000 WTNT44 KNHC 160908 TCDAT4 HURRICANE DEAN DISCUSSION NUMBER 12 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007 500 AM EDT THU AUG 16 2007 DEAN HAS CONTINUED TO STRENGTHEN THIS MORNING...WITH OCCASIONAL GLIMPSES OF AN EYE IN INFRARED SATELLITE IMAGERY AND CLOUD TOPS COLDER THAN -70C NEAR THE CENTER. SATELLITE INTENSITY ESTIMATES ARE 65 KT FROM TAFB AND SAB...SO DEAN IS UPGRADED TO THE FIRST HURRICANE OF THE 2007 HURRICANE SEASON. THE INITIAL MOTION IS 280/21. DEAN IS ON THE SOUTH SIDE OF A DEEP-LAYER RIDGE...WHICH LARGE-SCALE MODELS FORECAST TO BUILD WESTWARD DURING THE FORECAST PERIOD. THIS BUILDING RIDGE IS FORECAST TO PUSH ASIDE A MID/UPPER-LEVEL LOW CURRENTLY EAST OF FLORIDA...AND SHOULD THIS HAPPEN THAT SYSTEM WOULD HAVE LITTLE INTERACTION WITH DEAN. THE PATTERN EVOLUTION SHOULD KEEP DEAN MOVING QUICKLY WESTWARD TO WEST-NORTHWESTWARD THROUGH THE FORECAST PERIOD. THE TRACK GUIDANCE IS IN GOOD AGREEMENT WITH THIS SCENARIO...AND THE MODELS ARE VERY TIGHTLY CLUSTERED AROUND A TRACK THROUGH THE CARIBBEAN SEA TO NEAR THE YUCATAN PENINSULA IN FIVE DAYS. THE NEW FORECAST TRACK IS BASICALLY AN UPDATE OF THE PREVIOUS PACKAGE....AND IS IN BEST AGREEMENT WITH THE VARIOUS CONSENSUS MODELS. THERE APPEARS TO BE LITTLE TO KEEP DEAN FROM STRENGTHENING THROUGH THE FORECAST PERIOD. THE SHIPS MODEL CALLS FOR THE SYSTEM TO REACH 115 KT BY THE END OF THE PERIOD...WHILE THE EXPERIMENTAL LGE MODEL IS CALLING FOR 127 KT. THE GFDL CALLS FOR DEAN TO BECOME A MAJOR HURRICANE OVER THE WESTERN CARIBBEAN...ALTHOUGH ODDLY ENOUGH IT CALLS FOR LITTLE CHANGE IN STRENGTH DURING THE FIRST 60 HR OF THE FORECAST. THE INTENSITY FORECAST HAS BEEN NUDGED UPWARD FOR THE FIRST 96 HR IN GOOD AGREEMENT WITH THE SHIPS MODEL. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WILL BE INVESTIGATING DEAN THIS AFTERNOON..AND THE NOAA GULFSTREAM-IV WILL CONDUCT A SYNOPTIC SURVEILLANCE MISSION FOR THE 17/00Z ANALYSIS CYCLE. FORECAST POSITIONS AND MAX WINDS INITIAL 16/0900Z 13.4N 52.3W 65 KT 12HR VT 16/1800Z 13.9N 55.4W 70 KT 24HR VT 17/0600Z 14.4N 59.4W 80 KT 36HR VT 17/1800Z 14.9N 63.0W 90 KT 48HR VT 18/0600Z 15.4N 66.5W 100 KT 72HR VT 19/0600Z 16.5N 73.5W 105 KT 96HR VT 20/0600Z 18.0N 80.5W 110 KT 120HR VT 21/0600Z 20.0N 87.5W 115 KT $$ FORECASTER BEVEN