000 AXNT20 KNHC 132343 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN OCT 13 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. ...TROPICAL WAVES... TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS FROM 15N33W TO 6N34W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION DOT THE AREA WITHIN 250 NM EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE IN THE CARIBBEAN EXTENDS FROM 20N70W ACROSS HISPANIOLA TO 14N72W MOVING W 10-15 KT. WAVE IS BENEATH AN UPPER RIDGE WITH NO ASSOCIATED DEEP CONVECTION. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 8N13W AND CONTINUES TO 6N17W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 5N23W TO 10N30W THEN RESUMES NEAR 13N51W TO SOUTH AMERICA NEAR 11N61W. A SURFACE TROUGH EXTENDS FROM 16N43W THROUGH A 1010 MB LOW NEAR 13N48W TO 11N53. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS FROM 10N-13N BETWEEN 50W-60W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 11N-17N BETWEEN 42W-50W. SCATTERED MODERATE/STRONG CONVECTION IS INLAND AND WITHIN 90 NM ALONG THE COAST OF W AFRICA BETWEEN SIERRA LEONE TO DAKAR SENEGAL. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE DOMINATES THE GULF ANCHORED OVER MEXICO NW OF TAMPICO. WATER VAPOR SATELLITE IMAGERY SHOWERS DRY STABLE AIR ALOFT COVERING THE S GULF. A SURFACE RIDGE COVERS THE N GULF ANCHORED OVER THE NORTHERN PLAINS. THE SURFACE FLOW COMBINED BY THE DIFFLUNCE ALOFT FROM THE UPPER RIDGE IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 27N W OF 92W TO INLAND OVER W LOUISIANA/TEXAS. THE REMAINDER OF THE GULF IS EXPERIENCING FAIR WEATHER THIS EVENING. SURFACE RIDGE ACROSS THE N GULF WILL MOVE E TUE THROUGH FRI ALLOWING FOR A COLD FRONT TO MOVE OFF THE TEXAS COAST WED EVENING. THE COLD FRONT IS EXPECTED TO REACH FROM THE FLORIDA BIG BEND REGION TO NE MEXICO BY LATE THU. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS OVER THE FAR NW CARIBBEAN W OF LINE FROM HAVANA CUBA TO S BELIZE. ISOLATED SHOWERS DOT THE NW CARIBBEAN. THE CUTOFF UPPER LOW HAS ELONGATED OVER THE PAST 24 HOURS AND HAS MOVED INLAND OVER NICARAGUA WITH THE UPPER TROUGH EXTENDING FROM THE TIP OF NICARAGUA/HONDURAS TO CENTRAL CUBA. AN UPPER RIDGE IS BEING AMPLIFIED BY THE UPPER TROUGH OVER THE W CARIBBEAN AND THE UPPER TROUGH THAT COVERS THE E CARIBBEAN E OF 67W. THIS UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED TO HEAVY SHOWERS WITH EMBEDDED CLUSTERS OF ISOLATED THUNDERSTORMS ARE N OF 12N BETWEEN 72W-82W INCLUDING PORTIONS OF HISPANIOLA...CUBA...CAYMAN ISLANDS AND ALL OF JAMAICA. HEAVIER THUNDERSTORMS ARE INLAND OVER NICARAGUA/NE HONDURAS. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N74W ALONG 11N77W TO ACROSS COSTA RICA NEAR 10N83W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 12N TO OVER PANAMA BETWEEN 76W-82W. SMALL CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS THE E CARIBBEAN WITHIN 90 NM OF LINE FROM ACROSS THE WINDWARD ISLANDS NEAR 12N61W ALONG 15N65W TO OVER PUERTO RICO AND THE THE VIRGIN ISLANDS NEAR 19N66W. CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE W CARIBBEAN MON THROUGH WED. A LOW PRESSURE MAY FORM NEAR THE S PART OF THE WAVE IN THE SW CARIBBEAN ON TUE AND LINGER INTO FRI. HISPANIOLA... SCATTERED TO HEAVY SHOWERS WITH EMBEDDED CLUSTERS OF THUNDERSTORMS ARE CURRENTLY ACROSS PORTIONS OF THE ISLAND THIS EVENING. THE TROPICAL WAVE WILL MOVE W AWAY FROM THE HAITI BY LATE MON. THE UPPER RIDGE CONTINUES TO BRING SOUTHERLY FLOW ALOFT ACROSS THE ISLAND AND WILL CONTINUE THROUGH MON WHEN THE UPPER TROUGH OVER THE W ATLC MOVES E TO OVER HISPANIOLA. BY WED THE UPPER FLOW WILL BECOME MORE NORTHERLY LESSENING THE SHOWERS/THUNDERSTORMS. HOWEVER PEAK DAYTIME HEATING AND INSTABILITY COULD STILL BRING AFTERNOON SHOWERS/ISOLATED THUNDERSTORMS TO PORTIONS OF THE ISLAND. ATLANTIC OCEAN... A NARROW UPPER TROUGH COVERS THE FAR W ATLC W OF 80W TO THE FLORIDA PENINSULA SUPPORTING A WEAK 1015 MB LOW JUST N OF THE DISCUSSION AREA. AN UPPER RIDGE IN THE CARIBBEAN EXTENDS INTO THE W ATLC ACROSS HISPANIOLA THEN ALONG 24N63W TO BEYOND 32N40W. A SURFACE TROUGH IS BENEATH THIS UPPER RIDGE EXTENDING FROM 31N63W ALONG 27N69W TO THE BAHAMAS NEAR 22N74W. THE UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 180 NM E AND 75 NM W OF THE SURFACE TROUGH N OF 24N. SCATTERED TO HEAVY SHOWERS WITH EMBEDDED CLUSTERS OF THUNDERSTORMS ARE S OF 22N TO OVER CUBA BETWEEN 73W-77W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 75 NM OF LINE FROM 23N63W TO 28N53W. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC BASIN W OF 50W ANCHORED BY A 1023 MB HIGH N OF THE DISCUSSION AREA. SURFACE TROUGH WILL MOVE LITTLE THROUGH WED BEFORE IT BEGINS TO MOVE W ON THU. WEAK LOW PRES MAY FORM ALONG THE TROUGH ON TUE NEAR THE SE BAHAMAS AND LIFT TO N OF THE AREA BY WED EVENING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW