000 AXNT20 KNHC 301802 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON APR 30 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 6N10W 4N20W 2N30W 2N40W CROSSING THE EQUATOR NEAR 45W. NUMEROUS MODERATE TO STRONG CONVECTION IS WITHIN 150NM N AND 210NM S OF THE AXIS E OF 21W TO THE AFRICAN COAST. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM N OF THE AXIS BETWEEN 25W-46W. ...DISCUSSION... GULF OF MEXICO... WEAK SFC RIDGING CONTINUES TO CONTROL THE GULF THIS AFTERNOON AROUND A 1021MB HIGH PRES CENTER NEAR 28N89W. THIS IS PRODUCING ABUNDANT CLEAR SKIES...WINDS MOSTLY BELOW 15KT...AND SEAS MOSTLY BELOW 4' ACROSS THE GULF. MOISTURE CONTENT/CLOUD COVER CONTINUES TO BE GREATEST IN THE FAR WRN GULF WITH LOW LEVEL SE FLOW. IN ADDITION...UPPER MOISTURE IS PUSHING E INTO THE WRN GULF AHEAD OF THE CONVECTION OVER TX ASSOCIATED WITH THE PRONOUNCED UPPER LOW NEAR THE TX/NM BORDER. VERY DRY AIR IS SEEN IN WV IMAGERY OVER THE ERN GULF...BEING ADVECTING SE WITH NW FLOW ON THE E SIDE OF A MID LEVEL RIDGE. SFC HIGH PRES OVER THE N GULF WILL SLIDE E OVER THE NEXT COUPLE OF DAYS...ALLOWING RETURN FLOW TO BE STRONGEST/MOISTURE TO BE HIGHEST IN THE WRN PORTION. CARIBBEAN SEA... MODERATE TO FRESH TRADE FLOW WITH TYPICAL LOW LEVEL MOISTURE PATCHES DOMINATE MUCH OF THE BASIN E OF 80W. HOWEVER...THE LOW LEVEL CLOUD MOTIONS IN THE NE PORTION...MAINLY N OF 16N AND E OF 72W...ARE MORE FROM THE SE AHEAD OF THE REMNANT FRONTAL TROUGH EXTENDING NE FROM THE BAHAMAS. THIS HAS SUPPLIED GOOD LOW LEVEL MOISTURE TO THE LEEWARD ISLANDS THROUGH HISPANIOLA...WHICH HAS COMBINED WITH DIURNAL HEATING TO SUPPORT THE SHOWER ACTIVITY NOTED FROM THE SAN JUAN RADAR. THE MAIN FEATURE W OF 80W IS THE SFC TROUGH NEAR THE COAST OF NICARAGUA/HONDURAS ALONG 18N81W 12N83W. THIS IS GENERATING SCATTERED SHOWERS/ISOLATED TSTMS FROM 15N-19N BETWEEN 80W-86W. UPPER FLOW REMAINS HIGHLY ZONAL WITH JUST GENTLE RIDGING IN PLACE. SIMILAR TRADE WIND REGIME EXPECTED THE NEXT COUPLE OF DAYS WITH ATLC HIGH PRES REMAINING N OF THE AREA. ATLANTIC... WEAK SFC HIGH PRES IS BUILDING INTO THE THE WRN ATLC BEHIND THE REMNANT FRONTAL TROUGH THAT ENTERS THE AREA NEAR 31N61W AND CONTINUES SW TO THE SE BAHAMAS NEAR 23N75W. SATELLITE IMAGERY SHOWS A SECOND LOW LEVEL CONFLUENT ZONE ABOUT 90NM BEHIND THE ANALYZED TROUGH. THE LEADING BOUNDARY SEEMS MORE SIGNIFICANT AND CONTINUOUS SO HAVE OPTED FOR ONLY ANALYZING THIS FEATURE. SUSPECT WHAT WE ARE SEEING IS AN OLD PREFRONTAL TROUGH BEGINNING TO MERGE WITH THE MAIN PORTION OF THE OLD COLD FRONT. REGARDLESS...SCATTERED SHOWERS/ISOLATED TSTMS ARE WITHIN 60NM EITHER SIDE OF A LINE EXTENDING NE FROM CROOKED ISLAND TO 30N61W. VISIBLE IMAGERY ALSO CONTINUES TO SHOW THE SMOKE DISPERSING THROUGH FLORIDA AND THE WRN ATLC ASSOCIATED WITH THE WILDFIRES IN SE GEORGIA. OTHERWISE THE REMAINDER OF THE ATLC DISCUSSION AREA IS DOMINATED BY THE SRN PERIPHERY OF A 1030 MB SFC HIGH S OF THE AZORES NEAR 34N29W. THIS IS PRODUCING WIDESPREAD FAIR WEATHER AND MODERATE TO FRESH TRADES E OF 50W. WEAK HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE WRN ATLC WHILE STRONGER/LARGER HIGH PRESSURE REMAINS IN CONTROL OF THE ERN ATLC. WEAK CONFLUENCE BETWEEN THESE TWO HIGHS WILL SUPPORT THE SLOWLY DYING FRONTAL TROUGH NE OF THE SE BAHAMAS OVER THE NEXT DAY OR SO. $$ WILLIS