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#531643 (Received by flhurricane at: 10:44 PM 03.Aug.2012) TCDAT1 TROPICAL DEPRESSION SIX DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062012 1100 PM AST FRI AUG 03 2012 THE TROPICAL WAVE WHICH EMERGED FROM WEST AFRICA YESTERDAY QUICKLY DEVELOPED A WELL-DEFINED CENTER ALONG WITH SUBSTANTIAL DEEP CONVECTION TODAY. THE COLD CLOUD TOPS ARE MAINLY SOUTH OF THE CENTER DUE TO THE IMPINGING EFFECTS OF MODERATE NORTHEASTERLY VERTICAL SHEAR. DVORAK CURRENT INTENSITY NUMBERS AT 00Z WERE 2.0 FROM TAFB AND 1.5 FROM SAB...AND THE CONVECTIVE STRUCTURE HAS PERSISTED AND IMPROVED SLIGHTLY SINCE THAT TIME. THUS ADVISORIES ARE BEING INITIATED ON TROPICAL DEPRESSION SIX. IT APPEARS THAT THE GENESIS OF THIS CYCLONE WAS AIDED BY THE INTERACTION OF THE WESTWARD MOVING TROPICAL WAVE WITH AN EASTWARD MOVING CONVECTIVELY-COUPLED KELVIN WAVE AS DEPICTED BY ANALYSES FROM SUNY-ALBANY. MOVEMENT OF THE CYCLONE IS CURRENTLY 290 DEGREES AT 14 KT...AS THE SYSTEM IS PRIMARILY BEING STEERED BY A MID TO UPPER LEVEL RIDGE NORTH OF THE CYCLONE. FINDING THE INITIAL POSITION WAS SUBSTANTIALLY AIDED BY SOME SSMI AND WINDSAT MICROWAVE IMAGERY FROM NRL. THE TROPICAL CYCLONE SHOULD CONTINUE MOVING WEST- NORTHWEST FOR THE NEXT DAY OR TWO IN THE DEEP LAYER FLOW. AFTER ABOUT TWO DAYS...IT IS ANTICIPATED THAT THE CYCLONE WILL BE WEAKENING AND THUS ADVECTED ALONG WESTWARD BY THE LOWER TROPOSPHERIC WINDS. THE FORECAST TRACK FOLLOWS CLOSELY THE TCVA CONSENSUS OF THE DYNAMICAL MODELS. WHILE THE CYCLONE UNDERWENT GENESIS RATHER QUICKLY TODAY...IT MAY BE THAT THE SYSTEM WILL NOT DEVELOP MUCH FURTHER. CURRENTLY THE CYCLONE IS BEING AFFECTED BY MODERATE NORTHEASTERLY VERTICAL SHEAR. WHILE THIS SHOULD DIMINISH IN ABOUT A DAY...THE COMBINATION OF ONLY LUKEWARM SEA SURFACE TEMPERATURES AND A FAIRLY DRY STABLE ATMOSPHERE MAY ALLOW THE CYCLONE TO PEAK ONLY AS A LOW-END TROPICAL STORM. AFTER ABOUT TWO DAYS...THE SYSTEM SHOULD BE WEAKENING AND IT MAY NO LONGER BE A TROPICAL CYCLONE BY DAY FOUR OR FIVE AS SUGGESTED BY THE GLOBAL AND REGIONAL HURRICANE MODELS. THE INTENSITY FORECAST IS A BLEND OF THE STATISTICAL LGEM AND SHIPS MODELS AND THE DYNAMICAL GFDL AND HWRF MODELS...WITH A BIT MORE EMPHASIS ON THE LATTER. FORECAST POSITIONS AND MAX WINDS INIT 04/0300Z 13.8N 27.8W 30 KT 35 MPH 12H 04/1200Z 14.5N 29.5W 35 KT 40 MPH 24H 05/0000Z 15.1N 31.8W 40 KT 45 MPH 36H 05/1200Z 15.4N 34.0W 40 KT 45 MPH 48H 06/0000Z 15.6N 36.0W 35 KT 40 MPH 72H 07/0000Z 16.2N 41.1W 30 KT 35 MPH 96H 08/0000Z 16.5N 47.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 09/0000Z 16.5N 53.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ FORECASTER LANDSEA |