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2011 Changes to the Tropical Cyclone Discussion


Beginning with the 2011 season, the Tropical Cyclone Discussion (TCD) issued by NHC and CPHC will contain a new column with intensity in miles per hour (MPH).


Affected Products

Product Name WMO Header AWIPS IDs
Tropical Cyclone Discussion WTNT41-45 KNHC (Atlantic)
WTPZ41-45 KNHC (Eastern Pacific)
WTPA41-45 PHFO (Central Pacific)
TCDAT1-5
TCDEP1-5
TCDCP1-5


Old format

000
WTNT41 KNHC 130852
TCDAT1

TROPICAL STORM TOMAS DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT TUE NOV 02 2010
 
TOMAS HAS CERTAINLY BECOME BETTER ORGANIZED SINCE YESTERDAY...WITH A
LARGE AREA OF DEEP CONVECTION AND INCREASED BANDING SEEN IN
CONVENTIONAL SATELLITE AND MICROWAVE DATA.  HOWEVER...THE STORM HAS
CHANGED LITTLE IN ORGANIZATION SINCE THE RECONNAISSANCE AIRCRAFT
REPORTED SFMR SURFACE WINDS OF 45 KT AROUND 0800 UTC.  THEREFORE...
THE INITIAL INTENSITY IS HELD AT THAT VALUE...WHICH IS IN LINE WITH
THE LATEST DVORAK T-NUMBERS OF 2.5 AND 3.5 FROM SAB AND TAFB...
RESPECTIVELY.  THE NEXT AIR FORCE HURRICANE HUNTER AIRCRAFT IS
SCHEDULED TO INVESTIGATE TOMAS THIS AFTERNOON. 
   
WESTERLY SHEAR CONTINUES TO RELAX AND THE MID-LEVEL ENVIRONMENT
APPEARS TO BE MOISTENING.  THESE ATMOSPHERIC CONDITIONS...COMBINED
WITH HIGH OCEANIC HEAT CONTENT...FAVOR INTENSIFICATION DURING THE
NEXT FEW DAYS...WHICH IS SHOWN BY MOST OF THE GUIDANCE.  IN
FACT...THE SHIPS RAPID INTENSIFICATION INDEX GIVES A 48 PERCENT
CHANCE OF A 30-KT INCREASE IN WIND SPEED DURING THE NEXT 24 HOURS.
THE OFFICIAL FORECAST HAS BEEN ADJUSTED UPWARD FROM THE PREVIOUS
ADVISORY AND IS NOW AT OR JUST ABOVE THE HIGH END OF THE INTENSITY
GUIDANCE.  AFTER A FEW DAYS...LAND INTERACTION...DRIER AIR...AND
SOME INCREASE IN SOUTHERLY SHEAR IS LIKELY TO CAUSE WEAKENING. 
 
THE INITIAL MOTION ESTIMATE IS A LITTLE SLOWER THAN BEFORE...270/9.
A TURN TO THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN
FORWARD SPEED IS FORECAST DURING THE NEXT 24-48 HOURS AS A STRONG
TROUGH MOVES EASTWARD ACROSS THE GULF OF MEXICO. AS A RESULT...
TOMAS IS EXPECTED TO TURN NORTHWARD AND NORTHEASTWARD BEYOND 48
HOURS IN DEEP-LAYER SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE
TROUGH. SEVERAL OF THE GLOBAL MODELS SUGGEST THAT THE TROUGH WILL
NOT COMPLETELY CAPTURE TOMAS AND THERE REMAINS A LARGE DISAGREEMENT
IN THE FUTURE POSITION OF THE CYCLONE AT DAYS 4 AND 5. THE OFFICIAL
FORECAST IS OF LOW CONFIDENCE DURING THAT TIME PERIOD AND IS NEAR A
CONSENSUS OF THE GFS...GFDL... UKMET...NOGAPS...AND ECMWF MODELS.
  
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS
THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY
RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK.
 
FORECAST POSITIONS AND MAX WINDS

INITIAL      02/1500Z 13.5N  72.6W    45 KT
 12HR VT     03/0000Z 13.7N  73.8W    55 KT
 24HR VT     03/1200Z 14.1N  75.0W    65 KT
 36HR VT     04/0000Z 14.6N  75.8W    70 KT
 48HR VT     04/1200Z 15.2N  76.0W    80 KT
 72HR VT     05/1200Z 17.2N  74.9W    90 KT
 96HR VT     06/1200Z 20.0N  72.0W    65 KT
120HR VT     07/1200Z 22.5N  69.5W    60 KT
 
$$
FORECASTER CANGIALOSI/BROWN

New format

000
WTNT41 KNHC 130852
TCDAT1

TROPICAL STORM TOMAS DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 AM EDT TUE NOV 02 2010
 
TOMAS HAS CERTAINLY BECOME BETTER ORGANIZED SINCE YESTERDAY...WITH A
LARGE AREA OF DEEP CONVECTION AND INCREASED BANDING SEEN IN
CONVENTIONAL SATELLITE AND MICROWAVE DATA.  HOWEVER...THE STORM HAS
CHANGED LITTLE IN ORGANIZATION SINCE THE RECONNAISSANCE AIRCRAFT
REPORTED SFMR SURFACE WINDS OF 45 KT AROUND 0800 UTC.  THEREFORE...
THE INITIAL INTENSITY IS HELD AT THAT VALUE...WHICH IS IN LINE WITH
THE LATEST DVORAK T-NUMBERS OF 2.5 AND 3.5 FROM SAB AND TAFB...
RESPECTIVELY.  THE NEXT AIR FORCE HURRICANE HUNTER AIRCRAFT IS
SCHEDULED TO INVESTIGATE TOMAS THIS AFTERNOON. 
   
WESTERLY SHEAR CONTINUES TO RELAX AND THE MID-LEVEL ENVIRONMENT
APPEARS TO BE MOISTENING.  THESE ATMOSPHERIC CONDITIONS...COMBINED
WITH HIGH OCEANIC HEAT CONTENT...FAVOR INTENSIFICATION DURING THE
NEXT FEW DAYS...WHICH IS SHOWN BY MOST OF THE GUIDANCE.  IN
FACT...THE SHIPS RAPID INTENSIFICATION INDEX GIVES A 48 PERCENT
CHANCE OF A 30-KT INCREASE IN WIND SPEED DURING THE NEXT 24 HOURS.
THE OFFICIAL FORECAST HAS BEEN ADJUSTED UPWARD FROM THE PREVIOUS
ADVISORY AND IS NOW AT OR JUST ABOVE THE HIGH END OF THE INTENSITY
GUIDANCE.  AFTER A FEW DAYS...LAND INTERACTION...DRIER AIR...AND
SOME INCREASE IN SOUTHERLY SHEAR IS LIKELY TO CAUSE WEAKENING. 
 
THE INITIAL MOTION ESTIMATE IS A LITTLE SLOWER THAN BEFORE...270/9.
A TURN TO THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN
FORWARD SPEED IS FORECAST DURING THE NEXT 24-48 HOURS AS A STRONG
TROUGH MOVES EASTWARD ACROSS THE GULF OF MEXICO. AS A RESULT...
TOMAS IS EXPECTED TO TURN NORTHWARD AND NORTHEASTWARD BEYOND 48
HOURS IN DEEP-LAYER SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE
TROUGH. SEVERAL OF THE GLOBAL MODELS SUGGEST THAT THE TROUGH WILL
NOT COMPLETELY CAPTURE TOMAS AND THERE REMAINS A LARGE DISAGREEMENT
IN THE FUTURE POSITION OF THE CYCLONE AT DAYS 4 AND 5. THE OFFICIAL
FORECAST IS OF LOW CONFIDENCE DURING THAT TIME PERIOD AND IS NEAR A
CONSENSUS OF THE GFS...GFDL... UKMET...NOGAPS...AND ECMWF MODELS.
  
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS
THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY
RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK.

FORECAST POSITIONS AND MAX WINDS

INIT  13/0900Z 20.5N  86.0W   80 KT  90 MPH
 12H  13/1800Z 21.2N  85.9W   90 KT 105 MPH
 24H  14/0600Z 22.0N  85.7W   95 KT 110 MPH
 36H  14/1800Z 22.8N  85.6W  100 KT 115 MPH
 48H  15/0600Z 23.7N  85.5W  105 KT 120 MPH
 72H  16/0600Z 25.4N  85.2W  115 KT 135 MPH
 96H  17/0600Z 27.1N  85.0W  120 KT 140 MPH
120H  18/0600Z 28.8N  84.7W  105 KT 120 MPH
 
$$
FORECASTER CANGIALOSI/BROWN

Below is a formatting ruler showing the exact column spacing:
----------------------------------------------------------------------
0        1         2         3         4         5         6         7
1234567890123456789012345678901234567890123456789012345678901234567890
----------------------------------------------------------------------
FORECAST POSITIONS AND MAX WINDS
INIT  13/0900Z 20.5N  86.0W   80 KT  90 MPH
 12H  13/1800Z 21.2N  85.9W   90 KT 105 MPH
 24H  14/0600Z 22.0N  85.7W   95 KT 110 MPH
 36H  14/1800Z 22.8N  85.6W  100 KT 115 MPH
 48H  15/0600Z 23.7N  85.5W  105 KT 120 MPH
 72H  16/0600Z 25.4N  85.2W  115 KT 135 MPH
 96H  17/0600Z 27.1N  85.0W  120 KT 140 MPH
120H  18/0600Z 28.8N  84.7W  105 KT 120 MPH


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Page last modified: Wednesday, 20-Apr-2011 14:34:55 UTC