000 AXNT20 KNHC 161109 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT APR 16 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1100 UTC. ...THE ITCZ... ITCZ AXIS EXTENDS FROM THE SOUTHERN COAST OF SIERRA LEONE NEAR 7N12W...CONTINUING SW ALONG 3N20W EQ30W 2S40W INTO BRAZIL NEAR 3S44W. NUMEROUS STRONG CONVECTION IS MOVING ACROSS LIBERIA AND OFFSHORE FROM 1N-7N BETWEEN 7W-20W. A BROAD AREA OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 8S-5N BETWEEN 20W-32W. A SURFACE TROUGH IS EMBEDDED WITHIN THIS AREA FROM EQ22W TO 5S23W. ANOTHER SURFACE TROUGH IS EMBEDDED IN THE ITCZ ANALYZED FROM 4N37W TO 2S36W SUPPORTING SCATTERED MODERATE CONVECTION NEAR THE AXIS. ...DISCUSSION... THE GULF OF MEXICO... THE MAJORITY OF THE GULF OF MEXICO IS EXPERIENCING FAIR WEATHER CONDITIONS UNDER THE INFLUENCE OF DRY AIR ALOFT WITH A FEW HIGH LEVEL CIRRUS CLODS MOVING ACROSS THE AREA. HOWEVER...A DEEP LAYER TROUGH MOVES ACROSS THE EASTERN CONUS SUPPORTING A VIGOROUS DEEP LOW PRESSURE SYSTEM. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM IS MOVING ACROSS THE N CENTRAL GULF ANALYZED FROM THE FLORIDA PANHANDLE NEAR 30N85W ALONG 25N92W BECOMING NEARLY STATIONARY TO TAMPICO MEXICO NEAR 22N97W. WHILE SEVERE WEATHER IS ASSOCIATED WITH THE FRONTAL BOUNDARY ACROSS THE SE UNITED STATES...IT BECOMES MOSTLY DRY UPON ENTERING THE GULF REGION. ONLY A WEAK CLOUD BAND WITH A FEW ISOLATED SHOWERS AND WIND SHIFT DEFINE THE FRONT OVER THE GULF WATERS. SURFACE OBS INDICATE 20-25 KT SLY WINDS AHEAD OF THE FRONT. GUSTY NNW UP TO 30 KT ARE BEHIND THE FRONT N OF 27N. A SURFACE TROUGH IS S OF THE COLD FRONT ANALYZED OVER THE BAY OF CAMPECHE FROM 23N91W TO 18N93W. OTHER THAN A SE TO NE WIND SHIFT ALONG THE TROUGH AXIS ...NO CONVECTION IS ASSOCIATED WITH IT. EXPECT THE COLD FRONT TO CONTINUE TO PUSH ESE ACROSS THE GULF OF MEXICO WITH POSSIBLE ISOLATED SHOWERS ALONG THE BOUNDARY. THE CARIBBEAN SEA... MAINLY DRY AIR ALOFT AND STRONG AND SUBSIDENCE IS ACROSS THE CARIBBEAN SEA THIS EVENING...PROVIDING MOSTLY FAIR WEATHER CONDITIONS ACROSS THE BASIN. MARINE OBS INDICATE MODERATE TO FRESH TRADE WINDS ACROSS THE AREA. STRONGER TRADES ARE TURNING ACROSS THE COAST OF COLOMBIA...AROUND THE CLIMATOLOGICAL 1008 MB LOW WELL INLAND NEAR 7N75W. THIS FEATURE IS ENHANCING SCATTERED SHOWERS OVER THE COAST OF PANAMA AND COLOMBIA BETWEEN 75W-80W. WEAK ISOLATED SHOWERS ARE NOTED ACROSS THE SOUTHERN COASTS OF CUBA...HISPANIOLA...AND JAMAICA. SIMILAR ACTIVITY IS OVER THE LESSER ANTILLES S OF DOMINICA. FAIR WEATHER IS EXPECTED TO REMAIN ACROSS THE REST OF THE BASIN OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... A BROAD UPPER LEVEL TROUGH IS OVER THE NW ATLC SUPPORTING A SURFACE TROUGH ALONG 32N60W TO 26N59W. SCATTERED WEAK SHOWERS ARE E OF THE TROUGH UP TO 70 NM. AN UPPER LEVEL LONGWAVE PUSHES OUT OF THE EASTERN CARIBBEAN ACROSS THE LEEWARD ISLANDS SUPPORTING A SURFACE TROUGH EXTENDING 23N57W TO 16N60W. DIFFLUENCE FLOW ALOFT AROUND THE ERN SIDE OF THE UPPER LONGWAVE IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 120 NM E OF THE TROUGH AXIS. THIS SYSTEM IS EXPECTED TO DRIFT E OVER THE NEXT 24 HOURS. COMPUTER MODEL SUGGESTS A LOW COULD DEVELOP WITHIN THE TROUGH AXIS DURING THE FORECAST PERIOD. FARTHER E...A DEEP LAYERED 1000 MB LOW PRESSURE SYSTEM SPINS NEAR 30N30W. AN OCCLUDED FRONT EXTENDS AROUND THE WESTERN AND NORTHERN SEMI-CIRCLE OF THE LOW AND ENTERS THE AREA AS A WEAK COLD FRONT EXTENDING FROM 32N23W TO 25N25. SCATTERED WEAK SHOWERS ARE WITHIN 30 NM EITHER SIDE OF THE OCCLUDED FRONT...AND WITHIN 50 NM EITHER SIDE OF THE COLD FRONT. THIS LOW PRESSURE SYSTEM IS EXPECTED TO DRIFT E OVER THE NEXT 24 HOURS PRODUCING SCATTERED WEAK TO ISOLATED MODERATE CONVECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA