000 AXNT20 KNHC 012358 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED SEP 01 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... THE CENTER OF HURRICANE EARL AT 02/0000 UTC IS NEAR 27.2N 73.5W...OR ABOUT 565 MI...910 KM SSE OF CAPE HATTERAS NORTH CAROLINA... MOVING NORTH-NORTHWEST AT 15 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 941 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 115 KT WITH GUSTS TO 140 KT. EARL IS AGAIN A CATEGORY FOUR HURRICANE. NUMEROUS STRONG CONVECTION IS FROM 25N-28N BETWEEN 72W-74W. IN ADDITION... SCATTERED MODERATE CONVECTION IS FROM 24N-30N BETWEEN 71W-76W. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE LATEST PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. THE CENTER OF TROPICAL STORM FIONA AT 01/2100 UTC IS NEAR 20.2N 62.9W...OR ABOUT 140 MI...225 KM N OF ANGUILLA...MOVING NORTHWEST AT 17 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 50 KT WITH GUSTS TO 60 KT. THE CENTER OF FIONA IS PRESENTLY EXPOSED DUE TO WINDSHEAR. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 19N-23N BETWEEN 63W-66W. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT3/WTNT33 KNHC FOR MORE DETAILS. TROPICAL STORM GASTON AT 01/2100 UTC IS NEAR 12.9N 37.0W OR ABOUT 895 MI...1440 KM WSW OF THE CAPE VERDE ISLANDS...MOVING WEST AT 13 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. THIS SYSTEM IS EMBEDDED WITHIN A SURGE OF ELEVATED MOISTURE VALUES NOTED IN TOTAL PRECIPITABLE WATER IMAGERY. CONVECTION IS MOSTLY W OF THE CENTER. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 11N-15N BETWEEN 36W-40W. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT3/WTNT33 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... NO OTHER TROPICAL WAVES ARE IN THE ATLANTIC BASIN AT THIS TIME. ...THE ITCZ... THE ITCZ AXIS IS CENTERED FROM 11N16W TO 9N20W...RESUMING WEST OF T.S. GASTON NEAR 8N40W CONTINUING TO 8N50W 10N60W. BESIDES THE CONVECTION MENTIONED IN THE SPECIAL FEATURES AND TROPICAL WAVE SECTIONS...SCATTERED MODERATE TO STRONG CONVECTION IS ALONG THE COAST OF WEST AFRICA FROM 7N-10N BETWEEN 15W-22W...AND FROM 12N-14N BETWEEN 14W-21W. SCATTERED MODERATE CONVECTION IS FROM 8N-10N BETWEEN 43W-49W. ...DISCUSSION... THE GULF OF MEXICO... A 1020 MB HIGH IS CENTERED OVER VIRGINIA NEAR 37N81W PRODUCING E TO SE SURFACE FLOW OVER THE GULF OF MEXICO. THE SURFACE PRESSURE GRADIENT IS RATHER LAX THUS WINDS ARE MOSTLY 10-15 KT. A SURFACE TROUGH IS OVER THE BAY OF CAMPECHE THAT IS EXPECTED TO FORM INTO A SURFACE LOW WITHIN 24 HOURS. ISOLATED MODERATE CONVECTION IS FROM 16N-22N BETWEEN 91W-96W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER THE YUCATAN FROM 18N-22N BETWEEN 87W-90W. IN ADDITION...A GOOD AMOUNT OF TROPICAL MOISTURE HAS ADVECTED OVER W CUBA AND THE SE GULF FROM THE CARIBBEAN SEA AND W ATLANTIC. SCATTERED SHOWERS ARE FROM 22N-26N BETWEEN 80W-90W. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER CENTRAL TEXAS NEAR 32N99W. AN UPPER LEVEL LOW IS CENTERED NEAR THE MOUTH OF THE MISSISSIPPI RIVER NEAR 29N90W. UPPER LEVEL DIFFLUENCE S OF THIS LOW IS PRODUCING ENHANCING THE CONVECTION OVER THE SE GULF. EXPECT...SHOWERS AND CONVECTION TO MOVE W OVER THE NEXT 24 HOURS. THE CARIBBEAN SEA... PRESENTLY CONVECTION IS N OF THE LEEWARD ISLANDS DUE TO T.S. FIONA. SEE ABOVE. SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE ALSO OVER THE LEEWARD ISLANDS FROM 15N-19N BETWEEN 60W-70W. ELSEWHERE...ISOLATED MODERATE CONVECTION IS OVER THE SW CARIBBEAN FROM 7N-11N BETWEEN 73W-82W. ISOLATED MODERATE CONVECTION IS ALSO OVER THE HIGHER ELEVATIONS OF HISPANIOLA AND CUBA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER CENTRAL AMERICA FROM COSTA RICA TO THE YUCATAN PENINSULA. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS OVER THE W CARIBBEAN NEAR 16N80W. UPPER LEVEL EASTERLY FLOW IS OVER THE E CARIBBEAN E OF 70W. EXPECT...CONVECTION ASSOCIATED WITH FIONA TO MOVE AWAY FROM THE LEEWARD ISLANDS OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... HURRICANE EARL...TROPICAL STORM FIONA... AND TROPICAL STORM GASTON ARE THE MAIN FEATURES OVER THE ATLANTIC. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. OUTSIDE OF THE TROPICS...A 1021 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 31N56W PRODUCING FAIR WEATHER. DRY SAHARAN AIR IS ALSO NOTED ON SATELLITE IMAGERY E OF 50W N OF 16N. OF NOTE IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC N OF 25N BETWEEN 35W-55W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA