000 AXNT20 KNHC 192350 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI APR 19 2013 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 10N13W THEN ALONG 6N17W TO 4N21W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 3N31W 2N37W THEN S OF THE EQUATOR NEAR 44W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 4N-6N BETWEEN 13W-20W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 75 NM N OF THE ITCZ BETWEEN 25W-40W AND FROM 4N TO S OF THE EQUATOR BETWEEN 40W-51W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS S MEXICO AND THE BAY OF CAMPECHE TO OVER THE YUCATAN PENINSULA ALONG 21N87W TO ACROSS FLORIDA INTO THE W ATLC NEAR NAPLES. THIS UPPER RIDGE IS GIVING WAY TO A LARGE UPPER TROUGH MOVING FROM THE MISSISSIPPI VALLEY TOWARD THE EASTERN SEABOARD AND SUPPORTING A COLD FRONT THAT AT 19/2100 UTC ENTERS THE GULF OVER APALACHEE BAY FLORIDA ALONG 25N89W 20N94W TO INLAND OVER S MEXICO NEAR COATZACOALCOS. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE W OF THE FRONT TO A LINE FROM ATCHAFALAYA BAY LOUISIANA TO MEXICO NEAR LA PESCA. A SURFACE RIDGE IS BUILDING IN BEHIND THE FRONT ANCHORED BY A 1024 MB HIGH OVER S TEXAS. COLD FRONT WILL REACH FROM CENTRAL FLORIDA TO THE BAY OF CAMPECHE LATER TONIGHT STALLING AND WEAKENING FROM SW FLORIDA TO THE YUCATAN PENINSULA SAT THEN DISSIPATE SUN. GALE FORCE WINDS AND LARGE SEAS ARE W OF THE FRONT IN THE SW GULF AND WILL DIMINISH EARLY SAT. ANOTHER COLD FRONT IS EXPECTED TO MOVE INTO THE NW GULF WED. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE FAR NW CARIBBEAN. A SECOND UPPER RIDGE ANCHORED IN THE TROPICAL ATLC COVERS MOST OF THE REMAINDER OF THE CARIBBEAN. BETWEEN THE TWO UPPER RIDGES IS AN INDUCED UPPER TROUGH THAT EXTENDS FROM HAITI W-SW TO OVER CENTRAL NICARAGUA. THE TROPICAL ATLC UPPER RIDGE IS ADVECTING UPPER LEVEL MOISTURE OVER THE E CARIBBEAN AND COUPLED WITH SURFACE MOISTURE STREAMING W ON THE TRADE WINDS ARE GENERATING SCATTERED SHOWERS N OF A LINE FROM 18N79W TO OVER THE LESSER ANTILLES NEAR SAINT LUCIA. GUADELOUPE REPORTED EARLIER THIS MORNING OVER 2 INCHES OF RAIN IN THE PAST 24 HOURS. SCATTERED SHOWERS ARE ARE ALSO INLAND AND WITHIN 90 NM ALONG THE COAST OF FROM VENEZUELA TO PANAMA BETWEEN 64W-78W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES THIS EVENING. SURFACE RIDGE OVER THE W AND CENTRAL ATLC IS MAINTAINING MODERATE TO FRESH TRADE WINDS ACROSS THE REGION WITH FRESH TO STRONG WINDS IN THE CENTRAL CARIBBEAN AND GULF OF HONDURAS THROUGH SAT. WINDS AND SEAS WILL GRADUALLY DIMINISH SUN THROUGH TUE. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS INTO THE W ATLC ACROSS FLORIDA NEAR MELBOURNE TO BEYOND 32N76W. THIS UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS N OF 28N W OF 80W TO INLAND OVER FLORIDA TO SOUTH CAROLINA. A BROAD UPPER RIDGE DOMINATES THE CENTRAL ATLC ANCHORED ABOUT 300 NM NE OF BERMUDA. A SURFACE RIDGE DOMINATES THE W AND CENTRAL ATLC W OF 45W INTERRUPTED BY A WEAK SURFACE TROUGH THAT EXTENDS FROM 27N59W TO 23N61W. AN UPPER TROUGH IS IN THE E/CENTRAL ATLC EXTENDING THROUGH 32N39W TO 22N50W SUPPORTING A SURFACE TROUGH THAT EXTENDS THROUGH 32N36W TO 27N40W. SCATTERED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH. THE GULF OF MEXICO COLD FRONT WILL MOVE OFF THE COAST OF N FLORIDA LATER TONIGHT THEN SLOWLY WEAKEN INTO A TROUGH SAT FROM 32N76W TO S FLORIDA. THE TROUGH WILL LINGER OVER THE NW BAHAMAS THROUGH TUE. SURFACE RIDGE WILL BUILD NW OF THE TROUGH SAT NIGHT THROUGH MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW