000 AXNT20 KNHC 060604 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 3N20W 1N30W EQ40W EQ50W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OVER AFRICA AND ADJACENT ATLC WATERS FROM EQ-11N BETWEEN 7W-17W. ISOLATED CLUSTERS OF MODERATE CONVECTION ARE WITHIN 150NM N AND 90NM S OF THE AXIS BETWEEN 25W-33W. NUMEROUS MODERATE TO STRONG CONVECTION IS OFF THE SOUTH AMERICAN COAST FROM 3S-2N BETWEEN 36W-47W. ...DISCUSSION... GULF OF MEXICO... RETURN FLOW DOMINATING THE GULF REMAINS STRONGEST W OF 90W IN RESPONSE TO A TIGHTER PRES GRADIENT ASSOCIATED WITH 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 W OF 94W...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. MOSTLY DRY MID TO UPPER AIR IS OVER THE ERN PORTION WITH NW FLOW. SE FLOW AND SEAS REMAIN HIGHEST WRN PORTION THROUGH SUN. BACKDOOR FRONT ASSOCIATED WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST U.S. COAST WILL AFFECT THE MIDDLE AND ERN GULF LATE SUN 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 THROUGH FLORIDA INTO THE NW PORTION. 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 29N58W 24N66W TO THE COAST OF HISPANIOLA REMAINS THE DOMINATE FEATURE IN THE WRN ATLC TONIGHT. A 1013MB LOW IS ATTACHED TO THE TROUGH NEAR 27N61W AND IS EXPECTED TO MOVE SLOWLY NE OVER THE NEXT DAY OR SO. IN ADDITION TO THE SFC FEATURES...UPPER DIFFLUENCE BETWEEN THE TROUGHING IN THE WRN ATLC AND RIDGING IN THE CENTRAL ATLC IS SUPPORTING THE BROKEN TO OVERCAST CLOUDINESS WITH EMBEDDED SHOWERS N OF 22N BETWEEN 46W-64W. ALTHOUGH THE FOCUS HAS BEEN ON THIS AREA THE LAST FEW DAYS...THAT WILL CHANGE OVER THE NEXT 48 HOURS. THE GLOBAL MODELS HAVE CONTINUED TO COME INTO BETTER AGREEMENT REGARDING LOW PRES DEVELOPMENT OFF THE COAST OF THE SOUTHEAST UNITED STATES SUNDAY EVENING 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 1032MB SFC HIGH E OF THE AZORES NEAR 39N20W. THIS IS EXPECTED TO REMAIN NEARLY STATIONARY THROUGH THE END OF THE WEEKEND. THERE IS AN UPPER LOW NEAR 27N28W BUT IT DOES NOT APPEAR TO BE GENERATING MUCH IN THE WAY OF SENSIBLE WEATHER. $$ WILLIS