000 WTPZ42 KNHC 250234 TCDEP2 TROPICAL STORM DALILA DISCUSSION NUMBER 13 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP072007 800 PM PDT TUE JUL 24 2007 OVER THE LAST SEVERAL HOURS DALILA'S CONVECTION HAS ACQUIRED A MORE BANDED APPEARANCE IN THE SOUTHEAST AND SOUTHWEST QUADRANTS... ALTHOUGH CLOUD TOPS HAVE BEEN WARMING A LITTLE OF LATE. THE LATEST DVORAK T-NUMBERS FROM TAFB AND SAB WERE 3.0...OR 45 KT...WHILE THE CIMSS ADT GAVE ABOUT 50 KT. GIVEN THIS...THE ADVISORY INTENSITY REMAINS 50 KT. A QUIKSCAT PASS OVER THE CYCLONE IS DUE SHORTLY AFTER ADVISORY TIME THAT MIGHT HELP WITH THE INTENSITY ASSESSMENT. MICROWAVE PASSES AROUND 01Z INDICATE THAT THE CIRCULATION CENTER HAS MOVED OUT AHEAD OF THE DEEP CONVECTION...WITH AN INITIAL MOTION OF 330/6. MODEL FIELDS AND WATER VAPOR IMAGERY SUGGEST A SMALL INVERTED MID-LEVEL TROUGH IS LOCATED A COUPLE HUNDRED MILES NORTHWEST OF THE CYCLONE...AND SOME OF THE GUIDANCE...INCLUDING THE GFS...ECMWF...GFDL...AND 18Z UKMET...SUGGESTS THAT THIS TROUGH COULD INDUCE A MORE NORTHWARD MOTION OVER THE NEXT 12-24 HOURS. AFTER THAT...RIDGING OVER THE SOUTHWESTERN UNITED STATES IS EXPECTED TO TURN DALILA TOWARED THE NORTHWEST AND THEN WEST-NORTHWEST. AT THE PRESENT TIME...NONE OF THE GUIDANCE INDICATES A TRACK ANY CLOSER THAN ABOUT 150 NM TO THE BAJA CALIFORNIA PENINSULA. THE OFFICIAL FORECAST HAS BEEN ADJUSTED SLIGHTLY TO THE RIGHT OF THE PREVIOUS ADVISORY TO REFLECT MORE OF AN INTERACTION WITH THE INVERTED TROUGH...AND IS IN BEST AGREEMENT WITH THE FSSE SUPERENSEMBLE. ALTHOUGH THE BANDING STRUCTURE HAS IMPROVED TODAY...DALILA IS STILL HAVING DIFFICULTY MAINTAINING CONVECTION IN THE NORTHERN SEMICIRCLE...AND THE LOW LEVEL CENTER IS EXPOSED. HOWEVER... ANTICYCLONIC OUTFLOW HAS NOW REPLACED NORTHEASTERLY SHEAR OVER THE STORM...AND DALILA STILL HAS ANOTHER 36 HOURS OR SO OF WARM WATER AHEAD. THE OFFICIAL FORECAST IS IN BEST AGREEMENT WITH THE HWRF GUIDANCE...ALTHOUGH THE SHIPS GUIDANCE IS A LITTLE HIGHER AND CALLS FOR DALILA TO REACH HURRICANE STATUS. FORECAST POSITIONS AND MAX WINDS INITIAL 25/0300Z 18.2N 110.6W 50 KT 12HR VT 25/1200Z 19.1N 110.9W 55 KT 24HR VT 26/0000Z 20.0N 111.7W 60 KT 36HR VT 26/1200Z 20.7N 112.6W 60 KT 48HR VT 27/0000Z 21.4N 113.9W 55 KT 72HR VT 28/0000Z 22.5N 117.0W 45 KT 96HR VT 29/0000Z 23.0N 120.0W 30 KT 120HR VT 30/0000Z 23.5N 123.0W 25 KT...DISSIPATING $$ FORECASTER FRANKLIN