000 AXNT20 KNHC 042349 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI OCT 04 2013 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 FEATURES... TROPICAL STORM KAREN IS CENTERED 25.9N 90.3W AT 04/2100 UTC OR ABOUT ABOUT 205 NM S-SW OF THE MOUTH OF THE MISSISSIPPI RIVER AND ABOUT 235 NM S-SE OF MORGAN CITY LOUISIANA WITH THE PRESENT MOVEMENT NEAR STATIONARY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. PLEASE SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MAITCPAT2/WTNT32 KNHC AND THE NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 25N-27N BETWEEN 87W-90W. CLUSTERS OF SCATTERED TO HEAVY SHOWERS WITH EMBEDDED ISOLATED THUNDERSTORMS ARE OVER THE E GULF AND THE YUCATAN CHANNEL FROM 21N-29N BETWEEN 84W-89W INCLUDING PORTIONS OF W CUBA AND NW YUCATAN PENINSULA. ...TROPICAL WAVES... A TROPICAL WAVE WAS ADDED TO THE 04/1800 UTC ANALYSIS FROM 15N18W TO 5N18W MOVING W 5-10 KT. BASED ON THE UPPER AIR SOUNDING FROM BAMAKO MALI AND DAKAR SENEGAL THIS WAVE MOVED OFF THE COAST OF AFRICA LAST NIGHT. WAVE IS WELL DEFINED AT LOW LEVELS IN THE SATELLITE DERIVED WINDS AS WELL AS THE GLOBAL MODELS AT THE MID AND UPPER LEVELS. WAVE IS EMBEDDED WITHIN A NEW SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...THERE IS NO ASSOCIATED CONVECTION. TROPICAL WAVE EXTENDS FROM 18N47W TO 11N49W MOVING W5-10 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED CONVECTION. TROPICAL WAVE EXTENDS FROM 19N55W THROUGH A 1011 MB LOW NEAR 14N57W TO 12N57W MOVING W 5-10 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP MOISTURE THAT COVERS THE CARIBBEAN ACROSS THE LESSER ANTILLES INTO THE W TROPICAL ATLC AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. A BROAD UPPER E/W RIDGE ANCHORED NEAR 12N48W IS PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 9N-17N BETWEEN 52W-62W ENCOMPASSING THIS WAVE. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 11N14W ALONG 8N22W TO 7N29W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 5N34W 6N47W TO 9N56W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM THE ITCZ TO 10N BETWEEN 40W-49W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE INLAND AND WITHIN 60 NM ALONG THE COAST OF W AFRICA FROM LIBERIA TO GUINEA BISSAU. ...DISCUSSION... GULF OF MEXICO... THE PRIMARY CONCERN THIS EVENING CONTINUES TO BE TROPICAL STORM KAREN MOVING THROUGH THE CENTRAL GULF. SEE SPECIAL FEATURES ABOVE. BROAD UPPER RIDGE ASSOCIATED WITH TROPICAL STORM KAREN COVERS MOST OF THE GULF AND IS ANCHORED NEAR 21N91W. THE WEAK SURFACE RIDGE IS GIVING WAY WITH THE APPROACH OF KAREN. THE WATER VAPOR SATELLITE IMAGERY SHOWS THE NW GULF DOMINATED BY DRY STABLE AIR ALOFT. HOWEVER...VISIBLE SATELLITE IMAGERY AND MOSAIC RADAR SHOWS LOW LEVEL FEEDER BANDS OF KAREN PRODUCING ISOLATED SHOWERS N OF 24N BETWEEN 89W-95W. TROPICAL STORM KAREN WILL BE CLOSE TO THE MISSISSIPPI DELTA LATE SAT/EARLY SUN THEN WILL MOVE INLAND OVER THE W FLORIDA PANHANDLE LATER SUN. A COLD FRONT WILL MOVE OFF SE TEXAS COAST SUN REACHING FROM THE FLORIDA PANHANDLE TO W BAY OF CAMPECHE LATE MON BEFORE BECOMING DIFFUSE TUE. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT WED. CARIBBEAN SEA... TROPICAL STORM KAREN IS STILL PRODUCING SHOWERS/THUNDERSTORM ACTIVITY OVER THE YUCATAN CHANNEL. SEE SPECIAL FEATURES ABOVE. THE UPPER RIDGE ASSOCIATED WITH KAREN COVERS THE W CARIBBEAN W OF 73W AND IS PROVIDING DIFFLUENCE ALOFT TO ENHANCE AFTERNOON SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 60/75 NM ALONG THE S COAST OF CUBA. AN UPPER TROUGH OVER THE W ATLC DIPS S OVER THE N/CENTRAL CARIBBEAN N OF 16N BETWEEN THE VIRGIN ISLANDS AND HAITI GENERATING SCATTERED TO HEAVY SHOWERS WITH EMBEDDED THUNDERSTORMS N OF 17N BETWEEN PUERTO RICO AND HAITI INCLUDING THE MONA PASSAGE. A BROAD E/W UPPER RIDGE OVER THE TROPICAL ATLC COVERS THE REMAINDER OF THE E CARIBBEAN PROVIDING DIFFLUENCE ALOFT TO GENERATE ISOLATED SHOWERS/THUNDERSTORMS S OF 16N BETWEEN 69W-78W AND S OF 17N E OF 69W TO OVER THE LESSER ANTILLES. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N75W TO ACROSS COSTA RICA NEAR 11N84W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 11N W OF 80W. SURFACE RIDGE OVER THE W ATLC WILL MAINTAIN MOSTLY GENTLE TO MODERATE TRADE WINDS ACROSS ENTIRE BASIN THROUGH WED. HISPANIOLA... AN UPPER TROUGH OVER THE W ATLC DIPS S ACROSS HISPANIOLA GENERATING SCATTERED TO HEAVY SHOWERS WITH EMBEDDED THUNDERSTORMS OVER THE ISLAND INCLUDING THE MONA PASSAGE. THIS UPPER TROUGH WILL PERSIST THROUGH MID WEEK PROVIDING INSTABILITY AND COUPLE WITH THE PERSISTENCE OF LOW LEVEL MOISTURE BROUGHT IN BY THE EASTERLY TRADE WINDS THEN COUPLED WITH PEAK DAYTIME HEATING COULD GENERATE DAILY AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS. ATLANTIC OCEAN... THE UPPER RIDGE ASSOCIATED WITH TROPICAL STORM KAREN COVERS THE W ATLC W OF 73W. A CUT-OFF UPPER LOW IS TO THE E CENTERED NEAR 26N66W COVERING THE AREA S OF 30N TO OVER THE N/CENTRAL CARIBBEAN BETWEEN 60W-72W GENERATING SCATTERED TO HEAVY SHOWERS WITH EMBEDDED THUNDERSTORMS S OF 20N BETWEEN 65-71W AND CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 20N-28N BETWEEN 62W-66W. A WEAK SURFACE RIDGE COVERS THE W ATLC TO OVER THE FAR THE NE GULF OF MEXICO ANCHORED BY A PAIR 1021 MB HIGHS N OF THE DISCUSSION AREA BETWEEN BERMUDA AND NORTH CAROLINA. A WEAK SURFACE TROUGH IS NE OF THE LEEWARD ISLANDS EXTENDING FROM 25N49W THROUGH A WEAK 1015 MB LOW NEAR 21N52W TO 20N53W WITH POSSIBLE ISOLATED SHOWERS WITHIN 30 NM OF LINE FROM 22N46W TO 23N51W. A SHORTWAVE UPPER TROUGH IS IN THE E/CENTRAL ATLC ALONG 40W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 27N38W TO 21N41W GENERATING ISOLATED SHOWERS WITHIN 250 NM E OF THE SURFACE TROUGH. A WEAK SURFACE RIDGE COVERS THE E ATLC ANCHORED BY A 1020 MB HIGH NEAR 32N26W. W ATLC SURFACE RIDGE WILL PERSIST THROUGH SAT. SOUTHERLY SURFACE FLOW OFF NE FLORIDA WILL INCREASE SUN AND MON AS KAREN PASSES ACROSS THE SE CONUS AHEAD OF A COLD FRONT THAT WILL WEAKEN AS IT MOVES OFF THE NE FLORIDA COAST WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW