000 AXNT20 KNHC 051041 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT MAY 05 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 3N20W 1N25W 2N35W 1N50W. NUMEROUS MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120NM N AND 30NM S OF THE AXIS BETWEEN 17W-40W. SIMILAR ACTIVITY NOTED FROM 2N-5N BETWEEN 40W-52W. ...DISCUSSION... GULF OF MEXICO... MODERATE RETURN FLOW DOMINATES THE GULF AROUND HIGH PRES NE OF THE AREA. THE STRONGEST SE WINDS REMAIN W OF 90W WHERE A TIGHTER GRADIENT EXISTS IN RESPONSE TO LOWER PRESSURE OVER MEXICO. NO DEEP CONVECTION IS EVIDENT ACROSS THE GULF EARLY THIS MORNING THOUGH BROKEN TO OVERCAST LOW CLOUDS ARE SEEN PUSHING N THROUGH THE NW GULF. THIS WILL PRODUCE LOW CEILINGS AT SOME OF THE AIRPORTS ALONG THE GULF COASTAL REGION...SEE TAFS AND TWEBS FROM LOCAL FORECAST OFFICES FOR MORE INFO. UPPER RIDGING IS BUILDING INTO THE WRN GULF BEHIND THE TROUGHING OVER THE FAR ERN GULF. HIGH CLOUDS FROM THE EPAC AND FROM CONVECTION OVER MEXICO ARE SPILLING INTO THE WRN GULF. LIGHT TO MODERATE E TO SE WINDS EXPECTED E OF 90W THROUGH THE WEEKEND. SE WINDS INCREASE IN THE WRN GULF...ALLOWING SE WIND WAVES TO BUILD THROUGH SUN. WW3 GUIDANCE SHOWING SEAS NEARING 10' BY SUNDAY MORNING AT BUOY 42020. CARIBBEAN SEA... LIGHT TO MODERATE TRADES DOMINATE MUCH OF THE BASIN EXCEPT FOR THE NORTH CENTRAL PORTION...N OF 16N BETWEEN 67W-80W...WHERE LIGHTER AND MORE VARIABLE WINDS EXIST. TRADE FLOW HAS BEEN DISRUPTED HERE DUE TO THE TROUGHING IN THE SW NORTH ATLC. THE TRADES ARE ADVECTING THEIR TYPICAL PATCHES OF LOW LEVEL MOISTURE WWD...THOUGH THE MAIN THING NOTED IN THIS MORNINGS SATELLITE IMAGERY IS THE ABUNDANT UPPER MOISTURE/HIGH CLOUDINESS STREAMING NE ESPECIALLY E OF 80W...DOWNSTREAM FROM ITCZ CONVECTION. AN UPPER TROUGH IS BUILDING INTO THE WRN GULF WHILE BROAD RIDGING FROM SOUTH AMERICA GENERALLY DOMINATES THE ERN PORTION. LIGHT TO MODERATE TRADES EXPECTED ACROSS THE CARIB THROUGH THE WEEKEND...ALTHOUGH TROUGHING FROM THE ATLC EXPECTED TO CONTINUE TO AFFECT THE WINDS/WEATHER IN THE NRN PORTION. ATLANTIC... MAIN FEATURE IN THE WRN ATLC CONTINUES TO BE THE SFC TROUGH EXTENDING NE FROM THE TURKS AND CAICOS. THIS...ALONG WITH UPPER DIFFLUENCE BETWEEN AN UPPER TROUGH OVER THE WRN ATLC AND AND UPPER RIDGE OVER THE CENTRAL ATLC...IS SUPPORTING THE OVERCAST CLOUDINESS WITH SCATTERED SHOWERS/ISOLD TSTMS N OF 20N BETWEEN 55W-72W. MODEL GUIDANCE HAS NOT BEEN HANDLING THIS SITUATION PARTICULARLY WELL...THOUGH THE CURRENT CONSENSUS IS FOR TROUGHING TO CONTINUE EXTENDING NE FROM HISPANIOLA/TURKS AND CAICOS INTO SUNDAY WITH POSSIBLE WEAK WAVES OF CLOSED LOW PRESSURE FORMING ALONG THE BOUNDARY AND MOVING NE. THE GLOBAL MODELS ARE ALSO GRADUALLY COMING INTO BETTER AGREEMENT REGARDING ANOTHER LOW TO DEVELOP OFF THE SOUTHEAST U.S. COAST DURING THE SUN-TUE TIMEFRAME. THIS SYSTEM COULD HAVE SIGNIFICANT MARINE IMPACTS FOR THE AREA INTO EARLY NEXT WEEK...SEE OFFSHORE WATERS FORECAST UNDER AWIPS HEADER MIAOFFNT3 FOR MORE DETAILS. OTHERWISE MUCH OF THE REMAINDER OF THE ATLC DISCUSSION AREA IS DOMINATED BY THE SRN PERIPHERY OF A 1030MB SFC HIGH S OF THE AZORES NEAR 36N29W. THERE IS AN UPPER LOW NEAR 27N35W THAT HAS A TROUGH EXTENDING S ALONG 35W TO NEAR 10N...BUT DOES NOT APPEAR TO BE GENERATING ANY SIGNIFICANT WEATHER. $$ WILLIS