000 WTNT41 KNHC 252216 TCDAT1 TROPICAL DEPRESSION ONE SPECIAL DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010 600 PM EDT FRI JUN 25 2010 THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING THE DISTURBANCE IN THE WESTERN CARIBBEAN SEA HAS FOUND A WELL-DEFINED CIRCULATION CENTER WITH A MINIMUM CENTRAL PRESSURE OF AROUND 1004 MB. BASED ON DATA FROM THE AIRCRAFT...ADVISORIES ARE BEING INITIATED ON TROPICAL DEPRESSION ONE AT THIS TIME. THE INITIAL INTENSITY IS SET AT 30 KT BASED ON A BLEND OF WIND DATA FROM THE AIRCRAFT AND SURROUNDING OBSERVATIONS. THE DEPRESSION IS VERY CLOSE TO TROPICAL STORM STRENGTH...AND CONDITIONS APPEAR FAVORABLE FOR SOME INTENSIFICATION BEFORE IT REACHES THE YUCATAN PENINSULA IN A DAY OR SO. AFTER WEAKENING OVER LAND...THE CYCLONE COULD REGAIN SOME STRENGTH WHEN IT ENTERS THE SOUTHERN GULF OF MEXICO. THE OFFICIAL INTENSITY FORECAST IS CLOSE TO THE DECAY SHIPS MODEL...WHICH INCLUDES THE EFFECTS OF INTERACTION WITH THE YUCATAN PENINSULA. THE INITIAL MOTION IS RATHER UNCERTAIN BUT THE BEST ESTIMATE IS 300/09. A MID-LEVEL RIDGE IS FORECAST TO PERSIST OVER THE GULF OF MEXICO FOR THE NEXT 48 TO 72 HOURS...THEREFORE A GENERAL WEST-NORTHWESTWARD MOTION IS EXPECTED DURING THAT TIME...WHICH SHOULD BRING THE CYCLONE ACROSS THE YUCATAN PENINSULA AND INTO THE SOUTHERN GULF OF MEXICO. AFTER 72 HOURS THE TRACK MODEL GUIDANCE DIVERGES...WITH ONE GROUP...INCLUDING THE HWRF AND GFDL...TAKING THE SYSTEM ON A MORE NORTHERLY OR NORTHEASTERLY TRACK. A SECOND GROUP OF GUIDANCE...INCLUDING THE GFS...ECMWF AND NOGAPS KEEPS THE SYSTEM ON A MORE WESTERLY TRACK OVER THE SOUTHERN GULF OF MEXICO. THE OFFICIAL FORECAST IS A BLEND OF THESE TWO. A TROPICAL STORM WARNING IS REQUIRED FOR THE EAST COAST OF THE YUCATAN PENINSULA AT THIS TIME. IF THE CYCLONE MOVES SOUTH OF THE OFFICIAL FORECAST TRACK...A TROPICAL STORM WARNING FOR BELIZE MAY BE REQUIRED LATER THIS EVENING. FORECAST POSITIONS AND MAX WINDS INITIAL 25/2200Z 16.5N 83.5W 30 KT 12HR VT 26/0600Z 17.4N 84.7W 35 KT 24HR VT 26/1800Z 18.5N 86.5W 40 KT 36HR VT 27/0600Z 19.5N 88.0W 45 KT...INLAND 48HR VT 27/1800Z 21.0N 89.5W 25 KT...INLAND 72HR VT 28/1800Z 23.0N 91.5W 30 KT 96HR VT 29/1800Z 24.0N 92.5W 35 KT 120HR VT 30/1800Z 25.0N 93.5W 40 KT $$ FORECASTER AVILA/BRENNAN