000 WTNT42 KNHC 131433 TCDAT2 TROPICAL DEPRESSION TWO DISCUSSION NUMBER 10 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009 1100 AM AST THU AUG 13 2009 TROPICAL DEPRESSION TWO CURRENTLY CONSISTS OF A SWIRL OF LOW CLOUDS WITH ISOLATED SHOWERS AND THUNDERSTORMS...TOO FEW TO GET A DATA-T NUMBER USING THE DVORAK TECHNIQUE. SSMI/DATA AT ABOUT 09Z SUGGESTED 25 KT WINDS IN THE NORTHERN SEMICIRCLE...AND THAT IS USED AS THE INITIAL INTENSITY. SSM/I AND AMSR-E PRECIPITABLE WATER IMAGERY SUGGESTS THAT A TONGUE OF DRIER AIR HAS WRAPPED ALMOST ALL THE WAY AROUND THE CIRCULATION...AND WATER VAPOR IMAGERY SHOWS MID/UPPER-LEVEL DRY AIR IN THE VICINITY OF THE DEPRESSION. THESE FACTORS...COMBINED WITH ABOUT 15 KT OF EASTERLY VERTICAL WIND SHEAR...MAY BE PREVENTING THE SYSTEM FROM MAINTAINING ORGANIZED CONVECTION. THE INITIAL MOTION IS NOW 270/8. THERE IS LITTLE CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS FORECAST. THE DEPRESSION IS ON THE SOUTH SIDE OF A LOW/MID-LEVEL RIDGE...WHICH SHOULD RESULT IN A WESTWARD MOTION FOR THE NEXT COUPLE OF DAYS. AFTER THAT...THE SYSTEM SHOULD GRADUALLY TURN WEST-NORTHWESTWARD TOWARD A WEAKNESS IN THE RIDGE OVER THE WESTERN ATLANTIC. THE OVERALL GUIDANCE ENVELOPE HAS SHIFTED SOUTHWARD SINCE THE LAST ADVISORY...SO THE NEW FORECAST TRACK IS ALSO SHIFTED SOUTHWARD. IT SHOULD BE NOTED THAT IF THE CYCLONE WEAKENS TO A TROPICAL WAVE...THE REMNANTS WOULD LIKELY MOVE FARTHER SOUTH THAN CURRENTLY FORECAST...AS SHOWN BY THE BAMM AND BAMS MODELS. THE SHIPS MODEL CONTINUES TO FORECAST MODERATE TO OCCASIONALLY STRONG SHEAR OVER THE SYSTEM DURING THE FORECAST PERIOD...AND THUS THE SHIPS AND LGEM MODELS SHOW LITTLE OR NO STRENGTHENING. ON THE OTHER HAND...THE HWRF AND GFDN SHOW SIGNIFICANT STRENGTHENING... WITH THE HWRF MAKING THE SYSTEM A HURRICANE BY 120 HR. BASED ON THE FORECAST SHEAR AND CURRENT TRENDS...THE INTENSITY FORECAST NOW CALLS FOR LITTLE CHANGE IN STRENGTH DURING THE FORECAST PERIOD IN BEST AGREEMENT WITH THE LGEM MODEL. THERE IS A DISTINCT POSSIBILITY THE CYCLONE COULD WEAKEN TO A REMNANT LOW OR TROPICAL WAVE DURING THE FORECAST PERIOD...AS FORECAST BY ALL THE GLOBAL MODELS EXCEPT THE NOGAPS. FORECAST POSITIONS AND MAX WINDS INITIAL 13/1500Z 14.0N 37.6W 25 KT 12HR VT 14/0000Z 14.0N 39.1W 25 KT 24HR VT 14/1200Z 14.2N 41.3W 25 KT 36HR VT 15/0000Z 14.4N 43.9W 25 KT 48HR VT 15/1200Z 14.8N 46.6W 25 KT 72HR VT 16/1200Z 16.0N 52.5W 25 KT 96HR VT 17/1200Z 18.5N 59.5W 25 KT 120HR VT 18/1200Z 22.0N 66.0W 25 KT $$ FORECASTER BEVEN