000 WTNT43 KNHC 112032 TCDAT3 TROPICAL STORM PAULA DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL182010 500 PM EDT MON OCT 11 2010 SATELLITE IMAGERY...SURFACE OBSERVATIONS AND DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT THE LOW PRESSURE AREA NEAR THE COAST OF HONDURAS HAS BECOME A TROPICAL STORM...AND AN INTENSIFYING ONE AT THAT. IN THE LAST COUPLE OF HOURS THE AIRCRAFT FOUND A CENTRAL PRESSURE OF 1000 MB AND FLIGHT-LEVEL AND SFMR WINDS THAT SUPPORT AN INITIAL INTENSITY OF 50 KT...AND THIS COULD BE A BIT CONSERVATIVE. THE INTENSITY FORECAST IS ABOVE THE SHIPS AND LGEM GUIDANCE GIVEN THE CURRENT INTENSITY TRENDS...AND PAULA COULD REACH HURRICANE STATUS IN THE NEXT 24 HOURS. BEYOND THAT TIME...PAULA MAY ENCOUNTER SOME STRONGER WINDS ALOFT ON THE SOUTHERN EDGE OF THE WESTERLIES. THE INTENSITY GUIDANCE SHOWS A BROAD PEAK FROM 36 TO 72 HOURS AND THEN SLOW WEAKENING AT DAYS 4 AND 5. THE OFFICIAL FORECAST FOLLOWS THIS TREND AND IS CLOSEST TO THE LGEM AT DAYS 3 THROUGH 5. THE INITIAL MOTION ESTIMATE IS 315/8 BASED ON AIRCRAFT FIXES AND EARLIER ESTIMATES OF THE LOCATION OF THE DEVELOPING CENTER. PAULA IS CURRENTLY MOVING AROUND THE SOUTHWESTERN SIDE OF A SUBTROPICAL RIDGE THAT EXTENDS ACROSS THE NORTHERN CARIBBEAN. OVER THE NEXT COUPLE OF DAYS...THE WESTERN EDGE OF THE RIDGE WEAKENS AS A BROAD DEEP-LAYER TROUGH MOVES EAST ACROSS THE SOUTHEASTERN UNITED STATES. THIS SHOULD CAUSE THE CYCLONE TO TURN TOWARD THE NORTHWEST AND NORTH WITHIN 48 HOURS. AFTER THAT TIME...MOST OF THE GUIDANCE SUGGESTS THAT THE TROUGH WILL MOVE EAST AND LEAVE THE CYCLONE BEHIND IN AN AREA OF WEAK STEERING CURRENTS OVER THE NORTHWESTERN CARIBBEAN. THE OFFICIAL FORECAST SHOWS PAULA DRIFTING SLOWLY EASTWARD AT DAYS 3 AND 4...WITH A SLOW SOUTHWARD MOTION AT DAY 5. THIS FORECAST IS BASED ON A BLEND OF THE GFS...UKMET...AND ECMWF...BUT CONFIDENCE IS QUITE LOW IN THE DETAILS OF THE TRACK FORECAST AT THIS TIME RANGE. BASED ON THE FORECAST...A HURRICANE WARNING HAS BEEN ISSUED FOR PORTIONS OF THE YUCATAN PENINSULA. FORECAST POSITIONS AND MAX WINDS INITIAL 11/2100Z 16.0N 84.0W 50 KT 12HR VT 12/0600Z 16.8N 84.8W 55 KT 24HR VT 12/1800Z 18.3N 86.2W 65 KT 36HR VT 13/0600Z 19.6N 86.6W 70 KT 48HR VT 13/1800Z 20.0N 86.4W 70 KT 72HR VT 14/1800Z 20.0N 85.5W 70 KT 96HR VT 15/1800Z 20.0N 85.0W 65 KT 120HR VT 16/1800Z 19.5N 85.0W 65 KT $$ FORECASTER BRENNAN