000 AXNT20 KNHC 091711 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI APR 09 2010 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 1645 UTC... ...ITCZ... ITCZ AXIS IS CENTERED FROM LIBERIA NEAR 6N10W ALONG 3N20W 3N30W 2N40W TO THE NE BRAZIL COAST NEAR EQ50W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-6N BETWEEN 27W-34W. SCATTERED MODERATE/STRONG CONVECTION IS FROM EQ-7N BETWEEN 34W-50W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...A COLD FRONT PUSHES ACROSS THE ERN GULF OF MEXICO FROM S OF CAPE CANAVERAL FLORIDA TO FORT MYERS CONTINUING ALONG 27N82W 23N86W 22N89W CONTINUING AS A STATIONARY BOUNDARY INTO THE BAY OF CAMPECHE AND CENTRAL MEXICO ALONG 19N92W 19N97W 23N103W. MOST OF THE SHOWER/THUNDERSTORM ACTIVITY ASSOCIATED WITH THE FRONT HAS DISSIPATED. HOWEVER...MOSAIC RADAR IMAGERY INDICATES SCATTERED SHOWERS REMAIN WITHIN 15 NM OF THE FRONT ACROSS CENTRAL FLORIDA...AS WELL AS WITHIN 30 NM EITHER SIDE OF THE FRONT BETWEEN 85W-89W. POSSIBLE ISOLATED SHOWERS ARE ALSO ACROSS THE BAY OF CAMPECHE S OF 22N. SURFACE HIGH PRESSURE BUILDS BEHIND THE FRONT ANCHORED BY A 1021 MB HIGH NEAR 23N97W...AND A 1023 MB HIGH OVER NE LOUISIANA. ALOFT...AN UPPER LEVEL TROUGH OVER THE ERN CONUS EXTENDS INTO THE ERN GULF ALONG 83W...SUPPORTING THE FRONTAL SYSTEM. AN UPPER LEVEL RIDGE MOVES IN ACROSS THE WRN GULF SUPPORTING THE SURFACE RIDGE. DRY AIR AND SUBSIDENCE ACCOMPANY THE ERN SIDE OF THE UPPER LEVEL RIDGE SUPPORTING CLEAR SKIES ACROSS THE NRN GULF OF MEXICO BEHIND THE FRONT. EXPECT THE FRONT TO CONTINUE TO PUSH EWD OUT OF THE AREA WITH HIGH PRESSURE BUILDING IN ITS WAKE. HOWEVER...COMPUTER MODEL DATA INDICATES A SURFACE TROUGH FORMING IN THE BAY OF CAMPECHE IN THE NEXT 24 HRS WITH ENHANCED MOISTURE. IT IS POSSIBLE THAT ENERGY AND MOISTURE ASSOCIATED WITH THE TROUGH WILL BE LEFT BEHIND BY THE FRONTAL SYSTEM. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER THIS AFTERNOON INFLUENCED BY SURFACE HIGH PRESSURE ACROSS THE W ATLC. HOWEVER...LOW-LEVEL MOISTURE DEPICTED IN TOTAL PRECIPITABLE WATER IMAGERY IS MAKING ITS WAY ACROSS THE ERN HALF OF THE BASIN ENHANCING A FEW ISOLATED SHOWERS S OF HISPANIOLA FROM 15N-17N BETWEEN 65W-73W. THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE ACROSS THE W ATLC AND LOWER PRESSURE ACROSS NRN COLOMBIA IS SUPPORTING FRESH TO MODERATE TRADEWINDS. ALOFT...MAINLY ZONAL WLY FLOW COVERS THE BASIN ALONG WITH DRY AIR AND STRONG SUBSIDENCE ACROSS THE CENTRAL AND ERN CARIBBEAN. SOME UPPER LEVEL MOISTURE IS MAKING ITS WAY INTO THE NW CARIBBEAN ASSOCIATED WITH THE COLD FRONT IN THE ERN GULF OF MEXICO. LOW-LEVEL MOISTURE AND SHOWER ACTIVITY ASSOCIATED WITH THE FRONT MAY ALSO BEGIN TO IMPACT THE NW CARIBBEAN OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AS OF 1500 UTC...A COLD FRONT MOVES ACROSS THE FAR WRN ATLC EXTENDING FROM A 1005 MB LOW OFF THE COAST OF NORTH CAROLINA. THE FRONT ENTERS THE AREA NEAR 32N78W CONTINUING SW TO THE FLORIDA COAST NEAR CAPE CANAVERAL. RECENT LIGHTNING DATA INDICATES SCATTERED SHOWERS/THUNDERSTORMS WITHIN 90 NM E OF THE FRONT N OF 29N. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH OVER THE ERN CONUS ALONG 82W. A SURFACE RIDGE COVERS THE REMAINDER OF THE W ATLC ANCHORED BY A 1027 MB HIGH NEAR 32N58W PROVIDING GENERALLY FAIR WEATHER ACROSS THIS AREA. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE ALONG 60W ACCOMPANIED BY SIGNIFICANT DRY AIR AND SUBSIDENCE. FARTHER E...A WEAKENING STATIONARY FRONT ENTERS THE DISCUSSION AREA NEAR 31N28W CONTINUING ALONG 24N31W 18N40W CONTINUING AS A SURFACE TROUGH ALONG 16N49W 13N55W TO THE LESSER ANTILLES NEAR 14N61W. ISOLATED SHOWERS ARE WITHIN 30 NM EITHER SIDE OF THE FRONT...WITH SIMILAR ACTIVITY WITHIN 30 NM S AND 90 NM N OF THE SURFACE TROUGH. TOTAL PRECIPITABLE WATER IMAGERY INDICATES ENHANCED MOISTURE NEAR THE SURFACE TROUGH SUPPORTING THE LARGER AREA OF SHOWERS. THE FRONTAL BOUNDARY IS SUPPORTED BY A SHORTWAVE UPPER LEVEL TROUGH EXTENDING FROM E OF THE AZORES ISLANDS NEAR 38N22W ALONG 27N29W TO 23N40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON