000 AXNT20 KNHC 162344 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAY 16 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...8N10W 6N20W 5N30W 4N40W 3N52W. ISOLATED MODERATE TO STRONG SHOWERS AND LOCALLY STRONG THUNDERSTORMS ARE WITHIN 45 NM ON EITHER SIDE OF THE AXIS BETWEEN 21W-38W. CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION ARE OVER SW AFRICA FROM 6N-11N BETWEEN 3W-10W. SIMILAR CONVECTION IS FOUND OVER SURINAME. ...DISCUSSION... THE GULF OF MEXICO... COLD FRONT HAS MOVED OFF THE TEXAS COAST AND EXTENDS ACROSS THE NORTHWEST GULF...WHERE IS GENERATING SOME SHOWER/TSTM ACTIVITY. MOSAIC DOPPLER RADAR FROM THE SE ALSO SHOWS A BAND OF SHOWERS WITH EMBEDDED TSTMS ASSOCIATED WITH THE LEADING EDGE OF THE FRONT...WHICH STRETCHES FROM SE LOUISIANA TO THE FLORIDA PANHANDLE AND THE ADJACENT GULF WATERS. A PRE-FRONTAL TROUGH IS ALONG 29N90W 24N94W. A BROAD SURFACE RIDGE AND A WEAK SURFACE PRESSURE GRADIENT ARE ANALYZED OVER THE REMAINDER OF THE GULF. ALOFT...A MID/UPPER LEVEL TROUGH IS OVER THE E GULF AND THE NW CARIBBEAN WHILE A RIDGE IS BUILDING ACROSS THE W PART OF THE GULF. DRY AIR/SUBSIDENCE COVERS THE AREA SOUTH OF 27N. THE WEAK COLD FRONT IS FORECAST BY THE COMPUTER MODELS TO MOVE ACROSS THE GULF OF MEXICO DURING THE NEXT 24 TO 48 HOURS. THE CARIBBEAN SEA... UPPER LEVEL NORTHWESTERLY-TO-WESTERLY WIND FLOW DOMINATES THE BASIN THANKS TO AN UPPER RIDGE EXTENDING E/W OVER NORTHERN SOUTH AMERICA/CENTRAL AMERICA AND THE EPAC. A SURFACE TROUGH RUNS FROM NEAR CABO GRACIAS A DIOS IN NICARAGUA TO THE COLOMBIAN LOW NEAR 9N75W. THIS TROUGH COMBINED WITH THE CLOSE PROXIMITY OF THE EPAC ITCZ AND A DIFFLUENT PATTERN ALOFT IS GENERATING BROKEN TO OVERCAST MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS AND TSTMS OVER THE SW CARIBBEAN...COSTA RICA AND PANAMA AS WELL AS THE CARIBBEAN PLAINS OF NICARAGUA. THIS TROUGH WILL REMAIN NEARLY STATIONARY OVER THE NEXT COUPLE OF DAYS KEEPING THE LIKELIHOOD OF RAIN IN THIS REGION. NOW OF MORE SIGNIFICANCE IS A SFC LOW THAT THE NWP MODELS DEVELOP NEAR THE BAHAMAS...WHERE THERE IS ALREADY AN EXTENSIVE AREA OF CLOUDINESS WITH SOME CYCLONIC TURNING. ANOTHER SFC TROUGH IS IN THIS AREA AN EXTENDS ACROSS THE CENTRAL BAHAMAS/CUBA INTO THE NW CARIBBEAN. DIURNAL SEABREEZE SHOWERS HAVE DEVELOPED ACROSS CUBA AND HISPANIOLA. UNDER AN ELY WIND FLOW...STREAMERS HAVE ALSO DEVELOPED ACROSS THE LESSER ANTILLES. MODERATE TRADE WINDS OF 20 TO 25 KT ARE BLOWING ACROSS THE CENTRAL AND EASTERN CARIBBEAN. THE ATLANTIC OCEAN... A RIDGE/TROUGH/RIDGE PATTERN DOMINATES MOST OF THE DISCUSSION AREA. A RIDGE IS OVER THE W ATLC. DIFFLUENCE ASSOCIATED WITH IT IS ENHANCING THE CONVECTIVE ACTIVITY PREVIOUSLY MENTIONED THAT IS OVER THE BAHAMAS. A MIDDLE/UPPER LEVEL TROUGH/LOW IS OVER THE CENTRAL ATLC SUPPORTING THE FRONTAL SYSTEM THAT ENTERS THE AREA NEAR 31N43W...THEN CONTINUES SW TO NEAR 20N62W. AN UPPER LEVEL RIDGE IS E OF THE TROUGH DOMINATING THE E ATLC. WV IMAGERY ALSO SHOWS AN UPPER LOW WEST OF THE MADEIRA ISLANDS NEAR 32N23W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 60 TO 120 NM ON EITHER SIDE OF THE FRONT. A SURFACE RIDGE RUNS FROM A 1029 MB HIGH PRESSURE CENTER NEAR 34N55W TO THE NEAR THE GEORGIA COAST. ANOTHER SURFACE RIDGE EXTENDS ACROSS THE E-CENTRAL ATLC FROM A 1031 SFC HIGH ANCHORED NEAR THE AZORES. THE COMBINATION OF THIS RIDGE AND LOWER PRES OVER AFRICA IS PRODUCING MODERATE TO FRESH NLY FLOW N OF 20 EAST OF 20W INCLUDING THE MADEIRA/CANARY ISLANDS. $$ GR