000 AXNT20 KNHC 111728 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI JAN 11 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 1645 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE SOUTHERN COAST OF LIBERIA FROM 5N9W TO 5N16W WHERE IT TRANSITIONS INTO ITCZ AND CONTINUES ALONG 5N30W 4N40W EQ48W. ISOLATED MODERATE CONVECTION IS FROM 1N-5N BETWEEN 25W-30W. SIMILAR ACTIVITY IS FROM EQ-3N BETWEEN 43W-49W. ...DISCUSSION... GULF OF MEXICO... THE STATIONARY FRONT THAT HAS BEEN IMPACTING THE NW GULF OF MEXICO THE PAST COUPLE OF DAYS IS FINALLY BEGINNING TO WEAKEN SOME. A STATIONARY BOUNDARY STILL EXISTS FROM SE LOUISIANA NEAR 29N91W TO 26N94W WHERE IT THEN BEGINS TO DISSIPATE TO 21N95W. SCATTERED SHOWERS STILL REMAIN WITHIN 30 NM EITHER SIDE OF THE AXIS WITH POSSIBLE SHOWERS NEAR THE DISSIPATING PORTION OF THE FRONT. IN THE UPPER LEVELS...A NARROW UPPER TROUGH EXTENDS FROM THE FLORIDA PANHANDLE TO THE YUCATAN PENINSULA. DUE TO THE FACT THAT THE UPPER TROUGH IS NOW EAST OF THE LOW-LEVEL BOUNDARY...THE FRONT WILL QUICKLY WEAKEN. UPPER LEVEL RIDGING DOMINATES THE REMAINDER OF THE BASIN ACCOMPANIED BY DRY AIR ALOFT...WHICH IS HELPING MAINTAIN FAIR CONDITIONS ACROSS THE BASIN BESIDES NEAR THE FRONT. WIND SPEEDS STILL REMAIN IN THE RANGE OF 15-20 KT EAST OF THE FRONT WITH LIGHTER WINDS WEST OF THE AXIS. SURFACE RIDGING IS EXPECTED TO BUILD ACROSS THE BASIN BEFORE THE NEXT FRONT MOVES INTO THE NW CARIBBEAN ON SUNDAY. CARIBBEAN SEA... THE CARIBBEAN IS EXPERIENCING MOSTLY FAIR WEATHER WITH SURFACE RIDGING TO THE NORTH SUPPORTED BY AN UPPER LEVEL RIDGE COVERING THE WESTERN HALF OF THE BASIN ACCOMPANIED BY DRY AIR. A BROAD UPPER TROUGH IS ACROSS THE EASTERN CARIBBEAN WITH AN AREA OF STRONG SUBSIDENCE NEAR THE COAST OF COLOMBIA. THIS...ALONG WITH A TIGHT PRESSURE GRADIENT DUE TO THE SURFACE RIDGE TO THE NORTH IS HELPING SUPPORT GALE FORCE WINDS NORTH OF COLOMBIA. MAINLY 20-25 KT TRADEWIND FLOW IS ACROSS THE REMAINDER OF THE BASIN. PATCHES OF LOW-LEVEL CLOUDS WITH ISOLATED SHOWERS ARE MOVING QUICKLY ACROSS THE AREA MAINLY IN THE EASTERN AND CENTRAL PORTIONS ESPECIALLY ALONG THE COAST OF VENEZUELA. THE GALE FORCE WINDS ARE EXPECTED TO REMAIN ANOTHER SIX HOURS BEFORE DIMINISHING BELOW GALE FORCE. LITTLE CHANGE IS EXPECTED ELSEWHERE. ATLANTIC OCEAN... SURFACE RIDGING COVERS THE WEST ATLC PROVIDING MOSTLY FAIR CONDITIONS. THE RIDGE IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE COVERING THE EASTERN CONUS AND WEST ATLC. BROAD UPPER TROUGHING AROUND AN UPPER LEVEL LOW WELL NORTH OF THE AREA NEAR 42N50W COVERS THE CENTRAL ATLC SUPPORTING A COLD FRONT THAT HAS PUSHED INTO THE AREA ALONG 32N47W 28N53W 27N61W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE FRONT. GALE FORCE WINDS ARE EXPECTED BEHIND THIS FRONT BY 1800 UTC TODAY NORTH OF 29N WEST OF THE FRONT TO 55W. A WEAK SURFACE TROUGH...REMNANTS OF AN OLD FRONTAL BOUNDARY...IS SOUTH OF THE COLD FRONT FROM 26N46W TO 21N51W. ISOLATED SHOWERS ARE WITHIN 30 NM EITHER SIDE OF THE AXIS. THE REMAINDER OF THE EASTERN ATLC IS DOMINATED BY SURFACE RIDGING AROUND A 1026 MB HIGH NEAR 35N14W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE THAT IS NORTH OF THE AREA AND EAST OF THE BROAD UPPER LEVEL LOW. ACROSS THE TROPICS...MAINLY ZONAL WESTERLY FLOW IS ALOFT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON