000 AXNT20 KNHC 042346 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT APR 04 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 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 12N16W ALONG 4N16W TO S OF THE EQUATOR NEAR 19W. THE ENTIRE ITCZ IS S OF THE EQUATOR. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM 5N TO S OF THE EQUATOR E OF 18W TO THE PRIME MERIDIAN. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH COVERS THE E CONUS AND IS SUPPORTING A COLD FRONT THAT EXTENDS ACROSS TALLAHASSEE FLORIDA INTO THE GULF OF MEXICO ALONG 28N90W 26N96W THEN S INTO MEXICO NEAR 24N98W. SCATTERED TO NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60 NM S OF THE FRONT E OF 84W TO INLAND OVER FLORIDA. ISOLATED SHOWERS DOT THE AREA N OF THE WESTERN PORTION OF THE FRONT TO 29N W OF 88W TO INLAND OVER TEXAS AND FAR NE MEXICO. AN UPPER RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS S MEXICO AND THE BAY OF CAMPECHE TO THE NW GULF NEAR 28N94W. A SURFACE RIDGE IS BRIDGING THE FRONT COVERING THE REMAINDER OF THE GULF AND IS ANCHORED BY A 1031 MB HIGH OVER N ARKANSAS. THIS IS GIVING THE REMAINDER OF THE GULF MOSTLY CLEAR SKIES THIS EVENING. THE COLD FRONT WILL STALL FROM NEAR TAMPA FLORIDA TO NE MEXICO TONIGHT THEN BECOME DIFFUSE THROUGH SUN. SURFACE RIDGE WILL THEN PREVAIL ACROSS THE NE GULF THROUGH THE FIRST OF THE WEEK. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE NW CARIBBEAN WHILE AN UPPER TROUGH OVER THE W/CENTRAL ATLC EXTENDS S OVER THE NE CARIBBEAN N OF 15N E OF 78W. NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE S CARIBBEAN. SATELLITE WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE AND THUS DRY STABLE AIR ACROSS THE ENTIRE BASIN. AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND OVER PUERTO RICO...PORTIONS OF HISPANIOLA...JAMAICA...AND ALONG THE S COAST OF CUBA. NE TO E TRADE WINDS ARE SHIFTING THE SHOWERS INTO THE MONA PASSAGE OFF PUERTO RICO AND ALONG THE S COAST OF CUBA...HAITI...AND JAMAICA. EASTERLY TRADE WINDS ARE GENERATING ISOLATED SHOWERS ACROSS THE LESSER ANTILLES. SURFACE RIDGE OVER THE W ATLC WILL SHIFT E THROUGH SUN NIGHT THEN BE REPLACED BY A NEW HIGH MOVING E OFF THE U.S. ATLC COAST TO MAINTAIN MODERATE TO FRESH TRADE WINDS ACROSS THE AREA. HISPANIOLA... AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED OVER PORTIONS OF THE ISLAND THIS EVENING WITH THE SHOWERS SHIFTING INTO THE CARIBBEAN ALONG THE S COAST OF HAITI. LOW LEVEL MOISTURE WILL LINGER THROUGH MON AND COUPLED WITH THE EASTERLY TRADE WINDS COULD GENERATE AFTERNOON SHOWERS/THUNDERSTORMS THROUGH MON...ESPECIALLY OVER THE HIGHER TERRAIN. ATLANTIC OCEAN... AN UPPER TROUGH EXTENDS FROM THE NE ATLC ALONG 32N35W ALONG 2960W TO THEN S TO AN UPPER LOW NEAR 24N63W THEN OVER THE NE CARIBBEAN AND IS SUPPORTING A COLD FRONT THAT ENTERS THE E ATLC NEAR 32N30W ALONG 28N37W TO 27N44W WHERE IT BECOMES A STATIONARY FRONT ALONG 24N56W TO 23N66W. A SURFACE TROUGH IS TO THE S OF THE STATIONARY FRONT EXTENDING FROM 23N59W TO 21N65W. THE UPPER DIFFLUENCE TO THE E OF THE UPPER LOW IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 19N-26N BETWEEN 56W-64W. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC WITH A RIDGE AXIS EXTENDING FROM A 1029 MB HIGH IN THE N/CENTRAL ATLC NEAR 34N45W ALONG 32N54W 29N67W TO JUST N OF THE BAHAMA ISLANDS NEAR 27N80W AND A WEAKER RIDGE BRIDGING THE FRONT OVER THE E ATLC. THIS IS KEEPING MOST OF THE ATLC WITH CLEAR SKIES THIS EVENING. SURFACE RIDGE OVER THE W ATLC WILL SHIFT E THROUGH SUN NIGHT AS THE GULF OF MEXICO COLD FRONT MOVES OFF THE SE GEORGIA COAST LATER THIS EVENING AND WILL REACH FROM 32N75W TO N CENTRAL FLORIDA TONIGHT AND FROM BERMUDA TO S/CENTRAL FLORIDA SUN WHERE IT WILL STALL AND BECOME DIFFUSE ALONG 28N THROUGH SUN NIGHT. A NEW HIGH WILL MOVE E OFF THE U.S. ATLC COAST SUN NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW