Show Selection: |
#109193 (Received by flhurricane at: 10:40 PM 06.Sep.2006) TCDAT1 TROPICAL STORM FLORENCE DISCUSSION NUMBER 14 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062006 1100 PM EDT WED SEP 06 2006 AS HAS BEEN THE CASE DURING THE PAST SEVERAL DAYS...THE CENTER OF FLORENCE REMAINS VERY DIFFICULT TO IDENTIFY. THE LATEST SATELLITE POSITION ESTIMATES FROM THE THREE AGENCIES ARE OVER 90 NM APART...AND THERE HAS NOT BEEN ANY CONCLUSIVE EVIDENCE FROM A COUPLE OF MICROWAVE OVERPASSES OR SHIP REPORTS. GIVEN THE LACK OF A WELL DEFINED CENTER...THE INITIAL MOTION IS A RATHER UNCERTAIN 300/9. NOTWITHSTANDING OUR LACK OF CONFIDENCE IN THE CURRENT LOCATION...THE MODEL GUIDANCE REMAINS IN GOOD AGREEMENT ON A WEST-NORTHWESTWARD TRACK FOR THE NEXT 2 TO 3 DAYS FOLLOWED BY A TURN TO THE NORTHWEST AND NORTH...AROUND THE PERIPHERY OF A STRONG MID- TO UPPER-LEVEL HIGH PRESSURE SYSTEM. MOST OF THE TRACK MODELS INSIST ON AN INCREASE IN FORWARD MOTION WITHIN THE NEXT 12-24 HOURS. HOWEVER...THE OFFICIAL FORECAST WILL NOT SHOW AS MUCH ACCELERATION AND IS CLOSE TO THE SPEED INDICATED BY THE LATEST GFDL MODEL RUN. OVERALL...THE OFFICIAL FORECAST TRACK IS IN EXCELLENT AGREEMENT WITH BOTH THE SIMPLE DYNAMICAL MODEL CONSENSUS AND THE FSU SUPERENSEMBLE. DETERMINING THE CURRENT INTENSITY IS ALSO PROBLEMATIC BECAUSE OF THE AMBIGUITY OF THE CENTER POSITION. HOWEVER OUR BEST ESTIMATE... USING THE DVORAK SHEAR PATTERN...INDICATES THAT THE CURRENT WIND SPEED REMAINS AT 45 KT. FLORENCE'S CLOUD PATTERN IS SOMEWHAT AMORPHOUS AND CONTINUES TO LACK DEFINITE BANDING FEATURES...AS APPARENTLY SOME SOUTHERLY SHEAR IS STILL INFLUENCING THE SYSTEM. WATER VAPOR ANIMATION...HOWEVER...SHOWS THAT AN UPPER-LEVEL LOW LOCATED A FEW HUNDRED MILES WEST OF THE TROPICAL CYCLONE IS SLOWLY RETREATING WESTWARD. THIS WOULD CAUSE THE SHEAR TO RELAX AND PERMIT FLORENCE TO STRENGTHEN. THE OFFICIAL INTENSITY FORECAST IS IN GOOD AGREEMENT WITH THE CONSENSUS OF THE SHIPS...GFDL...AND FSU SUPERENSEMBLE OUTPUT AND SIMILAR TO THAT FROM THE PREVIOUS ADVISORY...SHOWING A MAJOR HURRICANE LATER IN THE PERIOD. WE SHOULD NOTE...HOWEVER...THERE IS LIMITED SKILL IN TROPICAL CYCLONE INTENSITY PREDICTION PARTICULARLY IN THE 3 TO 5 DAY TIME FRAME. FORECAST POSITIONS AND MAX WINDS INITIAL 07/0300Z 19.6N 52.5W 45 KT 12HR VT 07/1200Z 20.5N 54.0W 50 KT 24HR VT 08/0000Z 21.9N 56.7W 55 KT 36HR VT 08/1200Z 23.1N 59.4W 65 KT 48HR VT 09/0000Z 24.3N 62.1W 75 KT 72HR VT 10/0000Z 27.0N 66.0W 90 KT 96HR VT 11/0000Z 30.0N 67.0W 100 KT 120HR VT 12/0000Z 33.5N 66.5W 95 KT $$ FORECASTER BROWN/PASCH |