000 AXNT20 KNHC 260001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED DEC 25 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 2345 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS OVER AFRICA. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N11W TO 04N20W TO 04N30W TO 04N40W TO 03N15W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS WITHIN 120 NM N OF THE ITCZ W OF 40W. WIDELY SCATTERED MODERATE CONVECTION IS SEEN FROM 04N-07N BETWEEN 20W-26W...AND ALSO WITHIN 60-90 NM N OF THE ITCZ BETWEEN 31W-37W. ...DISCUSSION... GULF OF MEXICO... IN THE UPPER LEVEL...SOUTHWESTERLY UPPER LEVEL WINDS ARE NOTED DUE TO AN UPPER LEVEL TROUGH SEE ON WATER VAPOR IMAGERY WITH AXIS ROUGHLY ALONG 106W. THIS UPPER FLOW IS KEEPING THE ATMOSPHERE OVER MUCH OF THE GULF RATHER MOIST AS NOTED BY THE MOSTLY OVERCAST TO BROKEN LOW AND MID LEVEL CLOUDS W OF ABOUT 90W WITH BROKEN TO OVERCAST HIGH LEVEL CLOUDS STREAMING NEWD ALOFT. PATCHES OF RAIN ARE UNDERNEATH THESE CLOUDS. ELSEWHERE ...BROKEN TO SCATTERED LOW CLOUDS WITH SCATTERED TO WIDELY SCATTERED SHOWERS ATTRIBUTED TO MOISTURE FROM A STALLED OUT FRONTAL BOUNDARY ACROSS THE STRAITS OF FLORIDA ARE SEEN OVER THE MIDDLE AND EASTERN PORTIONS OF THE GULF. AT THE SURFACE...A RIDGE REMAINS IN PLACE WITH AXIS EXTENDING FROM THE OHIO RIVER VALLEY S-SW TO THE LOWER MISSISSIPPI RIVER VALLEY AND TO ALONG THE EASTERN MEXICO GULF COAST. A 1024 MB HIGH IS INLAND MEXICO NEAR 23N100W. THE RESULTANT PRES GRADIENT BETWEEN THE RIDGE AND STALLED OUT FRONT OVER THE STRAITS OF FLORIDA WILL ALLOW FOR NE WINDS GENERALLY IN THE RANGE OF 10-15 KT WITH POCKETS OF 15-20 KT WINDS IN THE WESTERN GULF THROUGH TONIGHT. THE PRES GRADIENT IS THEN EXPECTED TO STRENGTHEN EARLY ON THU AS ANOTHER SURFACE RIDGE SAGS SOUTHEASTWARD FROM THE SOUTHERN PLAINS STATES AND LOWER MISSISSIPPI RIVER VALLEY...AND INTERACTS WITH THE REMNANTS OF THE STALLED OUT FRONT AS IT DRIFTS WESTWARD THROUGH FRI. WEAK LOW PRES IS EXPECTED TO DEVELOP IN THE CENTRAL GULF BEGINNING ON FRI IN RESPONSE TO A SHORTWAVE TROUGH THAT EVOLVES FROM AFOREMENTIONED UPPER TROUGH...AND THEN MOVES ACROSS THE GULF. CARIBBEAN SEA... SATELLITE WATER VAPOR IMAGERY SHOWS A PERSISTENT MID/UPPER LEVEL LOW OVER THE EASTERN CARIBBEAN NEAR 16N65W. THE IMAGERY CONTINUES TO DEPICT VERY DRY AND STABLE AIR ON THE WESTERN PERIPHERY OF THE UPPER LEVEL LOW WHILE TO ITS E AND SE ...PRACTICALLY ACROSS THE ENTIRE PORTION OF THE EASTERN PART OF THE SEA...ABUNDANT DEEP ATMOSPHERIC MOISTURE IS OBSERVED. SCATTERED SHOWERS AND ISOLATED TSTMS ARE QUITE PREVALENT OVER IN THAT PORTION OF THE SEA. A RATHER BROAD SURFACE TROUGH IS ALONG 69W...WITH ISOLATED SHOWERS WITHIN 180 NM EITHER SIDE OF IT N OF 15N. THE MID/UPPER LEVEL LOW IS FORECAST BY THE GFS TO MOVE E TO JUST E OF THE LEEWARD ISLANDS BY THU NIGHT...WHILE THE SURFACE TROUGH ALONG 69W...BEGINS TO MOVE WESTWARD TONIGHT AND BECOMES STATIONARY OVER THE WESTERN CARIBBEAN THU AND FRI. WITH REGARDS TO THE SURFACE WINDS...NE-E TRADES ARE IN THE RANGE OF 10-20 KT ...WITH EVEN LIGHTER WINDS OF 5-10 KT W OF 80W. NE-E TRADES ARE FORECAST TO INCREASE OVER THE S CENTRAL AND EASTERN PORTIONS BEGINNING LATE THU INTO FRI AS CENTRAL ATLC HIGH PRES RIDGING STRENGTHENS. A WEAKENING STATIONARY FRONT EXTENDS FROM THE STRAITS OF FLORIDA SW ACROSS THE YUCATAN CHANNEL AND INLAND ACROSS THE YUCATAN PENINSULA. ONLY ISOLATED SHOWERS ARE NOTED WITHIN 120 N OF THE FRONT...AND WITHIN 30-60 NM S OF THE FRONT. ...HISPANIOLA... ISOLATED SHOWERS AND TSTMS THAT DEVELOPED THIS AFTERNOON OVER THE INTERIOR PORTION AS WELL AS ALONG THE SOUTHERN COAST OF HAITI ARE PRESENTLY DISSIPATING...FOR THE MOST PART. SCATTERED TO BROKEN LOW AND MID LEVEL CLOUDS ARE OBSERVED OVER MUCH OF THE INTERIOR SECTIONS. HOWEVER...THE ISLANDS REMAINS UNDER DRY SUBSIDENT CONDITIONS ALOFT INHIBITING THE POTENTIAL FOR THE DEVELOPMENT OF SCATTERED SHOWERS AND TSTMS EVEN WITH THE BROAD SURFACE TROUGH JUST TO THE E OF THE ISLAND. MODEL GUIDANCE SUGGESTS THAT THESE CONDITIONS ALOFT WILL CHANGE VERY LITTLE THROUGH THE NEXT 48 HOURS ALLOWING FOR LITTLE OVERALL VARIANCES TO PRESENT OBSERVED CONDITIONS. ATLANTIC OCEAN... UPPER LEVEL TROUGHING IS OVER THE N CENTRAL ATLC...AND SUPPORTS A COLD FRONT THAT EXTENDS FROM 32N61W SW TO 27N74W WHERE IT BECOMES STATIONARY TO ACROSS THE CENTRAL BAHAMAS AND TO THE STRAITS OF FLORIDA...CONTINUING TO INLAND THE NE YUCATAN PENINSULA. PLENTIFUL MOISTURE THROUGH ALL LEVELS OF THE ATMOSPHERE IS ALLOWING FOR SCATTERED SHOWERS TO CONTINUE TO THE N OF THE FRONT WHERE A THETA-E GRADIENT EXISTS. THE VERY MOIST SURFACE NE WIND FLOW AROUND A STRONG 1034 HIGH CENTER OVER THE EASTERN SEABOARD IS ADVECTING THESE SHOWERS WSW TOWARDS THE FLORIDA COAST AND KEYS. ISOLATED SHOWERS ARE NOTED TO THE SE OF THE FRONT. FURTHER TO THE SE...SATELLITE WATER VAPOR IMAGERY REVEALS A MID/UPPER LEVEL LOW NEAR 21N65W...ACTING AS A COUPLET WITH THE EASTERN CARIBBEAN LOW DESCRIBED ABOVE. MID TO UPPER LEVEL DIFFLUENCE IS OCCURRING TO THE NE OF THE LOW CENTER GENERATING BROKEN TO SCATTERED MULTILAYERED CLOUDINESS WITH WIDELY SCATTERED SHOWERS AND TSTMS FROM 10N-32N BETWEEN 55W-63W. THE NORTHERN EXTENSION OF THE BROAD CARIBBEAN SURFACE TROUGH EXTENDS ALONG 69W...AND REACHES N TO 26N. ONLY ISOLATED SHOWER AND TSTMS ARE SEEN WITHIN 360 NM E OF THIS TROUGH. THE TROUGH IS FORECAST TO MOVE WESTWARD AND EVENTUALLY MERGE WITH THE REMNANTS OF THE ABOVE MENTIONED STATIONARY FRONT ON THU. THE RESULTANT MERGED TROUGH WILL THEN TOO MERGE WITH A COLD FRONT EXPECTED TO MOVE OFF THE FLORIDA PENINSULA...AND EXTEND FROM NEAR 31N69W TO THE NORTHERN BAHAMAS BY LATE FRI WITH AMPLE LOW LEVEL MOISTURE WITH SCATTERED SHOWERS FORECAST TO ITS NW. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC REMAINS UNDER THE INFLUENCE OF A VERY BROAD SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 33N37W. THIS HIGH WILL MOVE SE TO NEAR 28.5N33.5W BY THU EVENING WHILE WEAKENING SLIGHTLY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE