000 AXNT20 KNHC 020003 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON OCT 01 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 VALID THROUGH 2315 UTC. ...SPECIAL FEATURE... THE CENTER OF TROPICAL STORM NADINE AT 02/0000 UTC IS NEAR 34.8N 39.1W. NADINE IS MOVING SSE AT 8 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 995 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 55 KNOTS WITH GUSTS TO 65 KNOTS. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/ WTNT24 KNHC...AND THE PUBLIC ADVISORY... MIATCPAT4/WTNT34 KNHC ...FOR MORE DETAILS. SCATTERED MODERATE CONVECTION IS FROM 35N-37N BETWEEN 39W-41W...AND FROM 36N-38N BETWEEN 36W-39W. TROPICAL WAVE EXTENDS FROM 17N32W TO 10N34W THROUGH A 1008 MB SURFACE LOW NEAR 12N33W. THE WAVE/LOW ARE MOVING WEST NEAR 15 KT. THE SYSTEM COINCIDES WITH A SURFACE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR GRADUAL DEVELOPMENT OF THIS SYSTEM OVER THE NEXT COUPLE OF DAYS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 13N-18N BETWEEN 27W-33W...AND FROM 8N-13N BETWEEN 34W-39W. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 16N46W TO 7N49W MOVING WEST AT 10-15 KT. THE WAVE CONTINUES TO LIE ON THE WESTERN EDGE OF A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE IS ALSO APPROACHING AN UPPER LEVEL TROUGH...WHICH MAY BE CONTRIBUTING TO THE ACTIVITY NEAR THE WAVE AXIS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-17N BETWEEN 45W-51W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST OF GUINEA AT 10N14W CONTINUING OVER ATLANTIC WATERS ALONG 14N23W 10N34W 9N43W 7N50W. BESIDES CONVECTION NEAR THE TROPICAL WAVES...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-9N BETWEEN 26W-29W. SIMILAR ACTIVITY IS FROM 8N-11N BETWEEN 39W-45W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 2100 UTC...A COLD FRONT EXTENDS THROUGH ALABAMA AND THE FLORIDA PANHANDLE INTO THE CENTRAL GULF OF MEXICO ALONG 31N86W 26N86W 22N90W INTO THE YUCATAN PENINSULA ALONG 18N92W 17N95W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60 NM EITHER SIDE OF THE AXIS. SCATTERED SHOWERS/THUNDERSTORMS CONTINUE FARTHER EAST ACROSS MUCH OF THE YUCATAN PENINSULA AND ARE ALSO ACROSS MUCH OF SOUTH FLORIDA WITH ISOLATED ACTIVITY ACROSS THE REMAINDER OF THE FLORIDA PENINSULA. SOME OF THE ACTIVITY OVER FLORIDA IS DUE TO MOIST SOUTHERLY FLOW ALOFT STREAMING OVER THE AREA AROUND AN UPPER LEVEL LOW IN THE NW CARIBBEAN. A LONGWAVE UPPER TROUGH IS MOVING OVER THE GULF WITH AXIS CURRENTLY EXTENDING THROUGH TEXAS AND MUCH OF THE CENTRAL CONUS. THE UPPER TROUGH IS BRINGING DRY AIR AND SUBSIDENCE ACROSS MUCH OF THE WESTERN GULF WEST OF THE FRONT. WINDS OF 15-20 KTS ARE OBSERVED BOTH AHEAD AND BEHIND THE FRONT. THE FRONT IS EXPECTED TO CONTINUE EASTWARD FOR THE NEXT 24 HOURS BEFORE BECOMING STATIONARY AND THEN RETREATING NW LATE IN THE WEEK. MOIST CONDITIONS WILL REMAIN OVER MUCH OF THE EASTERN GULF THROUGHOUT THE WEEK. THE CARIBBEAN SEA... AN UPPER LEVEL LOW IN THE NW CARIBBEAN CENTERED NEAR 17N87W IS PRODUCING A LARGE AREA OF SHOWERS/THUNDERSTORMS ACROSS THE WESTERN CARIBBEAN. NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS ARE FROM 14N-21N BETWEEN 77W-84W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO ACROSS WESTERN CUBA...NICARAGUA...AND HONDURAS. A SURFACE TROUGH WAS PREVIOUSLY ANALYZED IN THIS AREA...REMNANTS OF A TROPICAL WAVE THAT HAD BECOME STATIONARY. AN ASCAT SCATTEROMETER PASS FROM EARLIER TODAY INDICATES THAT THE SURFACE TROUGH HAS DISSIPATED AND WEAK SURFACE RIDGING IS NOW PRESENT. THE REMAINDER OF THE CARIBBEAN IS UNDER MOSTLY FAIR CONDITIONS DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE EXTENDING FROM THE WESTERN ATLC. A FEW ISOLATED SHOWERS/THUNDERSTORMS ARE NOTED ACROSS HISPANIOLA AND THE NORTHERN LEEWARD ISLANDS DUE TO A SMALL AREA OF ENHANCED MOISTURE MOVING INTO THE AREA FROM THE EAST. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS WITH CONTINUING SHOWER/THUNDERSTORM ACTIVITY ACROSS THE WESTERN CARIBBEAN. THE ATLANTIC OCEAN... AN UPPER LEVEL RIDGE COVERS THE WEST ATLC SUPPORTING BROAD SURFACE RIDGING ACROSS THE CENTRAL AND WEST ATLC AROUND A 1022 MB HIGH NEAR 35N50W. MOISTURE IS BEING WRAPPED AROUND THE WESTERN SIDE OF THE UPPER RIDGE FROM THE NW CARIBBEAN PRODUCING SCATTERED SHOWERS/THUNDERSTORMS FROM THE EAST COAST OF FLORIDA TO 76W. THE REMAINDER OF THE WEST AND CENTRAL ATLC ARE EXPERIENCING MOSTLY FAIR CONDITIONS. AN UPPER LEVEL LOW IS SPINNING NEAR 27N49W HELPING ENHANCE CONVECTION NEAR A TROPICAL WAVE TO THE SOUTH. IT IS ALSO PRODUCING A FEW ISOLATED SHOWERS FROM 24N-28N BETWEEN 43W-51W. UPPER LEVEL RIDGING COVERS THE REMAINDER OF THE BASIN SUPPORTING BROAD SURFACE RIDGING AND PROVIDING FAIR CONDITIONS ACROSS THE EASTERN ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON