000 AXNT20 KNHC 032352 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED OCT 03 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 04/0000 UTC IS NEAR 36.5N 31.0W. NADINE IS ABOUT 210 NM WSW OF THE AZORES. NADINE IS MOVING NE AT 16 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 40 KT. PLEASE READ THE FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC...AND THE PUBLIC ADVISORY...MIATCPAT4/WTNT34 KNHC...FOR MORE DETAILS. MOST OF THE CONVECTION HAS BEEN SHEARED OFF TO THE EAST WITH ONLY WEAK CONVECTION RANGING FROM 33N-36N BETWEEN 26W-29W. THE CENTER OF TROPICAL DEPRESSION FIFTEEN AT 03/2100 UTC IS NEAR 18.6N 42.0W OR ABOUT 1040 NM W OF THE CAPE VERDE ISLANDS MOVING NNW AT 12 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. PLEASE READ THE FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC...AND THE PUBLIC ADVISORY...MIATCPAT5/WTNT35 KNHC...FOR MORE DETAILS. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS EAST OF THE CENTER FORM 17N-21N BETWEEN 37W-41W...WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 21N-24N BETWEEN 32W-41W. ...TROPICAL WAVES... TROPICAL WAVE IS JUST EAST OF THE LESSER ANTILLES ALONG 19N58W TO 8N61W MOVING W NEAR 15 KT. THE WAVE LIES WITHIN A SURGE OF DEEP LAYER MOISTURE INDICATED IN TOTAL PRECIPITABLE WATER IMAGERY. ANALYSIS OF LOW LEVEL CLOUDS IN VISIBLE SATELLITE IMAGERY ALSO INDICATES THAT LOW LEVEL CYCLONIC FLOW IS PRESENT AROUND THE WAVE AXIS. CURRENTLY SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 12N-16N BETWEEN 57W-61W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF MAURITANIA AT 17N16W TO 11N23W 6N31W. THE ITCZ BEGINS AT 6N31W TO 11N37W WHERE IT SPLITS DUE TO T.D. FIFTEEN AND PICKS UP ON THE WEST SIDE OF THE SYSTEM ALONG 12N46W 14N51W 11N56W 12N59W. A CLUSTER OD NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS MOVING OFF THE COAST OF AFRICA FROM 10N-14N BETWEEN 14W-18W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-8N BETWEEN 30W-38W...AND FROM 10N-12N BETWEEN 51W-54W. ...DISCUSSION... THE GULF OF MEXICO... AN UPPER LEVEL TROUGH EXTENDING THROUGH THE EASTERN CONUS AND INTO THE WESTERN GULF OF MEXICO IS PROVIDING A LARGE AREA OF DIFFLUENT FLOW ACROSS THE EASTERN HALF OF THE GULF. THIS DIFFLUENCE ALOFT ALONG WITH THE INFLUENCE OF A DISSIPATING STATIONARY FRONT AT THE SURFACE EXTENDING FROM THE FLORIDA PANHANDLE NEAR 31N85W THROUGH THE YUCATAN PENINSULA TO 17N89W IS SUPPORTING WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS EAST OF THE FRONTAL BOUNDARY CONTINUING INTO CENTRAL FLORIDA. THE FRONT IS BEGINNING TO LOSE ITS FRONTAL CHARACTERISTICS...BUT A CLEAR BOUNDARY STILL REMAINS AT THE SURFACE. SOUTH FLORIDA IS THE ONLY AREA OF THE EASTERN GULF STILL WITH CLEAR SKIES. THE FAR WESTERN GULF...ESPECIALLY THE NW CORNER...ALSO HAS EXCEPTIONALLY CLEAR SKIES TONIGHT AS DRY AIR AND SUBSIDENCE SINK DOWN AROUND THE WEST SIDE OF THE UPPER TROUGH. WINDS ARE LIGHT IN THE NW CORNER WITH STRONG WINDS NEAR THE FRONT REACHING UP TO 15 KT. THE FRONT WILL LIKELY BECOME A TROUGH WITHIN THE NEXT 12-24 HOURS. THE TROUGH...ALONG WITH MOIST CONDITIONS...WILL BEGIN TO DRIFT WESTWARD SPREADING MOISTURE IN THE CENTRAL AND WESTERN GULF THROUGH THE END OF THE WEEK AND WEEKEND. UPPER LEVEL TROUGHING WILL ALSO REMAIN OVER THE BASIN PROVIDING DIFFLUENT FLOW ALOFT FURTHER SUPPORTING MOIST CONDITIONS. THE CARIBBEAN SEA... AN UPPER LEVEL TROUGH OVER THE WESTERN GULF OF MEXICO IS PROVIDING DIFFLUENCE ALOFT ACROSS THE EASTERN GULF AS WELL AS THE NW CARIBBEAN AND CENTRAL AMERICA WEST OF 83W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS MUCH OF HONDURAS AND NICARAGUA. ACTIVITY CONTINUES FARTHER SOUTH ACROSS COSTA RICA AND PANAMA...BUT IS MORE ASSOCIATED WITH THE MONSOON TROUGH THAT EXTENDS THROUGH BOTH COUNTRIES TO NORTHERN COLOMBIA. AN AREA OF ENHANCED MOISTURE IS ALSO ACROSS THE NORTH CENTRAL CARIBBEAN AROUND THE NORTHERN EXTENT OF AN UPPER LEVEL LOW CENTERED IN THE SW CARIBBEAN NEAR 13N77W. ISOLATED SHOWERS/THUNDERSTORMS ARE FROM 15N-19N BETWEEN 73W-83W AND ACROSS SOUTHERN CUBA. MOST OF THE EASTERN CARIBBEAN IS EXPERIENCING FAIR WEATHER. HOWEVER...A TROPICAL WAVE APPROACHES FROM THE EAST AND IS ALREADY SUPPORTING SHOWERS/THUNDERSTORMS ACROSS THE FAR EASTERN CARIBBEAN INCLUDING PORTIONS OF THE LESSER ANTILLES. TRADEWIND FLOW OF 15-20 KT IS ACROSS THE MAJORITY OF THE AREA. EXPECT MOIST CONDITIONS TO REMAIN OVER THE WESTERN CARIBBEAN AND INCREASE OVER THE EASTERN CARIBBEAN AS THE TROPICAL WAVE MOVES INTO THE BASIN WITHIN THE NEXT 6-12 HOURS. THE ATLANTIC OCEAN... A LARGE UPPER LEVEL RIDGE COVERS THE WEST ATLC SUPPORTING A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH NEAR 32N66W...WHICH IS PROVIDING MOSTLY FAIR CONDITIONS ACROSS THE WEST ATLC. A FEW SHOWERS/THUNDERSTORMS HAVE EMERGED OFF THE NE COAST OF FLORIDA ASSOCIATED WITH AN UPPER LEVEL TROUGH IN THE GULF OF MEXICO. A SMALL UPPER LEVEL LOW IS IN THE CENTRAL ATLC NEAR 23N56W SANDWICHED BETWEEN THE LARGE UPPER RIDGE OVER THE WESTERN ATLC AND AN UPPER LEVEL RIDGE COVERING THE TROPICAL ATLC. THE UPPER LOW SUPPORTS A FEW ISOLATED SHOWERS FROM 18N-24N BETWEEN 51W-57W. TO THE E...TROPICAL DEPRESSION FIFTEEN SPINS IN THE TROPICAL REGION...WHILE TROPICAL STORM NADINE CONTINUES TO MORE TOWARDS THE AZORES ISLANDS NORTH OF THE DISCUSSION AREA. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS ON BOTH SYSTEMS. ANOTHER UPPER LEVEL RIDGE COVERS THE EASTERN ATLC SUPPORTING ANOTHER SURFACE RIDGE THAT IS PROVIDING FAIR CONDITIONS ACROSS THE FAR EASTERN ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON