000 AXNT20 KNHC 142343 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN OCT 14 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 RAFAEL IS CENTERED NEAR 21.4N 64.5W AT 15/0000 UTC OR ABOUT 195 NM NNE OF SAN JUAN PUERTO RICO...AND ABOUT 660 NM S OF BERMUDA. RAFAEL IS MOVING NNW AT 9 KT. MINIMUM CENTRAL PRESSURE IS 991 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 70 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC. NUMEROUS STRONG CONVECTION IS EAST AND NORTH OF THE CENTER FROM 19N-22N BETWEEN 61W-63W...AND FROM 21N-23N BETWEEN 61W-65W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ELSEWHERE FROM 13N-24N BETWEEN 60W-65W. EVEN THOUGH RAFAEL HAS MOVED NORTH OF THE CARIBBEAN...GUSTY WINDS AND HEAVY RAINS ARE STILL IMPACTING PORTIONS OF THE LEEWARD ISLANDS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 18N40W TO 11N39W MOVING WEST NEAR 15 KT. THE WAVE LIES JUST WEST OF A LOW-AMPLITUDE SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION IS FROM 7N-13N BETWEEN 36W-41W. ACTIVITY CONTINUES FARTHER AWAY FROM THE AXIS IN BOTH DIRECTIONS...BUT IS LIKELY MORE TIED TO AN UPPER LEVEL TROUGH. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF SENEGAL AT 14N17W CONTINUING ALONG 9N24W TO 9N30W. THE ITCZ BEGINS AT 9N30W ALONG 10N36W AND PICKING UP ON THE WEST SIDE OF THE TROPICAL WAVE ALONG 9N41W 9N50W. A WEAK SURFACE TROUGH IS ANALYZED WITHIN THE ITCZ REGION ALONG 12N49W TO 8N53W. AN UPPER LEVEL TROUGH OVER THE TROPICAL ATLC BETWEEN 30W-50W IS DRAWING MOISTURE NORTHWARD FROM THE MONSOON TROUGH AND ITCZ CAUSING ISOLATED MODERATE CONVECTION TO BE FROM 10N-17N BETWEEN 23W-36W...AND FROM 9N-12N BETWEEN 41W-45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-9N BETWEEN 32W-35W. SIMILAR ACTIVITY IS ALSO WEST OF THE SURFACE TROUGH FROM 9N-11N BETWEEN 52W-54W. ...DISCUSSION... GULF OF MEXICO... FAIR WEATHER CONTINUES ACROSS MUCH OF THE GULF OF MEXICO TONIGHT DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE EXTENDING FROM CENTRAL MEXICO TO WEST ATLC. A FEW ISOLATED SHOWERS ARE NOTED OVER SOUTH FLORIDA AND THE FLORIDA STRAITS. THE UPPER RIDGE SUPPORTS A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED OVER SOUTH CAROLINA. THIS PATTERN IS PROVIDING ANTI-CYCLONIC SURFACE FLOW ACROSS THE GULF WITH WIND SPEEDS AVERAGING AT 10 KT WITH STRONGER 15 KT TO POSSIBLY 20 WINDS RESIDING IN THE SE GULF AND CONTINUING THROUGH THE FLORIDA STRAITS. A WEAK FRONTAL BOUNDARY IS EXPECTED TO SKIRT THE NORTHERN GULF EARLY IN THE WEEK WITH A STRONGER FRONT PUSHING IN BEHIND IT LATER IN THE WEEK. CARIBBEAN SEA... THE MAJORITY OF THE CARIBBEAN IS UNDER FAIR CONDITIONS TONIGHT. DRY AIR ALOFT COVERS THE NW CARIBBEAN AROUND A NARROW UPPER LEVEL TROUGH EXTENDING FROM WESTERN CUBA TO HONDURAS. HOWEVER...SOME MODERATE MOISTURE IS WRAPPING AROUND THE EAST SIDE OF THE UPPER TROUGH HELPING SUPPORTS A FEW SHOWERS/THUNDERSTORMS OVER NICARAGUA AND CUBA. ONLY A FEW ISOLATED SHOWERS/THUNDERSTORMS EXIST OVER WATER. ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO OVER THE SW CARIBBEAN DUE TO THE MONSOON TROUGH THAT EXTENDS FROM COSTA RICA TO NORTHERN COLOMBIA ALONG 11N. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE BASIN PROVIDING MOSTLY FAIR WEATHER. HOWEVER...TROPICAL STORM RAFAEL IS STILL PRODUCING HEAVY SHOWERS AND GUSTY WINDS ACROSS PORTIONS OF THE LEEWARD ISLANDS EVEN THOUGH THE STORM HAS MOVED NORTH OF THE BASIN. SEE SPECIAL FEATURES FOR MORE DETAILS. MOIST CONDITIONS ARE EXPECTED TO REMAIN OVER THE NE CARIBBEAN. LITTLE CHANGE IS EXPECTED ELSEWHERE ACROSS THE CARIBBEAN FOR THE NEXT 24 HOURS. ATLANTIC OCEAN... A SURFACE TROUGH PREVIOUSLY ANALYZED OVER THE BAHAMAS HAS NOW DISSIPATED...BUT BROAD CYCLONIC FLOW STILL REMAINS ACROSS MUCH OF THE WEST ATLANTIC WITH THE FOCAL POINT BEING TROPICAL STORM RAFAEL. DUE TO DIFFLUENT FLOW BETWEEN A WEAK UPPER TROUGH OVER THE SW NORTH ATLC AND A NARROW UPPER LEVEL RIDGE EAST OF RAFAEL...A LARGE AREA OF SHOWERS/THUNDERSTORMS EXTENDS NORTH AND EASTWARD OF THE STORM. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. ACROSS THE EASTERN ATLC...BROAD SURFACE RIDGING DOMINATES ANCHORED BY A 1024 MB HIGH NEAR 34N35W PROVIDING FAIR CONDITIONS. A WEAK SURFACE TROUGH IS ALONG 28N43W TO 21N46W...BUT IS NOT CAUSING ANY SIGNIFICANT WEATHER. ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM THE CANARY ISLANDS ALONG 28N33W TO 13N44W. DIFFLUENCE AROUND THE EAST SIDE OF THE TROUGH AXIS IS ENHANCING CONVECTION NEAR THE ITCZ REGION. AN UPPER LEVEL RIDGE COVERS THE FAR EASTERN TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON