000 AXNT20 KNHC 041139 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED MAR 04 2015 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1130 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE SW CARIBBEAN... A GALE WARNING IS IN EFFECT FOR COLOMBIA COASTAL WATERS FROM FROM 11N TO 13N BETWEEN 74W AND 76W WITH ASSOCIATED SEAS RANGING BETWEEN 9 TO 12 FT. THESE CONDITIONS ARE FORECAST THROUGH WEDNESDAY AFTERNOON...RESUMING AGAIN DURING THE NIGHT HOURS. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/ FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLANTIC NEAR 07N12W SW TO 04N18W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 01S32W TO THE COAST OF NORTHERN BRAZIL NEAR 02S44W. ISOLATED SHOWERS ARE WITHIN 100 NM EITHER SIDE OF THE ITCZ W OF 24W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES RELATIVELY STRONG SUBSIDENCE IN ASSOCIATION WITH A BROAD MIDDLE TO UPPER LEVEL RIDGE. AT THE SURFACE...A 1028 MB HIGH PRESSURE CENTER OVER THE W ATLC NEAR 35N59W EXTENDS A RIDGE AXIS SW ACROSS THE FLORIDA PENINSULA AND THE GULF...THUS PROVIDING WITH SE WIND FLOW OF 10 TO 15 KT. WITH OVERALL STABLE CONDITIONS ALOFT AND AT THE SURFACE...FAIR WEATHER AND CLEAR SKIES DOMINATE S OF 26N. HOWEVER...LINGERING SHALLOW MOISTURE ADVECTED FROM THE CARIBBEAN SUPPORTS FOG OVER THE NW GULF N OF 26N W OF 90W AND OVER THE NE GULF N OF 29N E OF 88W...THIS COINCIDING WITH MEDIUM TO HIGH GOES-13 IFR PROBABILITIES OF FOG. BY EARLY THURSDAY MORNING...THE NEXT COLD FRONT IS EXPECTED TO EMERGE OFF THE TEXAS AND LOUISIANA COASTS INTRODUCING STRONG TO NEAR GALE FORCE NORTHERLIES...WITH GALE FORCE CONDITIONS POSSIBLE...ACROSS THE WESTERN AND NORTH-CENTRAL GULF WATERS THROUGH FRIDAY MORNING. CARIBBEAN SEA... BROAD UPPER LEVEL TROUGHING IS OBSERVED ON WATER VAPOR IMAGERY WITH AXIS EXTENDING FROM THE CENTRAL ATLC SW THROUGH THE NORTHERN LEEWARD ISLANDS TO A BROAD BASE OVER PANAMA. RELATIVELY DRY AND STABLE AIR IS EMBEDDED WITHIN THIS TROUGHING ALOFT WHICH CONTINUE TO PROVIDE OVERALL FAIR CONDITIONS ACROSS THE BASIN. AT THE LOWER LEVELS...MOISTURE PATCHES CONTINUE TO MOVE ACROSS THE BASIN THUS ENHANCING SCATTERED SHOWERS OVER THE SE CARIBBEAN...PUERTO RICO...HAITI AND CENTRAL AMERICA COASTAL WATERS. TRADES OF 15 TO 20 KT DOMINATE OVER THE BASIN...EXCEPT FOR THE SW CARIBBEAN WHERE WINDS RANGE FROM 25 TO 30 KT...INCREASING TO GALE FORCE WINDS ALONG THE COAST OF COLOMBIA. PLEASE SEE THE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. WINDS TO GALE FORCE IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA ARE EXPECTED TO PULSE DURING THE LATE NIGHT AND EARLY MORNING HOURS DURING THE NEXT THREE DAYS. ...HISPANIOLA... SHALLOW MOISTURE IN THE TRADEWIND FLOW SUPPORTS SCATTERED CLOUDS ACROSS THE ISLAND...MODEL GUIDANCE INDICATING POSSIBLE SHOWERS DURING THIS AFTERNOON. DEEP LAYER DRY AIR IS FORECAST TO MOVE OVER HISPANIOLA STARTING THIS EVENING THROUGHOUT SATURDAY MORNING THUS FAVORING FAIR WEATHER CONDITIONS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH OVER THE CENTRAL ATLC EXTENDING SW TO A BASE OVER THE SW CARIBBEAN SUPPORTS A COLD FRONT FROM 30N49W SW TO 27N67W. SCATTERED SHOWERS ARE OCCURRING AHEAD OF THE FRONT N OF 28N W OF 42W. THE FRONT WILL CONTINUE TO GRADUALLY WEAKEN THROUGH TONIGHT. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1038 MB HIGH CENTERED NE OF THE AZORES NEAR 45N13W. THE NEXT COLD FRONT ENTERS THE SW N ATLC WATERS FRIDAY MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR