000 AXNT20 KNHC 011152 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE SEP 01 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 18.2N 26.5W AT 01/1200 UTC OR ABOUT 195 NM NW OF THE CAPE VERDE ISLANDS MOVING N-NW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 17N-20N BETWEEN 25W- 27W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IN THE E CARIBBEAN EXTENDS FROM 21N61W ACROSS THE N LEEWARD ISLANDS TO 11N63W MOVING W NEAR 15 KT OVER THE PAST 24 HOURS. SSMI TPW INDICATES THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE. NO ASSOCIATED DEEP CONVECTION. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 18N-22N BETWEEN 57W-64W ENHANCED BY AN UPPER LEVEL TROUGH. TROPICAL WAVE IN THE W CARIBBEAN IS ALONG 80W FROM 10N-19N MOVING W 15-20 KT OVER THE PAST 24 HOURS. SSMI TPW INDICATES THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE. ACTIVITY TO THE W IS GENERATED BY THE UPPER LOW JUST S OF JAMAICA AND ENHANCED BY THE TROPICAL WAVE. SEE CARIBBEAN SEA BELOW. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS OVER AFRICA TO THE COAST THEN RESUMES S-SW OF TROPICAL STORM FRED NEAR 11N29W THROUGH A WEAK 1013 MB LOW NEAR 87N42W ALONG 5N47W TO 7N52W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE COAST OF W AFRICA FROM 15N-18N BETWEEN 17W-19W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 9N-12N BETWEEN 25W-31W AND FROM 5N- 9N BETWEEN 31W-54W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH EXTENDS FROM AN UPPER LOW OVER INDIANA ACROSS THE MIDDLE MISSISSIPPI VALLEY TO OVER E TEXAS AND ALONG THE COAST OF NE MEXICO COVERING THE W GULF AND GENERATING SCATTERED TO NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS FROM 25N-28N W OF 94W TO THE COASTAL PLAINS OF TEXAS AND SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 23N-25N W OF 89W TO THE COAST OF MEXICO. ISOLATED SHOWERS/THUNDERSTORMS ARE ALONG THE REMAINDER OF THE COAST OF MEXICO W OF 95W WITH SCATTERED SHOWERS N OF 28N W OF 92W TO THE COAST OF LOUISIANA AND NE TEXAS. AN UPPER RIDGE ANCHORED IN THE W ATLC COVERS THE E GULF. A SURFACE TROUGH EXTENDS FROM FLORIDA NEAR 30N83W INTO THE GULF NEAR CEDAR KEY ALONG 27N84W TO 24N87W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH. A WEAK SURFACE RIDGE IS BUILDING S OVER THE N GULF AND IS ANCHORED BY A 1020 MB HIGH OVER SW NORTH CAROLINA. THE SURFACE TROUGH WILL REMAIN NEARLY STATIONARY THROUGH WED BEFORE DISSIPATING. WEAK SURFACE RIDGE WILL PREVAIL THROUGH THU. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS FROM THE W ATLC ACROSS S FLORIDA AND THE YUCATAN CHANNEL TO THE GULF OF HONDURAS. AN UPPER TROUGH EXTENDS FROM THE WINDWARD PASSAGE THROUGH AN UPPER LOW JUST S OF JAMAICA TO CENTRAL PANAMA AND COMBINED THE TROPICAL WAVE IS GENERATING SCATTERED TO NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS FROM 17N-20N BETWEEN 79W-83W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVERING THE REMAINDER OF THE AREA FROM 16N-22N W OF 75W TO THE COAST OF THE YUCATAN. THE MONSOON TROUGH EXTENDS FROM COLOMBIA ACROSS COSTA RICA ALONG 9N/10N GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 11N E OF 83W TO OVER COLOMBIA AND PANAMA. FRESH TO STRONG TRADE WINDS WILL CONTINUE ACROSS THE CENTRAL CARIBBEAN THROUGH EARLY WED THEN WILL DIMINISH AS THE SURFACE RIDGE OVER THE W ATLC SHIFTS SE AND WEAKENS. THE W CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE W CARIBBEAN THROUGH WED. THE E CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE E CARIBBEAN TODAY AND THE CENTRAL CARIBBEAN TONIGHT AND WED ENTERING THE W CARIBBEAN WED NIGHT. ...HISPANIOLA... SKIES HAVE CLEARED ACROSS THE ISLAND THIS MORNING. MOISTURE WILL AGAIN MOVE IN TONIGHT PRECEDING THE NEXT TROPICAL WAVE TO CROSS THE ISLAND. THIS WILL INCREASE THE CHANCE OF SHOWER/THUNDERSTORM ACTIVITY FOR WED AND EARLY THU. ATLANTIC OCEAN... AN UPPER RIDGE IS ANCHORED IN THE W ATLC NEAR 29N79W WITH THE RIDGE AXIS EXTENDING ACROSS S FLORIDA INTO THE NW CARIBBEAN AND A SECOND SURFACE RIDGE AXIS EXTENDING E TO 29N50W. SCATTERED TO NUMEROUS SHOWERS WITH ISOLATED THUNDERSTORMS ARE N OF 30N W OF 78W TO THE COAST OF NE FLORIDA AND GEORGIA. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 28N-32N BETWEEN 59W-63W. THE ATLC BASIN IS DOMINATED BY A WEAK SURFACE RIDGE WITH A 1021 MB HIGH IN THE W ATLC NEAR 30N69W. SURFACE RIDGE WILL PERSIST THROUGH WED THEN WILL SHIFT SE AND GRADUALLY WEAKEN AS A WEAK COLD FRONT SINKS SLOWLY S ACROSS THE NW PORTION OF THE ATLC WED NIGHT AND THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW