000 AXNT20 KNHC 202356 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN MAY 20 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. ...SPECIAL FEATURES... TROPICAL STORM ALBERTO IS CENTERED NEAR 30.9N 80.0W AT 20/2100 UTC OR ABOUT 105 MI...170 KM SE OF SAVANNAH GEORGIA...OR ABOUT 130 MI...210 KM S OF CHARLESTON SOUTH CAROLINA MOVING SW OR 235 DEGREES AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. ALBERTO IS INGESTING DRY AIR...AND IT HAS MOVED OVER SHELF WATERS THAT ARE COLDER THAN 26C. WESTERLY VERTICAL WIND SHEAR IS ALSO EXPECTED TO INCREASE MARKEDLY DURING THE NEXT 24 HOURS. SCATTERED MODERATE CONVECTION IS WITHIN 15 NM OF THE CENTER. DANGEROUS SURF CONDITIONS...INCLUDING RIP CURRENTS...ARE POSSIBLE ALONG THE COASTS OF NORTHEASTERN FLORIDA...GEORGIA...AND SOUTH CAROLINA THROUGH MONDAY. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 12N33W TO 4N34W MOVING W AT 10-15 KT. WAVE REMAINS EMBEDDED WITHIN AN AREA OF DEEP LAYERED MOISTURE AS DEPICTED ON THE MIMIC-TOTAL PRECIPITABLE WATER ANIMATION. THE WAVE IS HOWEVER VOID OF DEEP CONVECTION. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH ENTERS THE E TROPICAL ATLANTIC AT 10N14W AND EXTENDS SW TO 4N20W. THE ITCZ AXIS EXTENDS FROM 4N20W TO 7N34W TO 5N52W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS S OF THE MONSOON TROUGH FROM 2N-5N BETWEEN 6W-9W...AND FROM 3N-7N BETWEEN 15W-19W. WIDELY SCATTERED MODERATE CONVECTION IS N OF THE ITCZ ALONG THE COAST OF SOUTH AMERICA FROM 5N-10N BETWEEN 52W-57W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING IS PRODUCING 10-15 KT NE TO E FLOW OVER MOST OF THE GULF OF MEXICO. A 1009 MB SURFACE LOW IS CENTERED OVER THE YUCATAN PENINSULA NEAR 20N88W. A SURFACE TROUGH EXTENDS N FROM THE LOW TO N OF THE YUCATAN CHANNEL AT 23N86W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE TROUGH AXIS. ISOLATED MODERATE CONVECTION IS ALSO INLAND OVER S FLORIDA FROM 24N-26N. ELSEWHERE ...SCATTERED RAIN AND SHOWERS ARE OVER THE SW GULF S OF 23N BETWEEN 88W-98W. MOSTLY FAIR WEATHER IS OVER THE REMAINDER OF THE GULF. IN THE UPPER LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE E GULF WITH AXIS ALONG 80W. STRONG SUBSIDENCE COVERS THE ENTIRE GULF. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A 1009 MB SURFACE LOW IS CENTERED OVER THE YUCATAN PENINSULA NEAR 20N88W. A SURFACE TROUGH EXTENDS S FROM THE LOW TO THE GULF OF HONDURAS AT 16N88W. SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE NW CARIBBEAN FROM 15N-19N BETWEEN 82W-89W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FURTHER S OVER CENTRAL AMERICA AND THE SW CARIBBEAN FROM 8N-15N BETWEEN 82W-90W. SIMILAR CONVECTION IS ALONG THE COAST OF N COLOMBIA FROM 10N-14N BETWEEN 75W-79W. ISOLATED MODERATE CONVECTION IS OVER E CUBA AND HISPANIOLA FROM 18N-22N BETWEEN 71W-77W. IN THE UPPER LEVELS... AN UPPER LEVEL HIGH IS CENTERED OVER GUATEMALA. UPPER DIFFLUENCE ASSOCIATED WITH THIS FEATURE IS ENHANCING THE CONVECTION OVER CENTRAL AMERICA AND THE W CARIBBEAN. EXPECT OVER THE NEXT 24 HOURS FOR RAIN AND SHOWERS TO ADVECT OVER THE WINDWARD ISLANDS. EXPECT LITTLE CHANGE ELSEWHERE. ATLANTIC OCEAN... ATTENTION REMAINS FOCUSED ON ALBERTO...A SMALL OUT-OF-SEASON TROPICAL CYCLONE. ALBERTO IS THE EARLIEST FORMING TROPICAL STORM IN THE ATLANTIC BASIN SINCE ANA IN 2003. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. A SURFACE TROUGH IS IN VICINITY OF THE BAHAMAS FROM 29N72W TO 22N74W. ISOLATED MODERATE CONVECTION IS FROM 20N-27N BETWEEN 71W-77W. A 1033 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 34N40W. SURFACE RIDGING IS OVER MOST OF THE ATLANTIC N OF 15N E OF 65W TO WEST AFRICA. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED OVER SOUTHERN SOUTH CAROLINA NEAR 33N80W. UPPER DIFFLUENCE ASSOCIATED WITH THIS FEATURE IS PRODUCING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION N OF 22N BETWEEN 64W-71W. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA