000 AXNT20 KNHC 242356 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU DEC 24 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... A STRONG PRESSURE GRADIENT EXISTS BETWEEN LOWER PRESSURE ACROSS NORTHWESTERN SOUTH AMERICA AND A 1032 MB HIGH CENTERED NEAR BERMUDA INFLUENCING THE SW NORTH ATLC. NEAR GALE TO GALE FORCE WINDS ACROSS THE SOUTH-CENTRAL AND SW CARIBBEAN ARE OCCURRING FROM 11N-15N BETWEEN 73W-79W. THESE CONDITIONS ARE FORECAST TO PERSIST THROUGH LATE SATURDAY. PLEASE SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 02N AT THE PRIME MERIDIAN TO 04N20W TO 02N35W TO 03N44W. SCATTERED MODERATE CONVECTION IS FROM 01N-05N BETWEEN 17W-34W. A SURFACE TROUGH IS ANALYZED TO THE WEST OF THE AXIS FROM 04N50W TO 10N48W GENERATING ISOLATED MODERATE CONVECTION FROM 03N-08N BETWEEN 45W- 52W. ...DISCUSSION... GULF OF MEXICO... THE GULF BASIN REMAINS UNDER THE INFLUENCE OF GENERALLY SOUTHWESTERLY FLOW ALOFT WITH AN EMBEDDED SHORTWAVE TROUGH NOTED ON WATER VAPOR IMAGERY IN THE VICINITY OF 27N92W. THIS TROUGHING IS GENERATING MIDDLE TO UPPER LEVEL DIFFLUENCE E OF 92W AND POSSIBLE ISOLATED SHOWERS ACROSS PORTIONS OF THE CENTRAL GULF THIS EVENING. STRONGER CONVECTIVE ACTIVITY IS OCCURRING ACROSS THE COASTAL PLAIN AND INTERIOR AREAS OF THE SE CONUS AS THE SHORTWAVE ENERGY ADVECTS NORTHEASTWARD. OTHERWISE...THE WESTERN PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1032 MB HIGH ANCHORED IN THE VICINITY OF BERMUDA CONTINUES TO PROVIDE MODERATE TO OCCASIONAL FRESH E-SE WINDS THAT ARE EXPECTED TO PERSIST THROUGH LATE SATURDAY. THEREAFTER...SOUTHERLY RETURN FLOW IS FORECAST TO INCREASE W OF 90W AHEAD OF THE NEXT STRONG COLD FRONT TO EMERGE OFF THE TEXAS COAST LATE SUNDAY INTO EARLY MONDAY. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR AND SUBSIDENCE ALOFT OVER A MAJORITY OF THE BASIN THIS EVENING RESULTING IN MOSTLY CLEAR SKIES. THE PRIMARY MARINE IMPACT TO THE CARIBBEAN IS THE STRONG TO OCCASIONAL NEAR GALE TRADES OCCURRING AT THIS TIME DUE TO A STRENGTHENED PRESSURE GRADIENT BETWEEN LOWER PRESSURE ACROSS NW SOUTH AMERICA AND A STRONG SURFACE RIDGE ANCHORED IN THE VICINITY OF BERMUDA. GALE FORCE CONDITIONS ARE EXPECTED TO PERSIST THROUGH SATURDAY WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA AS MENTIONED ABOVE IN THE SPECIAL FEATURES SECTION. OTHERWISE...BY EARLY NEXT WEEK...THE SW NORTH ATLC RIDGING IS FORECAST TO WEAKEN AND SLIDE EASTWARD RELAXING THE PRESSURE GRADIENT SOMEWHAT AND DECREASING THE TRADES INTO FRESH TO STRONG LEVELS. ...HISPANIOLA... DRY AIR AND STABILITY ALOFT ARE PROVIDING FOR OVERALL FAIR CONDITIONS AND CLEAR SKIES ACROSS THE ISLAND THIS EVENING. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL RIDGE IS NOTED ON WATER VAPOR IMAGERY ANCHORED NEAR 29N67W. THE RIDGING ALOFT SUPPORTS A STRONG 1032 MB HIGH CENTERED E OF BERMUDA NEAR 33N60W PROVIDING OVERALL FAIR CONDITIONS FOR MUCH OF THE SW NORTH AND CENTRAL ATLC WATERS THIS EVENING. THE PRIMARY IMPACT FROM THE ANTICYCLONE IS STRONG WINDS WITHIN THE SOUTHERN PERIPHERY DUE TO A STRENGTHENED PRESSURE GRADIENT BETWEEN THE HIGH AND LOWER PRESSURE ASSOCIATED WITH THE INTERTROPICAL CONVERGENCE ZONE REGION ACROSS NORTHERN SOUTH AMERICA. FRESH TO STRONG EASTERLY WINDS ARE FOUND GENERALLY FROM 15N-25N BETWEEN 53W-77W. OTHERWISE...MODERATE TO FRESH ANTI- CYCLONIC FLOW PREVAILS N OF 25N W OF 50W. OTHERWISE...THE EASTERN ATLC IS UNDER RELATIVELY QUIET CONDITIONS AS WELL... HOWEVER A MID-LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY NEAR 29N36W THAT IS SUPPORTIVE OF A FRONTAL TROUGH EXTENDING FROM 32N30W TO 27N36W WITH POSSIBLE ISOLATED SHOWERS OCCURRING WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN