000 AGXX40 KNHC 181821 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 121 PM EST TUE FEB 18 2014 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: GFS/OFFICIAL BLEND WITH NWPS OUTPUT FOR SEAS HEIGHTS. A SURFACE RIDGE EXTENDS ACROSS THE NORTHERN GULF THIS MORNING FROM A 1024 MB HIGH CENTERED NEAR CAPE CANAVERAL WESTWARD ALONG ROUGHLY 29N TO EASTERN TEXAS. BUOY OBSERVATIONS SHOW LIGHT TO MODERATE SE FLOW SOUTH OF THE RIDGE AXIS WITH SEAS GENERALLY 2 TO 4 FT. DENSE SEA FOG LINGERS ALONG THE COAST FROM CENTRAL LOUISIANA TO SOUTH TEXAS. LOCAL FORECASTS FROM THOSE REGIONS SHOW THIS LIFTING AROUND NOW...BUT WITH AREAS OF FOG REMAINING THROUGH TONIGHT. OTHERWISE THROUGH EARLY THU...THE MAIN ISSUE WILL BE INCREASING SE TO S RETURN FLOW OVER THE NW GULF WATERS...BETWEEN THE RIDGE AND DEEP LAYER TROUGH DIGGING THROUGH THE CENTRAL PLAINS. WHILE THERE REMAIN DIFFERENCES IN MODEL OUTPUT REGARDING THE TIMING AND INTENSITY OF THE APPROACHING MID/UPPER TROUGH AND ITS ATTENDANT COLD FRONT...THE IMPACT ON SENSIBLE WEATHER IN THE GULF IS ABOUT THE SAME. THE CONSENSUS SHOWS THE FRONT REACHING THE TEXAS COAST THU NIGHT WITH STRONG WINDS BEHIND THE FRONT FUNNELING ALONG TAMAULIPAS AND VERACRUZ COASTS THROUGH FRI. THE GFS ALONG WITH THE SREF HANDLE THIS FUNNELING BETTER THAN THE ECMWF AND SO ARE THE BASIS FOR THE GRIDDED FORECASTS. AREAS OF SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE FRONT OVER THE NW AND N CENTRAL GULF LATE THU INTO FRI. DYNAMIC AND ENSEMBLE MODELS SHOW THE UPPER SUPPORT FOR THE FRONT LIFTING THROUGH THE GREAT LAKES TO VARYING DEGREES BY EARLY FRI...ALLOWING THE FRONT TO STALL FROM THE FLORIDA BIG BEND AREA IN THE NE GULF TO THE FAR SW GULF BY LATE FRI. HIGH PRES BUILDING BEHIND THE FRONT THROUGH THE CAROLINAS WILL ALLOW WINDS TO DIMINISH RAPIDLY. THE WEAK FRONTAL BOUNDARY IS EXPECTED TO LIFT INTO THE NORTHERN GULF THIS WEEKEND WITH GENERALLY ZONAL FLOW ALOFT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 65W... MODEL PREFERENCE: GFS/OFFICIAL BLEND WITH NWPS FOR SEA HEIGHTS. 1024 MB HIGH PRES CENTERED OVER EAST CENTRAL FLORIDA IS SUPPORTING STRONG TO NEAR GALE FORCE TRADE WINDS OVER MAINLY THE S CENTRAL CARIBBEAN. AN ASCAT PASS FROM 14 UTC SHOWED A BROAD AREA OF WINDS TO 30 KT OFF THE COAST OF COLOMBIA FROM OFF BARRANQUILLA TO CARTAGENA. THIS FLOW HAS PROBABLY RELAXED TO 20 TO 25 KT BY NOW BUT WILL LIKELY SURGE AGAIN TONIGHT TO NEAR GALE CONDITIONS AND GAIN THU NIGHT INTO FRI MORNING. GIVEN THE CONTINUOUS PULSING OF OVERNIGHT WINDS TO NEAR GALE...SEAS OFF THE PART OF THE COLOMBIAN COAST WILL REACH 13 FT THROUGH LATE THU. THE RIDGE N OF THE AREA WILL BUILD EASTWARD THROUGH THU AHEAD OF A DEEP LAYER TROUGH MOVING ACROSS THE SOUTHERN STATES...MAINTAINING FRESH TO STRONG TRADES OVER MOST OF THE CENTRAL CARIBBEAN. THESE TRADES WILL DIMINISH THIS WEEKEND AS THE RIDGE SHIFTS FARTHER EAST AHEAD OF A COLD FRONT MOVING INTO THE GULF...ALTHOUGH STRONG TRADES WILL PERSIST OFF COLOMBIA. NO MAJOR MODEL DIFFERENCES. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GFS BLEND WITH OFFICIAL. MWW3 FOR SEAS. A WEAKENING STATIONARY FRONT EXTENDS FROM 24N65W TO THE WINDWARD PASSAGE. AN ASCAT PASS FROM 15 UTC THIS MORNING ALONG WITH A COUPLE OF SHIP OBSERVATIONS INDICATED 15 TO 20 KT NE WINDS WITHIN 90 NM N OF THIS BOUNDARY SOUTH OF 25N THROUGH THE SOUTHERN BAHAMAS. OTHER BUOY AND SHIP OBSERVATIONS FROM WITHIN THIS SWATH HOWEVER INDICATE THESE WINDS ARE ALREADY DIMINISHING. WHILE THE DIFFERENCE IN WIND SPEED DOES NOT MEET THE STRICT CRITERIA FOR A SHEAR LINE...THERE IS ENOUGH SHEARING TO SUPPORT SMALL VORTICIES AND RELATED SHOWERS ALONG THIS LINE INTO THE TURKS AND CAICOS AND GREAT INAGUA ISLAND. INTERPOLATING BUOY AND ALTIMETER DATA FARTHER TO THE NORTHEAST...IT IS PLAUSIBLE THAT SIGNIFICANT WAVE HEIGHTS ARE 8 FT OR GREATER EAST OF 70W DUE IN LARGE PART TO LINGERING NE TO E SWELL. THE MAIN WEATHER FEATURE THROUGH THE REMAINDER OF THE WEEK WILL BE RIDGING ALONG 28N/29N...MAINTAINING GENERALLY MODERATE E TO S FLOW NORTH OF 22N...AND FRESH TRADES SOUTH 22N. NO SIGNIFICANT MODEL DIFFERENCES REMAIN. WAVE GUIDANCE SUGGESTS THE SWELL WILL DECAY BELOW 8 FT FOR THIS REGION EXCEPT FOR THE WATERS NE OF THE LEEWARD ISLANDS WHERE EASTERLY TRADES EAST OF THE AREA WILL ALLOW FRESH SWELL TO PROPAGATE INTO THE AREA THROUGH THE WEEKEND. THE RIDGE WILL SHIFT EAST THROUGH THU...AHEAD OF A DEEP LAYER TROUGH MOVING ACROSS THE SOUTHEASTERN UNITED STATES. FRESH SE TO S RETURN FLOW CAN BE EXPECTED OFF THE NE FLORIDA COAST N OF THE BAHAMAS THU NIGHT. THE FRONT WILL EMERGE OFF THE NE FLORIDA COAST BY FRI NIGHT...BUT THE CONSENSUS OF THE MODELS SHOWS THE UPPER SUPPORT FOR THE FRONT LIFTING AWAY FROM THE REGION AND ALLOWING IT TO STALL INTO SAT. A REINFORCING SHORT WAVE TROUGH MOVING ACROSS THE NORTHEASTERN STATES BY SUNDAY WILL ALLOW THE FRONT TO MOVE EASTWARD OVER THE WATERS NORTH OF 28N THROUGH LATE SUNDAY. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER CHRISTENSEN. NATIONAL HURRICANE CENTER.