000 WTNT42 KNHC 121442 TCDAT2 TROPICAL DEPRESSION TWO DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009 1100 AM AST WED AUG 12 2009 TROPICAL DEPRESSION TWO SHOWS A CLASSICAL SHEAR PATTERN IN SATELLITE IMAGERY THIS MORNING...WITH UPPER-LEVEL EASTERLY WINDS DISPLACING THE CONVECTION TO THE WEST OF THE EXPOSED LOW-LEVEL CENTER. SATELLITE INTENSITY ESTIMATES HAVE INCREASED TO 35 KT FROM TAFB AND SAB. HOWEVER...A QUIKSCAT OVERPASS AT 0812Z DID NOT SHOW TROPICAL-STORM-FORCE WIND VECTORS THAT LOOKED RELIABLE. THUS...THE INITIAL INTENSITY REMAINS 30 KT FOR THIS ADVISORY. AT THIS TIME... MOST OF THE LOW-LEVEL INFLOW INTO THE DEPRESSION SEEMS TO BE COMING FROM THE NORTH...REPRESENTING POSSIBLY MORE STABLE AIR PASSING OVER COOLER WATERS. THE FLOW ON THE SOUTH SIDE OF THE DEPRESSION IS FEEDING INTO A LARGE DISTURBANCE BETWEEN THE CAPE VERDE ISLANDS AND AFRICA. THE INITIAL MOTION IS NOW 265/11. THE DEPRESSION IS ON THE SOUTH SIDE OF A LARGE LOW/MID-LEVEL RIDGE...AND THE LARGE-SCALE MODELS FORECAST THIS TO CONTINUE FOR THE NEXT TWO DAYS OR SO. AFTER THAT TIME...THE MODELS FORECAST A SERIES OF MID/UPPER-LEVEL WEAKNESSES IN THE RIDGE THAT WOULD STEER THE CYCLONE WEST-NORTHWESTWARD. THE TRACK MODEL GUIDANCE MOSTLY AGREES WITH THIS SCENARIO...ALTHOUGH THERE ARE TWO CLUSTERS IN THE GUIDANCE. THE HWRF...BAMD...LBAR... AND CLIPER CALL FOR AN EARLIER WEST-NORTHWESTWARD MOTION...AND AS A RESULT THEY WIND UP NORTH OF THE OTHER GUIDANCE BY DAY 5. THE NEW FORECAST TRACK...WHICH IS ADJUSTED TO THE SOUTH OF THE PREVIOUS FORECAST...IS DOWN THE MIDDLE OF THE SOUTHERN GUIDANCE CLUSTER IN BEST OVERALL AGREEMENT WITH THE CONSENSUS MODELS TVCN AND TVCC. ALTHOUGH IT APPEARS UNLIKELY...THE UKMET SUGGESTS AN ALTERNATIVE SCENARIO...WITH THE DEPRESSION WEAKENING AND THE REMNANTS MOVING WEST INTO THE CARIBBEAN. THE DEPRESSION IS CURRENTLY OVER SEA SURFACE TEMPERATURES NEAR 27C...AND THE SSTS ALONG THE FORECAST TRACK INCREASE TO 28C AFTER 72 HR. THE LARGE-SCALE MODELS FORECAST THE DEPRESSION TO ENCOUNTER MODERATE VERTICAL WIND SHEAR DURING THE FORECAST PERIOD...FIRST FROM THE EAST AND LATER FROM THE SOUTH AND WEST. ALSO...WATER VAPOR IMAGERY SHOWS VERY DRY AIR AT THE MID/UPPER-LEVELS TO THE NORTHWEST OF THE DEPRESSION. THE LATTER TWO FACTORS SUGGEST THE SYSTEM MAY BE SLOW TO STRENGTHEN...AND AT THIS TIME NONE OF THE INTENSITY GUIDANCE FORECASTS AN INTENSITY OF HIGHER THAN 55 KT DURING THE FORECAST PERIOD. THE NEW INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS FORECAST IN CALLING FOR A 50 KT INTENSITY IN 72 HR...AND IT IS IN BEST AGREEMENT WITH THE SHIPS MODEL. FORECAST POSITIONS AND MAX WINDS INITIAL 12/1500Z 14.3N 33.8W 30 KT 12HR VT 13/0000Z 14.2N 35.4W 35 KT 24HR VT 13/1200Z 14.2N 37.6W 35 KT 36HR VT 14/0000Z 14.2N 40.1W 40 KT 48HR VT 14/1200Z 14.5N 42.8W 45 KT 72HR VT 15/1200Z 16.0N 48.5W 50 KT 96HR VT 16/1200Z 19.0N 54.5W 50 KT 120HR VT 17/1200Z 23.0N 60.5W 45 KT $$ FORECASTER BEVEN