000 AXNT20 KNHC 252341 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN DEC 25 2011 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 08N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N16W TO 04N30W TO 03N43W. SCATTERED MODERATE CONVECTION IS FROM 03N-08N BETWEEN 30W-36W. ...DISCUSSION... GULF OF MEXICO... SOUTHWESTERLY UPPER LEVEL FLOW IS NOTED ACROSS THE ENTIRE GULF THIS EVENING BETWEEN A BROAD UPPER LEVEL RIDGE OVER THE CARIBBEAN SEA AND SW NORTH ATLC...AND AN UPPER LEVEL LOW AND ASSOCIATED TROUGHING CENTERED OVER SE NEW MEXICO NEAR 33N105W. THIS UPPER LEVEL FLOW PATTERN CONTINUES TO ADVECT MIDDLE TO UPPER LEVEL MOISTURE NORTHEASTWARD ACROSS MUCH OF THE GULF. WITH LITTLE MOVEMENT OF THE UPPER LEVEL FEATURES OVER THE PAST 24 HOURS...A WEAK 1020 LOW CENTERED IN THE NW GULF NEAR 28N92W CONTINUES TO DRIFT SLOWLY N-NW TOWARDS THE LOUISIANA COAST. A COLD FRONT EXTENDS SOUTHWARD FROM THE LOW TO 23N93W WHERE IT BECOMES STATIONARY TO THE MEXICO COAST NEAR 18N94W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT. A WARM FRONT IS ANALYZED EAST OF THE LOW CENTER TO THE BIG REGION OF FLORIDA NEAR 30N83W. MOSAIC DOPPLER RADAR INDICATES SCATTERED SHOWERS ARE OCCURRING N OF A LINE FROM THE COLD FRONT NEAR 25N93W TO 29N83W. MORE NUMEROUS SHOWER ACTIVITY SPREADS NORTHWARD OVER THE INTERIOR SE CONUS. WEST OF THE FRONT ALONG 93W...STRONG N-NW WINDS IN THE RANGE OF 20 TO 30 KT ARE FORECAST TO CONTINUE THROUGH THE OVERNIGHT HOURS AND GRADUALLY DECREASE THROUGH MONDAY INTO TUESDAY AS HIGH PRESSURE ANCHORED OVER EASTERN TEXAS BUILDS IN ACROSS THE WESTERN GULF. CARIBBEAN SEA... AN UPPER LEVEL RIDGE EXTENDS ACROSS THE CARIBBEAN SEA WITH AXIS FROM NORTH-CENTRAL VENEZUELA NEAR NEAR 10N66W NW TO THE YUCATAN CHANNEL NEAR 22N85W. WATER VAPOR IMAGERY INDICATES DRY AIR AND SUBSIDENCE OVER MUCH OF THE BASIN WITH THE EXCEPTION OF SOME MIDDLE TO UPPER LEVEL CLOUDINESS OVER THE NW CARIBBEAN AND YUCATAN PENINSULA. OTHERWISE...FRESH TO STRONG E-NE TRADES CONTINUE ACROSS MUCH OF THE BASIN THIS EVENING WITH GENERALLY FAIR SKIES. THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH LATE MONDAY. ALSO...LOW-LEVEL CONVERGENCE OF THE TRADES ACROSS THE WESTERN CARIBBEAN IS GENERATING A FEW ISOLATED SHOWERS OVER INTERIOR PORTIONS OF CENTRAL AMERICA FROM COSTA RICA NORTHWARD TO BELIZE AND GUATEMALA. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE IS ACROSS MUCH OF THE WESTERN ATLC W OF 50W AND SUPPORTS SURFACE RIDGING BUILDING IN AS A 1026 MB HIGH CENTERED OFF THE CAROLINA COAST NEAR 34N73W IS FORECAST TO MOVE SOUTHEASTWARD. SLICING THROUGH THE RIDGE HOWEVER IS A WEAKENING COLD FRONT ANALYZED FROM 32N55W TO 29N60W TO 28N68W WHERE LOW-LEVEL MOISTURE BECOMES MORE DIFFUSE AND A DISSIPATING STATIONARY FRONT EXTENDS TO THE W-NW TO 29N79W. THE REMAINING LOW-LEVEL MOISTURE IS GENERATING POSSIBLE ISOLATED SHOWERS WITHIN 90 NM EITHER SIDE OF THE FRONT. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 21N41W AND THE ASSOCIATED TROUGH AXIS EXTENDS ALONG 41W TO 12N. A SURFACE TROUGH IS ANALYZED FROM 10N48W TO 19N42W AND GENERALLY DELINEATES BETWEEN STRONGER E-NE TRADES TO THE EAST OF THE AXIS AND A SIGNIFICANT AMOUNT OF MOISTURE AND PRECIPITATION DUE TO STRONG MIDDLE TO UPPER LEVEL DIFFLUENCE. THE SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 08N-25N BETWEEN 21W-40W. THE REMAINDER OF THE EASTERN ATLC N OF 25N IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS EXTENDING FROM 42N15W TO 27N35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN