000 AXNT20 KNHC 171744 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SUN NOV 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... A GALE WARNING IS IN EFFECT FOR THE CENTRAL ATLANTIC N OF 28N BETWEEN 50W-55W ASSOCIATED WITH A STATIONARY FRONT THAT EXTENDS INTO THE CENTRAL ATLC NEAR 32N45W ALONG 29N48W TO A 1005 MB LOW NEAR 23N52W CONTINUING ALONG 19N54W TO 17N57W. GALE FORCE WINDS ARE FORECAST TO PERSIST THROUGHOUT THE NEXT 48 HOURS. ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR THIS LOW TO ACQUIRE SUBTROPICAL OR TROPICAL CHARACTERISTICS DURING THE NEXT FEW DAYS WHILE IT MOVES SLOWLY NORTHWARD TO NORTHWESTWARD. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A SUBTROPICAL OR TROPICAL CYCLONE DURING THE NEXT 48 HOURS. SEE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS HSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 8N12W AND CONTINUES TO 6N18W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 8N31W TO 7N48W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM BOTH SIDES OF THE ITCZ BETWEEN 27W-33W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N-7N BETWEEN 12W-22W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE ANCHORED IN THE NW CARIBBEAN CONTINUES TO GIVE THE GULF SW FLOW ALOFT. A WEAK SURFACE TROUGH IS IN THE SW GULF EXTENDING ALONG THE COAST OF MEXICO FROM 22N97W TO 19N95W WITH POSSIBLE ISOLATED SHOWERS WITHIN 45 NM OF THE TROUGH AXIS. THE SURFACE RIDGE THAT IS ANCHORED BY IN THE NW ATLC COVERS THE E GULF OF MEXICO. THIS IS GIVING THE N GULF SOUTHERLY SURFACE FLOW WHICH IS USHERING IN SOME ISOLATED LOW LEVEL SHOWERS MAINLY N OF 25N W OF 90W AND OVER THE E GULF N OF 24N BETWEEN 82W-86W LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES THIS AFTERNOON. SURFACE RIDGE WILL WEAKEN TODAY IN ADVANCE OF A COLD FRONT. THE FRONT WILL MOVE INTO THE N GULF EARLY MON THEN EXTEND FROM TAMPA BAY TO NE MEXICO EARLY TUE AND BEGIN TO WEAKEN FROM SW FLORIDA TO THE S TEXAS COAST WED AND OVER THE FAR SE AND S/CENTRAL GULF THU. CARIBBEAN SEA... THE CARIBBEAN IS DOMINATED BY A LARGE UPPER RIDGE ANCHORED NEAR 19N84W. WATER VAPOR IMAGERY SHOWS DRY STABLE AIR ALOFT ACROSS THE ENTIRE CARIBBEAN THIS AFTERNOON. SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS ARE ACROSS THE N/CENTRAL CARIBBEAN N OF 15N BETWEEN 67W-75W. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN ALONG 9N FROM COLOMBIA TO PANAMA/COSTA RICA. NE TO E TRADE WINDS ARE BANKING ISOLATED LOW LEVEL SHOWERS WITHIN 60 NM ALONG THE COAST OF COSTA RICA AND PANAMA W OF 80W. FRESH TO STRONG TRADE WINDS WILL DIMINISH IN THE S/CENTRAL CARIBBEAN LATER TODAY. GENTLE TO MODERATE TRADE WINDS WILL PREVAIL ELSEWHERE ACROSS MOST OF THE REGION THROUGH THU. ...HISPANIOLA... ALTHOUGH THE WATER VAPOR IMAGERY SHOWS DRY STABLE AIR ALOFT...NE SURFACE FLOW IS GENERATING ISOLATED LOW LEVEL SHOWERS ACROSS THE THE MOUNTAIN REGIONS OF HISPANIOLA. THIS NE SURFACE FLOW AND ACCOMPANYING SHOWERS WILL PERSIST THROUGH MON NIGHT. THE FLOW WILL THEN RELAX AND BECOME EASTERLY ON TUE DIMINISHING SHOWERS THROUGH THE END OF THE WEEK. ATLANTIC OCEAN... THE UPPER RIDGE ANCHORED OVER THE NW CARIBBEAN EXTENDS OVER THE W ATLC W OF 60W WHILE A SURFACE RIDGE COVERS THE SAME AREA ANCHORED BY A 1026 MB HIGH N OF BERMUDA. ALTHOUGH THE WATER VAPOR IMAGERY SHOWS DRY STABLE AIR ALOFT...NE SURFACE FLOW IS GENERATING ISOLATED LOW LEVEL SHOWERS S OF 25N BETWEEN 68W-75W INCLUDING THE TURKS AND CAICOS. AN UPPER TROUGH OVER THE CENTRAL ATLC EXTENDS FROM THROUGH 32N59W TO 20N49W SUPPORTING THE FRONT/LOW IN THE SPECIAL FEATURES ABOVE. AN UPPER RIDGE TO THE E EXTENDS FROM THE TROPICS NEAR 14N35W ALONG 24N40W TO BEYOND 32N40W PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150/175 NM OF A LINE FROM 10N49W 20N47W TO 24N48W AND SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS FROM 24N-31N BETWEEN 42W-55W. A SURFACE TROUGH IS E OF THE WINDWARD ISLANDS EXTENDING FROM BARBADOS TO 9N59W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 11N-14N BETWEEN 57W-60W. A SURFACE RIDGE DOMINATES THE E ATLC ANCHORED BY A 1033 MB HIGH N OF AZORES. A COLD FRONT WILL MOVE OFF THE NE FLORIDA COAST EARLY TUE REACHING FROM NEAR 31N71W TO CENTRAL FLORIDA TUE AFTERNOON AND FROM NEAR 32N56W TO S FLORIDA BY WED EVENING THEN GRADUALLY DISSIPATE ALONG 27W THU. STRONG SURFACE RIDGE WILL BUILD IN BEHIND THE FRONT. THE SURFACE TROUGH E OF THE WINDWARD ISLANDS WILL REMAIN STATIONARY WHILE DISSIPATING THROUGH MON NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW