000 AXNT20 KNHC 301743 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED DEC 30 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... A STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE ANCHORED ACROSS THE SW NORTH ATLC AND LOWER PRESSURE ANALYZED ACROSS NW SOUTH AMERICA IS PRODUCING NEAR GALE TO GALE FORCE WINDS ACROSS PORTIONS OF THE SW AND SOUTH-CENTRAL CARIBBEAN SEA. THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH FRIDAY. SEE THE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADER MIAHSFAT2/ FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W INTO A 1015 MB LOW NEAR 10N15W TO 06N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N20W TO 03N26W TO 02N40W TO THE EQUATOR NEAR 48W. ISOLATED MODERATE CONVECTION IS FROM 02N- 05N BETWEEN 18W-27W. ...DISCUSSION... GULF OF MEXICO... BROAD LONGWAVE TROUGHING IS NOTED ON WATER VAPOR IMAGERY OVER THE CENTRAL CONUS WITH MID-LEVEL SHORTWAVE ENERGY STRETCHING FROM OVER THE NW GULF SOUTHWESTWARD TO OVER CENTRAL MEXICO. THIS SHORTWAVE SUPPORTS A STATIONARY FRONT EXTENDING FROM NEAR MOBILE BAY SW TO OFFSHORE OF BROWNSVILLE TEXAS THEN SOUTHWARD AS A SURFACE TROUGH TO 20N96W. GIVEN THAT THE SUPPORTING MID-LEVEL DYNAMICS ARE OVER THE NW GULF WATERS... SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE NORTH-CENTRAL GULF N OF 27N BETWEEN 86W-92W...INCLUDING INLAND PORTIONS OF NORTHERN GEORGIA...ALABAMA...AND SOUTHERN MISSISSIPPI. ISOLATED SHOWERS ARE ALSO WITHIN 90 NM EITHER SIDE OF THE FRONT W OF 92W. OTHERWISE...GENTLE TO MODERATE SOUTHEASTERLY FLOW INFLUENCES THE GULF SE OF THE FRONTAL BOUNDARY UNDER MOSTLY CLEAR SKIES WITHIN THE SOUTHWESTERN PERIPHERY OF A RIDGE ANCHORED ACROSS THE SW NORTH ATLC. NORTH AND WEST OF THE FRONT...FRESH TO OCCASIONAL STRONG N TO NE WINDS PREVAIL THAT ARE EXPECTED TO PERSIST AND EVENTUALLY BEGIN SPREADING EASTWARD BY LATE FRIDAY AS THE FRONT TRANSITIONS TO COLD AND IS ENERGIZED BY MIDDLE TO UPPER LEVEL ENERGY AND A STRONG SURFACE RIDGE BUILDING IN FROM THE CENTRAL PLAINS. CARIBBEAN SEA... DRY AIR AND OVERALL STABLE CONDITIONS ALOFT CONTINUE TO SUPPORT RATHER TRANQUIL CONDITIONS ACROSS THE CARIBBEAN BASIN THIS AFTERNOON. ASIDE FROM A FEW PASSING LOW-TOPPED ISOLATED SHOWERS...THE PRIMARY MARINE CONCERN REMAINS STRONG TO NEAR GALE TRADES WITH THE INCLUSION OF THE SPECIAL FEATURES GALE FORCE WINDS OCCURRING WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. THE OVERALL PRESSURE GRADIENT ACROSS THE BASIN IS EXPECTED TO PERSIST THROUGH LATE FRIDAY WITH THE SURFACE RIDGE ANCHORED ACROSS THE SW NORTH ATLC EVENTUALLY WEAKENING AND SLIDING EASTWARD BY SATURDAY RESULTING IN A SLIGHT DECREASE IN THE TRADE WIND REGIME. ...HISPANIOLA... DRY AIR ALOFT IS PROMOTING FAIR SKIES FOR THE ISLAND THIS AFTERNOON. A FEW PASSING ISOLATED SHOWERS ARE POSSIBLE HOWEVER DUE TO PEAK DAYTIME HEATING AND OROGRAPHIC LIFT. ATLANTIC OCEAN... SURFACE HIGH PRESSURE ALONG WITH A MIDDLE TO UPPER LEVEL RIDGE IS PROMOTING OVERALL FAIR CONDITIONS AND MOSTLY CLEAR SKIES ACROSS THE SW NORTH ATLC WATERS THIS AFTERNOON. THE SURFACE RIDGE IS EXPECTED TO PERSIST THROUGH LATE THURSDAY WHEN IT BEGINS TO RETREAT EASTWARD AS A FRONT EMERGES OFF THE SE CONUS COAST. FARTHER EAST...RELATIVELY ZONAL FLOW IS NOTED ON WATER VAPOR IMAGERY N OF 30N E OF 50W WITH ONLY A WEAK COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N26W EXTENDING W-SW TO 30N34W THEN BECOMING STATIONARY TO 30N46W. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT. OTHERWISE...EASTERLY FLOW INFLUENCES MUCH OF THE CENTRAL AND EASTERN ATLC ON THE SOUTHERN PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1034 MB HIGH CENTERED NEAR 34N40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN