  THE STEERING
SCENARIO AND TRACK FORECAST FOR THE NEXT TWO DAYS APPEAR TO BE
RELATIVELY STRAIGHTFORWARD.  NADINE SHOULD CONTINUE TO MOVE AROUND
THE WESTERN PERIPHERY OF A SUBTROPICAL ANTICYCLONE...AND THE TRACK
MODELS ARE IN REASONABLY GOOD AGREEMENT THROUGH 48 HOURS.  LATER
ON...THE TRACK MODELS BECOME MORE DIVERGENT...WITH A SPREAD OF OVER
600 N MI BY DAY 5.  THE GFDL IS THE LEFT-MOST OF THE MODEL
SUITE...AND IS CONSIDERED AN OUTLIER AT THIS TIME.  THE MOST LIKELY
OUTCOME DURING DAYS 3-5 SEEMS TO BE AN EAST-NORTHEASTWARD TO
EASTWARD MOTION WITHIN THE MID-LEVEL WESTERLIES TO THE NORTH OF THE
SUBTROPICAL RIDGE.  THEREFORE...THE OFFICIAL FORECAST TRACK IS
CLOSE TO A SELECTIVE CONSENSUS THAT EXCLUDES THE GFDL.  THIS IS
ALSO ROUGHLY IN AGREEMENT WITH THE PREVIOUS NHC FORECAST THROUGH 72
HOURS...AND A LITTLE TO THE RIGHT AT THE LONGER TIME RANGES.

NADINE IS CURRENTLY EXPERIENCING MODERATE SOUTHWESTERLY SHEAR
ASSOCIATED WITH A MID- TO UPPER-LEVEL TROUGH AND SHEAR AXIS LOCATED
A FEW HUNDRED MILES TO ITS WEST.  ANALYSIS OF THE GFS MODEL FIELDS
REVEALS THE SHEAR IS MOST PROMINENT IN THE MID LEVELS AT THIS TIME. 
DYNAMICAL GUIDANCE INDICATES SHEAR WILL BECOME RATHER STRONG BY 36
HOURS AND BEYOND.  ALTHOUGH THE STORM IS RUNNING OUT OF TIME TO
BECOME A HURRICANE...SOME OF THE BETTER-PERFORMING GUIDANCE SUCH AS
SHIPS SHOW SOME STRENGTHENING WITHIN THE NEXT 24-36 HOURS.  THE
OFFICIAL INTENSITY FORECAST CONTINUES TO CALL FOR NADINE TO
STRENGTHEN INTO A HURRICANE IN THE SHORT TERM...WITH GRADUAL
WEAKENING PREDICTED AS SHEAR INCREASES BEYOND 36 HOURS.

FORECAST POSITIONS AND MAX WINDS
 
INIT  13/1500Z 22.6N  52.2W   60 KT  70 MPH
 12H  14/0000Z 24.2N  53.3W   65 KT  75 MPH
 24H  14/1200Z 26.4N  54.2W   70 KT  80 MPH
 36H  15/0000Z 28.6N  53.8W   70 KT  80 MPH
 48H  15/1200Z 30.1N  52.6W   65 KT  75 MPH
 72H  16/1200Z 31.8N  48.2W   60 KT  70 MPH
 96H  17/1200Z 32.5N  42.5W   60 KT  70 MPH
120H  18/1200Z 34.0N  37.0W   60 KT  70 MPH
 
$$
FORECASTER BURKE/PASCH
 

WTNT44 KNHC 132035
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
500 PM AST THU SEP 13 2012
 
NADINE CONTINUES TO MAINTAIN THE APPEARANCE OF A STRONG TROPICAL
STORM PER SATELLITE IMAGERY...AND THIS IS CONFIRMED BY DATA FROM A
RECENT SCATTEROMETER OVERPASS.  ALTHOUGH THE CYCLONE EXHIBITS A
FAIRLY WELL DEFINED CENTRAL DENSE OVERCAST...NO EYE IS APPARENT IN
EITHER VISIBLE OR INFRARED IMAGERY.  WATER VAPOR IMAGERY SUGGESTS
THAT VERTICAL SHEAR HAS NOT BECOME PROHIBITIVELY STRONG OVER THE
STORM.  THE SHEAR HAS...HOWEVER...BEEN STRONG ENOUGH TO PREVENT
NADINE FROM STRENGTHENING TODAY.  THE DYNAMICAL GUIDANCE DOES NOT
SHOW AS MUCH SHEAR DURING THE FORECAST PERIOD AS IN PREVIOUS
CYCLES.  THIS LIKELY RESULTS FROM THE PREDICTION OF THE GLOBAL
MODELS THAT A TROUGH TO THE WEST OF NADINE WILL DE-AMPLIFY AND
PHASE WITH ANOTHER CYCLONE EXITING EASTERN CANADA.  THIS WOULD
LEAVE THE TROPICAL CYCLONE SOUTH OF AN AMPLIFYING RIDGE...IN AN
ENVIRONMENT THAT COULD ALLOW FOR SOME RELAXATION OF THE SHEAR. 
THEREFORE...NADINE MAY STILL HAVE AN OPPORTUNITY TO STRENGTHEN...AS
SUGGESTED BY THE OFFICIAL FORECAST.  HOWEVER...IT SHOULD BE NOTED
THAT THE TIMING AND DURATION OF A POTENTIAL STRENGTHENING EPISODE
IS UNCERTAIN.

THE MOTION CONTINUES TO BEND TOWARD THE RIGHT...AND IS NOW NEAR
325/14.  THE SYNOPTIC TRACK FORECAST REASONING IS BASICALLY
UNCHANGED FROM THE PREVIOUS ADVISORY...AND THE GFS AND ECMWF
FORECASTS HAVE COME INTO BETTER AGREEMENT DURING THE LATTER PART OF
THE FORECAST PERIOD.  THE GFDL CONTINUES TO APPEAR AS A LEFT
OUTLIER...ALTHOUGH NOT AS FAR LEFT AS IN ITS PREVIOUS RUN.  THE
OFFICIAL FORECAST TRACK HAS CHANGED VERY LITTLE...EXCEPT TO LOOP
JUST SLIGHTLY FARTHER WEST DURING THE FIRST COUPLE OF DAYS...BEFORE
RETURNING TO THE PREVIOUS NHC TRACK FOR DAYS 3-5.  THIS FALLS
BETWEEN THE LATEST TVCN CONSENSUS AND THE GFS/ECMWF TRACKS.

THE SCATTEROMETER PASS SHOWED A MUCH LARGER TROPICAL CYCLONE THAN
PREVIOUSLY ANALYZED...ESPECIALLY OVER THE EASTERN SEMICIRCLE WHERE
TROPICAL STORM FORCE WINDS EXTEND OUTWARD AT LEAST 200 N MI.  THIS
IS CONSISTENT WITH THE SATELLITE PRESENTATION IN WHICH NADINE IS
SEEN TO HAVE A LARGE AREA OF DEEP CONVECTION THAT EXTENDS WELL TO
THE EAST AND NORTHEAST OF THE CENTER.

FORECAST POSITIONS AND MAX WINDS
 
INIT  13/2100Z 24.0N  53.0W   60 KT  70 MPH
 12H  14/0600Z 25.7N  54.0W   60 KT  70 MPH
 24H  14/1800Z 28.0N  54.4W   60 KT  70 MPH
 36H  15/0600Z 30.1N  53.8W   65 KT  75 MPH
 48H  15/1800Z 31.3N  52.0W   65 KT  75 MPH
 72H  16/1800Z 32.0N  47.0W   60 KT  70 MPH
 96H  17/1800Z 33.0N  41.0W   60 KT  70 MPH
120H  18/1800Z 35.0N  34.0W   60 KT  70 MPH
 
$$
FORECASTER BURKE/PASCH
 

WTNT44 KNHC 140243
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 PM AST THU SEP 13 2012
 
THE SATELLITE PRESENTATION OF NADINE HAS NOT CHANGED MUCH OVER THE
PAST FEW HOURS...AS THE CLOUD PATTERN IS CHARACTERIZED BY A
CDO-LIKE PATTERN WITH NO EVIDENCE OF AN EYE. THE INITIAL INTENSITY
REMAINS 60 KT BASED ON A BLEND OF THE LATEST DVORAK ESTIMATES FROM
TAFB AND SAB AND RECENT ADT ESTIMATES. THE SIGNALS FOR THE
INTENSITY FORECAST ARE MIXED. RECENT WATER VAPOR IMAGERY SHOWS THAT
THE OUTFLOW HAS BECOME A LITTLE BETTER ESTABLISHED OVER THE PAST
FEW HOURS. HOWEVER...SATELLITE ANALYSIS FROM UW-CIMSS SUGGEST THAT
SOUTHWESTERLY SHEAR OF 10 TO 15 KT IS AFFECTING NADINE...WHICH IS
CONSISTENT WITH MICROWAVE IMAGERY THAT SHOWS THE LOW-LEVEL CENTER
LOCATED SOUTH-SOUTHWEST OF THE DEEP CONVECTION. WHILE THE SHIPS
MODEL SHOWS THE SHEAR INCREASING OVER THE CYCLONE IN THE NEXT DAY
OR TWO...MOST OF THE GUIDANCE NOW SHOWS NADINE BECOMING A HURRICANE
BY 36 HOURS. LATER IN THE PERIOD...THE CYCLONE MAY BE IN A SLIGHTLY
MORE FAVORABLE ENVIRONMENT OF MODERATE SOUTHWESTERLY SHEAR OVER
WARM SSTS. MOST OF THE GUIDANCE HAS TRENDED UPWARD THIS CYCLE...AND
THE INTENSITY FORECAST HAS BEEN ADJUSTED IN THAT DIRECTION AT DAYS
3 THROUGH 5. THE NHC FORECAST IS CLOSE TO THE SHIPS AND LGEM
GUIDANCE BUT IS BELOW THE LATEST INTENSITY CONSENSUS MODELS.
 
THE INITIAL MOTION ESTIMATE IS 330/13...AS NADINE IS NOW SITUATED ON
THE SOUTHWESTERN PERIPHERY OF A WEAKENING MID-LEVEL RIDGE. THE
OVERALL TRACK FORECAST REASONING IS UNCHANGED...AS NADINE WILL MOVE
AROUND THE RIDGE IN THE NEXT 24 TO 36 HOURS AND THEN TURN EAST-
NORTHEASTWARD OR EASTWARD IN THE MID-LATITUDE WESTERLIES. THE
GUIDANCE IS TIGHTLY CLUSTERED THROUGH ABOUT 48 HOURS...AND THE NHC
FORECAST IS LARGELY AN UPDATE OF THE PREVIOUS ONE THROUGH THAT
TIME. A LARGE SPREAD PERSISTS IN THE TRACK MODELS AT DAYS 3 THROUGH
5. THE GFS...ECMWF...AND FSU SUPERENSEMBLE ARE ON THE SOUTHERN EDGE
OF THE GUIDANCE SUITE WHILE THE GFDL CONTINUES TO BE A FAR LEFT
OUTLIER SHOWING NADINE TURNING NORTHWARD AFTER 3 DAYS. THE NHC
TRACK LATE IN THE PERIOD IS SOUTH OF THE TVCA MULTI-MODEL CONSENSUS
AND NORTH OF THE AFOREMENTIONED SOUTHERNMOST MODEL GROUP. THROUGH
MOST OF THE PERIOD THE NHC FORECAST IS ALSO A LITTLE FASTER THAN THE
PREVIOUS...FOLLOWING THE LEAD OF THE GFS AND ECMWF MODELS.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/0300Z 25.0N  53.7W   60 KT  70 MPH
 12H  14/1200Z 26.8N  54.2W   60 KT  70 MPH
 24H  15/0000Z 29.1N  54.0W   60 KT  70 MPH
 36H  15/1200Z 30.7N  52.7W   65 KT  75 MPH
 48H  16/0000Z 31.4N  50.4W   65 KT  75 MPH
 72H  17/0000Z 32.3N  44.6W   70 KT  80 MPH
 96H  18/0000Z 33.5N  38.5W   70 KT  80 MPH
120H  19/0000Z 35.5N  32.5W   70 KT  80 MPH
 
$$
FORECASTER BRENNAN
 

WTNT44 KNHC 140844
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST FRI SEP 14 2012

THE SATELLITE APPEARANCE OF NADINE HAS BECOME MORE RAGGED DURING THE
PAST FEW HOURS.  THE CENTRAL CONVECTION HAS DECREASED IN BOTH
COVERAGE AND INTENSITY...AND THE CONVECTIVE BANDING IN THE EASTERN
SEMICIRCLE HAS ALSO DIMINISHED.  THIS CHANGE MAY BE DUE TO 20 KT OF
SOUTHWESTERLY VERTICAL WIND SHEAR ANALYZED BY THE SHIPS MODEL AND
BY CIMSS.  SATELLITE INTENSITY ESTIMATES ARE 65 KT FROM TAFB AND 55
KT FROM SAB...SO THE INITIAL INTENSITY REMAINS 60 KT.

NADINE CONTINUES ITS TURN TOWARD THE NORTH WITH AN INITIAL MOTION OF
340/13.  THE OVERALL TRACK FORECAST REASONING IS UNCHANGED...AS
NADINE WILL MOVE AROUND THE RIDGE IN THE NEXT 24 TO 36 HOURS AND
THEN TURN EAST-NORTHEASTWARD OR EASTWARD IN THE MID-LATITUDE
WESTERLIES. THE GUIDANCE IS TIGHTLY CLUSTERED THROUGH ABOUT 36
HOURS...AND THE NHC FORECAST IS LARGELY AN UPDATE OF THE PREVIOUS
ONE THROUGH THAT TIME.  A SIGNIFICANT SPREAD PERSISTS IN THE TRACK
MODELS AFTER THAT TIME.  THE NOGAPS IS A FAR LEFT OUTLIER...SHOWING
A NORTHWARD MOTION BY 120 HR.  THE UKMET AND GFDL ARE ON THE
NORTHERN OR LEFT EDGE OF THE MAIN TRACK GUIDANCE CLUSTER...WHILE
THE THE ECMWF AND FSU SUPERENSEMBLE REMAIN NEAR THE SOUTHERN OR
RIGHT EDGE OF THE MAIN CLUSTER.  THE GFS AND GFS ENSEMBLE MEAN LIE
NEAR THE CENTER OF THE ENVELOPE.  THERE HAS BEEN A SLIGHT SOUTHWARD
SHIFTED OF THE GUIDANCE ENVELOPE SINCE THE LAST ADVISORY...SO THE
FORECAST TRACK AFTER 36 HR IS SHIFTED A LITTLE SOUTHWARD...WHERE IT
LIES NEAR THE GFS AND GFS ENSEMBLE MEAN.

THE GLOBAL MODELS ARE IN GOOD AGREEMENT THAT THE WESTERLY SHEAR
SHOULD INCREASE TO 30-40 KT DURING THE NEXT 24-48 HR.  WHILE MUCH
OF THE INTENSITY GUIDANCE STILL FORECASTS STRENGTHENING...THIS
LOOKS OPTIMISTIC GIVEN THE FORECAST SHEAR VALUES.  THE INTENSITY
FORECAST KEEPS THE WINDS AT 60 KT FOR THE NEXT 48 HR...AND IT WOULD
BE NO SURPRISE IF NADINE WEAKENED INSTEAD.  THE SHEAR IS LIKELY TO
SLOWLY DECREASE AFTER 48 HR...AND THE FORECAST SHOWS A LITTLE
STRENGTHENING DURING THIS TIME WHILE THE CENTER REMAINS OVER WARM
WATER.  THE NEW INTENSITY FORECAST IS IN BEST AGREEMENT WITH THE
LGEM MODEL AND IS WEAKER THAN THE INTENSITY CONSENSUS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/0900Z 26.3N  54.1W   60 KT  70 MPH
 12H  14/1800Z 28.1N  54.2W   60 KT  70 MPH
 24H  15/0600Z 30.1N  53.2W   60 KT  70 MPH
 36H  15/1800Z 31.1N  51.2W   60 KT  70 MPH
 48H  16/0600Z 31.4N  48.9W   60 KT  70 MPH
 72H  17/0600Z 32.0N  43.0W   65 KT  75 MPH
 96H  18/0600Z 33.5N  37.5W   65 KT  75 MPH
120H  19/0600Z 35.5N  32.5W   65 KT  75 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 141440
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1100 AM AST FRI SEP 14 2012
 
NADINE CONTINUES TO SHOW LITTLE CHANGE IN ORGANIZATION ON SATELLITE
IMAGERY.  THE LOW CLOUD LINES ON VISIBLE IMAGERY SUGGEST THAT THE
CENTER IS DISPLACED A LITTLE TO THE SOUTHWESTERN PART OF THE
CENTRAL DENSE OVERCAST.  DVORAK INTENSITY ESTIMATES FROM TAFB AND
SAB REMAIN AT 65 AND 55 KT...RESPECTIVELY...SO THE CURRENT
INTENSITY ESTIMATE IS KEPT AT 60 KT.  THE INTENSITY FORECAST FOR
NADINE HAS BEEN A BIT CHALLENGING AS THE SYSTEM HAS REMAINED IN A
MARGINAL ATMOSPHERIC ENVIRONMENT OVER THE PAST FEW DAYS.  A LARGE
UPPER-LEVEL TROUGH IN THE VICINITY OF 65-70W LONGITUDE HAS BEEN
PRODUCING SOUTHWESTERLY SHEAR OVER NADINE.  AS THE TROPICAL CYCLONE
MOVES NORTHEASTWARD TO EASTWARD OVER THE NEXT FEW DAYS...THE
INFLUENCE OF THIS TROUGH WILL DIMINISH.  THE GLOBAL MODELS THEN
SHOW AN UPPER-LEVEL RIDGE MOVING MORE OR LESS IN TANDEM WITH THE
TROPICAL CYCLONE DURING THE FORECAST PERIOD.  THESE MODELS INDICATE
THAT SOME DECREASE IN SHEAR IS LIKELY IN A FEW DAYS...WHICH WOULD
GIVE NADINE THE OPPORTUNITY FOR SOME STRENGTHENING.  THIS IS
REFLECTED IN THE OFFICIAL FORECAST...WHICH IS ALSO IN GOOD
AGREEMENT A CONSENSUS THAT INCLUDES GUIDANCE FROM THE HURRICANE
FORECAST IMPROVEMENT PROGRAM...HFIP...MODELS.  

NADINE HAS MADE ITS EXPECTED TURN TO THE NORTH AND THE INITIAL
MOTION IS NOW 360/14.  THE TROPICAL CYCLONE SHOULD CONTINUE TO MOVE
AROUND THE PERIPHERY OF A SUBTROPICAL RIDGE AND TURN EASTWARD IN
THE FLOW ON THE NORTH SIDE OF THE RIDGE.  BY THE END OF THE FORECAST
PERIOD...NADINE IS EXPECTED TO TURN TOWARD THE LEFT AS IT INTERACTS
WITH A CYCLONIC CIRCULATION NEAR THE AZORES.  THE GUIDANCE ENVELOPE
IS BRACKETED BY THE ECMWF TO THE RIGHT/SOUTH AND THE GFDL TO THE
LEFT/NORTH.  THE OFFICIAL TRACK FORECAST IS CLOSE TO THE PREVIOUS
ONE...AND LIES BETWEEN THE GFS AND THE MULTI-MODEL CONSENSUS TVCN.     
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/1500Z 28.0N  53.5W   60 KT  70 MPH
 12H  15/0000Z 29.6N  53.1W   60 KT  70 MPH
 24H  15/1200Z 31.0N  51.5W   60 KT  70 MPH
 36H  16/0000Z 31.5N  49.4W   60 KT  70 MPH
 48H  16/1200Z 31.8N  46.8W   65 KT  75 MPH
 72H  17/1200Z 32.5N  40.5W   65 KT  75 MPH
 96H  18/1200Z 34.5N  35.0W   65 KT  75 MPH
120H  19/1200Z 36.5N  30.5W   60 KT  70 MPH
 
$$
FORECASTER PASCH/HAMRICK/FRACASSO
 

WTNT44 KNHC 142033
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  14
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 PM AST FRI SEP 14 2012
 
A 1624 UTC TRMM PASS SUGGESTS THAT THE CORE CONVECTION MAY BE
IMPROVING IN ORGANIZATION...BUT THE MID-LEVEL CENTER IS DISPLACED
ABOUT HALF A DEGREE NORTH OF THE LOW-LEVEL CENTER DUE TO VERTICAL
SHEAR.  DVORAK ESTIMATES REMAIN 65 KT FROM TAFB AND 55 KT FROM
SAB...AND THE MOST RECENT UW-CIMSS ADT ESTIMATE HAS ACTUALLY FALLEN
TO 55 KT.  THE SATELLITE SIGNATURE SEEMS LARGELY UNCHANGED FROM
THIS MORNING AND DOES NOT LEAD ME TO BELIEVE THAT NADINE HAS
WEAKENED...SO THE INITIAL INTENSITY IS KEPT AT 60 KT.

THE VERTICAL SHEAR IS NOT EXPECTED TO WEAKEN DURING THE FORECAST
PERIOD.  HOWEVER...THE SHEAR DIRECTION IS FORECAST TO CHANGE FROM
SOUTHWESTERLY TO WESTERLY IN A DAY OR TWO...AND THE SHIPS GUIDANCE
SHOWS THE NEGATIVE CONTRIBUTIONS OF STRONG SHEAR BEING CANCELED OUT
BY THE POSITIVE CONTRIBUTIONS OF A MORE FAVORABLE SHEAR DIRECTION. 
AS A RESULT...THE STATISTICAL GUIDANCE SHOWS LITTLE CHANGE IN
INTENSITY OVERALL...BUT DOES STILL PRESENT THE POSSIBILITY OF
NADINE BECOMING A HURRICANE DURING THE NEXT FEW DAYS.  THE HWRF
SHOWS NADINE STRENGTHENING SIGNIFICANTLY IN A COUPLE OF DAYS...BUT
THIS SCENARIO APPEARS LESS LIKELY SINCE THE CYCLONE WILL BE
APPROACHING COLDER WATER.  THE UPDATED NHC INTENSITY FORECAST IS
VERY CLOSE TO THE SHIPS MODEL AND SHOWS A LITTLE MORE WEAKENING BY
DAY 5 THAN INDICATED IN THE PREVIOUS ADVISORY.

NADINE IS NOW MOVING NORTH-NORTHEASTWARD WITH A MOTION OF 015/12 KT. 
THE STORM IS ENTERING THE BELT OF MID-LATITUDE WESTERLIES...AND IT
SHOULD TURN EASTWARD DURING THE NEXT DAY OR TWO.  A NORTHEASTWARD
TURN IS THEN FORECAST BY DAYS 4 AND 5 AS NADINE APPROACHES A LARGE
DEEP-LAYER LOW NEAR THE AZORES.  THE TRACK MODELS HAVE SHIFTED
SOUTHWARD BEYOND 24 HOURS...LEAVING THE PREVIOUS OFFICIAL FORECAST
ON THE NORTHERN EDGE OF THE GUIDANCE ENVELOPE.  THE NEW FORECAST
HAS BEEN MOVED A LITTLE SOUTHWARD AS WELL...SHOWING A MORE
PRONOUNCED DUE-EAST MOTION FOR A TIME.  THE NHC TRACK LIES VERY
CLOSE TO THE TIGHTLY CLUSTERED GFS...ECMWF...AND MODEL CONSENSUS
TVCA.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/2100Z 28.8N  53.4W   60 KT  70 MPH
 12H  15/0600Z 30.1N  52.6W   60 KT  70 MPH
 24H  15/1800Z 30.9N  50.4W   60 KT  70 MPH
 36H  16/0600Z 31.0N  47.5W   60 KT  70 MPH
 48H  16/1800Z 31.1N  44.1W   65 KT  75 MPH
 72H  17/1800Z 32.5N  37.5W   65 KT  75 MPH
 96H  18/1800Z 35.0N  33.5W   65 KT  75 MPH
120H  19/1800Z 37.0N  32.0W   55 KT  65 MPH
 
$$
FORECASTER BERG
 

WTNT44 KNHC 150246
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  15
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 PM AST FRI SEP 14 2012

NADINE HAS GOTTEN BETTER ORGANIZED OVER THE PAST FEW HOURS...WITH
THE CORE CONVECTION BECOMING MORE SYMMETRICAL AND MICROWAVE IMAGERY
SHOWING THAT THE LOW-LEVEL CENTER IS LOCATED A LITTLE CLOSER TO THE
DEEP CONVECTION. SATELLITE INTENSITY ESTIMATES RANGE FROM 65 KT
FROM TAFB TO 77 KT FROM SAB AND THE UW-CIMSS ADT. GIVEN THAT SOME
TILT STILL APPEARS TO EXIST IN THE CIRCULATION...THE INITIAL
INTENSITY WILL BE BASED ON THE MORE CONSERVATIVE ESTIMATE FOR THIS
ADVISORY. SOUTHWESTERLY VERTICAL SHEAR OF 25 TO 30 KT IS AFFECTING
NADINE...AND THIS MODERATE TO STRONG SHEAR IS FORECAST TO CONTINUE
FOR THE NEXT SEVERAL DAYS. GIVEN THIS MARGINAL ENVIRONMENT...ONLY
MINIMAL STRENGTHENING IS FORECAST IN THE SHORT TERM. LATE IN THE
PERIOD...THE CYCLONE WILL BE MOVING OVER COOLER WATERS...WHICH IN
COMBINATION WITH EVEN STRONGER SHEAR SHOULD LEAD TO GRADUAL
WEAKENING. THE NEW NHC INTENSITY FORECAST IS CLOSE TO THE DECAY
SHIPS MODEL THROUGH 72 HOURS AND TRENDS TOWARD THE LGEM BY DAY 5. 

THE INITIAL MOTION ESTIMATE IS 025/12...AS NADINE IS MOVING AROUND
THE NORTHWESTERN SIDE OF THE SUBTROPICAL RIDGE. THE CYCLONE WILL
ENTER THE MID-LATITUDE WESTERLIES WITHIN 24 HOURS...WHICH SHOULD
RESULT IN A QUICK EASTWARD MOTION UNTIL ABOUT DAY 3. A SLOWER
MOTION TOWARD THE NORTHEAST IS EXPECTED AT DAYS 4 AND 5 AS AN
UPPER-LEVEL TROUGH APPROACHES FROM THE WEST. THE GLOBAL MODEL
GUIDANCE IS IN GENERALLY GOOD AGREEMENT ON THIS SCENARIO...WHILE
THE REGIONAL HURRICANE MODELS APPEAR TO BE OUTLIERS AT THIS TIME.
THE NHC FORECAST IS LARGELY AN UPDATE OF THE PREVIOUS ONE...BUT
WITH A FASTER FORWARD SPEED THROUGH 72 HOURS. THE NEW NHC TRACK IS
VERY CLOSE TO A BLEND OF THE GFS...ECMWF...UKMET...AND THE GEFS
ENSEMBLE MEAN...AND LIES NEAR THE MIDDLE OF THE GUIDANCE ENVELOPE.

NADINE MARKS THE THIRD-EARLIEST FORMATION OF AN EIGHTH HURRICANE FOR
THE SEASON IN THE ATLANTIC BASIN...BEHIND 1893 AND 2005.  

FORECAST POSITIONS AND MAX WINDS
 
INIT  15/0300Z 30.0N  52.8W   65 KT  75 MPH
 12H  15/1200Z 30.8N  51.4W   70 KT  80 MPH
 24H  16/0000Z 31.2N  48.7W   70 KT  80 MPH
 36H  16/1200Z 31.1N  45.5W   70 KT  80 MPH
 48H  17/0000Z 31.2N  42.1W   70 KT  80 MPH
 72H  18/0000Z 33.0N  36.0W   65 KT  75 MPH
 96H  19/0000Z 35.5N  33.0W   60 KT  70 MPH
120H  20/0000Z 37.5N  31.5W   50 KT  60 MPH
 
$$
FORECASTER BRENNAN
 

WTNT44 KNHC 150852
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  16
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST SAT SEP 15 2012

NADINE HAS CHANGED LITTLE IN ORGANIZATION OVER THE PAST SEVERAL
HOURS. THE HURRICANE IS MAINTAINING CENTRAL CONVECTIVE BANDING...
ALTHOUGH A RECENT AMSU OVERPASS SUGGESTS THAT THE MID-LEVEL CENTER
IS DISPLACED TO THE NORTHEAST OR EAST OF THE LOW-LEVEL CENTER.
SATELLITE INTENSITY ESTIMATES ARE 77 KT FROM SAB AND 65 KT FROM
TAFB...AND RECENT AMSU INTENSITY ESTIMATES FROM CIMSS AND CIRA ARE
76 AND 73 KT RESPECTIVELY. DUE TO THE UNCERTAINTY ABOUT THE
ORGANIZATION...THE INITIAL INTENSITY REMAINS 65 KT. HOWEVER...THIS
INTENSITY COULD BE A LITTLE CONSERVATIVE.

NADINE CONTINUES ITS RECURVATURE INTO THE WESTERLIES WITH AN INITIAL
MOTION OF 050/13.  THE CYCLONE SHOULD MOVE GENERALLY EASTWARD IN
THE WESTERLIES FOR THE NEXT 2-3 DAYS...AND THERE IS A CHANCE IT
COULD MOVE A LITTLE SOUTH OF EAST AS SHOWN BY THE ECMWF.  AFTER
THREE DAYS...NADINE IS LIKELY TO TURN NORTHEASTWARD AS A DEEP-LAYER
LOW PRESSURE SYSTEM FORMS TO THE WEST OVER THE CENTRAL ATLANTIC. 
THE GFS...GFS ENSEMBLE MEAN...ECMWF...UKMET...AND FLORIDA STATE
SUPERENSEMBLE ARE NEAR THE CENTER OF THE TRACK GUIDANCE ENVELOPE...
AND THE NEW TRACK FORECAST LIES NEAR THESE MODELS. THE NEW FORECAST
IS SIMILAR TO THE OLD FORECAST THROUGH 48 HR...AND THEN IS SHIFTED
TO THE EAST OF THE PREVIOUS FORECAST DUE TO AN OVERALL SHIFT IN THE
TRACK GUIDANCE.
 
NADINE CONTINUES TO EXPERIENCE 25-35 KT OF SOUTHWESTERLY VERTICAL
WIND SHEAR...AND IT IS UNCLEAR HOW THE CYCLONE HAS BEEN ABLE TO
MAINTAIN ITSELF SO WELL IN THIS ENVIRONMENT. ALL GLOBAL MODEL
GUIDANCE FORECASTS AT LEAST 25-35 KT OF SHEAR TO CONTINUE THROUGH
THE FORECAST PERIOD...WHICH SHOULD PRECLUDE ANY SIGNIFICANT
STRENGTHENING. THE GFS...ECMWF...AND UKMET FORECAST A SHORTWAVE
TROUGH IN THE WESTERLIES TO INTERACT WITH NADINE IN 72-96 HR...
WHICH COULD CHANGE THE INTENSITY AND STRUCTURE. HOWEVER...THE
RESULTS OF THIS INTERACTION ARE NOT CURRENTLY REFLECTED IN ANY OF
THE INTENSITY GUIDANCE. THE NEW INTENSITY FORECAST IS THE SAME AS
THE PREVIOUS FORECAST AND IS SIMILAR TO THE SHIPS...LGEM...AND THE
INTENSITY CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/0900Z 30.7N  51.4W   65 KT  75 MPH
 12H  15/1800Z 31.1N  49.6W   70 KT  80 MPH
 24H  16/0600Z 31.1N  46.8W   70 KT  80 MPH
 36H  16/1800Z 31.0N  43.6W   70 KT  80 MPH
 48H  17/0600Z 31.4N  40.5W   70 KT  80 MPH
 72H  18/0600Z 33.0N  35.0W   65 KT  75 MPH
 96H  19/0600Z 35.5N  31.5W   60 KT  70 MPH
120H  20/0600Z 37.5N  29.5W   50 KT  60 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 151449
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 AM AST SAT SEP 15 2012
 
ALTHOUGH NADINE IS STILL A TILTED HURRICANE...THE CONVECTIVE
ORGANIZATION IS IMPROVING.  A RAGGED EYE FEATURE IS TRYING TO FORM
IN VISIBLE IMAGERY...AND RECENT MICROWAVE DATA SHOWED DEEP
CONVECTION NEARLY SURROUNDING THE CENTER.  CURRENT INTENSITY
ESTIMATES ARE 65 KT FROM TAFB AND 77 KT FROM SAB...SO THE ADVISORY
INTENSITY IS SET AT 70 KT.  THIS IS SUPPORTED BY RECENT UW-CIMSS
ADT ESTIMATES BETWEEN 65 AND 75 KT.

NADINE IS QUICKLY RECURVING AND NOW HAS AN ESTIMATED MOTION OF
070/13 KT.  THE HURRICANE IS ENTERING THE FLOW TO THE SOUTH OF A
COMPLEX DEEP-LAYER LOW PRESSURE SYSTEM LOCATED NEAR THE AZORES...
AND NADINE SHOULD TURN EASTWARD AND ACCELERATE DURING THE NEXT
COUPLE OF DAYS.  HOWEVER...A BLOCKING PATTERN IS EXPECTED TO
DEVELOP OVER THE NORTHEASTERN ATLANTIC BY DAY 3 WITH ANOTHER
DEEP-LAYER LOW FORMING OVER THE CENTRAL ATLANTIC ON DAYS 4 AND 5. 
THIS PATTERN CHANGE SHOULD CAUSE NADINE TO TURN NORTHEASTWARD AND
BECOME NEARLY STATIONARY JUST TO THE SOUTHWEST OF THE AZORES BY THE
END OF THE FORECAST PERIOD.  MANY OF THE TRACK MODELS ARE SHOWING A
FASTER FORWARD SPEED WHILE NADINE IS WITHIN THE WESTERLY FLOW...AND
THE NEW NHC FORECAST IS A LITTLE FASTER THAN AND SOUTH OF THE
PREVIOUS FORECAST DURING THE FIRST 3 DAYS.  THE FORECASTS ARE VERY
SIMILAR ON DAYS 4 AND 5...WITH THE NEW ONE LYING BETWEEN THE MODEL
CONSENSUS TVCA AND FLORIDA STATE SUPERENSEMBLE.

NADINE IS EXPECTED TO REMAIN IN A HIGHLY SHEARED ENVIRONMENT DURING
THE ENTIRE FORECAST PERIOD...BUT THE SHEAR DIRECTION IS SUCH THAT
IT SHOULD TEMPER SIGNIFICANT WEAKENING.  THEREFORE...THE NHC
INTENSITY FORECAST MAINTAINS NADINE AS A CATEGORY ONE HURRICANE FOR
THE NEXT 3 DAYS...WHICH IS SUPPORTED BY MOST OF THE INTENSITY
GUIDANCE.  COLDER WATER SHOULD ULTIMATELY INDUCE SOME WEAKENING ON
DAYS 4 AND 5...AND THAT IS REFLECTED IN THE OFFICIAL FORECAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/1500Z 30.9N  49.9W   70 KT  80 MPH
 12H  16/0000Z 31.0N  47.8W   70 KT  80 MPH
 24H  16/1200Z 30.9N  44.2W   70 KT  80 MPH
 36H  17/0000Z 31.0N  40.6W   70 KT  80 MPH
 48H  17/1200Z 31.7N  37.5W   70 KT  80 MPH
 72H  18/1200Z 34.0N  33.0W   65 KT  75 MPH
 96H  19/1200Z 36.5N  31.5W   60 KT  70 MPH
120H  20/1200Z 37.0N  31.0W   50 KT  60 MPH
 
$$
FORECASTER BERG
 

WTNT44 KNHC 152037
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 PM AST SAT SEP 15 2012
 
NADINE HAS BEGUN TO LOOK A LITTLE MORE RAGGED THIS AFTERNOON. RECENT
MICROWAVE DATA INDICATE THAT THE DEEP CONVECTION IS BEING SHEARED
TO THE NORTHEAST OF THE LOW-LEVEL CENTER. DESPITE THE MORE
DISHEVELED APPEARANCE...THE INTENSITY IS BEING HELD AT 70 KT BASED
ON DVORAK CURRENT INTENSITY ESTIMATES OF 65 KT FROM TAFB AND 77 KT
FROM SAB...AND A 70-KT ESTIMATE FROM THE UW-CIMSS ADT.

NADINE HAS TURNED EASTWARD WITH AN INITIAL MOTION OF 090/14 KT.
VISIBLE SATELLITE IMAGERY SHOWS LOW-LEVEL NORTHERLY FLOW IMPINGING
ON THE NORTHERN SIDE OF NADINE...AND THE HURRICANE MAY RESPOND IN
THE SHORT TERM BY MOVING A LITTLE SOUTH OF DUE EAST. HOWEVER...A
GENERAL EASTWARD MOTION IS EXPECTED DURING THE NEXT 36 HOURS WHILE
NADINE MOVES TOWARDS A COMPLEX AREA OF LOW PRESSURE NEAR THE
AZORES. THIS COMPLEX LOW IS FORECAST TO BE REPLACED BY A MID-LEVEL
ANTICYCLONE NORTH OF THE AZORES IN A FEW DAYS...WHILE ANOTHER LARGE
DEEP-LAYER LOW DEVELOPS OVER THE CENTRAL ATLANTIC. THESE FEATURES
WILL CAUSE NADINE TO MOVE NORTHEASTWARD ON DAYS 3 THROUGH 5 AND
BECOME NEARLY STATIONARY NEAR THE AZORES. THE NHC TRACK FORECAST
CONTINUES TO FOLLOW THE FASTER MODELS...PARTICULARLY THE GFS...
ECMWF...AND THE FSU SUPERENSEMBLE...AND LITTLE CHANGE WAS REQUIRED
TO THE PREVIOUS FORECAST.

THE SHIPS DIAGNOSTICS SUGGEST THAT THE WESTERLY SHEAR AFFECTING
NADINE COULD LIGHTEN UP A BIT OVER THE NEXT COUPLE OF DAYS...AND
THE STATISTICAL GUIDANCE FLATLINES THE INTENSITY FOR ABOUT 48
HOURS. GRADUAL WEAKENING IS EXPECTED BY DAY 3 AS THE SHEAR
CONTINUES AND NADINE MOVES OVER SEA SURFACE TEMPERATURES COLDER
THAN 26C. THE NHC INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE
AND JUST SHOWS A LITTLE MORE WEAKENING AT THE LATTER PART OF THE
FORECAST PERIOD.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/2100Z 30.8N  48.2W   70 KT  80 MPH
 12H  16/0600Z 30.7N  45.7W   70 KT  80 MPH
 24H  16/1800Z 30.7N  41.9W   70 KT  80 MPH
 36H  17/0600Z 31.3N  38.4W   70 KT  80 MPH
 48H  17/1800Z 32.4N  35.7W   70 KT  80 MPH
 72H  18/1800Z 35.0N  32.5W   65 KT  75 MPH
 96H  19/1800Z 37.0N  31.5W   55 KT  65 MPH
120H  20/1800Z 38.0N  30.5W   50 KT  60 MPH
 
$$
FORECASTER BERG
 

WTNT44 KNHC 160257
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  19
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 PM AST SAT SEP 15 2012
 
THE STRUCTURE OF NADINE HAS NOT CHANGED MUCH THIS EVENING. RECENT
MICROWAVE IMAGERY INDICATES THAT THE LOW-LEVEL CENTER REMAINS
DISPLACED TO THE SOUTHWEST OF THE MID-LEVEL CENTER BY ABOUT 30 N
MI...LIKELY DUE TO THE 30 KT OF WESTERLY SHEAR AS ANALYZED BY
UW-CIMSS SATELLITE ANALYSES AND THE SHIPS MODEL. THE INITIAL
INTENSITY IS HELD AT 70 KT BASED ON A BLEND OF THE 00Z UW-CIMSS ADT
ESTIMATE AND THE LATEST DVORAK ESTIMATES FROM TAFB AND SAB. NADINE
IS EXPECTED TO REMAIN IN A MODERATE TO STRONG WESTERLY TO
SOUTHWESTERLY SHEAR ENVIRONMENT THOUGH THE FORECAST PERIOD. MOST OF
THE INTENSITY GUIDANCE INDICATES LITTLE CHANGE FOR THE NEXT DAY OR
SO...FOLLOWED BY GRADUAL WEAKENING AS THE CYCLONE MOVES OVER
PROGRESSIVELY COOLER WATERS. THE NHC FORECAST HAS BEEN ADJUSTED
DOWNWARD JUST A LITTLE...BUT STILL KEEPS NADINE AS A HURRICANE FOR
THE NEXT COUPLE OF DAYS. AT 36 HOURS AND BEYOND THE NHC FORECAST IS
CLOSE TO THE LATEST INTENSITY CONSENSUS.
 
THE INITIAL MOTION ESTIMATE IS 095/15...AS NADINE HAS MOVED A LITTLE
SOUTH OF DUE EAST OVER THE PAST FEW HOURS. A SHORTWAVE MID-LEVEL
RIDGE CENTERED ALONG 50W SHOULD CONTINUE TO PUSH NADINE SOUTH OF DUE
EAST FOR THE NEXT 12 HOURS OR SO. NADINE IS FORECAST TO GRADUALLY
TURN NORTHEASTWARD BY 48 HOURS AS THE CYCLONE MOVES TOWARD A
DEEP-LAYER LOW NEAR THE AZORES. THIS LOW THEN MOVES EASTWARD AND
WEAKENS AS A COMPLEX STEERING PATTERN EVOLVES OVER THE NORTHEASTERN
ATLANTIC. NADINE SHOULD TURN SLOWLY NORTHWARD BY DAY 4 AS THE
CYCLONE BECOMES SITUATED BETWEEN A RIDGE TO THE EAST...A MID/
UPPER-LEVEL LOW TO THE SOUTHWEST...AND A SECOND RIDGE BUILDING TO
THE NORTHWEST. BY DAY 5 ANOTHER MID/UPPER-LEVEL LOW DIGS SOUTH TO
THE NORTHEAST OF NADINE. THERE HAS BEEN LARGE RUN-TO-RUN
VARIABILITY WITH THE INTERACTION OF NADINE AND THIS LOW. SOME
SOLUTIONS HAVE SHOWN NADINE MERGING WITH THE LOW...WHILE THE LATEST
RUNS OF THE ECMWF AND GFS KEEP THE LOW FARTHER EAST AND TURN NADINE
SOUTHWARD. THE NEW NHC FORECAST IS CLOSE TO A BLEND OF THE ECMWF...
GFS...GEFS ENSEMBLE MEAN AND THE FSU SUPERENSEMBLE THROUGH THE
PERIOD...WHICH RESULTS IN LITTLE CHANGE FROM THE PREVIOUS FORECAST
THROUGH 72 HOURS. THE NEW NHC TRACK SHOWS A SHARPER NORTHWARD TURN
AT DAY 4 BUT INTRODUCES A SLOW SOUTHEASTWARD MOTION AT DAY 5. THIS
MOTION IS SLOWER THAN THE GFS AND ECMWF HOWEVER...DUE TO THE LARGE
UNCERTAINTY AT THESE TIME RANGES.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/0300Z 30.6N  46.6W   70 KT  80 MPH
 12H  16/1200Z 30.5N  43.8W   70 KT  80 MPH
 24H  17/0000Z 30.9N  40.0W   70 KT  80 MPH
 36H  17/1200Z 31.8N  37.0W   65 KT  75 MPH
 48H  18/0000Z 33.0N  34.8W   65 KT  75 MPH
 72H  19/0000Z 35.5N  32.5W   60 KT  70 MPH
 96H  20/0000Z 37.0N  32.0W   55 KT  65 MPH
120H  21/0000Z 36.5N  31.5W   50 KT  60 MPH
 
$$
FORECASTER BRENNAN
 

WTNT44 KNHC 160849
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  20
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST SUN SEP 16 2012

NADINE LOOKS A LITTLE RAGGED IN SATELLITE IMAGERY THIS MORNING...AS
THE CENTRAL CONVECTION LOOKS MORE SHEARED THAN IT DID EARLIER.  AN
AMSU OVERPASS AT 0448 UTC SUGGESTS THAT THE SYSTEM REMAINS TILTED
VERTICALLY...WITH THE MID-LEVEL CENTER DISPLACED EAST OF THE
LOW-LEVEL CENTER DUE TO 25 KT OF WESTERLY VERTICAL WIND SHEAR. 
SATELLITE INTENSITY ESTIMATES ARE 77 KT FROM SAB AND 65 KT FROM
TAFB...AND AN AMSU-BASED INTENSITY ESTIMATE FROM CIMSS IS 72 KT. 
BASED ON THESE DATA...THE INITIAL INTENSITY REMAINS 70 KT.

THE INITIAL MOTION REMAINS 095/15.  NADINE IS EMBEDDED IN
MID-/UPPER-LEVEL WESTERLY FLOW THAT SHOULD CONTINUE TO STEER THE
CYCLONE EASTWARD FOR THE NEXT 12-24 HR.  AFTER THAT TIME...THE
GLOBAL MODELS AGREE ON THE FORMATION OF A DEEP-LAYER LOW WEST OF
NADINE...WHICH SHOULD CAUSE THE CYCLONE TO TURN NORTHEASTWARD. 
NEAR THE END OF THE FORECAST PERIOD...THE MODELS DIVERGE ON THE
INTERACTION OF NADINE WITH AN MID-/UPPER-LEVEL LOW OVER THE
NORTHEASTERN ATLANTIC.  THE ECMWF...CANADIAN...AND NOGAPS SHOW
NADINE TRYING TO MERGE WITH THIS LOW.  THE GFS DOES NOT SHOW A
MERGER AND TRAPS NADINE SOUTH OF A BUILDING RIDGE.  THE UKMET SHOWS
THE LOW MOVING FARTHER EAST THAN THE ECMWF/CANADIAN/NOGAPS...AND AS
A RESULT...FORECASTS NADINE TO MOVE MUCH FARTHER TO THE EAST THAN
THE OTHER MODELS.  GIVEN THE UNCERTAINTY AND THE SPREAD IN THE
TRACK GUIDANCE BY 120 HR...THE NEW TRACK FORECAST FOLLOWS THE
PREVIOUS FORECAST IN SHOWING A SLOW MOTION.  OVERALL...THE NEW
TRACK FORECAST IS SIMILAR TO THE PREVIOUS FORECAST AND LIES NEAR
THE CENTER OF THE TRACK GUIDANCE ENVELOPE.

THE INTENSITY FORECAST IS FULL OF ISSUES.  THE FIRST IS THE WESTERLY
SHEAR...WHICH LIKELY SHOULD CONTINUE FOR THE NEXT 24 HR AND COULD
CAUSE WEAKENING.  THE SECOND IS THAT THE GLOBAL MODELS FORECAST TWO
UPPER-LEVEL SHORTWAVE TROUGHS WEST OF NADINE TO OVERTAKE THE
HURRICANE BETWEEN 24-72 HR.  THIS COULD DECREASE THE SHEAR...
PROVIDE AN IMPROVED OUTFLOW...AND PERMIT SOME INTENSIFICATION.  THE
THIRD IS THE POSSIBILITY OF A MERGER WITH THE UPPER-LEVEL LOW NEAR
120 HR...WHICH...IF IT OCCURS...WOULD SIGNIFICANTLY CHANGE THE
STRUCTURE OF NADINE.  FINALLY...THE FORECAST TRACK TAKES THE
CYCLONE OVER DECREASING SEA SURFACE TEMPERATURES.  DESPITE THIS
COMPLEXITY...THE INTENSITY GUIDANCE IS IN RELATIVELY GOOD AGREEMENT
THAT NADINE SHOULD CHANGE LITTLE IN STRENGTH DURING THE NEXT 48
HR...FOLLOWED BY A SLOW WEAKENING.  THE NEW INTENSITY FORECAST
FOLLOWS THAT SCENARIO AND IS UNCHANGED FROM THE PREVIOUS FORECAST. 
IT IS ALSO IN GOOD AGREEMENT WITH THE SHIPS...LGEM...AND THE
INTENSITY CONSENSUS.  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/0900Z 30.5N  44.7W   70 KT  80 MPH
 12H  16/1800Z 30.5N  42.0W   70 KT  80 MPH
 24H  17/0600Z 31.3N  38.6W   70 KT  80 MPH
 36H  17/1800Z 32.3N  36.0W   65 KT  75 MPH
 48H  18/0600Z 33.5N  34.3W   65 KT  75 MPH
 72H  19/0600Z 36.0N  32.5W   60 KT  70 MPH
 96H  20/0600Z 36.5N  32.0W   55 KT  65 MPH
120H  21/0600Z 36.5N  31.5W   50 KT  60 MPH
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 161443
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  21
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 AM AST SUN SEP 16 2012
 
FIRST FEW VISIBLE SATELLITE IMAGES INDICATE THE INNER-CORE BANDING
FEATURES OF NADINE HAVE IMPROVED...AND RECENT MICROWAVE IMAGERY
ALSO SUGGESTS THAT THE EASTWARD TILT TO THE EYE HAS DECREASED.
SINCE A BANDING EYE HAS BEEN TRYING TO DEVELOP OVER THE PAST FEW
HOURS...THE INITIAL INTENSITY WILL REMAIN AT 70 KT.
 
CONVENTIONAL AND MICROWAVE SATELLITE FIXES INDICATE NADINE HAS
ACCELERATED EASTWARD SINCE THE PREVIOUS ADVISORY...AND THE INITIAL
MOTION ESTIMATE IS NOW 090/20 KT. NADINE IS EXPECTED TO REMAIN
NORTH OF A DEEP-LAYER SUBTROPICAL RIDGE AND BE STEERED QUICKLY
EASTWARD WITHIN MID- TO UPPER-LEVEL WESTERLY FLOW FOR NEXT 24 HOURS
OR SO. AFTER THAT TIME...THE GLOBAL AND REGIONAL MODELS REMAIN IN
GOOD AGREEMENT ON THE DEVELOPMENT OF A DEEP-LAYER LOW TO THE WEST
OF NADINE...WHICH IS EXPECTED TO LIFT THE CYCLONE OUT TO THE
NORTHEAST AT A SLOWER FORWARD SPEED. BY DAYS 4 AND 5...NADINE IS
FORECAST TO BEGIN TO INTERACT WITH A SEPARATE MID- TO UPPER-LEVEL
LOW OVER THE NORTHEASTERN ATLANTIC...WHICH COULD RESULT IN ERRATIC
MOTION OCCURRING WHEN THE CYCLONE IS LOCATED JUST SOUTHWEST OF THE
AZORES. ALTHOUGH SOME OF THE MODELS INDICATE THAT MERGING COULD
OCCUR WITH THE AFOREMENTIONED NON-TROPICAL LOW...THE CURRENT
FORECAST IS DISCOUNTING THAT SCENARIO AT THIS TIME...AND ONLY
BINARY INTERACTION BETWEEN THE TWO LOWS IS EXPECTED. THE OFFICIAL
FORECAST TRACK HAS BEEN SHIFTED SLIGHTLY TO THE EAST OF THE
PREVIOUS TRACK...WHICH IS PRIMARILY DUE TO THE MORE EASTWARD
INITIAL POSITION...AND LIES BETWEEN THE CONSENSUS MODELS TV15 AND
TVCA...AND THE FLORIDA STATE SUPERENSEMBLE MODEL.
 
LITTLE CHANGE IN VERTICAL SHEAR IS EXPECTED FOR THE NEXT 72 HOURS...
SO THE MAIN WEAKENING FACTOR WILL BE COOLER OCEAN TEMPERATURES
AHEAD OF THE CYCLONE. AFTERWARDS...HOWEVER...THE SHEAR IS FORECAST
TO INCREASE TO NEAR 30 KT FROM THE SOUTHWEST AS A STRONG NORTHEAST
ATLANTIC LOW DROPS SOUTHWARD AND IMPINGES ON THE CYCLONE...AND MORE
SIGNIFICANT WEAKENING IS EXPECTED. THE NHC INTENSITY FORECAST IS
SIMILAR TO THE PREVIOUS FORECAST...AND FOLLOWS THE TREND
SHIPS...LGEM...AND FSSE INTENSITY CONSENSUS.

FORECAST POSITIONS AND MAX WINDS
 
INIT  16/1500Z 30.5N  41.7W   70 KT  80 MPH
 12H  17/0000Z 30.9N  39.3W   70 KT  80 MPH
 24H  17/1200Z 31.7N  36.4W   65 KT  75 MPH
 36H  18/0000Z 32.8N  34.2W   65 KT  75 MPH
 48H  18/1200Z 34.0N  32.9W   60 KT  70 MPH
 72H  19/1200Z 36.3N  31.6W   55 KT  65 MPH
 96H  20/1200Z 37.0N  30.5W   50 KT  60 MPH
120H  21/1200Z 37.0N  29.0W   45 KT  50 MPH
 
$$
FORECASTER STEWART
 

WTNT44 KNHC 162036
TCDAT4
 
HURRICANE NADINE DISCUSSION NUMBER  22
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 PM AST SUN SEP 16 2012
 
MICROWAVE IMAGERY CONTINUES TO INDICATE THAT NADINE NO LONGER HAS A
TILTED EYE. HOWEVER...DEEP CONVECTION HAS WANED SINCE THE PREVIOUS
ADVISORY...AND CONVECTIVE BANDING FEATURES HAVE ALSO BECOME A
LITTLE MORE FRAGMENTED. THE INITIAL INTENSITY HAS BEEN REDUCED TO
65 KT...WHICH IS SUPPORTED BY A CONSENSUS T4.0/65 KT SATELLITE
INTENSITY ESTIMATE FROM TAFB AND SAB.
 
THE INITIAL MOTION ESTIMATE IS 080/20 KT. NADINE IS ON TRACK
AND...THEREFORE...THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS
FORECAST TRACK OR REASONING. THE CYCLONE SHOULD GRADUALLY TURN
TOWARD THE EAST-NORTHEAST AND NORTHEAST OVER THE NEXT 12-24 HOURS
AHEAD OF A DEEP-LAYER LOW FORECAST TO DEVELOP TO THE WEST OF
NADINE. A TURN TOWARD THE NORTH ACCOMPANIED BY A SHARP DECREASE IN
FORWARD SPEED IS EXPECTED BY DAY 3. AFTER THAT...A SLOW TURN TO THE
EAST IS EXPECTED BY DAYS 4 AND 5 WHEN THE CYCLONE IS FORECAST TO
UNDERGO BINARY INTERACTION WITH A SEPARATE MID- TO UPPER-LEVEL LOW
THAT IS EXPECTED TO DROP SOUTHWARD OVER THE NORTHEASTERN ATLANTIC.
THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY
TRACK...AND LIES BETWEEN THE CONSENSUS MODELS TV15 AND TVCA...AND
THE FLORIDA STATE SUPERENSEMBLE MODEL.
 
ALTHOUGH THE VERTICAL WIND SHEAR IS FORECAST BY THE SHIPS MODEL 
TO DECREASE OVER THE NEXT 72 HOURS...MID-LEVEL MOISTURE...
INSTABILITY...AND SEA-SURFACE TEMPERATURES ARE ALSO EXPECTED TO
GRADUALLY DECREASE. THE LATTER UNFAVORABLE ENVIRONMENTAL AND
OCEANIC CONDITIONS SHOULD INDUCE STEADY WEAKENING THROUGH 72
HOURS...AND CONTINUE AFTER THAT AS THE SHEAR INCREASES FROM THE
SOUTHWEST AHEAD OF THE STRONG NORTHEAST ATLANTIC LOW. THE NHC
INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY...AND
FOLLOWS THE TREND OF THE SHIPS...LGEM...AND FSSE INTENSITY
CONSENSUS.

FORECAST POSITIONS AND MAX WINDS
 
INIT  16/2100Z 30.8N  39.1W   65 KT  75 MPH
 12H  17/0600Z 31.5N  36.7W   65 KT  75 MPH
 24H  17/1800Z 32.6N  34.4W   60 KT  70 MPH
 36H  18/0600Z 33.8N  32.7W   60 KT  70 MPH
 48H  18/1800Z 34.9N  32.0W   55 KT  65 MPH
 72H  19/1800Z 36.9N  31.3W   50 KT  60 MPH
 96H  20/1800Z 37.5N  29.5W   50 KT  60 MPH...NEAR AZORES
120H  21/1800Z 37.5N  28.0W   45 KT  50 MPH...NEAR AZORES
 
$$
FORECASTER STEWART
 

WTNT44 KNHC 170253
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  23
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 PM AST SUN SEP 16 2012
 
THE SATELLITE PRESENTATION OF NADINE HAS DEGRADED SINCE THIS
AFTERNOON WITH LESS CONVECTION NEAR THE CENTER AND A MORE
ASYMMETRIC APPEARANCE.  RECENT MICROWAVE IMAGES ALSO SHOW THAT THE
LOW-LEVEL CENTER IS DISPLACED TO THE SOUTHWEST OF THE PRIMARY
CONVECTIVE BAND.  AS A RESULT...DVORAK T-NUMBERS HAVE DECREASED AND
THE INITIAL INTENSITY IS LOWERED TO 60 KT...WHICH IS A BLEND OF 
THE LATEST AND T- AND CI-NUMBERS.  ALTHOUGH VERTICAL SHEAR IS
FORECAST TO DECREASE A LITTLE DURING THE NEXT DAY OR SO...IT IS
EXPECTED TO REMAIN MODERATE TO STRONG OVER THE NEXT 72 HOURS.
THE SHEAR ALONG WITH GRADUALLY DECREASING SSTS SHOULD INDUCE SOME
WEAKENING...HOWEVER MUCH OF THE INTENSITY GUIDANCE AND THE GLOBAL
MODELS SHOW LITTLE OVERALL CHANGE IN STRENGTH OVER THE NEXT COUPLE
OF DAYS.  THE LACK OF WEAKENING COULD BE DUE TO THE INTERACTION OF
NADINE AND A SHORT-WAVE TROUGH APPROACHING THE CYCLONE FROM THE
WEST.  THE NHC FORECAST IS IN GOOD AGREEMENT WITH THE GUIDANCE AND
ONLY PREDICTS A SLIGHT DECREASE IN INTENSITY DURING THE NEXT
SEVERAL DAYS. 
 
MICROWAVE DATA DURING THE PAST 6-12 HOURS SUGGESTS THAT NADINE
IS BEGINNING TO SLOW DOWN AND HAS TURNED EAST-NORTHEASTWARD.  THE
INITIAL MOTION ESTIMATE IS 075/16 KT.  AN ADDITIONAL REDUCTION IN
FORWARD SPEED AND A TURN TOWARD THE NORTHEAST ARE EXPECTED DURING
THE NEXT DAY OR TWO AS A MID-LEVEL RIDGE SLIDES EASTWARD TO THE
NORTH OF NADINE AND A CUT-OFF LOW FORMS TO THE WEST OF THE CYCLONE.
THE MODEL GUIDANCE IS IN GOOD AGREEMENT DURING THE FIRST 2 TO 3 DAYS
OF THE FORECAST PERIOD.  AFTER THAT TIME...ANOTHER MID- TO
UPPER-LEVEL LOW IS FORECAST TO MOVE SOUTHWARD OVER THE NORTHEASTERN
ATLANTIC.  AS THIS OCCURS...THE TRACK GUIDANCE BECOME QUITE
DIVERGENT AS THEY DEPICT VARYING INTERACTIONS OF NADINE AND THE
UPPER-LOW.  GIVEN THE LARGE SPREAD IN THE GUIDANCE...THE NHC
FORECAST REMAINS NEAR THE MODEL CONSENSUS AT DAYS 4 AND 5. 

ALTHOUGH NADINE HAS RECENTLY TAKEN ON A LESS TROPICAL APPEARANCE IN
SATELLITE DUE TO AN APPROACHING TROUGH...THE GLOBAL MODELS SUGGEST
THIS TROUGH WILL NOT BE STRONG ENOUGH TO CAUSE NADINE TO TRANSITION
INTO AN EXTRATROPICAL CYCLONE.  INSTEAD...THE GFS AND ECMWF
INDICATE THAT AS THE TROPICAL CYCLONE INTERACTS WITH THE CUT-OFF
LOW IN A FEW DAYS...NADINE WILL THEN TRANSITION INTO AN
EXTRATROPICAL CYCLONE...AND THIS TRANSFORMATION IS FORECAST TO 
BE COMPLETE IN ABOUT 5 DAYS.  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  17/0300Z 31.4N  38.1W   60 KT  70 MPH
 12H  17/1200Z 32.1N  35.8W   55 KT  65 MPH
 24H  18/0000Z 33.2N  33.9W   55 KT  65 MPH
 36H  18/1200Z 34.4N  32.9W   55 KT  65 MPH
 48H  19/0000Z 35.6N  32.5W   55 KT  65 MPH
 72H  20/0000Z 37.0N  31.5W   50 KT  60 MPH
 96H  21/0000Z 37.5N  29.5W   50 KT  60 MPH
120H  22/0000Z 37.5N  28.5W   50 KT  60 MPH...POST-TROP/EXTRATROP
 
$$
FORECASTER BROWN
 

WTNT44 KNHC 170838
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  24
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST MON SEP 17 2012

AIRMASS IMAGERY FROM EUMETSAT INDICATES THAT AN UPPER-LEVEL
SHORTWAVE TROUGH IS NOW INTERACTING WITH NADINE...WITH A TONGUE OF
DRY AIR WRAPPING AROUND THE SOUTH AND WEST SIDES OF THE CYCLONE. 
THIS HAS RESULTED IN A DECREASE IN THE CENTRAL CONVECTION AND AN
INCREASE IN CONVECTIVE BANDING OVER THE NORTHERN SEMICIRCLE. 
SATELLITE INTENSITY ESTIMATES ARE TROPICAL 65 KT FROM TAFB AND
SUBTROPICAL 55-65 KT FROM SAB.  A RECENT OSCAT OVERPASS SHOWED
SEVERAL 55 KT WIND VECTORS TO THE SOUTH AND SOUTHEAST OF THE
CENTER...WHILE RECENT CIMSS AMSU INTENSITY ESTIMATES WERE 77-79 KT. 
THE INITIAL INTENSITY REMAINS 60 KT BASED ON A BLEND OF THESE DATA.

THE INITIAL MOTION IS NOW 065/15.  AN ADDITIONAL REDUCTION IN
FORWARD SPEED AND A TURN TOWARD THE NORTH-NORTHEAST ARE EXPECTED
DURING THE NEXT DAY OR TWO AS A MID-LEVEL RIDGE SLIDES EASTWARD TO
THE NORTH OF NADINE...AND A CUT-OFF LOW FORMS TO THE WEST OF THE
CYCLONE.  THE MODEL GUIDANCE IS IN GOOD AGREEMENT DURING THE FIRST
48-72 HR...AND THIS PART OF THE NEW FORECAST IS LITTLE CHANGED FROM
THE PREVIOUS ADVISORY.  AFTER THAT TIME...ANOTHER MID-/UPPER-LEVEL
LOW IS FORECAST TO MOVE SOUTHWARD OVER THE NORTHEASTERN ATLANTIC
TOWARD NADINE...WITH THE TWO SYSTEMS LIKELY TO STRONGLY INTERACT
AFTER 96 HR.  AS THIS OCCURS...THE DYNAMICAL GUIDANCE BECOMES QUITE
DIVERGENT DUE TO THE DIFFERENCES IN HOW THEY DEPICT THIS
INTERACTION.  GIVEN THE UNCERTAINTY...THE NEW TRACK FORECAST
FOLLOWS THE TREND OF THE PREVIOUS FORECAST IN SHOWING A SLOW
MOTION...WHICH SMOOTHS THROUGH SOME POSSIBLY VERY ERRATIC MOTION
DURING THIS TIME.

THE GLOBAL MODELS FORECAST THAT NADINE WILL INTERACT WITH THE
CURRENT UPPER-LEVEL TROUGH...AND A SECOND TROUGH APPROACHING FROM
THE WEST...DURING THE NEXT 48 HR.  THESE INTERACTIONS SHOULD CAUSE
NADINE TO INGEST UPPER-LEVEL COOL/DRY AIR...WHICH COULD START
EXTRATROPICAL TRANSITION.  HOWEVER...THE GLOBAL MODELS AGREE THAT
THERE IS NOT ENOUGH COLD AIR TO COMPLETE TRANSITION...AND THEY
MAINTAIN NADINE AS A WARM-CORE SYSTEM THROUGH AT LEAST 96 HR...
POSSIBLY WITH SOME HYBRID CHARACTERISTICS.  THE FORECAST OF NADINE
BECOMING EXTRATROPICAL AT 120 HR IS BASED ON THE PREMISE THAT
INTERACTION WITH THE NORTH ATLANTIC LOW WILL BRING A LARGER BATCH
OF COLD AIR INTO THE SYSTEM.  HOWEVER...THIS IS A LOW CONFIDENCE
TRANSITION FORECAST.  REGARDLESS OF WHETHER THE CYCLONE IS
TROPICAL...EXTRATROPICAL...OR HYBRID...ALL OF THE INTENSITY
GUIDANCE FORECASTS NADINE TO REMAIN A LARGE AND VIGOROUS SYSTEM
OVER THE NORTHEASTERN ATLANTIC THROUGH THE FORECAST PERIOD. 

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  17/0900Z 32.0N  36.4W   60 KT  70 MPH
 12H  17/1800Z 32.8N  34.7W   55 KT  65 MPH
 24H  18/0600Z 34.0N  33.2W   55 KT  65 MPH
 36H  18/1800Z 35.2N  32.5W   55 KT  65 MPH
 48H  19/0600Z 36.3N  32.2W   55 KT  65 MPH
 72H  20/0600Z 37.0N  31.0W   50 KT  60 MPH
 96H  21/0600Z 37.0N  29.0W   50 KT  60 MPH
120H  22/0600Z 37.0N  27.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 
$$
FORECASTER BEVEN
 

WTNT44 KNHC 171442
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  25
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 AM AST MON SEP 17 2012
 
THE INNER-CORE CONVECTION HAS CONTINUED TO WEAKEN SINCE THE PREVIOUS
ADVISORY AS DRIER AND MORE STABLE AIR HAS WRAPPED INTO THE SYSTEM
FROM THE WEST AND SOUTH. RECENT AMSU SATELLITE INTENSITY ESTIMATES
RANGE FROM 63 KT TO 77 KT...AND THE 12Z TAFB CURRENT INTENSITY
ESTIMATE WAS T3.5/55 KT. AN AVERAGE OF THESE ESTIMATES SUPPORTS
MAINTAINING AN INITIAL INTENSITY OF 60 KT.
 
THE INITIAL MOTION ESTIMATE IS NOW 050/13 KT. A GRADUAL TURN TOWARD
THE NORTH-NORTHEAST AND NORTH WITH A FURTHER REDUCTION IN FORWARD
SPEED IS EXPECTED OVER THE NEXT 72 HOURS AS NADINE IS INFLUENCED BY
SOUTHERLY FLOW ON THE EAST SIDE OF A DEEP-LAYER TROUGH LOCATED TO
ITS WEST. AFTER DAY 3...NADINE WILL INTERACT WITH A DEEP MID- TO
UPPER-LEVEL LOW FORECAST TO DEVELOP TO THE NORTH OF THE CYCLONE AND
DROP SOUTHWARD TO NEAR THE AZORES ON DAY 5. THE EXPECTED BINARY
INTERACTION BETWEEN THESE TWO SYSTEMS COULD RESULT IN SOME ERRATIC
MOTION...WITH NADINE POSSIBLY EVEN BECOMING STATIONARY AT TIMES IN
THE VICINITY OF THE AZORES. THE LATEST NHC MODEL GUIDANCE IS IN
MUCH BETTER AGREEMENT ON THIS DEVELOPING SCENARIO AS COMPARED TO
PREVIOUS ADVISORIES. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE
PREVIOUS ADVISORY TRACK AND LIES CLOSE TO A BLEND OF THE CONSENSUS
MODELS TVCA AND THE HFIP MODEL TV15...AND THE FLORIDA STATE
SUPERENSEMBLE MODEL.
 
THE INTRUSIONS OF DRIER...STABLE AIR IS BEING OFFSET SOMEWHAT BY THE
IMPRESSIVE OUTFLOW REGIME THAT HAS FORMED OVER THE PAST 12 HOURS...
AS SUGGESTED BY A RECENT BURST OF DEEP CONVECTION THAT HAS
DEVELOPED JUST NORTHEAST OF THE LOW-LEVEL CENTER. HOWEVER...COOLER
SSTS AND INCREASING VERTICAL WIND SHEAR BY 24 HOURS AND BEYOND
SHOULD STEADILY TAKE THEIR TOLL...CAUSING NADINE TO GRADUALLY
WEAKEN. BY 96 HOURS...INTERACTION WITH THE DEVELOPING LOW TO THE
NORTH OF NADINE...COUPLED WITH SSTS COOLER THAN 22C...IS EXPECTED
TO RESULT IN THE CYCLONE TRANSITIONING INTO A SIGNIFICANT
EXTRATROPICAL LOW...OR POSSIBLY EVEN A SUBTROPICAL LOW PRESSURE
SYSTEM. THE OFFICIAL INTENSITY FORECAST IS NEARLY IDENTICAL TO THE
PREVIOUS ADVISORY...AND IS SIMILAR TO THE CONSENSUS MODELS IV15 AND
ICON... WHICH ARE ON THE LOWER END OF THE GUIDANCE SUITE.

FORECAST POSITIONS AND MAX WINDS
 
INIT  17/1500Z 32.9N  35.3W   60 KT  70 MPH
 12H  18/0000Z 33.7N  34.1W   55 KT  65 MPH
 24H  18/1200Z 34.7N  33.0W   55 KT  65 MPH
 36H  19/0000Z 35.9N  32.6W   55 KT  65 MPH
 48H  19/1200Z 36.9N  32.4W   50 KT  60 MPH
 72H  20/1200Z 37.3N  30.5W   50 KT  60 MPH
 96H  21/1200Z 36.8N  29.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
120H  22/1200Z 36.5N  28.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 
$$
FORECASTER STEWART
 

