000 AXNT20 KNHC 052331 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN APR 05 2015 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 2245 UTC. ...SPECIAL FEATURES... A GALE WARNING WILL GO INTO EFFECT FOR THE COASTAL WATERS OF COLOMBIA MON NIGHT/EARLY TUE DUE TO THE STRENGTHENING PRESSURE GRADIENT BETWEEN THE LOWER PRESSURE ACROSS SOUTH AMERICA AND HIGH PRESSURE ANCHORED ACROSS THE W ATLC. PLEASE SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 13N17W ALONG 4N15W TO S OF THE EQUATOR NEAR 23W. THE ENTIRE ITCZ IS S OF THE EQUATOR. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM 2N TO S OF THE EQUATOR BETWEEN 10W-25W. A SURFACE TROUGH IS OFF THE COAST OF SOUTH AMERICA FROM 5N44W TO S OF THE EQUATOR NEAR 46W WITH ISOLATED MODERATE CONVECTION S OF 1N TO INLAND OVER BRAZIL SOUTH AMERICA BETWEEN 44W-49W. ...DISCUSSION... GULF OF MEXICO... A SHORTWAVE UPPER TROUGH IS MOVING FROM OKLAHOMA TO ACROSS THE MIDDLE MISSISSIPPI VALLEY LIFTING A WARM FRONT N RATHER RAPIDLY. AT 05/1800 UTC THE WARM FRONT WAS IN THE NW GULF AND IS INLAND OVER S LOUISIANA AND SE TEXAS BY 05/2100 UTC. HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS ARE INLAND OVER LOUISIANA AND MISSISSIPPI MOVING TOWARD ALABAMA WITH ISOLATED SHOWERS WITHIN 60 NM ALONG THE COAST FROM VERMILION BAY LOUISIANA TO GALVESTON TEXAS. THE BROAD UPPER TROUGH OVER THE NW ATLC IS SUPPORTING A COLD FRONT IN THE W ATLC THAT EXTENDS A STATIONARY FRONT ACROSS CENTRAL FLORIDA ENTERING THE GULF BETWEEN TAMPA AND CEDAR KEY FLORIDA TO 29N85W. LINGERING MOISTURE ACROSS THE N GULF COULD PRODUCE ISOLATED SHOWERS MAINLY N OF 26N. AN UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN THROUGH THE YUCATAN CHANNEL TO THE N GULF COAST NEAR THE ALABAMA/MISSISSIPPI BORDER. A WEAK SURFACE RIDGE IS BRIDGING THE STATIONARY FRONT COVERING THE REMAINDER OF THE GULF AND IS ANCHORED IN THE W ATLC. THIS IS GIVING THE S GULF MOSTLY CLEAR SKIES THIS EVENING. HIGH PRESSURE WILL PREVAIL ACROSS THE NE GULF THROUGH MID WEEK. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN INTO THE GULF OF MEXICO WHILE AN UPPER TROUGH OVER THE W/CENTRAL ATLC EXTENDS S OVER THE NE CARIBBEAN. SATELLITE WATER VAPOR IMAGERY CONTINUES TO INDICATE STRONG SUBSIDENCE AND THUS DRY STABLE AIR ACROSS THE ENTIRE BASIN. AFTERNOON SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS HAVE DEVELOPED INLAND OVER W PUERTO RICO...SE HISPANIOLA...S JAMAICA...AND ALONG THE S COAST OF CUBA. NE SURFACE WINDS ARE SHIFTING THE SHOWERS INTO THE CARIBBEAN WATERS. EASTERLY TRADE WINDS ARE GENERATING ISOLATED SHOWERS ACROSS THE LESSER ANTILLES. HIGH PRESSURE MOVING OFF THE MID ATLC COAST WILL MAINTAIN MODERATE TO FRESH TRADE WINDS ACROSS THE BASIN. STRONG WINDS OFF THE COAST OF COLOMBIA WILL PULSE TO GALE FORCE EACH NIGHT FROM MON NIGHT THROUGH WED NIGHT. HISPANIOLA... AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED OVER S HAITI AND SW DOMINICAN REPUBLIC. LOW LEVEL MOISTURE WILL LINGER THROUGH MON PRODUCING THE AFTERNOON SHOWERS. HOWEVER THE MOISTURE WILL INCREASE LATE MON INTO TUE INCREASING THE CHANCE OF SHOWERS WITH SHOWERS BECOMING MORE WIDESPREAD ACROSS THE ISLAND. ATLANTIC OCEAN... AN UPPER TROUGH IS N OF THE DISCUSSION AREA SUPPORTING A COLD FRONT THAT ENTERS THE W ATLC AT 05/2100 UTC NEAR 32N62W AND EXTENDS ALONG 29N67W TO 28N71W WHERE IT BECOMES STATIONARY ALONG 28N77W THEN ACROSS FLORIDA INTO THE GULF OF MEXICO NEAR CAPE CANAVERAL. ISOLATED SHOWERS ARE WITHIN 120 NM NW OF THE FRONT. A SURFACE RIDGE IS BUILDING IN OVER THE W ATLC NW OF THE ABOVE FRONT WITH A 1028 MB HIGH NEAR 35N69W. AN UPPER TROUGH IS OVER THE CENTRAL ATLC INTO THE NE CARIBBEAN WITH A SURFACE TROUGH EXTENDING FROM 30N57W ALONG 27N72W 23N64W TO 19N63W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM E OF THE SURFACE TROUGH N OF 26N. A SURFACE RIDGE COVERS MOST OF THE ATLC E OF THE ABOVE FRONT TO 30W ANCHORED BY A 1030 MB HIGH NEAR 35N40W. AN UPPER TROUGH EXTENDS OVER THE NE ATLC N OF 28N E OF 30W SUPPORTING A COLD FRONT THAT ENTERS THE E ATLC NEAR 32N19W ALONG 29N21W TO 27N24W WHERE IT DISSIPATES ALONG 27N29W 26N34W TO 26N37W. THE W ATLC COLD FRONT WILL MOVE SLOWLY SE ACROSS CENTRAL ATLC TONIGHT THEN STALL ALONG 28N EARLY MON. SURFACE RIDGE WILL CONTINUE TO BUILD N OF THE AREA THROUGH MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW