000 WTPZ42 KNHC 010239 TCDEP2 TROPICAL STORM BORIS DISCUSSION NUMBER 17 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP022008 800 PM PDT MON JUN 30 2008 AS IT DID AROUND THIS TIME LAST NIGHT...BORIS IS SHOWING EVIDENCE OF AN EYE IN BOTH CONVENTIONAL AND MICROWAVE IMAGERY. SUBJECTIVE DVORAK CLASSIFICATIONS FROM TAFB AND SAB AT 00Z WERE 65 AND 55 KT...RESPECTIVELY. THE LATEST UW/CIMSS ADT WAS 57 KT...WHILE A CIMSS AMSU ESTIMATE AT 21Z WAS 76 KT...INDICATING THAT BORIS HAS A STRONG UPPER WARM CORE SIGNATURE. WHILE THE CONVECTION IS NOW SHOWING EXCELLENT BANDING...THE CLOUD TOPS HAVE WARMED SOME OVER THE PAST FEW HOURS. THE ADVISORY INTENSITY IS INCREASED TO 60 KT. THERE IS LITTLE EVIDENCE OF VERTICAL WIND SHEAR...BUT THE CYCLONE WILL BE MOVING OVER WATERS NEAR 26C FOR THE NEXT SEVERAL DAYS. CONSEQUENTLY...A SLOW WEAKENING TREND IS EXPECTED OVER THE FORECAST PERIOD. HOWEVER...ALL OF THE INTENSITY GUIDANCE EXCEPT THE HWRF NOW MAINTAINS BORIS AS A TROPICAL STORM THROUGHOUT THE FIVE-DAY PERIOD...AND THE OFFICIAL FORECAST DOES NOT INDICATE AS RAPID A DECLINE AS THE PREVIOUS ADVISORY. THE INITIAL MOTION IS 260/11. THE GUIDANCE IS IN BETTER AGREEMENT NOW THAN IT HAS BEEN...AS ONE BY ONE THE MODELS ARE GIVING UP ON A TURN BACK TO THE EAST. IT IS STILL NOT CLEAR HOW STRONG THE RIDGE TO THE NORTH OF THE CYCLONE WILL BE IN THREE OR FOUR DAYS...BUT AS THE SYSTEM WEAKENS THE LOWER LEVEL FLOW WILL INCREASINGLY DOMINATE THE STEERING. CONSEQUENTLY...A WESTWARD MOTION SHOULD PERSIST OVER THE NEXT FIVE DAYS. THE OFFICIAL FORECAST IS A BLEND OF THE MEDIUM BAM...THE GFS...AND THE UKMET...AND IS A LITTLE FASTER THAN THE PREVIOUS ADVISORY. FORECAST POSITIONS AND MAX WINDS INITIAL 01/0300Z 14.6N 123.0W 60 KT 12HR VT 01/1200Z 14.5N 124.5W 60 KT 24HR VT 02/0000Z 14.5N 126.0W 55 KT 36HR VT 02/1200Z 14.5N 127.3W 55 KT 48HR VT 03/0000Z 14.5N 128.4W 50 KT 72HR VT 04/0000Z 14.5N 130.5W 40 KT 96HR VT 05/0000Z 14.5N 132.5W 35 KT 120HR VT 06/0000Z 14.5N 134.5W 30 KT $$ FORECASTER FRANKLIN