000 AXNT20 KNHC 300550 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT OCT 30 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 0515 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM TOMAS AT 30/0600 UTC IS NEAR 12.4N 58.8W...MOVING WNW NEAR 13 KT. TOMAS IS ABOUT 65 NM SE OF BARBADOS...AND ABOUT 150 NM ESE OF ST. VINCENT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. PLEASE READ THE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. NUMEROUS STRONG 10N-13N BETWEEN 55W-57W...AND FROM 12N-15N BETWEEN 55W-60W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS ELSEWHERE FROM 10N-17N BETWEEN 54W-62W. PORTIONS OF THE OUTER RAINBANDS ARE ALREADY BEGINNING TO IMPACT PORTIONS OF THE WINDWARD ISLANDS. THESE AREAS SHOULD BE PREPARED FOR HEAVY RAINFALL TO CONTINUE WITH THE POTENTIAL THREAT OF FLOODING. THE CENTER OF TROPICAL STORM SHARY AT 30/0300 UTC IS NEAR 31.9N 63.3W...OR ABOUT 130 KM TO THE SOUTH-SOUTHEAST OF BERMUDA. SHARY IS MOVING NORTH-NORTHEASTWARD 18 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 KT. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. SHARY HAS LOST MOST OF ITS ORGANIZED DEEP CONVECTION AS IT BEGINS TO BE SHEARED APART BY AN APPROACHING UPPER LEVEL TROUGH OFF THE ERN UNITED STATES SEABOARD. ISOLATED MODERATE CONVECTION IS FROM 30N-36N BETWEEN 61W-66W. STRONG SHEAR AND COOLER WATERS WILL CONTINUE TO IMPACT THE SYSTEM. SHARY IS EXPECTED TO MERGE WITH AN APPROACHING COLD FRONT AND UNDERGO EXTRATROPICAL TRANSITION DURING THE NEXT 24 HRS. ...THE ITCZ... THE ITCZ AXIS IS CENTERED FROM SIERRA LEONE NEAR 8N12W ALONG 11N21W 7N30W 8N36W 7N44W 10N50W. A SURFACE TROUGH IS JUST E OF THE CAPE VERDE ISLANDS ALONG 18N19W 12N21W 7N25W. SCATTERED MODERATE/STRONG CONVECTION IS NEAR THE TROUGH AXIS FROM 7N-11N BETWEEN 19W-23W. SIMILAR ACTIVITY IS ALSO FROM 3N-11N BETWEEN 32W-39W...AND FROM 4N-8N BETWEEN 38W-44W. ...DISCUSSION... THE GULF OF MEXICO... A DEEP LAYER LONGWAVE TROUGH EXTENDS OFF THE ERN U.S. COAST ACROSS CENTRAL FLORIDA TO THE SW GULF OF MEXICO SUPPORTING A COLD FRONT THAT EXTENDS FROM NEAR MIAMI FLORIDA NEAR 25N80W ALONG 23N86W 22N92W BECOMING STATIONARY ALONG 21N94W 18N94W...AS OF 0300 UTC. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 60 NM AHEAD OF THE FRONT BETWEEN 80W-82W. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO FROM 19N-21N BETWEEN 93W-96W. GALE FORCE WINDS ARE ALSO NOTED S OF 22N W OF 94W NEAR THE TAIL END OF THIS FRONT FORECAST TO CONTINUE THROUGH 31/1200 UTC. A DRY AND STABLE AIR MASS IS KEEPING CONDITIONS FAIR ACROSS THE REMAINDER OF THE GULF BEHIND THE FRONT AS HIGH PRESSURE BUILDS TO THE N ACROSS THE ERN CONUS SUPPORTED BY AN APPROACHING UPPER LEVEL RIDGE CENTERED OVER CENTRAL TEXAS. EXPECT FAIR CONDITIONS TO REMAIN ACROSS MUCH OF THE BASIN WITH A CHANCE OF SHOWERS/THUNDERSTORMS IN THE SW GULF IN THE BAY OF CAMPECHE DUE TO SURFACE WIND AND MOISTURE CONVERGENCE. THE CARIBBEAN SEA... THE MAJORITY OF THE CARIBBEAN IS EXPERIENCING FAIR WEATHER TONIGHT DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL TROUGH ACROSS THE WRN HALF OF THE BASIN. A FEW ISOLATED SHOWERS ARE NOTED FROM THE SW CARIBBEAN TO S OF HISPANIOLA MAINLY ASSOCIATED WITH MOIST SWLY AND DIFFLUENT FLOW ALOFT AROUND THE AFOREMENTIONED UPPER LEVEL TROUGH. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS NRN COLOMBIA...PANAMA...AND COSTA RICA. THE ERN HALF OF THE BASIN IS UNDER UPPER LEVEL ANTI-CYCLONIC OUTFLOW FROM T.S. TOMAS WHICH IS APPROACHING THE WINDWARD ISLANDS. PORTIONS OF THE WINDWARD ISLANDS ARE ALREADY BEGINNING TO SEE THE IMPACTS OF OUTER RAINBANDS OF TOMAS. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. THE ERN CARIBBEAN SHOULD MONITOR THE PROGRESS OF TOMAS AS IT TRACKS WNW THEN W. THE ATLANTIC OCEAN... A COLD FRONT IS MOVING ACROSS THE SW N ATLC ENTERING THE DISCUSSION AREA NEAR 32N68W CONTINUING TOWARDS THE SW ACROSS THE NW BAHAMAS TO NEAR MIAMI FLORIDA AT 25N80W. THE FRONT IS SUPPORTED BY A LONGWAVE UPPER TROUGH EXTENDING DOWN THE ERN UNITED STATES SEABOARD. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 60 NM AHEAD OF THE FRONT. THE FRONT IS APPROACHING T.S. SHARY. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. AN UPPER LEVEL RIDGE IS BETWEEN 45W-65W. MOIST SWLY AND DIFFLUENT FLOW ALOFT BETWEEN UPPER TROUGHING AND THE UPPER RIDGE ARE SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ALONG A 150 NM WIDE SWATH FROM N OF PUERTO RICO NEAR 20N66W TO 32N56W. TROPICAL STORM TOMAS IS THE S APPROACHING THE WINDWARD ISLANDS. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. TO THE NE...A WEAK 1016 MB SURFACE LOW IS NEAR 26N47W SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 22N-28N BETWEEN 45W-48W. THE REMAINDER OF THE BASIN IS UNDER A DRY AIR MASS SUPPORTING FAIR WEATHER ACROSS THE AREA. AN UPPER LEVEL RIDGE CENTERED SW OF THE AZORES ISLANDS SUPPORTS A SURFACE RIDGE ANCHORED BY A PAIR OF SURFACE HIGHS SW OF THE AZORES. AN UPPER LEVEL TROUGH IS S OF THE UPPER RIDGE EXTENDING S OF 27N BETWEEN 25W-45W. UPPER DIFFLUENCE AROUND THE BASE OF THE UPPER TROUGH IS ENHANCING CONVECTION ALONG THE ITCZ. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON