000 AXNT20 KNHC 071752 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 07 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM HENRI IS CENTERED NEAR 18.9N 57.4W AT 07/1500 UTC...OR ABOUT 325 NM E OF THE NRN LEEWARD ISLANDS MOVING WNW AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. NUMEROUS STRONG CONVECTION IS FROM 17N-20N BETWEEN 54W-56W. SCATTERED MODERATE CONVECTION IS FROM 16N-21N BETWEEN 52W-57W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 48W S OF 11N MOVING W NEAR 20 KT. A 0900 UTC QUIKSCAT PASS INDICATED LOW-LEVEL CYCLONIC FLOW AROUND THE WAVE AXIS. THE WAVE ALSO COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. WIDELY SCATTERED MODERATE CONVECTION IS FROM 6N-13N BETWEEN 44W-53W. TROPICAL WAVE IS ALONG 68W S OF 15N MOVING W NEAR 15 KT. VISIBLE SATELLITE IMAGERY INDICATES BROAD CYCLONIC TURNING OVER THE SE CARIBBEAN IN THE VICINITY OF THE WAVE...ALONG WITH A DEEP LAYER MOISTURE MAXIMUM AS INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE IS MOVING BENEATH UPPER LEVEL TROUGHING ACROSS THE ERN CARIBBEAN...WITH SCATTERED MODERATE CONVECTION FROM 12N-15N BETWEEN 65W-70W. THIS CONVECTION IS MORE LIKELY ASSOCIATED WITH THE UPPER LEVEL TROUGH THAN THE WAVE. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N15W 8N20W 7N30W 6N40W 8N46W 7N48W 6N58W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS LOCATED FROM THE COAST OF AFRICA FROM 4N-11N BETWEEN 13W-29W. ...DISCUSSION... GULF OF MEXICO... SURFACE HIGH PRESSURE IS CENTERED NEAR THE WEST COAST OF FLORIDA...WITH A RIDGE STRETCHING WSW ACROSS THE GULF. A COLD FRONT IS LOCATED 100 NM INLAND OVER THE GULF COAST STATES. DRY AIR AND SUBSIDENCE COVERS THE BASIN...RESULTING IN FAIR WEATHER. ANTI-CYCLONIC SURFACE FLOW REMAINS IN PLACE AROUND THE RIDGE... WITH WINDS BETWEEN 15-20 KT IN THE WESTERN GULF. EXPECT THE RIDGE TO PERSIST FOR THE NEXT FEW DAYS...AND THE COLD FRONT TO STALL OUT FROM THE FLORIDA BIG BEND TO SOUTHEAST TEXAS THIS WEEKEND. CARIBBEAN SEA... AN UPPER LEVEL LOW IS OVER THE WESTERN CARIBBEAN...MOVING INLAND NEAR THE BORDER OF NICARAGUA/HONDURAS. THE UPPER LOW IS SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE WESTERN PORTION OF THE BASIN S OF 19N BETWEEN 76W-87W. AN UPPER LEVEL TROUGH IS LOCATED OVER THE EASTERN CARIBBEAN WITH AXIS ALONG 15N FROM 61W-71W...OVER THE WINDWARD ISLANDS AND INTO THE ATLANTIC. MOIST DIFFLUENT FLOW AROUND THE UPPER TROUGH IS SUPPORTING A LINE/ZONE OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 14N60W TO 13N71W. A TROPICAL WAVE ALONG 68W IS ALSO ENHANCING THE CONVECTIVE ACTIVITY. MODERATE TO FRESH TRADEWINDS ARE ACROSS MUCH OF THE BASIN WITH STRONGER WINDS IN THE WESTERN AND CENTRAL CARIBBEAN. ATLANTIC OCEAN... TROPICAL STORM HENRI REMAINS THE BIGGEST WEATHER MAKER OVER THE ATLANTIC. SEE SPECIAL FEATURES ABOVE. A DYING COLD FRONT OVER THE NORTHWEST PORTION OF THE BASIN FROM 31N77W TO NORTHEAST OF THE DISCUSSION AREA WILL DISSIPATE TONIGHT. AN UPPER LEVEL TROUGH IS FARTHER EAST OVER THE NORTH CENTRAL PORTION OF THE BASIN SUPPORTING A COLD FRONT AT THE SURFACE FROM 31N49W TO NORTH OF THE AREA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 250 NM TO THE SOUTHEAST OF THE FRONT. A 1024 MB SURFACE HIGH IS CENTERED NEAR 25N41W WITH ANOTHER 1023 MB SURFACE HIGH CENTERED NEAR 30N36W. RIDGING EXISTS ACROSS THE MAJORITY OF THE ATLANTIC WITH THE EXCEPTION BEING A WEAKNESS IN THE RIDGE TO THE NORTHEAST OF TROPICAL STORM HENRI. AN UPPER LEVEL LOW CENTERED NEAR 30N32W IS MOVING THROUGH THE EASTERN PORTION OF THE RIDGE PRODUCING ISOLATED/SCATTERED SHOWERS. $$ LEWITSKY/HUFFMAN