000 AXNT20 KNHC 032352 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU FEB 03 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGE THROUGH 2300 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED FROM CENTRAL LIBERIA NEAR 6N11W ALONG 4N20W 1N30W CROSSING THE EQUATOR NEAR 40W TO NEAR 3S47W. WIDELY SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3S-6N BETWEEN 22W-39W...AS WELL AS OVER INLAND PORTIONS OF NR BRAZIL. ...DISCUSSION... GULF OF MEXICO... A FRONTAL BOUNDARY CONTINUES TO BISECT THE GULF OF MEXICO THIS EVENING IMPACTING MUCH OF THE BASIN. THE MAJORITY OF THE FRONT IN THE SW GULF REMAINS STATIONARY STRETCHING FROM NEAR 25N89W TO THE BAY OF CAMPECHE NEAR 17N93W. TO THE NE...THE FRONT IS BEGINNING TO LIFT N ALONG A WARM FRONT EXTENDING FROM THE NRN EXTENT OF THE STATIONARY BOUNDARY NEAR 25N89W TO OFF THE COAST OF TAMPA FLORIDA NEAR 28N84W. FROM HERE THE FRONTAL BOUNDARY BECOMES LESS DISCERNIBLE ACROSS THE FLORIDA PENINSULA AND INTO THE W ATLC WATERS. BEHIND THE FRONT...MULTI-LAYERED CLOUDS COVER THE AREA WITH SCATTERED SHOWERS EXTENDING TO THE COASTLINE WHERE TEMPERATURES DROP TO NEAR AND BELOW FREEZING TO PRODUCE SNOW AND OTHER TYPES OF FREEZING PRECIPITATION. ALOFT...MAINLY SWLY FLOW COVERS THE BASIN BETWEEN AN UPPER LEVEL TROUGH TILTED FROM THE GREAT LAKES REGION TO NE MEXICO...AND AN UPPER LEVEL RIDGE ACROSS THE CARIBBEAN AND W ATLC. AS THIS UPPER TROUGH PROGRESSES EWD...SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE FRONTAL BOUNDARY...AND THE SYSTEM SHOULD GAIN MOTION AGAIN AND MOVE OUT OF THE BASIN SOMETIME SUNDAY BRINGING SHOWER ACTIVITY WITH IT. CURRENTLY NLY WINDS OF 20-25 KTS ARE NOTED BEHIND THE FRONT. AS THE LOW PRESSURE DEVELOPS ALONG THE FRONTAL BOUNDARY...THE PRESSURE GRADIENT WILL STRENGTHEN AND GALE FORCE WINDS ARE EXPECTED W OF 95W ON FRIDAY. CARIBBEAN SEA... A DRY AND SUBSIDENT AIRMASS SITS OVER THE CARIBBEAN AROUND AN UPPER LEVEL RIDGE EXTENDING FROM S AMERICA TO THE W ATLC PROVIDING MOSTLY FAIR WEATHER ACROSS THE BASIN. A TIGHT PRESSURE GRADIENT BETWEEN BROAD LOW PRESSURE OVER S AMERICA AND HIGHER PRESSURE ACROSS THE SW N ATLC IS SUPPORTING NE TRADE WINDS OF 20-25 KTS ACROSS MUCH OF THE ERN HALF OF THE BASIN. AN AREA OF LOW LEVEL MOISTURE IS CURRENTLY E OF THE LESSER ANTILLES...BUT IS EXPECTED TO PROPAGATE WWD BRINGING THE POTENTIAL FOR SHOWERS/THUNDERSTORMS ACROSS THE FAR ERN CARIBBEAN OVER THE WEEKEND. ATLANTIC OCEAN... A STATIONARY FRONT CLIPS THE NW PORTION OF THE DISCUSSION AREA EXTENDING FROM 32N72W TO THE CENTRAL FLORIDA COAST WHERE IT CONTINUES INTO THE GULF OF MEXICO. DUE TO MULTI-LAYER CLOUDS...THE EXACT FRONTAL LOCATION IS DIFFICULT TO LOCATE AND IS BASED OFF MODEL GUIDANCE AND FEW WIND AND TEMPERATURE OBSERVATIONS. SURFACE RIDGING AROUND A 1025 MB HIGH NEAR 29N68W COVERS THE REMAINDER OF THE SW N ATLC PROVIDING MOSTLY FAIR CONDITIONS. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE EXTENDING FROM THE CARIBBEAN INTO THE W ATLC. FARTHER E...A SURFACE TROUGH...REMNANTS OF A SURFACE LOW...EXTEND ALONG 28N61W TO 23N61W. THE UPPER LEVEL LOW PREVIOUSLY ASSOCIATED WITH THIS TROUGH HAS NOW PUSHED FARTHER S TO NEAR 21N50W SUPPORTING ANOTHER SURFACE TROUGH REFLECTION ALONG 19N54W TO 19N54W. SCATTERED SHOWERS ARE WITHIN 150 NM EITHER SIDE OF THE TROUGH AXIS. ACROSS THE ERN ATLC...SURFACE RIDGING CONTINUES TO DOMINATE AROUND A 1037 MB AZORES HIGH WHICH IS MAINTAINING FAIR CONDITIONS ACROSS THE AREA. ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM BETWEEN THE AZORES AND MADEIRA ISLANDS TO THE UPPER LEVEL LOW IN THE CENTRAL ATLC NEAR 21N50W. BROAD UPPER RIDGING COVERS THE DEEP TROPICAL ATLC AND THE AREA E OF TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON