000 AXNT20 KNHC 011805 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 3N20W 1N30W AND CROSSING THE EQUATOR NEAR 40W. ISOLATED CLUSTERS OF MODERATE TO STRONG CONVECTION HAVE BEEN POPPING UP S OF THE AXIS/OFFSHORE LIBERIA OVER THE LAST FEW HOURS FROM 1N-7N E OF 15W. THE LARGEST CONCENTRATION OF CONVECTION NEAR THE ITCZ IS THE NUMEROUS MODERATE FROM 2S-5N BETWEEN 25W-35W. THIS AREA HAS BEEN SHOWING SOME TROPICAL WAVE-LIKE CHARACTERISTICS OVER THE LAST DAY OR SO...AND MAY BE ADDED AS EITHER A TROUGH OR A WAVE TO THE 1800 UTC MAP. ...DISCUSSION... GULF OF MEXICO... THE SW PORTION OF AN ATLC SFC RIDGE AXIS EXTENDS INTO THE GULF THIS AFTERNOON WHICH IS PRODUCING LIGHT TO MODERATE RETURN FLOW ACROSS THE AREA. SKIES ARE MOSTLY CLEAR WITH JUST A FEW FAIR WEATHER CUMULUS CLOUDS NOTED. 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. UPPER FLOW OVER THE GULF IS MOSTLY OF A CYCLONIC NATURE AROUND TROUGHING EXTENDING S FROM THE UPPER LOW OVER OKLAHOMA. THIS IS TRANSPORTING SOME UPPER MOISTURE EWD BETWEEN LOUISIANA AND THE YUCATAN PENINSULA. OTHERWISE...FAIRLY DRY/STABLE AIR IS NOTED IN WV IMAGERY ESPECIALLY IN THE FAR NE PORTION. CARIBBEAN SEA... MODERATE TO FRESH TRADE FLOW WITH TYPICAL LOW LEVEL MOISTURE PATCHES DOMINATE MUCH OF THE BASIN THIS AFTERNOON. ADDITIONAL LOW LEVEL CONFLUENCE AND UPPER DIFFLUENCE ARE ALLOWING THESE SHOWERS TO GET A LITTLE DEEPER IN THE NW CARIB BETWEEN HONDURAS AND CUBA. THE LOW LEVEL CLOUD MOTIONS IN THE NE PORTION...MAINLY N OF 16N AND E OF 70W...ARE MORE FROM THE SE ON THE SW PORTION OF THE AZORES HIGH. THIS HAS SUPPLIED GOOD LOW LEVEL MOISTURE TO THE LEEWARD ISLANDS THROUGH HISPANIOLA...WHICH HAS COMBINED WITH DIURNAL HEATING FOR CONTINUED SUPPORT FOR THE SHOWER ACTIVITY NOTED FROM THE SAN JUAN RADAR. SWLY UPPER FLOW DOMINATES W OF 75W AHEAD OF THE UPPER TROUGHING EXTENDING S THROUGH THE GULF. FLOW IS MORE ZONAL E OF 75W N OF RIDGING FROM SOUTH AMERICA. SIMILAR TRADE WIND REGIME EXPECTED OVER THE NEXT COUPLE OF DAYS. ATLANTIC... WEAK HIGH PRESSURE DOMINATES THE WESTERN ATLC WITH A COUPLE OF EXCEPTIONS THANKS TO OUR OLD FRONTAL BOUNDARY. A REMNANT TROUGH EXTENDS THROUGH ELEUTHERA AND ADJACENT WATERS ALONG 28N75W 24N77W. THIS IS PRODUCING SCATTERED SHOWERS MAINLY NE OF THE BAHAMAS FROM 25N-28N BETWEEN 73W-78W. THIS TROUGH HAS BROKEN OFF FROM THE MAIN FRONTAL TROUGH THAT ENTERS THE AREA NEAR 31N55W AND CONTINUES SW TO 27N66W. ASSOCIATED SCATTERED SHOWERS WITH ISOLATED TSTMS ARE N OF 26N BETWEEN 51W-63W. THIS ACTIVITY ALSO BEING SUPPORTED BY UPPER DIFFLUENCE BETWEEN UPPER TROUGHING EXTENDING S FROM THE CANADIAN MARITIMES AND THE UPPER HIGH NEAR 33N35W. OTHERWISE THE REMAINDER OF THE ATLC DISCUSSION AREA IS DOMINATED BY THE SRN PERIPHERY OF A STATIONARY 1028 MB SFC HIGH S OF THE AZORES NEAR 34N31W. THIS IS PRODUCING WIDESPREAD FAIR WEATHER AND MODERATE TO FRESH TRADES E OF 50W. OVERALL LARGE SCALE SFC RIDGING WILL DOMINATE THE AREA OVER THE NEXT COUPLE OF DAYS...THOUGH MODEL GUIDANCE SUGGESTS TROUGHING WILL LINGER NEAR THE BAHAMAS SO ASSOCIATED SHOWER ACTIVITY SHOULD PERSIST. $$ WILLIS