000 WTNT44 KNHC 210856 TCDAT4 TROPICAL STORM DOLLY DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042008 500 AM EDT MON JUL 21 2008 SATELLITE IMAGERY AND RADAR OBSERVATIONS FROM CANCUN MEXICO INDICATE THAT THE MID-LEVEL CENTER OF THE TROPICAL CYCLONE REFORMED TO THE NORTH OF THE PREVIOUS TRACK. HOWEVER...SYNOPTIC DATA CAST DOUBT ON THE EXISTENCE OF A SURFACE CIRCULATION CENTER. SINCE THE SYSTEM CONTINUES TO GENERATE VIGOROUS CONVECTION AND STRONG WINDS...AND IT APPEARS LIKELY THAT THE SURFACE CENTER WILL SOON REAPPEAR...IT IS PRUDENT TO CONTINUE ISSUING ADVISORIES AND WARNINGS ON DOLLY. THE CURRENT INTENSITY ESTIMATE IS 45 KT...IN LINE WITH THE LATEST DVORAK ANALYSES FROM TAFB. AN UPPER-LEVEL LOW IS MOVING INTO THE BAY OF CAMPECHE AND SEEMS TO BE INCREASING ITS SEPARATION DISTANCE FROM THE TROPICAL CYCLONE...AND ALSO DIMINISHING ITS SHEARING INFLUENCE. UPPER-LEVEL OUTFLOW IS EXPANDING OVER THE NORTHERN SEMICIRCLE OF DOLLY AND THIS...COMBINED WITH THE WARM WATERS OF THE GULF OF MEXICO...PRESAGES INTENSIFICATION. THE CURRENT NHC INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND ALSO SIMILAR TO THE DYNAMICAL INTENSITY MODEL CONSENSUS. WITH THE LACK OF A SURFACE CENTER AND THE REFORMATION...INITIAL MOTION IS SOMEWHAT UNCERTAIN. MY BEST GUESS...305/13...IS NOT MUCH DIFFERENT THAN IN THE PREVIOUS PACKAGE. A MID-LEVEL RIDGE TO THE NORTH OF THE STORM IS FORECAST TO WEAKEN IN A COUPLE OF DAYS AND THE TRACK GUIDANCE IS FAIRLY CONSISTENT IN CALLING FOR A SLOWING OF FORWARD SPEED BY 48 HOURS...THEREAFTER...THE KEY PLAYER IN THE STEERING PATTERN FOR DOLLY IS A MID-LEVEL RIDGE OVER THE SOUTHERN PLAINS. GLOBAL MODELS SHOW SLIGHTLY DIFFERENT STRENGTHS AND CONFIGURATIONS OF THIS RIDGE AROUND 72 HOURS AND DIFFERENT LATITUDES OF LANDFALL ALONG THE WESTERN GULF OF MEXICO COAST. ALTHOUGH ONE SHOULD NOT FOCUS ON THE EXACT LANDFALL POINT IN 2 TO 3 DAYS TIME...INTERESTS IN THE WESTERN GULF OF MEXICO SHOULD MONITOR THE PROGRESS OF DOLLY. ANOTHER NOAA P3 AIRCRAFT IS SCHEDULED TO INVESTIGATE THE STORM LATER THIS MORNING. FORECAST POSITIONS AND MAX WINDS INITIAL 21/0900Z 21.3N 87.4W 45 KT 12HR VT 21/1800Z 22.6N 89.6W 50 KT 24HR VT 22/0600Z 23.6N 92.2W 55 KT 36HR VT 22/1800Z 24.4N 94.2W 65 KT 48HR VT 23/0600Z 25.0N 95.5W 75 KT 72HR VT 24/0600Z 26.0N 98.0W 65 KT...INLAND 96HR VT 25/0600Z 26.5N 100.5W 30 KT...INLAND 120HR VT 26/0600Z...DISSIPATED $$ FORECASTER PASCH