000 AXNT20 KNHC 012358 RRA TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON APR 01 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 2330 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS THROUGH THE COAST OF GUINEA NEAR 9N13W INTO THE EASTERN TROPICAL ATLC ALONG 5N16W 2N22W 2N30W. THE ITCZ BEGINS NEAR 2N31W AND CONTINUES ALONG 3N40W 1N49W. CLUSTERS OF MODERATE CONVECTION ARE WITHIN 90 NM EITHER SIDE OF THE MONSOON TROUGH AXIS BETWEEN 15W AND 28W. SCATTERED MODERATE CONVECTION IS S OF THE MONSOON TROUGH FROM 3S TO 3N BETWEEN 6W AND 23W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH IS MOVING OVER THE EASTERN CONUS SUPPORTING A WEAK SURFACE TROUGH THAT EXTENDS ACROSS NORTHERN FLORIDA AND THEN OVER THE NE GULF ALONG 29N83W 27N85W 25N88W. A FEW CLUSTERS OF SHOWERS/THUNDERSTORMS ARE NEAR THE AXIS OVER FLORIDA...OTHERWISE NO CONVECTIVE PRECIPITATION IS OBSERVED ALONG THE PORTION OF THE TROUGH OVER THE GULF. EXCEPT FOR THE NW GULF WHERE THE OBSERVED WINDS ARE UP TO 15 KT...SURFACE WINDS OVER THE GULF ARE RELATIVELY LIGHT RANGING FROM 5-10 KT. WEST OF THE TROUGH WIND IS FROM THE NW WHILE E OF IT WESTERLY FLOW DOMINATE...OVER THE WESTERN GULF W OF 90W EASTERLY WINDS DOMINATE. OVER THE COURSE OF 24 HOURS...THE SURFACE TROUGH IS EXPECTED TO DRIFT EASTWARD MERGING WITH A COLD FRONT TO THE NORTH WHICH WILL CONTINUE INTO THE WEST ATLC OVER THE NEXT COUPLE OF DAYS. SE RETURN FLOW WILL SPREAD ACROSS THE GULF BEFORE THE NEXT FRONTAL BOUNDARY MOVES OFF THE TEXAS COAST EARLY THURSDAY. CARIBBEAN SEA... MOSTLY CLEAR SKIES SPREAD ACROSS THE BASIN DUE TO MOSTLY DRY AIR ALOFT EMBEDDED IN A SHORT-WAVE TROUGH OVER THE CENTRAL CARIBBEAN. SOME MODERATE MOISTURE FLOWS AROUND THE EAST SIDE OF THE SHORT-WAVE TROUGH PRODUCING SOME UPPER LEVEL CLOUDS AND ISOLATED SHOWERS ACROSS LA HISPANIOLA...PUERTO RICO AS WELL AS OVER THE CENTRAL AND EASTERN CARIBBEAN WATERS E OF 73W. MOISTURE BEING ADVECTED FROM THE E PACIFIC BY MIDDLE-UPPER LEVEL WESTERLY FLOW IS SUPPORTING RAINSHOWERS AND THUNDERSTORMS OVER CUBA WHICH EXTEND WITHIN 60 NM OFF THE SOUTHERN COASTLINE OF THE ISLAND. THIS MOISTURE FROM THE E PACIFIC IS ALSO SUPPORTING PRECIPITATION ACTIVITY OVER THE ISLAND OF JAMAICA WHICH COULD EXTEND UP TO 83 NM OFF THE EASTERN COAST OF THIS ISLAND. A STRONG PRESSURE GRADIENT OVER THE CENTRAL...SOUTHERN AND EASTERN CARIBBEAN CONTINUES TO SUPPORT TRADEWIND FLOW OF 20-25 KT. A WEAKER PRESSURE GRADIENT OVER THE WESTERN CARIBBEAN ALLOWS FOR LIGHTER WINDS OF 5-15 KT. OVER THE COURSE OF 24 HOURS...LITTLE CHANGE IS EXPECTED. ATLANTIC OCEAN... A MIDDLE-UPPER LEVEL TROUGH EXTENDING OVER THE EASTERN CONUS IS SUPPORTING A WEAK SURFACE TROUGH ACROSS NORTHERN FLORIDA EXTENDING INTO THE GULF AS WELL AS ANOTHER SURFACE TROUGH ALONG THE E COAST OF FLORIDA FROM TITUSVILLE TO THE FLORIDA STRAITS. ABUNDANT MOISTURE IN THE MIDDLE-UPPER LEVELS ARE SUPPORTING SCATTERED MODERATE CONVECTION OVER THE WESTERN ATLC W OF 70W AND N OF 20N. OVER THE CENTRAL ATLC...AN UPPER LEVEL TROUGH N OF 32N SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 30N34W 26N43W 24N52W 24N57W. ISOLATED SHOWERS ARE POSSIBLE ALONG AND WITHIN 20 NM OF THE FRONTAL BOUNDARY. SURFACE RIDGING CONTINUES SOUTH OF THE FRONT AND INTO THE EASTERN ATLC WHERE IT IS SUPPORTED BY A BROAD UPPER RIDGE CENTERED NEAR 18N19W. A DISSIPATING COLD FRONT IS OVER THE FAR N EASTERN ATLC EXTENDING ALONG 30N8W 28N13W 27N18W WITH NO CONVECTIVE PRECIPITATION ASSOCIATED TO IT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR