000 AGXX40 KNHC 201029 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 629 AM EDT TUE SEP 20 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 SEVERAL DAYS. STLT IMAGERY AND OVERNIGHT ASCAT PASS SUGGEST SFC LOW HAS FORMED NEAR 27N88W AND MAY BE PRODUCING LOCALIZED WINDS AROUND 15 KT. 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 AGAIN 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 REMAINS N OF 35N AND BLOCKED FROM BUILDING INTO THE REGION DEEP LAYERED TROUGHING FROM JUST SE OF BERMUDA SW TO CENTRAL BAHAMAS. LIGHT TO MODERATE TRADES PERSIST ACROSS THE BASIN WITH SEAS GENERALLY 5 FT OR LESS...EXCEPT FOR STRONG NE TO E WINDS TO AROUND 20 KT ACROSS S CENTRAL PORTIONS AND ALONG THE NW COAST OF COLOMBIA...WHERE SEAS TONIGHT DID NOT BUILD TO 8 FT. A WEAK TROPICAL WAVE ALONG 69-70W CONTINUES TO INTERACT WITH UPPER LOW SHIFTING SLOWLY WWD ACROSS WRN HISPANIOLA AND E CUBA AND WILL CONTINUE TO PRODUCE ACTIVE WEATHER ACROSS N CENTRAL PORTIONS NEXT 24 HOURS. WAVE TO CONTINUE TO MOVE RATHER SLOWLY WWD NEXT FEW DAYS ACROSS THE CENTRAL CARIB. CONDITIONS ASSOCIATED WITH TROPICAL CYCLONE KARL WILL MOVE ACROSS FAR NE PORTION OF TROPICAL N ATLC WATERS...GENERALLY N OF 18N THIS AFTERNOON THROUGH TONIGHT BEFORE VEERING MORE NW AND LIFTING OUT OF THE AREA. ASSOCIATED ENE SWELL HAS ALREADY BEGUN TO MOVE INTO THE AREA DURING PAST 24 HOURS AND BEGINNING TO BLEED THROUGH THE CARIB PASSAGES OF THE LESSER ANTILLES. KARL CONTINUES TO STRUGGLE AND THERE HAS BEEN NO SIGNIFICANT WIND ACROSS THE S SEMICIRCLE OF KARL. ONCE IT BEGINS THE NW MOTION LITTLE SWELL ENERGY IS EXPECTED TO PROPAGATE SW ACROSS THE NE CARIB. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. A DEEP LAYERED LOW TO MIDDLE LEVEL TROUGH EXTENDS FROM JUST SE OF 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. TROUGHING TRAILING OUT OF SE SIDE OF REMNANTS OF JULIA PERSISTS ACROSS THE FAR NW WATERS AND ACTING AND CONVERGENCE BOUNDARY FOR ACTIVE CONVECTION AHEAD OF APPROACHING UPPER TROUGH. MEANWHILE...KARL CONTINUES TO STRUGGLE AND HAS BEEN PULSING WITH CONVECTION PAST 24 HOURS. RECENT MICROWAVE DATE AND STLT IMAGERY SUGGESTS A MORE WLY MOTION AND PARTIALLY EXPOSED CENTER OVERNIGHT. THUS LITTLE STRONG WIND STILL NOT LIKELY ACROSS S SIDE OF KARL. KARL WILL MOVE ACROSS THE FAR NE PORTIONS OF THE TROPICAL N ATLC WATERS THIS AFTERNOON THROUGH TONIGHT AND THEN GRADUALLY VEER MORE NW WED AND THU AND IS EXPECTED TO GRADUALLY INTENSIFY. CURRENT NHC FORECAST MOVES KARL ACROSS THE FAR NE WATERS THU AFTERNOON THROUGH EARLY SAT AS IT TURN N AND REACHES HURRICANE STRENGTH. THIS TO IMPACT ONLY E PORTIONS OF AMZ121 AND 115. A WEAK PRES PATTERN TO THE W AND SW OF KARL WILL PRODUCE LIGHT TO MODERATE WINDS AND SMOOTH SEAS...DOMINATED BY SWELL FROM KARL. E STORM SWELL EXPECTED TO CROSS 70W TONIGHT AND REACH 80W AND FLORIDA COASTS EARLY THU NIGHT...LIKELY PEAKING SAT THROUGH EARLY SUN FLORIDA COASTAL WATERS. .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 TODAY INTO TONIGHT. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER STRIPLING. NATIONAL HURRICANE CENTER.