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#109463 (Received by flhurricane at: 10:31 PM 07.Sep.2006) TCDAT1 TROPICAL STORM FLORENCE DISCUSSION NUMBER 18 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062006 1100 PM EDT THU SEP 07 2006 SATELLITE IMAGES INDICATE THAT FLORENCE REMAINS POORLY ORGANIZED WITH AN ELONGATED SHAPELESS CLOUD PATTERN WHICH IS NOT VERY TYPICAL OF A TROPICAL CYCLONE. IN FACT..CURRENT DVORAK ESTIMATES FROM SAB AND TAFB DO NOT SUPPORT WINDS HIGHER THAN 35 KNOTS. HOWEVER... USING CONTINUITY AND QUIKSCAT...THE INITIAL INTENSITY IS KEPT AT 45 KNOTS. THESE WINDS ARE CONFINED TO THE NORTHERN SEMICIRCLE. I CANNOT FIND ANY REAL GOOD REASON WHY FLORENCE HAS NOT YET INTENSIFIED SINCE THE INGREDIENTS COMMONLY USED TO FORECAST STRENGTHENING ARE PRESENT. THE OCEAN IS PLENTY WARM...ABOUT 29 DEGREES CELSIUS ACCORDING TO NEARBY BUOYS...THE SHEAR IS LOW...AND THERE IS A LARGE LOW-LEVEL CYCLONIC ENVELOPE WITH PLENTY OF CONVECTION. IN ADDITION...RELIABLE MODELS HAVE BEEN SHOWING INTENSIFICATION FOR THE PAST FEW DAYS...ALTHOUGH THEY HAVE BEGUN TO BACK OFF A LITTLE. THE ONLY SLIGHTLY NEGATIVE CONTRIBUTIONS TO INTENSITY CHANGE ACCORDING TO THE SHIPS MODEL ARE THE TEMPERATURES AT THE UPPER LEVELS...AND THE HUMIDITY. HAVING SAID THAT...I HAVE NO CHOICE BUT TO FORECAST STRENGTHENING AGAIN. THE INTENSITY FORECAST IS HIGHLY UNCERTAIN....HOWEVER...I AM CONFIDENT IN THE TRACK FORECAST. FLORENCE IS MOVING TOWARD THE WEST-NORTHWEST AT 13 KNOTS AROUND THE PERIPHERY OF A SUBTROPICAL RIDGE AND WITHIN WELL-DEFINED STEERING CURRENTS. IN ABOUT 48 HOURS...FLORENCE WILL BE ON THE WESTERN EDGE OF THE RIDGE AND SHOULD BEGIN TO TURN GRADUALLY NORTHWARD AND THEN NORTHEASTWARD AS IT BECOMES EMBEDDED IN THE MID-LATITUDE WESTERLIES. THIS IS THE SOLUTION PROVIDED BY THE TRACK MODELS. THIS FORECAST WOULD BRING THE CYCLONE NEAR BERMUDA IN A LITTLE MORE THAN 3 DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 08/0300Z 21.3N 56.1W 45 KT 12HR VT 08/1200Z 22.3N 58.0W 50 KT 24HR VT 09/0000Z 23.7N 60.4W 55 KT 36HR VT 09/1200Z 25.0N 62.5W 65 KT 48HR VT 10/0000Z 26.5N 64.5W 75 KT 72HR VT 11/0000Z 30.0N 65.5W 90 KT 96HR VT 12/0000Z 34.0N 64.5W 90 KT 120HR VT 13/0000Z 42.0N 58.0W 90 KT...BECOMING EXTRATROPICAL $$ FORECASTER AVILA |