[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 031449
TCDAT1
TROPICAL DEPRESSION TOMAS DISCUSSION NUMBER  22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT WED NOV 03 2010

TOMAS IS STRUGGLING TO MAINTAIN ITS IDENTITY THIS MORNING.
SATELLITE IMAGERY...SURFACE OBSERVATIONS...AND DATA FROM THE NOAA
G-IV JET INDICATE THE CYCLONE HAS BECOME PART OF AN ELONGATED AREA
OF LOW PRESSURE THAT INCLUDES AN AREA OF DISTURBED WEATHER JUST
NORTH OF PANAMA.  AS A RESULT...THE CIRCULATION OF TOMAS HAS BEEN
LOSING DEFINITION.  AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
WILL INVESTIGATE THE SYSTEM THIS AFTERNOON TO DETERMINE WHETHER
TOMAS STILL HAS ENOUGH CIRCULATION TO BE CONSIDERED A TROPICAL
CYCLONE.  SATELLITE IMAGERY SHOWS THAT A LARGE CONVECTIVE CLUSTER
TO THE EAST OF THE CENTER...AND BASED ON THIS AND THE AIRCRAFT DATA
THE INITIAL INTENSITY REMAINS 30 KT.

THE INITIAL MOTION IS AN UNCERTAIN 295/5.  THERE IS LITTLE CHANGE IN
THE FORECAST TRACK OR FORECAST PHILOSOPHY FOR THE FIRST 72 -96 HR
OF THE FORECAST.  A DEEP-LAYER TROUGH AND ACCOMPANYING COLD FRONT
MOVING THROUGH THE GULF OF MEXICO AND THE SOUTHEASTERN UNITED
STATES SHOULD CAUSE TOMAS TO RECURVE TOWARD THE NORTHEAST DURING
THE NEXT 48 HR...WITH A GENERALLY NORTHEASTWARD MOTION CONTINUING
THROUGH 72-96 HR.  AFTER THAT TIME...THE GUIDANCE BECOMES
DIVERGENT.  THE GFDL STALLS THE CYCLONE JUST WEST OF HAITI.  THE
UKMET AND NOGAPS FORECAST TOMAS TO SHEAR OFF WITH THE REMNANT
LOW-LEVEL CIRCULATION MOVING SOUTHWESTWARD.  FINALLY...THE GFS AND
ECMWF CALL FOR A CONTINUED EASTWARD TO EAST-NORTHEASTWARD MOTION.
THE NEW TRACK FORECAST SHOWS A SLOW EAST-NORTHEASTWARD MOTION FROM
96-120 HR AS A COMPROMISE BETWEEN THESE EXTREMES.  OVERALL...THE
FORECAST IS SIMILAR TO BUT FASTER THAN THE PREVIOUS FORECAST.

THE INTENSITY FORECAST IS PROBLEMATIC.  FIRST...THE CYCLONE NEEDS TO
SURVIVE ITS CURRENT STATE OF DISORGANIZATION.  IF THAT OCCURS...
LIGHT VERTICAL WIND SHEAR AND WARM SEA SURFACE TEMPERATURES APPEAR
FAVORABLE FOR STRENGTHENING FOR THE NEXT 48-72 HR OR SO IF THE
LOW-LEVEL CIRCULATION CAN CONSOLIDATE.  THE INTENSITY FORECAST
ASSUMES BOTH OF THESE THINGS WILL HAPPEN...AND THUS CALLS FOR SLOW
STRENGTHENING DURING THIS TIME.  WHILE THE GFDL AND SHIPS MODELS
STILL CALL FOR TOMAS TO REGAIN HURRICANE STRENGTH...THE NEW
INTENSITY FORECAST WILL NOT FOLLOW THIS SCENARIO DUE TO CURRENT
TRENDS AND THE LIKELIHOOD OF LAND INTERACTION WITH HISPANIOLA LATER
IN THE FORECAST PERIOD.  THE INTENSITY FORECAST IS CLOSE TO BUT
SLIGHTLY LOWER THAN THE INTENSITY CONSENSUS MODEL ICON.

REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL
CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL...
FLOODING... AND POTENTIAL MUD SLIDES OVER HAITI AND THE DOMINICAN
REPUBLIC LATER IN THE WEEK.

FORECAST POSITIONS AND MAX WINDS

INITIAL      03/1500Z 14.1N  75.9W    30 KT
 12HR VT     04/0000Z 14.5N  76.2W    30 KT
 24HR VT     04/1200Z 15.5N  76.2W    35 KT
 36HR VT     05/0000Z 16.8N  75.7W    45 KT
 48HR VT     05/1200Z 18.1N  74.7W    55 KT
 72HR VT     06/1200Z 21.0N  72.5W    60 KT
 96HR VT     07/1200Z 23.0N  71.0W    60 KT
120HR VT     08/1200Z 23.5N  69.0W    55 KT

$$
FORECASTER BEVEN



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