000 AXNT20 KNHC 061037 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN MAY 06 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 9N13W 4N20W 1N30W EQ40W 1S50W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OVER AFRICA AND ADJACENT ATLC WATERS FROM EQ-11N BETWEEN 7W-17W. NUMEROUS MODERATE TO STRONG CONVECTION IS OFF THE COAST OF LIBERIA FROM EQ-8N BETWEEN 9W-14W. ISOLATED MODERATE IS WITHIN 30NM EITHER SIDE OF THE AXIS BETWEEN 17W-22W...AND WITHIN 150NM EITHER SIDE BETWEEN 25W-36W. NUMEROUS MODERATE/ISOLATED STRONG IS OFF NE SOUTH AMERICA FROM 4S-5N BETWEEN 35W-52W. ...DISCUSSION... GULF OF MEXICO... RETURN FLOW DOMINATING THE GULF REMAINS STRONGEST W OF 90W WHERE A TIGHTER PRES GRADIENT EXISTS DUE TO LOWER PRESSURE OVER MEXICO. THIS HAS ALLOWED SE WIND WAVES AND SWELL TO BUILD INTO THE 6-9' RANGE FOR THE WRN GULF. ASIDE FROM A FEW ISOLATED CELLS OF ELEVATED CONVECTION OFF OF NE MEXICO...DEEP CONVECTION REMAINS AT A MINIMUM ACROSS THE GULF. ANTICYCLONIC FLOW AROUND AN UPPER RIDGE BUILDING INTO THE WRN GULF IS SPREADING UPPER MOISTURE EWD INTO THE GULF MAINLY W OF 90W. THIS IS OBSCURING LOW CLOUDS TRAPPED UNDERNEATH A FAIRLY SIGNIFICANT LOW LEVEL INVERSION. MOST ASOS STATIONS ALONG COASTAL TEXAS ARE REPORTING CEILINGS BELOW 2000'. MOSTLY DRY MID TO UPPER AIR IS OVER THE ERN PORTION WITH NW FLOW. SE WINDS AND SEAS REMAIN HIGHEST WRN PORTION THROUGH SUN BEFORE RELAXING A TOUCH MON INTO TUE. BACKDOOR FRONT ASSOCIATED WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST U.S. COAST WILL AFFECT THE MIDDLE AND ERN GULF LATE TONIGHT INTO MON. CARIBBEAN SEA... TRADE FLOW REMAINS FAIRLY LIGHT OVERALL AS THE TYPICAL SYNOPTIC PATTERN HAS BEEN DISRUPTED BY THE SFC TROUGHING IN THE SW NORTH ATLC. UPPER SW FLOW DOMINATES THE BASIN BETWEEN AN UPPER HIGH CENTERED OFF NE SOUTH AMERICA AND TROUGHING EXTENDING SSW FROM OFF THE SE U.S. COAST INTO NW CARIB. THIS IS TRANSPORTING UPPER MOISTURE NE THROUGH THE CENTRAL AND ERN CARIB. A CLUSTER OF SCATTERED MODERATE CONVECTION ASSOCIATED WITH THE ITCZ IS AFFECTING THE SW CARIB NEAR BOCAS DEL TORO PANAMA. FAIRLY WEAK PRES GRADIENT WILL KEEP TRADES IN THE LIGHT TO MODERATE CATEGORY OVER THE NEXT COUPLE OF DAYS. ATLANTIC... A SFC TROUGH ALONG 29N61W 19N66W HAS A 1012 MB LOW ATTACHED NEAR 26N62W. SATELLITE IMAGERY SHOWS A BROAD REGION OF LOW LEVEL CYCLONIC TURNING WITH MORE THAN ONE CENTER POSSIBLE. HAVE GONE WITH A MEAN CENTER OF THE OVERALL BROAD CIRCULATION. ASSOCIATED BROKEN TO OVERCAST CLOUDINESS WITH EMBEDDED SHOWERS IS N OF 20N BETWEEN 47W-64W. THE THICKEST CLOUDS/DEEPEST MOISTURE ARE E OF THE SFC FEATURES WHERE MORE UPPER SUPPORT EXISTS...WITH DIFFLUENCE BETWEEN THE TROUGHING IN THE WRN ATLC AND RIDGING IN THE CENTRAL ATLC. ALTHOUGH THE FOCUS HAS BEEN ON THIS AREA THE LAST FEW DAYS...THAT WILL CHANGE OVER THE NEXT 24-48 HOURS. THE GLOBAL MODELS HAVE CONTINUED TO COME INTO BETTER AGREEMENT REGARDING LOW PRES DEVELOPMENT OFF THE COAST OF THE SOUTHEAST UNITED STATES LATER TODAY THROUGH TUESDAY. THIS IS EXPECTED TO BRING SIGNIFICANT MARINE IMPACTS TO THE NW PORTION OF THE AREA INTO EARLY NEXT WEEK...INCLUDING GALE FORCE WINDS AND LARGE NLY SWELLS. SEE HIGH SEAS FORECAST UNDER AWIPS HEADER MIAHSFAT2 AND STATEMENTS FROM LOCAL WEATHER SERVICE OFFICES FOR MORE DETAILS. MUCH OF THE REMAINDER OF THE ATLC DISCUSSION AREA IS DOMINATED BY THE SRN PERIPHERY OF A QUASI-STATIONARY 1032MB SFC HIGH E OF THE AZORES NEAR 40N20W. THIS IS PRODUCING ABUNDANT MODERATE TO FRESH TRADES AND FAIR WEATHER E OF 45W. THERE IS AN UPPER LOW NEAR 28N27W BUT IT DOES NOT APPEAR TO BE GENERATING MUCH IN THE WAY OF SENSIBLE WEATHER. $$ WILLIS