000 AXNT20 KNHC 012341 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAY 01 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 4N20W 3N30W CROSSING THE EQUATOR AT 40W INTO NE BRAZIL NEAR 2N47W. THE LARGEST CONCENTRATION OF CONVECTION NEAR THE ITCZ IS ASSOCIATED WITH A TROUGH THAT IS ALONG 23/24W ON THE 18Z SURFACE MAP. DURING THE LAST FEW HOURS...THE STRONG CONVECTION ASSOCIATED WITH THIS TROUGH HAS DIMINISHED A BIT. THIS AREA OF CONVECTION CAME OFF THE AFRICAN COAST TWO DAYS AGO AND HAS BEEN MOVING WWD SHOWING SOME TROPICAL WAVE-LIKE CHARACTERISTICS. AS THE DAY WORE ON...A DRIFTING BUOY LOCATED NEAR 23W SHOWED A WIND SHIFT FROM NE TO SE WITH THE TROUGH PASSAGE. SCATTERED MODERATE CONVECTION IS FOUND AHEAD OF THE TROUGH AXIS FROM EQ-5N BETWEEN 25W-32W. ANOTHER CLUSTER OF STRONG CONVECTION IS INLAND OVER AFRICA APPROACHING THE PRIME MERIDIAN. ...DISCUSSION... GULF OF MEXICO... THE SW PORTION OF AN ATLC SFC RIDGE DOMINATES THE GULF AND THE SE US...INCLUDING THE FLORIDA PENINSULA. THIS RIDGE IS PRODUCING MOSTLY CLEAR SKIES AND LIGHT TO MODERATE RETURN FLOW ACROSS THE AREA. MODERATE RETURN FLOW WILL PERSIST IN THE WRN AND CENTRAL GULF OVER THE NEXT COUPLE OF DAYS AROUND RIDGING... WITH LIGHTER WINDS ANTICIPATED IN THE ERN WATERS. ALOFT...STRONG UPPER LOW OVER KANSAS/OKLAHOMA IS STILL GENERATING SOME STRONG TSTMS OVER E TEXAS. UPPER FLOW OVER THE GULF IS MOSTLY OF A CYCLONIC NATURE AROUND TROUGHING EXTENDING S FROM THE AFOREMENTIONED UPPER LOW ACROSS THE CENTRAL GULF TO THE YUCATAN PENINSULA. AN UPPER RIDGE IS BUILDING BEHIND THIS TROUGH COVERING MEXICO AND FAR W GULF. SOME UPPER LEVEL MOISTURE IS SEEN ON WV IMAGERY ALONG THE TROUGH AXIS. OTHERWISE...FAIRLY DRY/STABLE AIR IS NOTED IN THE FAR NE PORTION OF THE GULF AND ACROSS THE SUNSHINE STATE. HIGH PRESSURE WILL IN REMAIN IN CONTROL OF THE WEATHER ACROSS THE GULF FOR MOST OF THE WEEK. CARIBBEAN SEA... LIGHT STREAMER SHOWERS OR CLOUD LINES HAVE DEVELOPED AGAIN ACROSS THE WINDWARD/LEEWARD ISLANDS UNDER THE TRADE WIND FLOW. THE SAN JUAN DOPPLER RADAR IS DETECTING SCATTERED SHOWERS AND ISOLATED TSTMS MOVING FROM SE TO NW OVER PUERTO RICO...THE US/UK VIRGIN ISLANDS AND THE REGIONAL COASTAL WATERS. PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE PREVAILING MODERATE TO FRESH TRADE WIND FLOW AND THE LOCAL EFFECTS WILL COMBINE TO PRODUCE SOME SHOWER ACTIVITY OVER THESE ISLANDS FROM TIME TO TIME. A SFC TROUGH IS ALSO GENERATING SOME CONVECTIVE ACTIVITY OVER PARTS OF HISPANIOLA. UPPER DIFFLUENCE IS ALLOWING THESE SHOWERS TO GET A LITTLE DEEPER. SIMILAR TRADE WIND REGIME EXPECTED OVER THE NEXT COUPLE OF DAYS AS HIGH PRES REMAINS N OF THE AREA. IN THE UPPER LEVELS...SWLY UPPER FLOW DOMINATES THE WESTERN CARIBBEAN AND CUBA AHEAD OF THE UPPER TROUGHING EXTENDING S THROUGH THE GULF/YUCATAN PENINSULA. AN UPPER E-W RIDGE OVER N SOUTH AMERICA COVERS THE REMAINDER OF THE BASIN WITH MAINLY A ZONAL FLOW. A PLUME OF UPPER LEVEL MOISTURE IS BETWEEN THESE TWO UPPER LEVEL FEATURES AND EXTENDS FROM THE EPAC ACROSS CENTRAL AMERICA INTO THE NW CARIBBEAN AND E-CENTRAL CUBA CROSSING NEAR 20N80W. SCATTERED MODERATE CONVECTION IS SEEN OVER PANAMA AND COLOMBIA DUE TO THE CLOSE PROXIMITY OF THE EPAC ITCZ AN UPPER DIFFLUENCE. SIMILAR CONVECTION IS NEAR LAKE MARACAIBO IN NW VENEZUELA. ATLANTIC... WEAK HIGH PRESSURE DOMINATES THE WESTERN ATLC WITH A COUPLE OF SFC TROUGHS. ONE OF THEM IS OVER THE WESTERN BAHAMAS GENERATING SCATTERED SHOWERS. THE SECOND ONE...REMNANT OF A FRONTAL TROUGH ENTERS THE FORECAST AREA NEAR 30N54W THEN CONTINUES SW TO 27N62W. THIS TROUGH IS ALSO PRODUCING SOME SHOWER ACTIVITY. THIS ACTIVITY IS BEING SUPPORTED BY UPPER DIFFLUENCE BETWEEN UPPER TROUGHING EXTENDING S FROM THE CANADIAN MARITIMES AND THE UPPER HIGH NEAR 33N30W. THE REMAINDER OF THE ATLC DISCUSSION AREA IS DOMINATED BY THE SRN PERIPHERY OF A STATIONARY 1028 MB SFC HIGH LOCATED S OF THE AZORES NEAR 33N32W. POCKETS OF LOW LEVEL MOISTURE WITH EMBEDDED MAINLY LIGHT SHOWERS AND MODERATE TO FRESH TRADE WINDS ARE FOUND UNDER THE INFLUENCE OF THIS HIGH. OVERALL LARGE SCALE SFC RIDGING WILL DOMINATE THE E-CENTRAL ATLC OVER THE NEXT SEVERAL DAYS AS THE HIGH REMAINS NEARLY STATIONARY SOUTH OF THE AZORES. LATEST GFS MODEL RUN DEVELOPS A WEAK LOW OR TROUGH NE OF THE BAHAMAS BY THE END OF THE WEEK. $$ GR