703 
 WTNT45 KNHC 012058
 TCDAT5
 TROPICAL DEPRESSION TWENTY DISCUSSION NUMBER   2
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 PM EDT SAT OCT 01 2005
  
 AIR FORCE RECON AIRCRAFT THIS AFTERNOON FOUND A SMALL SURFACE
 CIRCULATION SOUTHWEST OF WHERE SATELLITE AND SURFACE OBSERVATIONS
 SUGGEST THE LARGER-SCALE CENTER OF ROTATION IS LOCATED. RECENT
 OBSERVATIONS FROM NOAA BUOY 42056 ALSO INDICATE VEERING SURFACE
 WINDS... WHICH SUGGESTS THAT ANOTHER SMALL-SCALE CIRCULATION MAY BE
 PASSING JUST SOUTHWEST OF THE BUOY. FLIGHT-LEVEL WINDS AT 850 MB
 SUGGEST THAT A BROADER CIRCULATION CENTER IS EITHER LOCATED OR
 FORMING NORTHEAST OF THE VORTEX MESSAGE POSITION. THE ADVISORY
 POSITION IS A COMPROMISE OF ALL THE SMALL SWIRLS AND LEANS MORE
 TOWARD THE LARGE-SCALE ROTATION NOTED IN SATELLITE IMAGERY AND THE
 SURFACE PRESSURE PATTERN. HOWEVER... ANY ONE OF THE SMALLER
 CIRCULATIONS COULD BECOME MORE DOMINANT IF DEEP CONVECTION DEVELOPS
 NEARBY. THE INITIAL INTENSITY OF 30 KT IS BASED ON A 31-KT SUSTAINED
 WIND REPORTED EARLIER BY NOAA BUOY 42056.
  
 THE INITIAL MOTION ESTIMATE IS AN UNCERTAIN 255/05.  THE VARIOUS
 GLOBAL AND REGIONAL MODELS DID NOT INITIALIZE THE DEPRESSION VERY
 WELL... ESPECIALLY THE GFS AND CANADIAN MODELS. HOWEVER... THE
 GENERAL TREND IN ALL OF THE MODELS IS FOR THE BROAD SUBTROPICAL
 RIDGE TO THE NORTH ALONG THE NORTHERN GULF COAST TO SLOWLY BUILD
 WESTWARD THROUGHOUT THE FORECAST PERIOD. THE MORE WESTWARD AND
 SOUTHERLY INITIAL POSITION HAS RESULTED IN A SOUTHWARD SHIFT OF THE
 BAM MODELS... AND AS RESULT... THE OFFICIAL FORECAST TRACK WAS ALSO
 SHIFTED SOUTHWARD. IT SHOULD BE NOTED THAT SOME ERRATIC MOTION WILL
 BE POSSIBLE UNTIL A WELL-DEFINED LOW-LEVEL CENTER DEVELOPS.
  
 EXCLUDING LAND INTERACTION... ENVIRONMENTAL CONDITIONS ARE EXPECTED
 TO BE QUITE FAVORABLE FOR SOME SIGNIFICANT INTENSIFICATION TO
 OCCUR. THE SHIPS MODEL INCREASES THE INTENSITY TO 86 KT BY 72 HOURS
 AND 94 KT BY 96 HOURS DUE TO VERY WARM SSTS AND LOW VERTICAL SHEAR.
 THE 12Z GFDL MODEL LOSES THE CYCLONE BY 24 HOURS... WHICH IS NOT
 UNUSUAL FOR SYSTEMS THAT ARE INITIALIZED WITH 25 KT WINDS. THE 18Z
 GFDL WILL LIKELY BE MORE ROBUST SINCE IT WAS INITIALIZED WITH 30 KT
 SURFACE WINDS.
  
 FORECASTER STEWART
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      01/2100Z 19.2N  86.5W    30 KT
  12HR VT     02/0600Z 19.8N  87.9W    35 KT...INLAND ERN YUCATAN
  24HR VT     02/1800Z 20.4N  89.8W    25 KT...INLAND WRN YUCATAN
  36HR VT     03/0600Z 21.0N  91.8W    35 KT...OVER WATER
  48HR VT     03/1800Z 21.4N  93.6W    50 KT
  72HR VT     04/1800Z 21.6N  96.2W    65 KT
  96HR VT     05/1800Z 21.0N  99.0W    30 KT...INLAND ERN MEXICO
 120HR VT     06/1800Z...DISSIPATED INLAND
  
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