000 AXNT20 KNHC 182347 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 18 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 FEATURE... TROPICAL STORM NADINE IS CENTERED NEAR 35.2N 32.6W AT 18/2100 UTC OR ABOUT 365 MI...590 KM WSW OF THE AZORES MOVING NNE AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS N OF THE CENTER FROM 33N-36N BETWEEN 33W-36W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 17N40W TO 5N47W MOVING W AT 10-15 KT. THIS WAVE IS WITHIN A SURGE OF DEEP LAYER MOISTURE AS SEEN ON SSMI TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS ARE WITHIN 90 NM W OF THE WAVE AXIS. TROPICAL WAVE OVER THE LESSER ANTILLES EXTENDS FROM 19N64W TO 10N68W TO MOVING W AT 10-15 KT. SCATTERED MODERATE CONVECTION IS WELL W OF THE WAVE AXIS S OF HISPANIOLA FROM 15N-18N BETWEEN 68W-71W. SCATTERED SHOWERS ARE ELSEWHERE FROM 15N-19N BETWEEN 61W-71W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF MAURITANIA AT 17N16W TO 7N23W TO 4N30W TO 8N41W. ISOLATED MODERATE CONVECTION IS FROM 5N-8N BETWEEN 27W-40W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 7N-10N BETWEEN 48W-56W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 2100 UTC...A COLD FRONT EXTENDS FROM THE FLORIDA PANHANDLE AT 30N84W TO THE BAY OF CAMPECHE AT 20N94W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF THE FRONT OVER THE E GULF AND FLORIDA N OF 23N BETWEEN 80W-89W. ELSEWHERE...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER CUBA...AND OVER THE YUCATAN PENINSULA N OF 18N. MOSTLY FAIR WEATHER IS OVER THE NW GULF AND TEXAS COAST. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE GULF SUPPORTING THE SURFACE FRONT. STRONG SUBSIDENCE IS OVER N MEXICO...TEXAS...AND THE NW GULF. EXPECT THE COLD FRONT TO DRIFT E AND EXTEND FROM N FLORIDA TO THE YUCATAN PENINSULA IN 24 HOURS WITH CONVECTION. THE CARIBBEAN SEA... A TROPICAL WAVE IS PRODUCING CONVECTION OVER THE E CARIBBEAN. SEE ABOVE. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER HISPANIOLA AND CUBA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER THE YUCATAN PENINSULA N OF 18N. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALSO INLAND OVER NICARAGUA...HONDURAS...AND GUATEMALA. FURTHER S...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER N VENEZUELA FROM 6N-11N BETWEEN 61W-72W. LIGHT 10-15 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS OVER JAMAICA NEAR 18N88W. AN UPPER LEVEL HIGH IS CENTERED N OF PUERTO RICO NEAR 20N68W. EXPECT OVER THE NEXT 24 HOURS FOR THE TROPICAL WAVE TO CONTINUE TO PRODUCE CONVECTION OVER THE EASTERN AND CENTRAL CARIBBEAN. ALSO EXPECT MORE CONVECTION OVER THE SW CARIBBEAN AND CENTRAL AMERICA. THE ATLANTIC OCEAN... TROPICAL STORM NADINE IS OVER THE EASTERN ATLANTIC. SEE THE SPECIAL FEATURE ABOVE. SCATTERED MODERATE CONVECTION IS OVER THE N BAHAMAS AND THE W ATLANTIC FROM 26N-32N BETWEEN 75W-80W. SHOWERS ARE OVER THE S BAHAMAS FROM 20N-24N BETWEEN 71W-76W. A 1015 MB LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 32N51W. A SURFACE TROUGH EXTENDS S FROM THE LOW TO 24N57W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE TROUGH. A WEAK 1018 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 25N48W. ANOTHER 1019 MB HIGH IS W OF THE CANARY ISLANDS NEAR 29N21W. A THICK LAYER OF SAHARAN DUST IS NOTED ON THE METEOSAT-9 SAL PRODUCT OVER THE E ATLANTIC FROM 10N-30N E OF 40W. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED NEAR 32N51W SUPPORTING THE CENTRAL ATLANTIC SURFACE LOW AND TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA