WTNT43 KNHC 052102
TCDAT3
TROPICAL DEPRESSION SEVENTEEN DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172008
400 PM EST WED NOV 05 2008
 
THE AREA OF DISTURBED WEATHER IN THE SOUTHWESTERN CARIBBEAN SEA HAS
DEVELOPED ENOUGH ORGANIZED CONVECTION AND LOW-LEVEL CIRCULATION TO
BE CONSIDERED A TROPICAL DEPRESSION.  AN AIR FORCE HURRICANE HUNTER
FOUND MAXIMUM WINDS OF 26 KT AT 1000 FT WITH A MINIMUM PRESSURE OF
1004 MB.  SATELLITE IMAGES SHOW THAT MOST OF THE CONVECTION IS
NORTHWEST OF THE CENTER BUT IS STARTING TO TAKE ON A BANDED
APPEARANCE.  THE INITIAL INTENSITY IS SET TO 25 KT IN ACCORDANCE
WITH THE AIRCRAFT DATA AND NOAA BUOY 42057.
 
ATMOSPHERIC AND OCEANIC PARAMETERS APPEAR TO BE VERY FAVORABLE FOR
STRENGTHENING DURING THE NEXT COUPLE OF DAYS.  IN FACT...THE GFDL
AND HWRF TURN THE DEPRESSION INTO A MAJOR HURRICANE BEFORE CROSSING
CUBA.  IN CONTRAST...THE SHIPS/LGEM MODELS KEEP THE SYSTEM BELOW
HURRICANE STRENGTH...WHICH SEEMS A LITTLE UNDERDONE GIVEN A LARGE
UPPER ANTICYCLONE THAT ALL OF THE GLOBAL MODELS ARE FORMING NEAR
THE DEPRESSION.  THE OFFICIAL FORECAST WILL BE CLOSER TO THE
DYNAMICAL GUIDANCE BUT NOT QUITE AS BULLISH AS THOSE MODELS FOR THE
TIME BEING.  NEAR THE END OF THE PERIOD...VERTICAL SHEAR IS
FORECAST TO INCREASE DRAMATICALLY AND THIS COULD RESULT IN AN
ABRUPT WEAKENING.
 
A TWELVE-HOUR MOTION OF THIS SYSTEM IS ESTIMATED AT 305/4.  A SLOW
NORTHWEST TO NORTH MOVEMENT IS EXPECTED DURING THE NEXT DAY OR TWO
AS THE DEPRESSION IS STEERED AROUND SOUTHWESTERN SIDE OF A MID-
TROPOSPHERIC HIGH OVER THE NORTH-CENTRAL CARIBBEAN SEA.  A DEEP
TROUGH IS EXPECTED TO MOVE INTO THE GULF OF MEXICO IN ABOUT 3
DAYS...WHICH SHOULD CAUSE THE CYCLONE TO TURN TOWARD THE NORTHEAST
AND ACCELERATE.  THERE ARE SOME SIGNIFICANT SPEED DISCREPANCIES IN
THE MODELS WITH THE GFDL/HWRF CONSIDERABLY FASTER THAN THE
GFS/ECMWF/UKMET MODELS.  LATE-SEASON TROPICAL CYCLONES ARE OFTEN
NOTORIOUSLY SLOW-MOVING...E.G. MITCH OR WILMA...AND THE MODELS CAN
BE TOO QUICK TO EJECT THESE SYSTEMS OUT OF THE CARIBBEAN.  WE'RE
GOING TO LEAN TOWARD THE SLOWER GUIDANCE AT THIS TIME...AND THE NHC
FORECAST IS A BIT BEHIND THE DYNAMICAL MODEL CONSENSUS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/2100Z 14.0N  81.8W    25 KT
 12HR VT     06/0600Z 14.3N  82.2W    30 KT
 24HR VT     06/1800Z 14.8N  82.5W    40 KT
 36HR VT     07/0600Z 15.5N  82.9W    50 KT
 48HR VT     07/1800Z 16.5N  83.0W    65 KT
 72HR VT     08/1800Z 18.0N  82.5W    75 KT
 96HR VT     09/1800Z 19.5N  80.0W    75 KT
120HR VT     10/1800Z 21.5N  75.5W    50 KT
 
$$
FORECASTER BLAKE/PASCH
 

WTNT42 KNHC 052220
TCDAT2
TROPICAL DEPRESSION SEVENTEEN DISCUSSION NUMBER   1...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172008
400 PM EST WED NOV 05 2008

CORRECTED AWIPS BIN NUMBER 3 TO NUMBER 2
 
THE AREA OF DISTURBED WEATHER IN THE SOUTHWESTERN CARIBBEAN SEA HAS
DEVELOPED ENOUGH ORGANIZED CONVECTION AND LOW-LEVEL CIRCULATION TO
BE CONSIDERED A TROPICAL DEPRESSION.  AN AIR FORCE HURRICANE HUNTER
FOUND MAXIMUM WINDS OF 26 KT AT 1000 FT WITH A MINIMUM PRESSURE OF
1004 MB.  SATELLITE IMAGES SHOW THAT MOST OF THE CONVECTION IS
NORTHWEST OF THE CENTER BUT IS STARTING TO TAKE ON A BANDED
APPEARANCE.  THE INITIAL INTENSITY IS SET TO 25 KT IN ACCORDANCE
WITH THE AIRCRAFT DATA AND NOAA BUOY 42057.
 
ATMOSPHERIC AND OCEANIC PARAMETERS APPEAR TO BE VERY FAVORABLE FOR
STRENGTHENING DURING THE NEXT COUPLE OF DAYS.  IN FACT...THE GFDL
AND HWRF TURN THE DEPRESSION INTO A MAJOR HURRICANE BEFORE CROSSING
CUBA.  IN CONTRAST...THE SHIPS/LGEM MODELS KEEP THE SYSTEM BELOW
HURRICANE STRENGTH...WHICH SEEMS A LITTLE UNDERDONE GIVEN A LARGE
UPPER ANTICYCLONE THAT ALL OF THE GLOBAL MODELS ARE FORMING NEAR
THE DEPRESSION.  THE OFFICIAL FORECAST WILL BE CLOSER TO THE
DYNAMICAL GUIDANCE BUT NOT QUITE AS BULLISH AS THOSE MODELS FOR THE
TIME BEING.  NEAR THE END OF THE PERIOD...VERTICAL SHEAR IS
FORECAST TO INCREASE DRAMATICALLY AND THIS COULD RESULT IN AN
ABRUPT WEAKENING.
 
A TWELVE-HOUR MOTION OF THIS SYSTEM IS ESTIMATED AT 305/4.  A SLOW
NORTHWEST TO NORTH MOVEMENT IS EXPECTED DURING THE NEXT DAY OR TWO
AS THE DEPRESSION IS STEERED AROUND SOUTHWESTERN SIDE OF A MID-
TROPOSPHERIC HIGH OVER THE NORTH-CENTRAL CARIBBEAN SEA.  A DEEP
TROUGH IS EXPECTED TO MOVE INTO THE GULF OF MEXICO IN ABOUT 3
DAYS...WHICH SHOULD CAUSE THE CYCLONE TO TURN TOWARD THE NORTHEAST
AND ACCELERATE.  THERE ARE SOME SIGNIFICANT SPEED DISCREPANCIES IN
THE MODELS WITH THE GFDL/HWRF CONSIDERABLY FASTER THAN THE
GFS/ECMWF/UKMET MODELS.  LATE-SEASON TROPICAL CYCLONES ARE OFTEN
NOTORIOUSLY SLOW-MOVING...E.G. MITCH OR WILMA...AND THE MODELS CAN
BE TOO QUICK TO EJECT THESE SYSTEMS OUT OF THE CARIBBEAN.  WE'RE
GOING TO LEAN TOWARD THE SLOWER GUIDANCE AT THIS TIME...AND THE NHC
FORECAST IS A BIT BEHIND THE DYNAMICAL MODEL CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/2100Z 14.0N  81.8W    25 KT
 12HR VT     06/0600Z 14.3N  82.2W    30 KT
 24HR VT     06/1800Z 14.8N  82.5W    40 KT
 36HR VT     07/0600Z 15.5N  82.9W    50 KT
 48HR VT     07/1800Z 16.5N  83.0W    65 KT
 72HR VT     08/1800Z 18.0N  82.5W    75 KT
 96HR VT     09/1800Z 19.5N  80.0W    75 KT
120HR VT     10/1800Z 21.5N  75.5W    50 KT
 
$$
FORECASTER BRENNAN/STEWART
 

WTNT42 KNHC 060257
TCDAT2
TROPICAL DEPRESSION SEVENTEEN DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172008
1000 PM EST WED NOV 05 2008
 
CONVECTION HAS INCREASED NEAR THE CENTER OF THE DEPRESSION OVER THE
PAST FEW HOURS...AND DVORAK T-NUMBERS FROM SAB AND TAFB AT 0000 UTC
SUPPORTED AN INTENSITY OF 30 AND 35 KT...RESPECTIVELY.  ANALYSIS OF
AMBIGUITIES FROM A QUIKSCAT PASS AT 2334 UTC SUGGESTS THAT THE
HIGHEST WINDS OUTSIDE OF RAIN NEAR THE CENTER WERE AROUND 25
KT...REASONABLY SUGGESTING THAT WINDS ARE NEAR 30 KT IN THE
CONVECTION.  ALSO...NOAA BUOY 42057 WELL NORTH OF THE CENTER
REPORTED A PEAK WIND OF 29 KT AT 2200 AND 2300 UTC...AND A GUST OF
33 KT.  BASED ON ALL OF THIS EVIDENCE...THE INITIAL INTENSITY IS
SET AT 30 KT.  AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WILL
INVESTIGATE THE CYCLONE LATER TONIGHT AND MAY FIND THAT THE SYSTEM
HAS REACHED TROPICAL STORM STATUS.  

THE DEPRESSION HAS BEEN MOVING SLOWLY NORTHWEST OVER THE PAST FEW
HOURS.  A SLOW MOVEMENT TOWARD THE NORTHWEST IS EXPECTED TO CONTINUE
FOR THE NEXT 24 HOURS...WITH A GRADUAL TURN TOWARD THE NORTH
EXPECTED BY 48 HOURS AS THE CYCLONE ROUNDS THE WESTERN EDGE OF THE
UPPER-LEVEL ANTICYCLONE CENTERED TO ITS EAST.  LATER IN THE
PERIOD...AN UPPER-LEVEL TROUGH IS FORECAST TO DIG INTO THE GULF OF
MEXICO...AND WILL CAUSE THE CYCLONE TO TURN TOWARD THE NORTHEAST
WITH AN INCREASE IN FORWARD SPEED.  THE CURRENT TRACK FORECAST IS
SLIGHTLY FASTER THAN THE PREVIOUS ADVISORY THROUGH ABOUT 36
HOURS...BUT IS STILL SLOWER THAN MOST OF THE MODEL GUIDANCE.  AFTER
36 HOURS...THE FORECAST TRACK IS ADJUSTED TO THE LEFT OF THE
PREVIOUS FORECAST TOWARD THE DYNAMICAL MODEL CONSENSUS...TVCN. 

THE UPPER-LEVEL ENVIRONMENT AND WARM SEA-SURFACE TEMPERATURES ARE 
VERY FAVORABLE FOR INTENSIFICATION THROUGH ABOUT 72 HOURS.  THE
GFDL AND HWRF BOTH MAKE THE CYCLONE A HURRICANE WITHIN 36 TO 48
HOURS...AND FORECAST AN INTENSITY NEAR MAJOR HURRICANE STATUS BY 72
HOURS.  THE SHIPS MODEL FORECASTS THE SYSTEM TO BE NEAR HURRICANE
INTENSITY AT 48 HOURS BUT DOES NOT SHOW AS MUCH STRENGTHENING
BEYOND THAT TIME.  THE INTENSITY FORECAST WAS ADJUSTED UPWARD...AND
IS IN EXCELLENT AGREEMENT WITH THE ICON INTENSITY MODEL CONSENSUS. 
HOWEVER...IF THE CYCLONE IS ABLE TO ESTABLISH AN INNER CORE...MORE
RAPID INTENSIFICATION MAY OCCUR THAN IS FORECAST HERE.  BEYOND 72
HOURS...THE VERTICAL WIND SHEAR INCREASES RAPIDLY AS THE CYCLONE
INTERACTS WITH THE WESTERLIES...AND WEAKENING IS FORECAST AT THOSE
TIME PERIODS.  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/0300Z 14.3N  82.1W    30 KT
 12HR VT     06/1200Z 14.8N  82.5W    40 KT
 24HR VT     07/0000Z 15.6N  82.9W    50 KT
 36HR VT     07/1200Z 16.4N  83.1W    60 KT
 48HR VT     08/0000Z 17.3N  83.2W    70 KT
 72HR VT     09/0000Z 19.0N  82.0W    90 KT
 96HR VT     10/0000Z 20.5N  79.5W    70 KT
120HR VT     11/0000Z 23.5N  74.5W    50 KT
 
$$
FORECASTER BRENNAN/STEWART
 

