000 AXNT20 KNHC 021047 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED SEP 02 2015 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM FRED IS CENTERED NEAR 19.5N 30.1W AT 02/0900 UTC OR ABOUT 410 NM W-NW OF THE CAPE VERDE ISLANDS MOVING W-NW AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. THE LOW LEVEL CENTER IS CURRENTLY EXPOSED DUE TO STRONG WESTERLY VERTICAL WIND SHEAR. ISOLATED MODERATE CONVECTION IS TO THE EAST FROM 17N-21N BETWEEN 25W-28W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS ALONG 44W/45W FROM 6N- 14N MOVING W NEAR 20 KT OVER THE PAST 12 HOURS. SSMI TPW DOES NOT SHOW ANY SURGE OF DEEP MOISTURE. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE CENTRAL CARIBBEAN EXTENDS FROM HISPANIOLA NEAR 18N71W TO OVER SOUTH AMERICA NEAR 11N72W MOVING W 20-25 KT OVER THE PAST 24 HOURS. THE N PORTION OF THIS WAVE HAS SPLIT AND IS NOW A SURFACE TROUGH FROM 22N65W TO THE MONA PASSAGE. SSMI TPW INDICATES THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE W CARIBBEAN IS ALONG 87W/88W S OF 19N TO INLAND OVER CENTRAL AMERICA MOVING W 15-20 KT OVER THE PAST 24 HOURS. SSMI TPW INDICATES THE WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP MOISTURE THAT COVERS THE W CARIBBEAN. NO ASSOCIATED DEEP CONVECTION. ISOLATED SHOWERS/THUNDERSTORMS ARE S OF 18N W OF 84W TO THE COAST OF HONDURAS AND YUCATAN. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS OVER AFRICA INTO THE E TROPICAL ATLC NEAR 19N16W TO 15N22W THEN RESUMES S OF TROPICAL STORM FRED NEAR 12N30W ALONG 9N39W TO 7N50W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM S OF THE MONSOON TROUGH BETWEEN 31N-45W AND WITHIN 150/180 NM N OF THE MONSOON TROUGH BETWEEN 39W-49W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 150 NM ALONG THE COAST OF W AFRICA S OF 10N W OF 10W AND FROM 11N-14N BETWEEN 17W-22W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH EXTENDS FROM AN UPPER LOW OVER ARKANSAS INTO THE GULF NEAR GALVESTON TEXAS TO THE E BAY OF CAMPECHE COVERING THE W GULF AND IS GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE FAR W GULF W OF 94W AND N OF 24N FROM 90W- 94W. AN UPPER RIDGE ANCHORED OVER TAMPA FLORIDA EXTENDS A RIDGE AXIS SW TO THE YUCATAN PENINSULA COVERING THE E GULF. A SURFACE TROUGH...REMNANTS OF ERIKA EXTENDS FROM S GEORGIA INTO THE GULF NEAR 30N84W TO A WEAK 1016 MB LOW NEAR 29N84W THEN SW TO 27N87W. ISOLATED SHOWERS/THUNDERSTORMS ARE N OF 28N E OF 85W AND WITHIN 60/75 NM OF LINE FROM 25N83W TO 23N91W. A WEAK SURFACE RIDGE IS BUILDING S OVER THE NW GULF AND IS ANCHORED BY A 1021 MB HIGH OVER TENNESSEE. THE SURFACE TROUGH WILL DRIFT NE AND GRADUALLY DISSIPATE TODAY. WEAK SURFACE RIDGE WILL SHIFT SLOWLY SE INTO THE E/CENTRAL GULF THROUGH FRI. CARIBBEAN SEA... AN UPPER LOW DOMINATES THE NW CARIBBEAN CENTERED S OF THE CAYMAN ISLANDS NEAR 18N81W GENERATING CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 17N-20N BETWEEN 72W-83W AND N OF 20N BETWEEN 80W-84W. THE UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC TO OVER HISPANIOLA AND IS SUPPORTING THE SURFACE TROUGH THAT WAS PREVIOUSLY THE N PORTION OF THE TROPICAL WAVE EXTENDING FROM 22N65W TO THE MONA PASSAGE AND IS GENERATING ISOLATED SHOWERS/THUNDERSTORMS FROM 18N-22N BETWEEN 60W-69W. THE MONSOON TROUGH IS S OF PANAMA AND IS GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF LINE FROM NICARAGUA NEAR 13N84W TO COLOMBIA NEAR 9N76W. FRESH TO STRONG TRADE WINDS WILL PULSE IN THE S/CENTRAL CARIBBEAN THROUGH FRI. THE W CARIBBEAN TROPICAL WAVE WILL MOVE W OF THE AREA TODAY. THE CENTRAL CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE W CARIBBEAN TONIGHT THROUGH THU NIGHT. ...HISPANIOLA... THE UPPER TROUGH FROM THE CENTRAL ATLC EXTENDS TO OVER HISPANIOLA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER HAITI AND THE GULF OF GONAVE. THE UPPER TROUGH WILL LINGER OVER THE ISLAND THROUGH TONIGHT BEFORE SHIFTING SE EARLY THU. MOISTURE WILL PERSIST ACROSS THE ISLAND THROUGH EARLY THU BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE ISLAND TODAY AND EARLY THU. ATLANTIC OCEAN... AN UPPER RIDGE IS ANCHORED OVER TAMPA FLORIDA AND EXTENDS A RIDGE AXIS E ALONG 27N73W TO 26N53W. A STRONG UPPER TROUGH IS OVER THE N/CENTRAL ATLC N OF THE DISCUSSION AREA SUPPORTING A WEAK SURFACE TROUGH THAT EXTENDS FROM 32N55W TO 29N57W AND IS GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 27N BETWEEN 45W-56W. A NARROW UPPER TROUGH DIPS S INTO THE E/CENTRAL ATLC THROUGH 32N35W ALONG 25N42W TO AN UPPER LOW NEAR 22N56W THEN TO OVER HISPANIOLA SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 32N37W ALONG 30N38W TO 28N40W. ISOLATED SHOWERS/ THUNDERSTORMS ARE WITHIN 45 NM E OF THE SURFACE TROUGH. ISOLATED SHOWERS/THUNDERSTORMS DOT THE AREA FROM 24N-27N BETWEEN 52W-71W. THE REMAINDER OF THE ATLC BASIN IS DOMINATED BY A WEAK SURFACE RIDGE WITH A 1019 MB HIGH IN THE W ATLC NEAR 29N69W. SURFACE RIDGE WILL SHIFT SE AND GRADUALLY WEAKEN AS A WEAK TROUGH SINKS SLOWLY SE INTO THE W ATLC OFF NE FLORIDA TONIGHT THROUGH FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW