000 AXNT20 KNHC 100001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON MAY 09 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 2345 UTC. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE COAST OF LIBERIA NEAR 6N11W SOUTHWESTWARD ALONG 3N20W 2N30W EQ40W TO NE BRAZIL ALONG EQ50W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM THE EQUATOR TO 5N BETWEEN 13W-26W. SIMILAR CONVECTION IS WITHIN 150 NM N OF THE AXIS W OF 38W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE MOVES ACROSS THE GULF THIS EVENING... ANCHORED BY A 1015 MB HIGH NEAR 28N87W. THESE CONDITIONS AT LOW AND UPPER LEVELS OF THE ATMOSPHERE ARE PROMOTING FAIR WEATHER ACROSS THE DISCUSSION AREA. LIGHT AND VARIABLE WINDS ARE OBSERVED NEAR THE HIGH CENTER...BECOMING ANTI-CYCLONIC ELSEWHERE ACROSS THE AREA...RANGING FROM 10 TO 20 KT. A SOMEWHAT TIGHTER PRESSURE GRADIENT OVER THE NW BASIN IS GENERATING STRONGER ONSHORE FLOW ALONG THE TEXAS COASTLINE. THE HIGH PRESSURE RIDGE IS FORECAST TO REMAIN NEARLY STATIONARY THROUGH THE WEEK WITH THE OVERALL SYNOPTIC PATTERN CHANGING VERY LITTLE OVER THE NEXT FEW DAYS. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES MODERATELY DRY AIR AND SUBSIDENCE ACROSS THE NW BASIN N OF 14N W OF 71W SUPPRESSING ANY AREAS OF CONVECTION IN THIS REGION. ON THE OTHER HAND...TOTAL PRECIPITABLE WATER VALUES REMAIN ELEVATED OVER THE NE CARIBBEAN...AND THIS LOWER LEVEL MOISTURE IS FOCUSED ALONG A WEAK SURFACE TROUGH ANALYZED FROM MONTSERRAT ISLAND TO NEAR 15N66W. SATELLITE IMAGERY SHOWS WIDELY SCATTERED SHOWERS OCCURRING WITHIN 90 NM EITHER SIDE OF THE SURFACE TROUGH AXIS... INCLUDING MANY OF THE LEEWARD ISLANDS. CONSIDERABLE LOW LEVEL MOISTURE IS ALSO FOUND OVER THE FAR SW BASIN...WHERE LOW LEVEL CONVERGENCE ASSOCIATED TO THE CYCLONIC TURNING OF THE EASTERLY TRADES ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 70 NM ALONG THE COASTS OF PANAMA...COSTA RICA...NICARAGUA AND COLOMBIA BETWEEN 73W AND THE COAST OF NICARAGUA S OF 13N. THIS AREA OF CONVECTION IS EXPECTED TO LINGER OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... A OCCLUDED DEEP LAYERED LOW IS OVER THE NW ATLC ROTATING AROUND 39N65W. THIS SYSTEM SUPPORTS A WEAK COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N55W EXTENDING SW ALONG 26N60W TO 25N67W. ISOLATED SHOWERS ARE OCCURRING WITHIN 20 NM ON EITHER SIDE OF THE FRONT. A SECONDARY COLD FRONT IS ANALYZED W OF THE LEADING COLD FRONT FROM NEAR 32N60W TO 28N67W TO 28N74W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM E OF THE FRONT. THIS FRONT IS FORECAST TO CONTINUE PUSHING SOUTHEASTWARD OVER THE NEXT 24 HOURS. AS THE FRONT MOVES EASTWARD...SURFACE RIDGING WILL TAKE OVER THE WEST ATLC DURING THE FORECAST PERIOD. FARTHER EAST OVER THE CENTRAL ATLC... ANOTHER UPPER LEVEL TROUGH IS LOCATED NORTH OF THE DISCUSSION AREA SUPPORTING A WEAKENING COLD FRONT ANALYZED FROM 30N29W TO 24N32W BECOMING A SURFACE TROUGH TO 20N40W. ISOLATED WEAK SHOWERS ARE OCCURRING WITHIN 70 NM EITHER SIDE OF THE BOUNDARY AS IT CONTINUES TO DRIFT NE. AN AREA OF LOW LEVEL MOISTURE CONVERGENCE IS NOTED ON THE WEST TROPICAL ATLC ALONG A SURFACE TROUGH ANALYZED FROM 19N52W INTO THE CARIBBEAN LESSER ANTILLES ALONG MONTSERRAT ISLAND. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 100 NM ON EITHER SIDE OF THE TROUGH AXIS. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGING PROVIDING MOSTLY FAIR CONDITIONS ACROSS THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA