000 AXNT20 KNHC 301205 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... THE CENTER OF HURRICANE SHARY AT 30/0900 UTC IS NEAR 33.6N 59.4W...OR ABOUT 280 NM ENE OF BERMUDA. SHARY IS MOVING ENE AT 30 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. CONVECTION HAS INCREASED NEAR THE CENTER OF SHARY. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS FROM 33N-37N BETWEEN 58W-61W. SHARY IS EXPECTED TO MERGE WITH AN APPROACHING COLD FRONT AND UNDERGO EXTRATROPICAL TRANSITION DURING THE NEXT 24 HRS. THE CENTER OF TROPICAL STORM TOMAS AT 30/1200 UTC IS NEAR 13.1N 60.1W...MOVING WNW NEAR 13 KT. TOMAS IS ABOUT 70 MI...115 KM SE OF ST. LUCIA AND ABOUT 70 MI...115 KM E OF ST. VINCENT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 993 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 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 CONVECTION IS FROM 14N-17N BETWEEN 55W-60W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS ELSEWHERE FROM 10N-18N BETWEEN 53W-62W. AN AREA OF SIMILAR ACTIVITY IS ALSO FARTHER S FROM 7N-9N BETWEEN 55W-58W. PORTIONS OF THE OUTER RAINBANDS CONTINUE TO IMPACT PORTIONS OF THE WINDWARD ISLANDS. THESE AREAS SHOULD BE PREPARED FOR HEAVY RAINFALL TO CONTINUE WITH THE POTENTIAL THREAT OF FLOODING. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N25W 9N37W 6N42W 8N51W. A SURFACE TROUGH IS JUST E OF THE CAPE VERDE ISLANDS FROM 17N21W TO 7N23W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NEAR THE TROUGH AXIS FROM 6N-11N BETWEEN 10W-25W. A SECOND EMBEDDED SURFACE TROUGH IS FROM 12N41W TO 7N39W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-8N BETWEEN 37W-46W. ...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 THROUGH THE STRAITS OF FLORIDA NEAR 24N81W TO N OF THE YUCATAN PENINSULA NEAR 22N91W BECOMING STATIONARY ALONG 21N92W 18N92W...AS OF 0900 UTC. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 30 NM EITHER SIDE OF THE FRONT BETWEEN 79W-81W. ISOLATED SHOWERS ARE WITHIN 60 NM BEHIND THE FRONT BETWEEN 85W-89W. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO IN THE BAY OF CAMPECHE 18N-23N BETWEEN 93W-97W. WIND TO 30 KT ARE ALSO NOTED S OF 22N W OF 94W NEAR THE TAIL END OF THIS FRONT. 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 JUST OFFSHORE OF SE TEXAS OVER THE NW GULF. 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/THUNDERSTORMS 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. MUCH OF THE WINDWARD ISLANDS ARE BEGINNING TO FEEL THE IMPACTS OF APPROACHING T.S. 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 32N65W CONTINUING TOWARDS THE SW ACROSS THE NW BAHAMAS TO THE STRAITS OF FLORIDA AT 24N81W. THE FRONT IS SUPPORTED BY A LONGWAVE UPPER TROUGH EXTENDING DOWN THE ERN UNITED STATES SEABOARD. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 75 NM BEHIND THE FRONT. THE FRONT IS APPROACHING T.S. SHARY AND IS EXPECTED TO MERGE AS SHARY UNDERGOES EXTRATROPICAL TRANSITION. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. AN UPPER LEVEL RIDGE IS BETWEEN 45W-65W. A SURFACE TROUGH EXTENDS ALONG 31N56W TO 20N65W. SURFACE CONVERGENCE ALONG WITH MOIST SWLY AND DIFFLUENT FLOW ALOFT BETWEEN UPPER TROUGHING AND THE UPPER RIDGE ARE SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ALONG A 150 NM EITHER SIDE OF THE AXIS N OF 25N. TROPICAL STORM TOMAS IS TO THE S APPROACHING THE WINDWARD ISLANDS. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. TO THE NE...A SECOND SURFACE TROUGH EXTENDS ALONG 30N48W TO 23N47W SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 22N-30N BETWEEN 45W-49W. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING ANCHORED BY A 1026 MB HIGH NEAR 35N35W UNDER A DRY AIR MASS SUPPORTING FAIR WEATHER ACROSS THE AREA. AN UPPER LEVEL RIDGE IS CENTERED SW OF THE AZORES ISLANDS SUPPORTS THE SURFACE RIDGE. 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. 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