000 AXNT20 KNHC 301749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT APR 30 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF SOUTH AMERICA...AND 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 1715 UTC. ...ITCZ... ITCZ AXIS IS ANALYZED ALONG 5N8W 2N19W CROSSING THE EQUATOR NEAR 19W CONTINUING S OF THE EQUATOR TO INLAND OVER SOUTH AMERICA. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM THE EQUATOR TO 3N BETWEEN 10W-16W WITH SMALL CLUSTERS FROM THE EQUATOR TO 4N BETWEEN 21W-35W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE FROM S OF THE EQUATOR TO INLAND OVER SW AFRICA E OF 10W ACROSS THE PRIME MERIDIAN AD FROM 2N-6N BETWEEN 45W-49W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS AN AXIS N OVER MEXICO COVERING THE GULF WITH NW FLOW ALOFT. A STATIONARY FRONT REMAINS OVER THE SE GULF EXTENDING ACROSS EXTREME S FLORIDA JUST S OF MIAMI N OF THE FLORIDA KEYS TO 24N84W GENERATING ISOLATED SHOWERS MAINLY INLAND OVER S FLORIDA AND OVER THE FLORIDA KEYS. A SURFACE RIDGE IS BUILDING OVER THE NE GULF GIVING THE GULF WATERS E TO SE FLOW. WATER VAPOR SATELLITE IMAGERY SHOWS THE GULF COVERED WITH DRY STABLE AIR ALOFT. HOWEVER...THE SURFACE FLOW IS BANKING LOW LEVEL CLOUDS WITH ISOLATED SHOWERS OVER THE NW GULF N OF 27N W OF 91W. VISIBLE SATELLITE IMAGERY SHOWS SIGNS OF SMOKE OVER THE W GULF MAINLY W OF 90W WITH SURFACE AND SHIPS OBSERVATIONS INDICATING SMOKE/HAZE/FOG FROM THE MANY FIRES OVER S MEXICO. THIS IS LEAVING THE E GULF UNDER MOSTLY CLEAR SKIES THIS AFTERNOON. SURFACE RIDGE IS EXPECTED TO REMAIN OVER THE NE GULF THROUGH LATE MON. THE NEXT COLD FRONT WILL MOVE OFF TEXAS TUE AND EXTEND FROM THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE WED. CARIBBEAN SEA... NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE CARIBBEAN THIS AFTERNOON WITH WATER VAPOR SATELLITE IMAGERY SHOWING DRY STABLE AIR ALOFT. THE SURFACE RIDGE OVER THE CENTRAL ATLC IS GIVING THE CARIBBEAN LIGHT EASTERLY TRADE WINDS. REMNANT LOW LEVEL MOISTURE REMAINS OVER THE E CARIBBEAN AND COUPLED WITH THE CONVERGENCE OF THE WINDS AT THE SURFACE AND ALOFT ARE GENERATING SCATTERED SHOWERS MAINLY FROM 13N-18N E OF 68W TO OVER THE LESSER ANTILLES. THIS SAME TYPE OF SCENARIO IS PLAYING OUT OVER NICARAGUA AND HONDURAS WITH SCATTERED SHOWERS DEVELOPING FROM 13N-16N BETWEEN 84W-87W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER FAIR WEATHER CONDITIONS THIS AFTERNOON. SURFACE RIDGE OVER THE CENTRAL ATLC WILL WEAKEN TODAY AND SHIFT EAST. LIGHT TRADE WINDS WILL CONTINUE TODAY BUILDING TO MODERATE TRADE WINDS SUN THROUGH TUE THEN WILL PREVAIL THROUGH WED. ATLANTIC OCEAN... A DEEP LAYERED TROUGH EXTENDS FROM NEW ENGLAND STATES INTO THE W ATLC SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA AT 30/1500 UTC NEAR 32N68W ALONG 27N75W ACROSS THE BAHAMAS TO 25N80W CONTINUING AS A STATIONARY BOUNDARY ACROSS S FLORIDA INTO THE GULF OF MEXICO JUST S OF MIAMI. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90/120 NM SE OF THE COLD FRONT. A WEAK SURFACE RIDGE AND CLEAR SKIES ARE BEHIND THE FRONT. A BROAD SURFACE RIDGE DOMINATES THE CENTRAL ATLC N OF 20N BETWEEN 30W-65W ANCHORED BY A 1030 MB HIGH N OF THE REGION NEAR 37N47W. A BENIGN UPPER LOW REMAINS IN THE CENTRAL ATLC NEAR 30N55W WITH A SECOND MORE SIGNIFICANT UPPER LOW IN THE E ATLC N OF THE CANARY ISLANDS NEAR 34N18W SUPPORTING A 999 MB SURFACE LOW N OF THE MADEIRA ISLANDS EXTENDING A SURFACE TROUGH INTO THE DISCUSSION AREA NEAR 32N15W OVER THE CANARY ISLANDS ALONG 28N16W TO 25N28W. ISOLATED SHOWERS ARE FROM THE CANARY ISLANDS NORTHWARD BETWEEN THE W COAST OF AFRICA TO 18W LEAVING THE REMAINDER OF THE ATLC WITH FAIR WEATHER THIS AFTERNOON. THE W ATLC FRONT WILL DISSIPATE S OF 27N TONIGHT. SURFACE RIDGE WILL BUILD IN BEHIND THIS FRONT AND PREVAIL SUN THROUGH TUE THEN SHIFT E WED AS ANOTHER COLD FRONT MOVES OFF THE SE U.S. COAST. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW