000 WTNT42 KNHC 072037 TCDAT2 TROPICAL DEPRESSION SEVEN DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009 500 PM AST MON SEP 07 2009 SATELLITE IMAGES INDICATE THAT THE BROAD LOW PRESSURE AREA LOCATED SOUTH OF THE CAPE VERDE ISLANDS HAS ACQUIRED ENOUGH ORGANIZATION TO BE CLASSIFIED AS A TROPICAL DEPRESSION...THE SEVENTH OF THE 2009 ATLANTIC HURRICANE SEASON. THE EXACT CENTER OF THE DEPRESSION IS SOMEWHAT DIFFICULT TO LOCATE. EARLIER TODAY THE LOW-LEVEL CENTER APPEARED TO BE NEAR THE EASTERN EDGE OF THE DEEP CONVECTION. HOWEVER NOW THE THE CENTER APPEARS TO BE UNDER THE DEEP CONVECTION ...BUT DISPLACED EAST OF THE MID-LEVEL CENTER SEEN IN SATELLITE IMAGERY. DESPITE A LARGE SPREAD IN THE SATELLITE POSITION ESTIMATES FROM TAFB AND SAB...BOTH CLASSIFICATIONS WERE T2.0...YIELDING AN INITIAL INTENSITY OF 30 KT. THE HIGHLY UNCERTAIN INITIAL MOTION ESTIMATE IS 280/14. THE DEPRESSION IS CURRENTLY LOCATED SOUTH OF A NARROW EAST-TO-WEST ORIENTED RIDGE. THE RIDGE IS FORECAST TO WEAKEN AS A MID-LEVEL TROUGH MOVES INTO THE EASTERN ATLANTIC AND AN UPPER-LEVEL LOW CUTS-OFF NEAR 27N40W DURING THE NEXT DAY OR TWO. THIS IS EXPECTED TO ALLOW THE CYCLONE TO TURN NORTHWESTWARD IN A COUPLE OF DAYS... FOLLOWED BY A TURN TO THE NORTH THEREAFTER. THE TRACK GUIDANCE IS IN REASONABLY GOOD AGREEMENT ON THIS SOLUTION...AND THE OFFICIAL FORECAST IS NEAR THE MIDDLE OF THE GUIDANCE ENVELOPE. THE DEPRESSION IS CURRENTLY WITHIN AN AREA OF MODERATE EASTERLY VERTICAL SHEAR...BUT THE SHEAR IS FORECAST TO ABATE WITHIN THE NEXT DAY OR SO. SEA SURFACE TEMPERATURES ARE WARM ALONG THE FORECAST TRACK AND THE DEPRESSION IS EXPECTED TO GRADUALLY STRENGTHEN DURING THE NEXT COUPLE OF DAYS. THEREAFTER...INCREASING SOUTHERLY TO SOUTHWESTERLY SHEAR IS FORECAST TO HALT FURTHER INTENSIFICATION. THE NHC FORECAST IS CLOSEST TO THE LGEM GUIDANCE...WHICH TYPICALLY ACCOUNTS FOR INCREASING SHEAR IN THE LONGER RANGES MORE ACCURATELY. THE OFFICIAL FORECAST IS LOWER THAN THE HWRF AND SHIPS GUIDANCE... WHICH BOTH BRING THE CYCLONE TO NEAR HURRICANE STRENGTH IN 2-3 DAYS. THE CENTER OF THE DEPRESSION IS FORECAST TO PASS WELL SOUTHWEST OF THE SOUTHERNMOST CAPE VERDE ISLANDS TONIGHT. OUTER RAIN BANDS ARE LIKELY TO CONTINUE TO SPREAD ACROSS THE ISLANDS...PRODUCING LOCALLY HEAVY RAIN AND GUSTY WINDS. FORECAST POSITIONS AND MAX WINDS INITIAL 07/2100Z 12.5N 24.5W 30 KT 12HR VT 08/0600Z 12.6N 26.5W 35 KT 24HR VT 08/1800Z 13.0N 28.7W 45 KT 36HR VT 09/0600Z 13.9N 30.5W 50 KT 48HR VT 09/1800Z 15.1N 32.1W 55 KT 72HR VT 10/1800Z 17.6N 33.9W 55 KT 96HR VT 11/1800Z 19.5N 34.5W 50 KT 120HR VT 12/1800Z 21.0N 34.5W 45 KT $$ FORECASTER BROWN