000 AXNT20 KNHC 171043 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN APR 17 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE SOUTHERN COAST OF LIBERIA NEAR 5N8W WESTWARD ALONG 1S20W EQ30W 2S40W INTO BRAZIL NEAR 4S47W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 170 NM EITHER SIDE OF THE ITCZ W OF 17W. CLUSTERS OF SIMILAR CONVECTION ARE DOTTING THE AREA S OF THE ITCZ FROM 4S-10S BETWEEN 5W-30W. ...DISCUSSION... GULF OF MEXICO... THE MAJORITY OF THE GULF OF MEXICO IS EXPERIENCING FAIR WEATHER CONDITIONS UNDER THE INFLUENCE OF DRY AIR ALOFT WITH A FEW HIGH LEVEL CLODS MOVING ACROSS THE AREA. A DEEP LAYER TROUGH MOVES ACROSS THE FAR EASTERN CONUS SUPPORTING A COLD FRONT THAT ENTERS THE AREA THROUGH THE FLORIDA PENINSULA NEAR CAPE CORAL AND EXTENDS SW TO 24N86W AS IT TRANSITIONS TO A WEAK STATIONARY FRONT. ONLY A WEAK CLOUD BAND ALONG WITH A WIND SHIFT AND LOWER DEW POINTS DEFINE THIS FRONTAL SYSTEM. MARINE OBS INDICATE 5-15 KT ANTI-CYCLONIC FLOW BEHIND THE FRONT. THE FRONT WILL CONTINUE TO WEAKEN AS IT LOOSES MOMENTUM ACROSS THE SE GULF IN THE MORNING HOURS. SURFACE RIDGE BEHIND THE FRONT WILL CONTINUE TO BUILD ACROSS THE GULF...ALLOWING FRESH SE FLOW OVER THE W GULF LATER TODAY. SE WINDS WILL INCREASE ACROSS THE ENTIRE GULF EARLY NEXT WEEK AHEAD OF AN APPROACHING TROUGH MOVING THROUGH THE SOUTHERN PLAINS. CARIBBEAN SEA... MAINLY DRY AIR ALOFT AND STRONG SUBSIDENCE IS ACROSS THE CARIBBEAN SEA THIS MORNING...PROVIDING MOSTLY FAIR WEATHER CONDITIONS ACROSS THE BASIN. AN UPPER RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS THE W CARIBBEAN FROM NICARAGUA TO ACROSS CENTRAL CUBA INTO THE W ATLC. STRONG SUBSIDENCE ASSOCIATED WITH AN UPPER TROUGH DIPS S OVER THE NE CARIBBEAN ACROSS HISPANIOLA AND PUERTO RICO TO THE LEEWARD ISLANDS. HIGH LEVEL CLOUDS ARE BEING DRAWN ACROSS THE S CARIBBEAN DUE TO UPPER ANTI-CYCLONIC FLOW AROUND AN UPPER RIDGE CENTERED IN NORTHERN S AMERICA . AT SURFACE...MARINE OBS INDICATE MODERATE TO FRESH ENE WIND FLOW ACROSS THE AREA. STRONGER TRADES ARE TURNING ACROSS THE COAST OF COLOMBIA...GENERATING SCATTERED SHOWERS ALONG THE COAST OF COLOMBIA BETWEEN 72W-77W. FAIR WEATHER IS EXPECTED TO REMAIN ACROSS THE REST OF THE BASIN OVER THE NEXT 24 HOURS. LIGHT TO MODERATE TRADE WINDS WILL PREVAIL ACROSS THE BASIN DUE TO THE BROAD PRESSURE GRADIENT. THESE TRADE WINDS WILL CONTINUE OVER MOST OF THE CARIBBEAN THROUGH NEXT WEEK. ATLANTIC OCEAN... A DEEP LAYER TROUGH MOVES OFF THE EASTERN CONUS SUPPORTING A VIGOROUS COLD FRONT EXTENDING ACROSS THE WESTERN ATLC ALONG 32N75W TO THE FLORIDA COAST NEAR 27N80W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE IN THE VICINITY OF THE FRONT N OF 29N. THIS FRONT WILL CONTINUE TO MOVE EASTWARD WITH CONVECTION OVER TH NEXT 24 HOURS. FARTHER E INTO THE CENTRAL ATLC...AN UPPER LEVEL TROUGH EXTENDS S TO OVER THE NE CARIBBEAN SUPPORTING A BROAD AREA OF SCATTERED WEAK TO ISOLATED MODERATE CONVECTION FROM 21N-30N BETWEEN 47W-58W. COMPUTER MODELS SUGGEST THIS AREA OF CONVECTION WILL LINGER FOR AT LEAST THE NEXT 24 HOURS. THE UPPER LEVEL TROUGH ALSO SUPPORTS TWO SURFACE TROUGHS ANALYZED W AND SSW FROM THE AREA OF CONVECTION. THE FIRST ONE IS ANALYZED FROM 29N62W TO 25N60W. THE SECOND ONE IS ANALYZED FROM 23N53W TO 14N54W. A DEEP LAYERED LOW IS OVER THE FAR E ATLC WITH THE UPPER LOW CENTERED NEAR 32N22W AND A 1003 MB SURFACE LOW NEAR 30N23W. A DISSIPATING COLD FRONT IS E OF THE LOW FROM 33N17W TO 25N19W. A RE-ENFORCING SURFACE TROUGH EXTENDS ALONG 31N21W 26N21W 23N24W. THESE TWO BOUNDARIES ALONG WITH THE LOW LEVEL CENTER ARE GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS N OF 27N BETWEEN 15W-26W. THIS LOW PRESSURE SYSTEM IS EXPECTED TO CONTINUE TO DRIFT E AND WEAKEN OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA