000 AGXX40 KNHC 051911 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 211 PM EST TUE JAN 5 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: BLEND OF GFS/WW3/NWPS GUIDANCE WITH PREVIOUS OFFICIAL FORECAST. MEDIUM CONFIDENCE EXCEPT LOW CONFIDENCE WED NIGHT THROUGH FRI WITH TROUGH/LOW EXPECTED TO PASS E ACROSS THE GULF. AN ASCAT-B PASS FROM 1554Z SHOWED A FRESH TO STRONG BREEZE OVER MUCH OF THE GULF WITHIN 100 NM OF THE MAINLAND FLORIDA COAST AS WELL AS ALONG 26N E OF 87W WITH THE LATEST REINFORCING PUSH OF COLD AIR. ALL OF THE GLOBAL MODELS APPEAR TO BE WEAK WITH THE WINDS HERE. THE 12Z GFS IS THE STRONGEST OF THOSE SOLUTIONS...BUT EVEN IT NEEDS TO BE BUMPED UP A KNOT OR TWO TO MATCH THE OBSERVATIONS. SIGNIFICANT UNCERTAINTY COMES INTO PLAY BY WED NIGHT WHEN THE 00Z ECMWF CARRIES A DEEPER LOW PRES SYSTEM WITH STRONGER SOUTHERLY RETURN FLOW IN THE NW GULF THAN THE 12Z GFS. THE ECMWF CARRIES 30 KT WINDS HERE WHILE THE GFS AND 12Z UKMET ARE WEAKER WITH THE LOW AND THE SOUTHERLY FLOW. BY EARLY FRI...THE ECMWF CARRIES A GALE INTO THE NE GULF WHILE THE 12Z GFS HAS A WEAK LOW NEAR PENSACOLA WITH A TROUGH THAT EXTENDS SE INTO THE NE GULF. THE UKMET IS SIMILAR TO THE GFS...BUT IT IS ABOUT 100 NM SLOWER WITH THE LOW AND TROUGH AND IT CARRIES A FRESH SE BREEZE AHEAD OF THE TROUGH. WITH THE UKMET SIDING MORE WITH THE GFS...LEANED TOWARD ITS SOLUTION WHEN ADJUSTING THE FORECAST...BUT INCREASED THE WINDS AHEAD OF THE TROUGH SLIGHTLY TO MORE CLOSELY RESEMBLE THE UKMET. THE ECMWF APPEARS TO BE AN OUTLIER. THE MODELS GENERALLY AGREE ON CARRYING A WEAK FRONT INTO THE NW GULF EARLY SAT...WITH THE UKMET AND ECMWF ABOUT 75-90 NM FASTER THAN THE 12Z GFS SAT MORNING. NONE OF THESE MODELS INCREASE WINDS BEYOND A FRESH BREEZE UNTIL AFTER A REINFORCING COLD AIR PUSH MOVES IN BEHIND THE FRONT LATER ON SAT. THE UKMET AND ECMWF REMAIN FASTER THAN THE GFS WITH THE LEADING FRONT THROUGH SAT NIGHT...BUT THE UKMET SIDES WITH THE GFS BY MOVING THE REINFORCING FRONT INTO THE W GULF MORE SLOWLY...CARRYING A SMALLER AREA OF FRESH TO STRONG N WINDS IN THE W GULF THAN THE 00Z ECMWF BY SAT NIGHT. CONFIDENCE IS LOW. THE MIDDLE-OF-THE-ROAD UKMET SOLUTION IS PREFERRED FOR SAT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: BLEND OF GFS/WW3/NWPS GUIDANCE WITH PREVIOUS OFFICIAL FORECAST. MEDIUM CONFIDENCE. THE 1556Z ASCAT PASS SHOWED 20-25 KT WINDS ALONG A LINE FROM THE N COAST OF BELIZE TO THE W COAST OF HONDURAS. NONE OF THE GLOBAL MODELS WERE STRONG ENOUGH WITH THE WIND HERE INITIALLY. WINDS IN THIS REGION SHOULD BE DIMINISHING RAPIDLY AS THE TIGHTEST PRESSURE GRADIENT SHIFTS NE TOWARD THE GREAT BAHAMA BANK AS THE LOW PRES SYSTEM OVER CENTRAL CUBA ENCOUNTERS BUILDING HIGH PRESSURE BEHIND A REINFORCING FRONT TONIGHT. WINDS WILL BE BUMPED UP HERE SLIGHTLY FOR THE INITIAL PERIOD AND THEN BLENDED BACK TO THE OFFICIAL FORECAST FOR THIS EVENING. OTHERWISE...HIGH PRES CENTERED ACROSS THE EASTERN/CENTRAL ATLC AND LOW PRES ACROSS NORTHERN COLOMBIA WILL SUPPORT MODERATE TO FRESH TRADES ACROSS MOST OF THE REGION THROUGH FRI EXCEPT THE NW CARIBBEAN...WITH A FRESH TO STRONG BREEZE EXPECTED ALONG THE COAST OF S AMERICA NEAR VENEZUELA AND COLOMBIA MAINLY IN THE OVERNIGHT HOURS. A COLD FRONT EXTENDING FROM 1014 MB LOW PRES OVER CENTRAL CUBA TO CENTRAL HONDURAS WILL STALL TONGIHT AND DISSIPATE WED. THE MODELS ARE IN REASONABLE AGREEMENT ON RATHER BENIGN CONDITIONS WED THROUGH FRI...WITH THE ECMWF NOT PREFERRED IN THE NW GULF WHERE IT CARRIES SLIGHTLY STRONGER RETURN FLOW DUE TO ITS STRONG...OUTLIER SOLUTION WITH A LOW PRESSURE SYSTEM IN THE NE GULF OF MEXICO. SEE THE GULF OF MEXICO SECTION FOR DETAILS. BY LATE SAT...THE GLOBAL MODELS GENERALLY AGREE ON BUILDING MODERATE TO FRESH SE RETURN FLOW OVER THE NW CARIBBEAN AHEAD OF A COLD FRONT MOVING THROUGH THE GULF OF MEXICO. WHILE THE UKMET WAS PREFERRED IN THE GULF FOR SAT...ITS SOLUTION MAY BE WEAK WITH THE TERRAIN ENHANCED FLOW N OF HONDURAS THAT THE GFS GENERALLY HANDLES BETTER. SIDED WITH THE GFS FOR ADJUSTING THE GRIDS. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: BLEND OF GFS/WW3/NWPS GUIDANCE WITH PREVIOUS FORECAST. LOW CONFIDENCE. 1014 MB LOW PRES ANALYZED OVER CENTRAL CUBA NEAR 22N79W EXTENDS A STATIONARY FRONT EASTWARD TO 24N71W AND A COLD FRONT TO 31N60W. A REINFORCING COLD FRONT WAS ANALYZED FROM THE NORTHERN BAHAMAS TO 31N66W...WITH FRESH TO STRONG WINDS SEEN BEHIND THE FRONT IN THE 1458Z ASCAT-A PASS AND MULTIPLE SURFACE OBSERVATIONS. THE SLIGHTLY STRONGER 12Z GFS SOLUTION COMPARES BETTER TO THE OBS THAN THE 00Z ECMWF. THE SURFACE LOW ALONG THE LEAD BOUNDARY IS FORECAST TO STALL JUST N OF CUBA TONIGHT BEFORE BECOMING REINVIGORATED BY AN UPPER TROUGH MAKING ITS WAY FROM THE SW TO THE S CENTRAL GULF OF MEXICO. WHEN THE UPPER TROUGH MEETS UP WITH THE SURFACE LOW WED...THE LOW IS EXPECTED TO BE SHOVED TO THE NE AND DEEPEN. THE MODELS HAVE COME INTO BETTER AGREEMENT ON THIS SCENARIO...BUT THE 00Z ECMWF WAS STILL ON THE SLOW SIDE OF THE GUIDANCE. THIS SEEMS UNLIKELY GIVEN THE SPEED OF THE STEERING FLOW. THE ECMWF HAS BEEN THE OUTLIER HERE. THE GFS APPEARS TO BE A COMPROMISE SOLUTION BETWEEN THE FASTER 12Z UKMET AND THE SLOWER ECMWF WED NIGHT THROUGH THU NIGHT. THE UKMET IS MORE WRAPPED UP THAN THE OTHER TWO MODELS BY THU NIGHT AS IT FORECASTS THE LOW TO APPROACH BERMUDA. THE EC ENS IS FASTER THAN THE ECMWF SOLUTION MOVING THE LOW AWAY FROM BERMUDA...MORE LIKE THE GFS AND GEFS. THE GFS SOLUTION IS PREFERRED OVER THE SW N ATLC. IT CARRIES GALES OVER FORECAST WATERS PRIMARILY N OF THE FRONT FROM 00Z THU THROUGH 00Z FRI. THE OFFICIAL GRIDS WERE ADJUSTED SLIGHTLY TOWARD THE GEFS WHICH SHOWS THE BEST CHANCE OF GALES STARTING 06Z THU. CONFIDENCE IS ALSO LOW IN THE ECMWF SOLUTION FRI NIGHT AS IT CARRIES A LOW PRESSURE SYSTEM FROM THE GULF OF MEXICO OFF THE CENTRAL FLORIDA E COAST. THE ECMWF IS A STRONG OUTLIER WITH THIS SYSTEM. THE GFS CONTINUES TO BE PREFERRED FOR ADJUSTING THE FORECAST INTO THE WEEKEND. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ113...ATLANTIC FROM 27N TO 31N BETWEEN 70W AND 77W... GALE WARNING WED NIGHT INTO THU. .AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W... GALE WARNING THU. $$ *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 SCHAUER. NATIONAL HURRICANE CENTER.