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| #287873 (Received by flhurricane at: 10:49 PM 12.Aug.2009) TCDAT2 TROPICAL DEPRESSION TWO DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009 1100 PM AST WED AUG 12 2009 AFTER BEING ON THE VERGE OF TROPICAL STORM STATUS EARLIER THIS AFTERNOON...THE DEPRESSION HAS MADE A COMPLETE TURNAROUND AND IS NOW VIRTUALLY DEVOID OF DEEP CONVECTION. THE LOW-LEVEL CENTER IS EXPOSED TO THE EAST OF WHAT CONVECTION IS LEFT...AND A 2042 UTC QUIKSCAT PASS BARELY SHOWED 30 KT. THE INITIAL INTENSITY IS HELD AT 30 KT...BUT THIS COULD BE GENEROUS. SHIPS GUIDANCE IS CURRENTLY DIAGNOSING 15-20 KT OF EASTERLY SHEAR OVER THE DEPRESSION AND KEEPS IT FOR ANOTHER 2-3 DAYS. IN ADDITION...DRY AIR AND MARGINALLY WARM SEA SURFACE TEMPERATURES WILL LIKELY INHIBIT MUCH STRENGTHENING OVER THE NEXT FEW DAYS. THE OFFICIAL FORECAST NOW ONLY SHOWS THE SYSTEM REACHING 45 KT...AND THIS IS STILL HIGHER THAN ICON...THE CONSENSUS OF THE INTENSITY MODELS. VERTICAL SHEAR IS EXPECTED TO INCREASE AGAIN BY DAY 5...THIS TIME STRONGER AND FROM THE WEST... AND THE FORECAST CONTINUES TO SHOW WEAKENING AT THAT POINT. ALL OF THIS IS MOOT IF DEEP CONVECTION DOES NOT RE-DEVELOP SOON...IN WHICH CASE WE WOULD LIKELY TERMINATE ADVISORIES. THE DEPRESSION HAS BEEN MOVING JUST SOUTH OF DUE WEST AT 260/12. THE GUIDANCE ENVELOPE CONTINUES TO INDICATE A WEST-NORTHWESTWARD TURN IN ABOUT 2-3 DAYS AS A WEAKNESS DEVELOPS IN THE SUBTROPICAL RIDGE...BUT THIS TURN COULD BE DELAYED IF THE DEPRESSION DOES NOT STRENGTHEN AND BECOMES STEERED BY THE LOW-LEVEL FLOW. THE NEW FORECAST IS SHIFTED A LITTLE MORE TO THE SOUTH TOWARDS THE MODEL CONSENSUS. THE HWRF WAS NOT INCLUDED IN THIS CONSENSUS SINCE IT HAS BEEN A CONSISTENT NORTHERN OUTLIER FOR A COUPLE OF DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 13/0300Z 14.0N 36.3W 30 KT 12HR VT 13/1200Z 14.0N 37.9W 30 KT 24HR VT 14/0000Z 14.1N 40.1W 35 KT 36HR VT 14/1200Z 14.3N 42.4W 40 KT 48HR VT 15/0000Z 14.7N 44.8W 45 KT 72HR VT 16/0000Z 16.5N 51.0W 45 KT 96HR VT 17/0000Z 19.0N 57.5W 45 KT 120HR VT 18/0000Z 23.0N 64.0W 40 KT $$ FORECASTER BERG |
