000 AXNT20 KNHC 132341 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAY 13 2014 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. ...SPECIAL FEATURES... A COLD FRONT IS ANALYZED FROM GALVESTON BAY SW TO NEAR BROWNSVILLE TEXAS THIS EVENING AND IS FORECAST TO MOVE WESTWARD ACROSS THE WESTERN GULF OVERNIGHT AND INTO THE CENTRAL GULF WATERS WEDNESDAY. GALE FORCE NORTHERLY WINDS ARE EXPECTED TO MATERIALIZE AT 14/1800 UTC FROM 22N-26N W OF 96W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 02N22W TO 11N21W MOVING WEST AT 10-15 KT. INFRARED SATELLITE IMAGERY INDICATES A WEAK INVERTED-V PRESENTATION THAT COINCIDES WITH GLOBAL MODEL INDICATED BROAD 700 MB TROUGHING AND 850 MB RELATIVELY VORTICITY. NO SIGNIFICANT CONVECTION IS NOTED IN THE VICINITY OF THE WAVE. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N25W TO THE EQUATOR TO 31W. ISOLATED MODERATE CONVECTION IS S OF 07N BETWEEN THE PRIME MERIDIAN AND 10W...AND S OF 04N BETWEEN 25W- 37W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE NORTHERN AND CENTRAL U.S. PLAINS EXTENDING S-SW OVER NEW MEXICO AND WESTERN TEXAS. THE TROUGH SUPPORTS A COLD FRONT ANALYZED ACROSS THE NW GULF WATERS THAT IS FORECAST TO MOVE ACROSS THE GULF THROUGH EARLY FRIDAY. AS MENTIONED ABOVE...THE COLD FRONT WILL GENERATE GALE FORCE NORTHERLY WINDS ACROSS PORTIONS OF THE WESTERN GULF BEGINNING WEDNESDAY AFTERNOON. IN ADDITION...A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM 29N93W SW TO 25N98W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 22N W OF 92W. ELSEWHERE...A WEAK SURFACE RIDGING INFLUENCES THE EASTERN GULF WITH PRIMARILY EASTERLY WINDS OCCURRING IN THE RANGE OF 10 TO 20 KT THROUGH THE OVERNIGHT HOURS INTO WEDNESDAY. FINALLY...AN UPPER LEVEL TROUGH AXIS EXTENDS FROM OVER NORTHERN FLORIDA SE TO 23N75W IN THE SW NORTH ATLC REGION THAT SUPPORTS A SURFACE TROUGH ANALYZED FROM THE NW BAHAMAS TO CENTRAL CUBA. MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE IN ASSOCIATION WITH THE SURFACE TROUGHING IS PROVIDING ISOLATED SHOWER ACTIVITY TO THE FAR SE GULF WATERS...FLORIDA STRAITS...AND PORTIONS OF THE SOUTHERN FLORIDA PENINSULA S OF 28N E OF 84W. CARIBBEAN SEA... GENERALLY DRY AND STABLE NORTHWESTERLY FLOW ALOFT PREVAILS ACROSS MUCH OF THE CARIBBEAN W OF 70W PROVIDING FOR MOSTLY FAIR WEATHER AND CLEAR SKIES THIS EVENING. AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE SW NORTH ATLC REGION THAT SUPPORTS A SURFACE TROUGH ANALYZED FROM THE NW BAHAMAS TO CENTRAL CUBA. WITH LOW-LEVEL MOISTURE CONVERGENCE MAXIMIZED IN THE VICINITY OF THE SURFACE TROUGH...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ACROSS CUBA THIS EVENING ALONG WITH THE NEARBY CARIBBEAN SEA WATERS N OF 18N BETWEEN 75W-85W. ALSO INCLUDED WITHIN THE INFLUENCE OF THE SURFACE TROUGHING TO THE NORTH OF THE BASIN IS SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING ACROSS HISPANIOLA. ELSEWHERE E OF 70W...DRY UPPER LEVEL SOUTHWESTERLY FLOW CONTINUES TO GENERATE FAIR WEATHER FOR THE LESSER ANTILLES AND PUERTO RICE OVERALL...WITH ONLY A FEW WESTWARD MOVING ISOLATED SHOWERS POSSIBLE ACROSS THE NE CARIBBEAN THIS EVENING. ...HISPANIOLA... SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ACROSS THE ISLAND CURRENTLY...AND THIS ACTIVITY IS EXPECTED TO BEGIN GRADUALLY DIMINISHING THROUGH THE LATE EVENING AND OVERNIGHT HOURS. AN UPPER LEVEL TROUGH REMAINS TO THE NORTH OVER THE SW NORTH ATLC AND WILL CONTINUE TO PROVIDE FOCUS FOR SCATTERED SHOWER AND ISOLATED TSTM ACTIVITY WEDNESDAY AFTERNOON AND EVENING WITH PEAK DAYTIME HEATING AND INSTABILITY. ATLANTIC OCEAN... A SURFACE TROUGH IS ANALYZED ACROSS THE NW BAHAMAS NEAR 27N78W S- SW TO CENTRAL CUBA NEAR 22N80W AND SUPPORTED ALOFT BY A BROAD UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM OVER NORTHERN FLORIDA SE TO A BROAD BASE NEAR 19N71W. GIVEN THE ORIENTATION OF THE SURFACE TROUGH AND UPPER LEVEL TROUGH AXIS...A BROAD AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS IS ACROSS THE SW NORTH ATLC THIS EVENING FROM 20N-28N BETWEEN 68W-82W...INCLUDING CUBA AND HISPANIOLA. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED SW OF BERMUDA BEAR 32N67W. THE SURFACE RIDGE EXTENDS EASTWARD ALONG 30N TO 38W WITH ONLY A VERY SUBTLE AND WEAK SURFACE TROUGH ANALYZED FROM 25N49W TO 29N47W EMBEDDED WITHIN THE SOUTHERN PERIPHERY OF THE RIDGE. POSSIBLE ISOLATED SHOWERS ARE FROM 26N-29N BETWEEN 43W-48W. FINALLY...A WEAKENING 1019 MB LOW IS CENTERED NEAR 29N32W WITH A SURFACE TROUGH EXTENDING NW TO 31N35W AND SE TO 27N30W. ISOLATED SHOWERS ARE POSSIBLE FROM 26N-31N BETWEEN 30W-37W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN