000 AXNT20 KNHC 230517 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI APR 23 2010 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC... ...THE ITCZ... ITCZ AXIS IS CENTERED FROM SIERRA LEONE NEAR 8N12W ALONG 5N20W 2N30W 2N40W AND INTO NE BRAZIL TO 1N51W. SCATTERED STRONG CONVECTION IS FROM 4N-8N BETWEEN 9W-16W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-3N BETWEEN 19W-23W. SIMILAR ACTIVITY IS FROM 1N-4N BETWEEN 35W-41W...AND FROM 2N-4N BETWEEN 46W-49W. ...DISCUSSION... THE GULF OF MEXICO... SURFACE RIDGING COVERS THE ERN GULF OF MEXICO TONIGHT ANCHORED BY A 1015 MB HIGH W OF FORT MYERS FLORIDA NEAR 27N84W MAINTAINING GENERALLY FAIR WEATHER ACROSS MUCH OF THE BASIN. THE SURFACE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE WITH AXIS EXTENDING FROM THE OHIO VALLEY TO THE CENTRAL GULF. HOWEVER...UPPER LEVEL MOISTURE BEING DRAWN FROM THE E PACIFIC AROUND THIS UPPER RIDGE COVERS THE GULF SUPPORTING HIGH CLOUDS MOSTLY ACROSS THE WRN HALF OF THE AREA. SURFACE OBSERVATIONS ALONG WITH SCATTEROMETER DATA INDICATE MAINLY SE FLOW OF 15-20 KT COVERING MOST OF THE BASIN. AN UPPER LEVEL TROUGH OVER THE WRN CONUS IS FORECAST TO MOVE EWD SUPPORTING A COLD FRONT FORECAST TO MOVE OFF THE TEXAS COAST LATE FRI. THE CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER TONIGHT UNDER THE INFLUENCE OF MODERATELY DRY AIR ALOFT IN UPPER LEVEL ZONAL WLY FLOW. A FEW ISOLATED SHOWERS/THUNDERSTORMS ARE NOTED OVER CENTRAL AMERICA INCLUDING HONDURAS AND ERN GUATEMALA. STRONGER ACTIVITY IS ALSO OVER CENTRAL COSTA RICA. A FEW ISOLATED SHOWERS ARE ALSO ACROSS THE NE CARIBBEAN ISLANDS INCLUDING PUERTO RICO AND HISPANIOLA. THIS ACTIVITY IS MOST LIKELY ASSOCIATED WITH SURFACE CONVERGENCE NEAR A FRONTAL TROUGH EXTENDING FROM A LOW PRESSURE CENTER IN THE SW N ATLC NEAR 27N62W TO THE VIRGIN ISLANDS NEAR 19N65W. TOTAL PRECIPITABLE WATER IMAGERY ALSO INDICATES ENHANCED LOW-LEVEL MOISTURE OVER THE ERN CARIBBEAN. MODERATE TO FRESH TRADEWINDS ARE ACROSS MUCH OF THE BASIN...AND ARE FORECAST TO INCREASE AS HIGH PRESSURE OVER THE ERN GULF SHIFTS EWD RESULTING IN A STRONGER PRESSURE GRADIENT ACROSS THE CARIBBEAN. THE ATLANTIC OCEAN... A BROAD UPPER LEVEL TROUGH COVERS THE W ATLC SUPPORTING A LOW PRESSURE SYSTEM E OF THE VIRGINIA COAST NEAR 38N66W. AN ASSOCIATED COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N66W TO 27N72W. ISOLATED SHOWERS ARE E OF THE FRONT FROM 26N-29N BETWEEN 65W-68W. TO THE SE...A 1012 MB LOW IS CENTERED NEAR 27N62W. A SURFACE TROUGH EXTENDS SWD TO THE VIRGIN ISLANDS TO NEAR 19N65W. A WARM FRONT EXTENDS TO THE E OF THE LOW ALONG 28N53W 26N45W AND CONNECTS UP TO A COLD FRONT THAT EXTENDS FROM A LOW PRESSURE SYSTEM IN THE N ATLC. THE COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N30W CONTINUING ALONG 28N36W TO 26N45W WHERE IT MEETS THE WARM FRONT. SCATTERED SHOWERS ARE FROM 23N-31N BETWEEN 34W-56W. THE COLD FRONT BISECTS A SURFACE RIDGE COVERING THE E ATLC ANCHORED BY A 1018 MB HIGH NEAR 24N30W...AND A 1018 MB HIGH NEAR 29N45W. THE SURFACE RIDGE IS MAINTAINING GENERALLY FAIR WEATHER ACROSS THIS PORTION OF THE BASIN BESIDES THE AFOREMENTIONED AREA OF SHOWERS ASSOCIATED WITH THE FRONTAL BOUNDARY. AN UPPER LEVEL RIDGE CENTERED NEAR 12N42W DOMINATES THE E ATLC SUPPORTING THE SURFACE RIDGE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON