000 AXNT20 KNHC 160538 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN SEP 16 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...SPECIAL FEATURES... HURRICANE NADINE IS CENTERED NEAR 30.6N 46.6W 16/0300 UTC OR ABOUT 940 NM E OF BERMUDA...AND ABOUT 1065 NM WSW OF THE AZORES. NADINE IS MOVING E AT 15 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 983 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS TO 85 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 30N-34N BETWEEN 39W-48W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM THE CAPE VERDE ISLANDS NEAR 17N25W TO 8N27W MOVING W AT 10-15 KT. THIS WAVE IS NOT AS ROBUST AS SOME OF THE STRONGER WAVES THAT HAVE EMERGED OFF AFRICA...BUT IT STILL ALIGNS WITH A SMALL SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-10N BETWEEN 26W-30W. TROPICAL WAVE APPROACHES THE LESSER ANTILLES ALONG 19N54W TO 8N54W MOVING W NEAR 12 KT. A 1010 MB SURFACE LOW IS ANALYZED ALONG THE WAVE AT 13N54W. THE WAVE LIES WITHIN AN AREA OF MAXIMUM MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 11N-13N BETWEEN 50W-55W. A CLUSTER OF MODERATE/STRONG CONVECTION HAS ALSO POPPED UP NEAR 14N52W...AND FROM 14N-16N BETWEEN 56W-57W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF MAURITANIA AT 18N16W CONTINUING OVER ATLC WATERS ALONG12N21W 7N27W 8N36W. THE ITCZ EXTENDS FROM 8N36W TO 12N52W AND CONTINUES ON THE WEST SIDE OF A TROPICAL WAVE ALONG 10N56W 10N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-9N BETWEEN 34W-44W. ...DISCUSSION... GULF OF MEXICO... THE LAST TRACES OF CONVECTION THAT BUILT DURING THE AFTERNOON HAVE MOSTLY DIED DOWN. ISOLATED SHOWERS/THUNDERSTORMS REMAIN OVER THE SE GULF NEAR THE WEST COAST OF FLORIDA AND ACROSS SOUTH FLORIDA AND THE FLORIDA STRAITS. THIS ACTIVITY IS LINKED TO DIFFLUENCE ALOFT AROUND THE E SIDE OF AN UPPER LEVEL TROUGH ALONG 87W. A SURFACE TROUGH IN THE WESTERN CARIBBEAN ALONG 26N94W TO 22N93W IS ALSO SUPPORTING A FEW SHOWERS/THUNDERSTORMS FROM 24N-27N BETWEEN 90W-94W. A FEW PATCHES ARE ALSO ALONG THE MEXICAN COAST IN THE BAY OF CAMPECHE. THE REMAINDER OF THE BASIN HAS MOSTLY CLEAR SKIES. WEAK UPPER RIDGING COVERS THE AREA TO EITHER SIDE OF THE UPPER TROUGH INCLUDING THE FAR WESTERN GULF AND FLORIDA. THE SURFACE TROUGH IS EXPECTED TO DRIFT WEST AND WILL EVENTUALLY BE ABSORBED BY A FRONTAL BOUNDARY THAT WILL REACH THE BASIN ON MONDAY. MOIST CONDITIONS AND BROAD SURFACE TROUGHING WILL REMAIN ACROSS THE BASIN UNTIL THEN. CARIBBEAN SEA... THE CARIBBEAN IS MOSTLY QUIET TONIGHT WITH CLEAR SKIES COVERING THE MAJORITY OF THE AREA. THIS FAIR WEATHER IS RELATED TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING THE WESTERN CARIBBEAN...AND AN INVERTED UPPER TROUGH COVERING THE EASTERN CARIBBEAN. A FEW SHOWERS/THUNDERSTORMS CONTINUE ACROSS WESTERN CUBA AND OFFSHORE OF HONDURAS AND NICARAGUA...BUT ALL OTHER ACTIVITY HAS NOW DIED DOWN. TRADEWIND FLOW OF 15-20 KT IS PRESENT ACROSS THE CENTRAL CARIBBEAN WITH LIGHTER WINDS TO EITHER SIDE. EXPECT SHOWERS/THUNDERSTORMS ACROSS THE SW CARIBBEAN AND CENTRAL AMERICA DURING THE DAYTIME HOURS WITH ACTIVITY INCREASING OVER THE EXTREME EASTERN CARIBBEAN AS A TROPICAL WAVE APPROACHES FROM THE EAST. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE COVERS THE FAR WESTERN ATLC PROVIDING MOSTLY FAIR CONDITIONS. AN UPPER LEVEL TROUGH IS ALONG 64W SUPPORTING A SURFACE TROUGH ALONG 32N60W 25N70W. DRY AIR IS MOVING AROUND THE UPPER TROUGH WHICH IS PREVENTING ANY DEEP CONVECTION. HOWEVER...POSSIBLE ISOLATED SHOWERS ARE ALONG THE SURFACE TROUGH AXIS. TO THE E...HURRICANE NADINE MOVES THROUGH THE CENTRAL ATLC. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. A WEAK 1018 MB SURFACE HIGH IS SE OF NADINE CENTERED NEAR 24N39W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED SOUTH OF NADINE NEAR 21N50W. THE UPPER RIDGE ALONG WITH THE SURFACE RIDGE ARE PROVIDING FAIR CONDITIONS ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC. A BROAD UPPER LEVEL TROUGH COVERS THE EASTERN ATLC CENTERED NEAR THE AZORES ISLANDS...BUT IS NOT CAUSING ANY ACTIVE WEATHER IN THE DISCUSSION AREA. VISIBLE SATELLITE IMAGERY FROM EARLIER IN THE DAY ALONG WITH GOES-R ENHANCED IMAGERY INDICATE THAT AN AREA OF SAHARAN DUST EXTENDS S OF 20N FROM THE COAST OF AFRICA AROUND THE TROPICAL WAVE TO NEAR 50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON