000 AXNT20 KNHC 192338 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAR 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 7N12W AND CONTINUES TO 4N18W WHERE THE ITCZ CONTINUES ALONG 2N24W 3N30W THEN S OF THE EQUATOR INTO SOUTH AMERICA NEAR 37W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM THE ITCZ TO 5N BETWEEN 20W-27W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N TO THE ITCZ BETWEEN 10W-13W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER TROUGH IS MOVING INTO THE W ATLC COVERING THE N GULF N OF 27N E OF 93W SUPPORTING A COLD FRONT THAT 19/21000 UTC EXTENDS FROM THE W ATLC ACROSS FLORIDA BETWEEN DAYTONA BEACH AND JUST N OF TAMPA TO 28N84W WHERE IT BECOMES STATIONARY TO 2689W THEN COLD AGAIN TO 25N92W AGAIN BECOMING STATIONARY ALONG 25N96W TO THE COAST OF MEXICO NEAR 24N97W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 30 NM OF THE FRONT E OF 89W. THE BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN DOMINATES THE REMAINDER OF THE GULF AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE AN AREA OF SCATTERED SHOWERS OVER THE STRAITS OF FLORIDA SE OF A LINE FROM 25N80W TO 23N82W TO INLAND OVER CUBA. A WEAK 1016 MB HIGH IS ANCHORED OVER THE STRAITS OF FLORIDA/CENTRAL CUBA EFFECTIVELY BLOCKING THE PROGRESSION OF THE FRONT. A SURFACE RIDGE IS BUILDING S TO THE N GULF COAST ANCHORED BY A 1022 MB HIGH OVER THE LOWER/MIDDLE MISSISSIPPI VALLEY. LOW STRATOCUMULUS CLOUDS ARE BANKING N OF THE FRONT W OF 92W TO ALONG THE COAST OF LOUISIANA AND TEXAS LEAVING THE REMAINDER OF THE GULF UNDER CLEAR SKIES THIS EVENING. THE COLD FRONT WILL STALL FROM NEAR TAMPA BAY TO EXTREME SE TEXAS TONIGHT THEN MERGE WITH A REINFORCING FRONT WED AND THEN MOVE S FROM SW FLORIDA TO TAMPICO MEXICO WED NIGHT REACHING FROM NW COAST OF CUBA TO NE MEXICO THU AFTERNOON BEFORE DISSIPATING THU NIGHT. SURFACE RIDGE WILL PREVAIL OVER THE N GULF FRI AND SAT WITH A GRADUAL INCREASE IN SOUTHERLY RETURN FLOW. CARIBBEAN SEA... A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED INLAND OVER VENEZUELA SOUTH AMERICA WITH AN UPPER RIDGE AXIS EXTENDING ACROSS HISPANIOLA INTO THE W ATLC. ISOLATED SHOWERS ARE OVER THE NW CARIBBEAN N OF 19N TO OVER CUBA BETWEEN 78W-84W INCLUDING THE CAYMAN ISLANDS. OTHERWISE THE EASTERLY TRADE WINDS ARE USHERING IN SOME POSSIBLE ISOLATED LOW LEVEL SHOWERS DOTTING THE REMAINDER OF THE CARIBBEAN BASIN. FRESH TO STRONG TRADE WINDS ARE ACROSS THE CENTRAL CARIBBEAN AND WILL WEAKEN THROUGH FRI AS THE W ATLC SURFACE RIDGE SHIFTS FURTHER E ACROSS THE CENTRAL ATLC. FRESH SE WINDS IN THE GULF OF HONDURAS WILL REDEVELOP FRI NIGHT AND SAT. THE GULF OF MEXICO COLD FRONT WILL REACH THE NW CARIBBEAN ON THU. ATLANTIC OCEAN... THE BROAD UPPER TROUGH OVER THE GULF OF MEXICO COVERS THE W ATLC N OF 28N W OF 72W SUPPORTING A COLD FRONT THAT AT 19/2100 UTC ENTERS THE W ATLC NEAR 32N74W AND EXTENDS INTO THE GULF OF MEXICO ACROSS FLORIDA NEAR DAYTONA BEACH. THIS FRONT IS ACCOMPANIED BY DRY AIR ALOFT LIMITING SHOWER ACTIVITY. THE UPPER RIDGE OVER THE CARIBBEAN DOMINATES THE REMAINDER OF THE W ATLC WITH A RIDGE AXIS EXTENDING ACROSS HISPANIOLA TO BEYOND 32N67W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 120/150 NM OF LINE FROM OVER CUBA NEAR 23N79W TO BEYOND 32N67W. AN UPPER TROUGH COVERS THE CENTRAL ATLC N OF 11N BETWEEN 35W-55W SUPPORTING A COLD FRONT THAT DIPS S INTO THE REGION NEAR 32N40W TO 29N49W THEN RETURNS N THROUGH 32N59W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 150 NM E OF THE FRONT E OF 44W. A SURFACE RIDGE DOMINATES THE ATLC BETWEEN 20N-29N E OF 20W TO THE ABOVE FRONT ANCHORED BY A 1021 MB SURFACE HIGH NEAR 27N54W. W ATLC COLD FRONT WILL REACH FROM 32N72W TO THE N BAHAMAS TONIGHT THEN STALL AND WEAKEN WED. REINFORCING COLD SURGE WILL OVERTAKE THE STATIONARY FRONT WED NIGHT PUSHING IT FROM BERMUDA TO FLORIDA STRAITS THU. THE FRONT WILL THEN MOVE INTO THE CENTRAL ATLC FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW