000 AXNT20 KNHC 201748 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI DEC 20 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 FEATURES... GALE FORCE WINDS ARE OCCURRING ACROSS PORTIONS OF THE SW CARIBBEAN SEA NORTH OF THE COAST OF COLOMBIA DUE TO A STRONG PRESSURE GRADIENT BETWEEN A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED NE OF BERMUDA NEAR 33N62W AND LOWER PRESSURE ACROSS NORTHERN SOUTH AMERICA. 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 THE AFRICAN COAST NEAR 05N08W TO 03N22W TO 05N42W TO THE EQUATOR NEAR 50W. SCATTERED MODERATE CONVECTION IS FROM 04N-08N BETWEEN 19W-29W. ENERGY ASSOCIATED WITH A SURFACE TROUGH CONTINUES TO GRADUALLY BREAK TO THE NORTH OF THE ITCZ AXIS ANALYZED FROM 08N38W TO 19N40W. MOST OF THE MIDDLE TO UPPER LEVEL DYNAMICS REMAIN TO THE EAST OF THE SURFACE FEATURE ASSOCIATED WITH AN UPPER LEVEL LOW CENTERED NEAR 23N35W. MOST CONVECTION IN THE FORM OF SCATTERED SHOWERS IS OCCURRING FROM 09N-28N BETWEEN 22W-37W WITH GALE FORCE NORTHEASTERLY OCCURRING IN THE VICINITY OF AND TO THE WEST OF THE CAPE VERDE ISLANDS NEAR 16N28W AS DEPICTED ON EARLIER MORNING ASCAT PASSES BETWEEN 20/1032 UTC AND 20/1216 UTC. SEE LATEST HIGH SEAS FORECASTS ISSUED BY METEO-FRANCE FOR MORE DETAILS. ...DISCUSSION... GULF OF MEXICO... MIDDLE TO UPPER LEVEL SOUTHWESTERLY WINDS ALOFT ARE NOTED ON WATER VAPOR IMAGERY THAT CONTINUES TO ADVECT MOISTURE NORTHEASTWARD ACROSS NORTHERN MEXICO AND THE CENTRAL CONUS AHEAD OF A VIGOROUS DEEP LAYERED LOW CENTERED OVER THE NORTHERN BAJA CALIFORNIA PENINSULA. SATELLITE IMAGERY INDICATES MOISTURE AND CLOUDINESS OVER THE NW GULF AND GULF COAST TO 86W WITH MOSTLY STABLE CONDITIONS ELSEWHERE OVER THE BASIN. AT THE SURFACE...A RIDGE ANCHORED BY A 1030 MB HIGH CENTERED NE OF BERMUDA NEAR 33N62W EXTENDS A RIDGE AXIS SW TO THE 1016 MB HIGH CENTERED OVER CENTRAL MEXICO NEAR 20N99W. S-SE WINDS IN THE RANGE OF 10 TO 20 KT PREVAIL ACROSS THE GULF WITH WINDS W OF 90W FORECAST TO GRADUALLY INCREASE THROUGH EARLY SATURDAY AHEAD OF THE NEXT COLD FRONT TO EMERGE OFF THE TEXAS AND LOUISIANA COAST LATE SATURDAY INTO EARLY SUNDAY. CARIBBEAN SEA... A MODERATE PRESSURE GRADIENT EXISTS OVER THE CARIBBEAN BETWEEN THE SEMI-PERMANENT LOW OVER SOUTH AMERICA AND A 1030 MB BERMUDA HIGH CENTERED NEAR 33N62W. THIS IS GENERATING TRADE WINDS OF GENERALLY 15 TO 25 KT WITH GALE FORCE CONDITIONS ALONG THE COAST OF COLOMBIA. OTHERWISE...THE MIDDLE TO UPPER LEVELS OVER THE CARIBBEAN ARE DOMINATED BY RELATIVELY DRY AND STABLE CONDITIONS WITHIN BROAD RIDGING ALOFT. THESE CONDITIONS RESULT IN MOSTLY TRANQUIL SKIES WITH ONLY A FEW LOW-TOPPED ISOLATED SHOWERS OCCURRING THIS AFTERNOON. NO SIGNIFICANT CHANGE IN THE CURRENT SYNOPTIC CONDITIONS IS EXPECTED THROUGH THE WEEKEND INTO MONDAY WHEN THE PRESSURE GRADIENT RELAXES AND TRADES DIMINISH SOMEWHAT. ...HISPANIOLA... AS WITH THE REST OF THE CARIBBEAN...NO SIGNIFICANT DEEP CONVECTION IS OCCURRING ACROSS HISPANIOLA. TRADES ARE EXPECTED TO REMAIN BRISK THROUGH THE WEEKEND WITH POSSIBLE ISOLATED LOW- TOPPED SHOWERS EMBEDDED WITHIN THE FLOW. OTHERWISE...FAIR AND TRANQUIL WEATHER IS EXPECTED. ATLANTIC OCEAN... A STATIONARY FRONT EXTENDS FROM 32N48W SW TO 29N56W AND BECOMES A SHEAR LINE TO 27N63W TO 26N70W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE BOUNDARY. THE BOUNDARY CONTINUES TO WEAKEN GRADUALLY WITH THE A 1030 MB BERMUDA HIGH DOMINATING THE REMAINDER OF THE SW NORTH ATLC REGION. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED TO THE SE OF THE STATIONARY FRONT FROM 32N45W TO 26N55W WITH ISOLATED SHOWERS OCCURRING WITHIN 60 NM EITHER SIDE OF THE TROUGH AXIS. OTHERWISE...EASTERLY WINDS PREVAIL ACROSS THE REMAINDER OF THE CENTRAL ATLC WITH ONLY A FEW PASSING ISOLATED SHOWERS POSSIBLE BETWEEN 40W-65W. A MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE EASTERN ATLC NEAR 23N34W THAT SUPPORTS THE GALE FORCE CONDITIONS DESCRIBED ABOVE IN THE ITCZ SECTION AND THE EXTENSIVE CLOUDINESS AND PRECIPITATION GENERALLY OCCURRING N OF 08N E OF 40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN