000 AXNT20 KNHC 052337 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAY 05 2012 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 ACROSS AFRICA INTO THE E TROPICAL ATLC ALONG THE COAST OF SIERRA LEONE NEAR 8N13W AND CONTINUES TO 5N17W TO 4N25W...WHERE THE ITCZ AXIS CONTINUES ALONG 6N38W TO THE COAST OF BRAZIL NEAR 4N51W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM THE EQUATOR TO 6N BETWEEN 16W-25W. SIMILAR CONVECTION IS FROM 1N-7N BETWEEN 32W-48W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE OF HIGH PRESSURE COVERS THE GULF BASIN THIS EVENING. HOWEVER...AT SURFACE...A WEAK SURFACE TROUGH IS ANALYZED OVER THE NE BASIN FROM 30N86W TO 24N87W. THIS FEATURE IS GENERATING A FEW LOW-TOP SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 130 NM E OF THE TROUGH AXIS. COMPUTER MODELS SUGGEST THIS FEATURE WILL CONTINUE TO WEAKEN OVER THE NEXT 24 HOURS WITH SOME LINGERING ISOLATED WEAK CONVECTION OVER THIS AREA. OTHERWISE... MOSTLY FAIR WEATHER IS OVER THE REMAINDER OF THE GULF DUE TO STRONG SUBSIDENCE AND DRY AIR ALOFT ASSOCIATED TO THE UPPER LEVEL RIDGE. CARIBBEAN SEA... TOTAL PRECIPITABLE WATER AND WATER VAPOR IMAGERY REFLECT SIGNIFICANT DEEP MOISTURE OVER THE ERN AND S-CENTRAL CARIBBEAN BASINS THIS EVENING. THE LARGE SCALE SURFACE WIND PATTERN FROM MARINE OBSERVATIONS SHOWS WIDE TROUGHINESS AROUND A SURFACE TROUGH AXIS THAT EXTENDS SW ACROSS THE AREA...ANALYZED ALONG ANGUILLA TO A 1008 MB LOW OVER THE COAST OF COLOMBIA NEAR 12N73W. SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE WITHIN 110 NM ON EITHER SIDE OF THE TROUGH. SIMILAR ACTIVITY IS OVER THE IMMEDIATE COAST OF PANAMA AND WRN COLOMBIA BETWEEN 74W-83W...AS THE MONSOON TROUGH EXTENDS INLAND OVER THESE TERRITORIES. SHORT RANGE COMPUTER MODELS SUGGEST THE ACTIVITY WILL BE SLOW TO MOVE EASTWARD DURING THE NEXT 24 HOURS. FAIR WEATHER CONDITIONS ARE ELSEWHERE ACROSS THE DISCUSSION AREA DUE TO STRONG SUBSIDENCE AND DRY AIR ALOFT ASSOCIATED TO AN UPPER LEVEL RIDGE OVER THE GULF OF MEXICO AND THE NW CARIBBEAN. ATLANTIC OCEAN... A 1016 MB HIGH IS CENTERED OVER THE NW BAHAMAS JUST A FEW MILES N OF NASSAU. THIS FEATURE IS KEEPING FAIR WEATHER ACROSS MOST OF THE WRN ATLC THIS EVENING. A BROAD DEEP OCCLUDED LOW WOBBLES OVER THE N-ATLC. THE SRN EXTENSION OF A WEAK COLD FRONT ASSOCIATED TO THE LOW ENTERS THE REGION ALONG 30N40W TO 27N55W WITH LIMITED SHOWER ACTIVITY. AN EARLIER ASCAT PASS REVEALED SW WINDS UP TO 20 KT WITHIN 130 NM E OF THE FRONT. TO THE SE OF THIS FRONT...A SURFACE TROUGH IS ANALYZED FROM 23N55W INTO THE CARIBBEAN BASIN ALONG THE ISLAND OF ANGUILLA. SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE WITHIN 150 NM E OF THE TROUGH AXIS. SOME OF THE CONVECTION ASSOCIATED TO THIS FEATURE ALSO EXTENDS BEYOND 150 NM...FROM 17N-23N BETWEEN 44W-52W...WHERE SURFACE CONVERGENCE AND UPPER DIFFLUENCE IS MAXIMIZED. THE REMAINDER S OF THE ATLC DISCUSSION AREA IS DOMINATED BY A BROAD UPPER LEVEL RIDGE CENTERED IN THE DEEP TROPICS NEAR 7N42W...AND A SURFACE 1019 MB HIGH NEAR 27N24W. COMPUTER MODELS SUGGESTS THE CONVECTION RELATED TO THE SURFACE TROUGH WILL LINGER OVER THE NEXT 24-48 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA