000 WTNT44 KNHC 230259 TCDAT4 HURRICANE DOLLY DISCUSSION NUMBER 11 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042008 1100 PM EDT TUE JUL 22 2008 THE CENTRAL PRESSURE HAD BEEN FALLING AT A LITTLE OVER 1 MB/HR EARLIER THIS EVENING...BUT OVER THE LAST COUPLE OF HOURS APPEARS TO HAVE LEVELED OFF. MAXIMUM SURFACE WINDS FROM THE SFMR ON THE NOAA AIRCRAFT WERE 70 KT...AND THE ADVISORY INTENSITY IS INCREASED ON THIS BASIS. DOLLY HAS SPENT THE LAST 12 HOURS OR SO TRAVERSING A COOL GULF RING...AND THIS ENCOUNTER MAY BE SLOWING THE INTENSIFICATION PROCESS. WATER VAPOR IMAGERY SHOWS THAT THE CYCLONE'S OUTFLOW IS BEGINNING TO BECOME RESTRICTED TO THE WEST BY A NARROW UPPER LOW OVER WEST TEXAS. CONVECTION REMAINS ASYMMETRIC...FAVORING THE WESTERN SEMICIRCLE...AND THE RADAR PRESENTATION HAS NOT IMPROVED APPRECIABLY OVER THE PAST SEVERAL HOURS. THESE OBSERVATIONS LEAD ME TO BELIEVE THAT ONLY MODEST ADDITIONAL INTENSIFICATION IS LIKELY PRIOR TO LANDFALL... ASSUMING...OF COURSE...THAT DOLLY DOES NOT REMAIN OVER WATER SIGNIFICANTLY LONGER THAN EXPECTED. THE OFFICIAL FORECAST SPLITS THE DIFFERENCE BETWEEN THE SHIPS/LGEM AND THE GFDL. THE INITIAL MOTION IS 310/8. THE FORWARD SPEED HAS BEEN GRADUALLY SLOWING DURING THE DAY...AS A MID-LATITUDE SHORT WAVE TROUGH DIGS SOUTHWARD FROM THE GREAT LAKES AND WEAKENS THE MID-LEVEL RIDGE TO THE NORTH OF THE TROPICAL CYCLONE. MODEL GUIDANCE...CONTINUES TO SLOW THE FORWARD MOTION OVER THE NEXT 12-18 HOURS...TO 5 KT OR LESS IN THE CASE OF THE GFS. THE MODELS HAVE BEEN QUITE GOOD WITH THE VARIATIONS IN SPEED WITH THIS STORM SO FAR...AND THE OFFICIAL FORECAST REMAINS IN GOOD AGREEMENT WITH THE NUMERICAL GUIDANCE. AFTER LANDFALL...DOLLY SHOULD TURN WESTWARD AT A SLIGHTLY FASTER SPEED TO THE SOUTH OF A SLIGHTLY STRONGER MID-LEVEL RIDGE. SHOULD DOLLY SLOW AS MUCH AS THE GFS IS FORECASTING...THE CURRENT RAINFALL ESTIMATES...OF UP TO 15 INCHES IN SPOTS...WILL LIKELY BE LOW. FORECAST POSITIONS AND MAX WINDS INITIAL 23/0300Z 25.1N 96.0W 70 KT 12HR VT 23/1200Z 25.7N 97.0W 80 KT 24HR VT 24/0000Z 26.1N 98.3W 50 KT...INLAND 36HR VT 24/1200Z 26.3N 99.8W 30 KT...INLAND 48HR VT 25/0000Z...DISSIPATED $$ FORECASTER FRANKLIN