000 AGXX40 KNHC 191958 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 358 PM EDT MON SEP 19 2016 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. WEAK LLVL TROUGH PERSISTS ACROSS THE N CENTRAL GULF EXTENDING SW TO NE...CARVED OUT BY PERSISTENT MID LEVEL TROUGH OF PAST FEW DAYS. CONVECTION CONTINUES TO PULSE MAINLY E AND SE OF THE TROUGHS AND EXPECTED TO PREVAIL THROUGH TONIGHT BEFORE SINKING SSE AND WEAKENING. WEAK ANTICYCLONES ARE ANALYZED AT THE SFC ON EITHER SIDE OF THE SFC TROUGH AND YIELDING GENTLE TO LIGHT WINDS AND MILD SEAS ACROSS THE BASIN. AS THE TROUGH DISSIPATES A WEAK RIDGE WILL ESTABLISH ACROSS THE N GULF THROUGH MOST OF THE WEEK. A WEAK THERMAL TROUGH WILL DEVELOP OVER THE YUCATAN PENINSULA DURING THE LATE AFTERNOONS...AND CONTINUE INTO THE EARLY EVENINGS. EXPECT GENTLE TO MODERATE NE-E WINDS TO DEVELOP EACH DAY ALONG THE N AND NW COASTS OF THE WESTERN YUCATAN PENINSULA BEGINNING IN THE LATE AFTERNOONS...AND ENDING BEFORE MIDNIGHT EACH NIGHT AS THE RESULTANT INVERTED TROUGH MOVES W ACROSS THE SW GULF ACCOMPANIED BY 2-3 FT SEAS. ASSOCIATED CNVTN TO SHIFT W OFF THE YUCATAN WITH TROUGH EACH EVENING. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. ATLC RIDGE IS WELL N OF 35N AND BLOCKED FROM BUILDING INTO THE REGION DEEP LAYERED TROUGHINGFROM NEAR BERMUDA SW TO CENTRAL BAHAMAS...ALTHOUGH RIDGE IS NOSING INTO NEAR THE NE CARIB BETWEEN THE APPROACHING KARL AND THIS TROUGH. LIGHT TO MODERATE TRADES PERSIST ACROSS THE BASIN WITH SEAS GENERALLY 5 FT OR LESS...EXCEPT FOR STRONG NE WINDS ACROSS S CENTRAL PORTIONS AND ALONG THE NW COAST OF COLOMBIA...WHERE SEAS TONIGHT HAVE BUILT TO AROUND 8 FT. A TROPICAL WAVE ALONG 66-67W IS INTERACTING WITH UPPER LOW SHIFTING SLOWLY WWD ALONG 68-69W AND WILL PRODUCE ACTIVE WEATHER NEXT 24 HOURS. WAVE TO MOVE RATHER SLOWLY WWD NEXT FEW DAYS ACROSS THE CENTRAL CARIB. CONDITIONS ASSOCIATED WITH TROPICAL CYCLONE KARL WILL JUST BRUSH THE FAR NE PORTION OF TROPICAL N ATLC WATERS...GENERALLY N OF 18N EARLY TUE THROUGH LATE WED BEFORE SHIFTING NW OF THE AREA. ASSOCIATED ENE SWELL EXPECTED TO REACH THE TROPICAL ATLC WATERS BY AFTERNOON AND THE LESSER ANTILLES BY TONIGHT. THUS FAR THERE HAS BEEN NO SIGNIFICANT WIND ACROSS THE S SEMICIRCLE OF KARL AND ONCE IT BEGINS THE NW MOTION LITTLE SWELL ENERGY EXPECTED TO PROPAGATE SW ACROSS THE NE CARIB. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. REMNANTS OF JULIA NEARLY STATIONARY NEAR 33N78.5W AT 09 UTC AND EXPECTED TO DRIFT N AND AWAY FROM THE AREA BY EVENING. IT IS TOO CLOSE TO THE COAST AND WINDS HAVE WEAKENED FOR ANY SWELL GENERATION FOR THE NW WATERS. A DEEP LAYERED LOW TO MIDDLE LEVEL TROUGH EXTENDS FROM NEAR BERMUDA TO THE CENTRAL BAHAMAS AND BLOCKS THE ATLC RIDGE. THIS WILL DRIFT NW OVER THE NEXT 48 HRS AND BECOME DIFFUSE BUT CONTINUE TO ACT AS CONVERGENCE ZONE FOR AREAS OF CONVECTION. MEANWHILE...KARL IS APPROACHING AND HAD WEAKENED IN THE PAST 24 HOURS TO BARELY A T.S. WITH MAX WINDS TO 20 KT IN S SEMICIRCLE. MIDDLE LEVEL LOW TO THE N AND NW PAST SEVERAL DAYS IT FINALLY LOSING SOME OF ITS INFLUENCE AND CONVECTION HAS BEGUN TO DEVELOP OVER THE CENTER AGAIN OVERNIGHT...SO THE LONG FORECAST GRADUAL INTENSIFICATION PROCESS MAY BEGIN NEXT 24 HOURS. A CONTINUES W-NW MOTION THROUGH TUE IS EXPECTED THEN MORE NW THEN N THROUGH THE WEEK TOWARDS BERMUDA. KARL EXPECTED TO MOVE ACROSS THE 2 FAR NE ZONES THU THROUGH EARLY SAT BEFORE EXITING TO THE N. OTHERWISE... MAIN IMPACTS TO LOCAL WATERS WILL BE ELY SWELL GENERATED DURING NEXT FEW DAYS. NWPS IS TYPICALLY WAY TOO HOT AND HAVE ONLY USED IT FOR CORE OF STORM...OTHERWISE GLOBAL WAVE MODELS HAVE A DECENT FEEL FOR BACKGROUND SWELL EXPECTED TO BE GENERATED BY OUTER WIND FIELD OF KARL...ALTHOUGH A BIT LOW. CURRENT NHC FORECAST FOR KARL FALLS ALMOST DIRECTLY BETWEEN GFS AND ECMWF AND UKMET TO THE RIGHT. GFS IS WEAKEST OF MODELS THROUGH THU AND THUS EXPECTED WW3 TO BE LOW WITH ELY SWELL. .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ127...ATLANTIC FROM 19N TO 22N BETWEEN 55W AND 65W... TROPICAL STORM WARNING TUE INTO WED. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER MN. NATIONAL HURRICANE CENTER.