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| #35771 (Received by flhurricane at: 4:34 PM 27.Jul.2005) TCDAT1 TROPICAL STORM FRANKLIN DISCUSSION NUMBER 26 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT WED JUL 27 2005 DEEP CONVECTION...WITH TOPS COLDER THAN -80C...HAVE DEVELOPED UP THE WEST SIDE OF AND VERY NEAR THE NOW PARTIALLY EXPOSED LOW-LEVEL CENTER. THE INITIAL INTENSITY WAS INCREASED TO 45 KT BASED ON A SATELLITE INTENSITY ESTIMATE OF T3.0/45 KT FROM TAFB AT 18Z. HOWEVER...SINCE THAT TIME...OBJECTIVE DVORAK T-NUMBERS HAVE BEEN RUNNING CLOSE TO T3.3/51 KT. THE UPPER-LEVEL OUTFLOW IS SLOWLY IMPROVING IN THE WESTERN SEMICIRCLE...BUT IS RESTRICTED ELSEWHERE. THROUGH 18Z...FRANKLIN HAD BEEN MOVING AT 340/05...BUT OVER THE LAST COUPLE OF HOURS THE MOTION APPEARS TO BE 360/06...AND THAT IS WHAT WAS USED FOR THIS ADVISORY. THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK OR REASONING. FRANKLIN SHOULD MOVE NORTHWARD FOR THE NEXT 6-12 HOURS BEFORE TURNING NORTHEASTWARD BY 24 HOURS AS A SHARP MID- TO UPPER-LEVEL TROUGH AND ASSOCIATED FRONTAL SYSTEM REACH THE NORTHEASTERN U.S. COAST BY 48 HOURS. THE DEEP-LAYER SOUTHWESTERLY FLOW AHEAD OF THIS SYSTEM SHOULD GRADUALLY ACCELERATE FRANKLIN TO THE NORTHEAST OVER COLDER WATER WHERE THE CYCLONE WILL WEAKEN AND EVENTUALLY BECOME ABSORBED BY THE FRONTAL SYSTEM. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE TO THE NHC MODEL CONSENSUS NOW THAT THE UKMET HAS COME BACK INTO THE FOLD. THE UPPER-LEVEL SHEAR VECTOR HAS BEEN GRADUALLY VEERING FROM NORTHEAST TO SOUTHEAST TODAY...AND MOST OF THE MODEL GUIDANCE INDICATES THAT VEERING OF THE SHEAR VECTOR WILL CONTINUE FOR ANOTHER 24 HOURS OR SO. THIS PATTERN...COUPLED WITH DECREASING WIND SHEAR VALUES AS LOW AS 5 KT...SHOULD RESULT INC CONVECTION GRADUALLY DEVELOPING OVER THE LOW-LEVEL CENTER. THIS SHOULD ALLOW FOR AT LEAST SOME MODEST INTENSIFICATION...AND PERHAPS EVEN ALLOW FRANKLIN TO BRIEFLY REACH HURRICANE STRENGTH BY ABOUT 24 HOURS. AFTER THAT...FRANKLIN IS EXPECTED TO REACH MUCH COLDER SSTS BY 48 HOURS...WHICH SHOULD HELP TO BRING ABOUT RAPID WEAKENING. THE OFFICIAL INTENSITY FORECAST IS SLIGHTLY HIGHER THAN THE SHIPS MODEL AND MUCH HIGHER...MORE THAN 25 KT...THAN THE GFDL MODEL. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 27/2100Z 33.9N 69.3W 45 KT 12HR VT 28/0600Z 35.2N 68.6W 50 KT 24HR VT 28/1800Z 37.0N 67.1W 55 KT 36HR VT 29/0600Z 38.8N 64.8W 45 KT 48HR VT 29/1800Z 40.9N 61.5W 35 KT...BECOMING EXTRATROPICAL 72HR VT 30/1800Z 45.0N 53.0W 30 KT...EXTRATROPICAL 96HR VT 31/1800Z...ABSORBED BY FRONTAL SYSTEM |
