000 AXNT20 KNHC 172351 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN MAR 17 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 11N15W AND CONTINUES TO 6N17W WHERE THE ITCZ CONTINUES ALONG 3N23W 4N29W 2N37W THEN S OF THE EQUATOR INTO SOUTH AMERICA NEAR 45W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-5N BETWEEN 20W-25W AND FROM 4N TO S OF THE EQUATOR BETWEEN 30W-35W. ...DISCUSSION... GULF OF MEXICO... A SHORTWAVE UPPER TROUGH IS MOVING ACROSS THE N GULF EXTENDING FROM CENTRAL MISSISSIPPI TO 28N88W GENERATING SCATTERED SHOWERS/ THUNDERSTORMS FROM 27N-30N BETWEEN 87W-92W INCLUDING THE MISSISSIPPI DELTA. AN UPPER RIDGE EXTENDING FROM THE CARIBBEAN DOMINATES THE REMAINDER OF THE GULF. SCATTERED SHOWERS AND A POSSIBLE STRAY ISOLATED THUNDERSTORM ARE OVER THE NE GULF N OF 26N E OF 88W TO INLAND OVER FLORIDA. THE SURFACE RIDGE CONTINUES TO RETREAT E ONLY COVERING THE E GULF AND LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES THIS EVENING. SURFACE RIDGE WILL GRADUALLY SHIFT E THROUGH MON ALLOWING FOR SOUTHERLY FLOW TO EXPAND ACROSS THE GULF FROM W TO E IN ADVANCE OF THE NEXT COLD FRONT. THIS FRONT WILL MOVE OFF THE TEXAS COAST MON EVENING THEN QUICKLY REACH FROM THE W FLORIDA TO NEAR CORPUS CHRISTI TEXAS LATE MON NIGHT INTO TUE. THE FRONT WILL THEN WEAKEN AND STALL FROM SW FLORIDA TO THE TEXAS/MEXICO BORDER LATE TUE INTO WED AS HIGH PRESSURE BUILDS SE ACROSS MOST OF THE N AND CENTRAL GULF. CARIBBEAN SEA... A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED BY AN UPPER HIGH OFF THE COAST OF GUYANA SOUTH AMERICA NEAR 8N58W. AN UPPER RIDGE AXIS EXTENDS ACROSS THE CARIBBEAN FROM THE WINDWARD ISLANDS THROUGH THE YUCATAN CHANNEL INTO THE GULF OF MEXICO. THE UPPER RIDGE IS DRAWING TROPICAL MOISTURE ACROSS THE SE CARIBBEAN. EASTERLY TRADE WINDS ACROSS THE CARIBBEAN ARE USHERING IN SOME ISOLATED LOW LEVEL SHOWERS DOTTING THE CARIBBEAN BASIN. FRESH TO STRONG TRADE WINDS WILL PREVAIL ACROSS THE CENTRAL CARIBBEAN THROUGH MON WEAKENING TUE THROUGH THU AS THE W ATLC SURFACE RIDGE SHIFTS E. FRESH TO STRONG EASTERLY TRADE WINDS ARE EXPECTED IN THE GULF OF HONDURAS EACH NIGHT THROUGH WED. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE CARIBBEAN DOMINATES THE W INTO THE CENTRAL ATLC S OF 25N WITH A RIDGE AXIS EXTENDING FROM CENTRAL CUBA N TO ALONG THE US EASTERN SEABOARD ENHANCING THE SCATTERED SHOWERS OVER THE NE GULF OF MEXICO. THESE SHOWERS ARE MOVING ACROSS THE FLORIDA PENINSULA INTO THE FAR W ATLC MAINLY N OF 26N W OF 80W. A SURFACE RIDGE COVERS THE W AND CENTRAL ATLC INTO THE FAR E GULF OF MEXICO ANCHORED BY A 1024 MB SURFACE HIGH NEAR 27N62W. AN UPPER TROUGH IS MOVING INTO THE E ATLC SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N30W TO A WEAK 1010 MB LOW NEAR 29N32W AND CONTINUES ALONG 25N37W TO 23N42W WHERE IT DISSIPATES ALONG 21N54W TO NE OF THE LEEWARD ISLANDS NEAR 19N61W. THIS FRONT IS EMBEDDED WITHIN AN AREA OF DRY AIR THUS NO ASSOCIATED SHOWERS. W ATLC SURFACE RIDGE WILL SHIFT EASTWARD THROUGH TUE ALLOWING A COLD FRONT TO MOVE OFF GEORGIA/NE FLORIDA LATE MON AND WILL REACH FROM NEAR BERMUDA TO THE CENTRAL BAHAMAS WHERE IT WILL BECOME STATIONARY TO W CUBA BY EARLY WED THEN WILL WEAKEN AS IT MOVES INTO THE CENTRAL ATLC LATE WED INTO THU. A STRONGER COLD FRONT WILL MOVE QUICKLY W ATLC THU AND MERGE WITH THE FIRST FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW