000 AXNT20 KNHC 261749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED SEP 26 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...SPECIAL FEATURES... TROPICAL STORM NADINE IS LOCATED NEAR 30.6N 30.3W AT 26/1500 UTC. THIS POSITION IS LOCATED ABOUT 475 NM SSW OF THE AZORES ISLANDS. NADINE IS MOVING S NEAR 3 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUST TO 55 KT. PLEASE SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE CONVECTION IS FROM 30N-33N BETWEEN 28W-32W. ...TROPICAL WAVES... TROPICAL WAVE IS JUST W OF THE CAPE VERDE ISLANDS ALONG 18N26W TO 7N25W MOVING W AT 10-15 KT. THE WAVE COINCIDES WELL WITH A 700 MB TROUGH IN MODEL GUIDANCE. IT ALSO LIES ON THE WEST SIDE OF A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS EAST OF THE WAVE AXIS FROM 14N-17N BETWEEN 22W-24W. SIMILAR ACTIVITY IS FROM 14N-18N BETWEEN 18W-20W. TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 17N71W TO 11N74W MOVING W AT 15-20 KT. THE WAVE LIES WITHIN A BROAD AREA OF DEEP LAYER MOISTURE PRESENT ACROSS THE CENTRAL CARIBBEAN. THE WAVE ALSO LIES UNDERNEATH THE DIFFLUENT SIDE OF AN UPPER LEVEL TROUGH...WHICH IS HELPING ENHANCE CONVECTION NEAR IT. SCATTERED MODERATE CONVECTION IS FROM 13N-17N BETWEEN 69W-75W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS WEST AFRICA TO THE COAST OF SENEGAL AT 13N16W CONTINUING SE ALONG 7N25W 7N38W. THE ITCZ BEGINS AT 7N38W TO 8N51W. SCATTERED MODERATE CONVECTION IS FROM 3N-5N BETWEEN 26W-33W. ...DISCUSSION... GULF OF MEXICO... WEAK SURFACE RIDGING IS ACROSS THE GULF OF MEXICO EXTENDING FROM A HIGH CENTER OVER NORTH CAROLINA. HOWEVER...AN UPPER LEVEL TROUGH ALONG 87W IS PROVIDING DIFFLUENT FLOW ACROSS PORTIONS OF THE EASTERN GULF. THE UPPER TROUGH ALSO SUPPORTS A SURFACE TROUGH IN THE CENTRAL GULF ALONG 26N89W TO 25N93W...AS OF 1500 UTC. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE NEAR THE SURFACE TROUGH FROM 24N-27N BETWEEN 88W-91W. SIMILAR ACTIVITY IS OVER THE EASTERN GULF FROM 23N-24N BETWEEN 87W-88W...AND FROM 26N-28N BETWEEN 83W-85W. SHALLOW ISOLATED SHOWERS COVER THE REMAINDER OF THE SE GULF AND SOUTHERN FLORIDA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. CARIBBEAN SEA... SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE JUST OFF THE EAST COAST OF THE YUCATAN PENINSULA FROM 18N-22N BETWEEN 84W-87W ASSOCIATED WITH AN UPPER LEVEL TROUGH OVER THE EASTERN GULF OF MEXICO THAT JUST BARELY EXTENDS INTO THE NW CARIBBEAN. THE REMAINDER OF THE WESTERN CARIBBEAN IS EXPERIENCING FAIR WEATHER. A TROPICAL WAVE MOVING THROUGH THE CENTRAL CARIBBEAN IS CAUSING AN AREA OF DISTURBED WEATHER SOUTH OF HISPANIOLA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 13N-17N BETWEEN 69W-75W. A FEW SHOWERS/THUNDERSTORMS ARE ALSO IN THE SW CARIBBEAN ALONG THE MONSOON TROUGH THAT EXTENDS FROM CENTRAL COSTA RICA TO NORTHERN COLOMBIA. THE SHOWERS/THUNDERSTORMS NEAR THE TROPICAL WAVE ARE ALSO BEING ENHANCED BY DIFFLUENCE ALOFT AROUND AN UPPER LEVEL TROUGH EXTENDING FROM HISPANIOLA TO VENEZUELA. THE EASTERN CARIBBEAN IS ALSO EXPERIENCING MOSTLY FAIR WEATHER. EXPECT THE TROPICAL WAVE TO CONTINUE TO MOVE WESTWARD WITH SHOWERS LIKELY NEAR THE AXIS. ATLANTIC OCEAN... A STATIONARY FRONT EXTENDS INTO THE W ATLC NEAR 32N68W TO 29N73W TRANSITIONING INTO A SURFACE TROUGH TO THE NW BAHAMAS AND FLORIDA STRAITS AT 24N81W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE AXIS. A CLUSTER OF SHOWERS/THUNDERSTORMS IS ALONG THE AXIS NEAR 28N75W. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH NORTH OF OF THE DISCUSSION AREA. AN UPPER LEVEL RIDGE CENTERED NEAR 25N70W IS PROVIDING FAIR CONDITIONS ACROSS THE REMAINDER OF THE W ATLC. FARTHER E...AN UPPER LEVEL TROUGH EXTENDS FROM NEAR 30N46W TO 16N61W. THE UPPER TROUGH SUPPORTS A SURFACE TROUGH ALONG 23N52W TO 19N53W SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 20N-23N BETWEEN 49W-58W. TROPICAL STORM NADINE IS NEAR THE EDGE OF THE DISCUSSION AREA TO THE NE. SEE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. FAIR WEATHER IS ACROSS THE REMAINDER OF THE E ATLC. UPPER LEVEL RIDGING COVERS THE EASTERN TROPICAL ATLC CENTERED OVER NW AFRICA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON