000 AXNT20 KNHC 180005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE... A GALE WARNING IS IN EFFECT FOR THE CENTRAL ATLANTIC N OF 25N BETWEEN 48W-61W ASSOCIATED WITH A STATIONARY FRONT THAT EXTENDS INTO THE CENTRAL ATLC NEAR 30N46W ALONG 27N50W TO A 1002 MB LOW NEAR 25N53W CONTINUING ALONG 21N54W. A DISSIPATING STATIONARY FRONT CONTINUES ALONG 17N56W TO 16N59W. 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 NORTH-NORTHWESTWARD TO NORTHWARD. 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 EASTERN ATLC NEAR 09N13W AND CONTINUES TO 06N23W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 07N37W TO 09N50W. SCATTERED MODERATE CONVECTION IS WITHIN 200 NM BOTH SIDES OF THE ITCZ BETWEEN 15W- 20W...FROM 05N-10N BETWEEN 26W-30W AND FROM 07N-15N BETWEEN 44W- 50W. ...DISCUSSION... GULF OF MEXICO... A BROAD MIDDLE TO UPPER RIDGE ANCHORED IN THE SE GULF IN THE MIDDLE LEVELS CONTINUES TO GIVE THE BASIN SW FLOW ALOFT. A SURFACE RIDGE ANCHORED IN THE NW ATLC EXTENDS AN AXIS TO THE EASTERN GULF OF MEXICO...THUS PROVIDING THE BASIN WITH SOUTHERLY- SOUTHEASTERLY FLOW IN THE RANGE OF 5-15 KT. THIS WIND FLOW IS USHERING SOME ISOLATED RAINSHOWERS AND LIGHT FOG MAINLY N OF 26N E OF 97W LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES THIS EVENING. THE SURFACE RIDGE WILL WEAKEN TODAY IN ADVANCE OF A COLD FRONT. THE FRONT WILL MOVE INTO THE N GULF EARLY MON. THEN ON EARLY TUE...IT IS EXPECTED TO EXTEND FROM CENTRAL FLORIDA TO THE CENTRAL GULF WHERE IT WILL TRANSITION INTO A STATIONARY FRONT TOWARDS THE WESTERN GULF. CARIBBEAN SEA... EXCEPT FOR THE FAR EASTERN CARIBBEAN...A MIDDLE TO UPPER LEVEL RIDGE DOMINATES THE BASIN WITH DRY AIR SUBSIDENCE SUPPORTING FAIR WEATHER. IN THE SW BASIN...THE MONSOON TROUGH AXIS EXTENDS ACROSS THE COSTA RICA-PANAMA BORDER EASTWARD TO NORTHERN COLOMBIA AND IS ENHANCING ISOLATED SHOWERS S OF 10N. AN UPPER- LEVEL TROUGH OVER THE CENTRAL ATLC EXTENDS AN AXIS SW TO THE LESSER ANTILLES AND SUPPORTS A SURFACE TROUGH EXTENDING FROM 13N59W TO 10N59W. THIS AREA OF LOW PRESSURE IS GENERATING RAINSHOWERS FOR SOME OF THE WINDWARD ISLANDS. GENTLE TO MODERATE TRADE WINDS ARE FORECAST ACROSS MOST OF THE REGION FROM THIS EVENING THROUGH THU. ...HISPANIOLA... ALTHOUGH THE WATER VAPOR IMAGERY SHOW DRY STABLE AIR ALOFT...NE SURFACE FLOW IS GENERATING RAINSHOWERS ACROSS THE EASTERN MOUNTAINOUS REGION OF THE ISLAND. THIS NE SURFACE FLOW AND ACCOMPANYING SHOWERS WILL PERSIST THROUGH LATER TONIGHT. A DRY AIRMASS IS EXPECTED TO ENTER THE NORTHERN ISLAND ON MONDAY SUPPORTING MOSTLY FAIR WEATHER. ATLANTIC OCEAN... AN UPPER-LEVEL TROUGH OVER THE CENTRAL ATLC EXTENDING INTO THE FAR EASTERN CARIBBEAN IS SUPPORTING THE FRONTAL SYSTEM IN THE SPECIAL FEATURES ABOVE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ASSOCIATED WITH THIS SYSTEM ARE N OF 17N BETWEEN 42W-50W AND N OF 23N BETWEEN 50W-57W. A SURFACE TROUGH IS E OF THE WINDWARD ISLANDS EXTENDING FROM 13N59W TO 10N59W WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM 11N-13N BETWEEN 57W-59W. OTHERWISE...SURFACE RIDGING DOMINATES W AND E OF THE FRONTAL SYSTEM. A COLD FRONT WILL MOVE OFF THE NE FLORIDA COAST EARLY TUE REACHING FROM NEAR 30N73W TO CENTRAL FLORIDA TUE AFTERNOON. 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 $$ NR