marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 407 am EDT Thu may 25 2017
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
00z global models in good agreement into Saturday night, then diverge thereafter. Will lean towards 00z GFS through most of the forecast period, except will switch towards the 00z UKMET between 00z Sunday and 12z Monday.
Cold front approaching the southeast coast. Latest surface observations showing sustained winds in the 25 to 30 kt range with some gusts to gale force. Models continue to show potential of gales in the southerly flow ahead of the front over the nt2 waters today into tonight, with the highest winds near the Gulf Stream where instability is the greatest. Will continue to populate the first sigma winds in the unstable areas and will limit winds to 40 kt for the most part. Will have a small area of 40 to 45 kt winds over northern nt2 waters this morning as both the GFS and the ECMWF trying to develop a potential triple point low in the region. Gales expected to continue mostly in and near the Gulf Stream in the southwesterly winds behind the front tonight into Fri before low and conditions move east of the forecast area.
To the north, warm front moves north across the nt1 waters today and tonight. Global models seem to be a bit stronger with the easterly winds to the north of the front as it pinches up near land. Latest GFS does indicate 10m winds to 35 kt for a brief period in the Gulf of Maine later today into tonight. With both the ECMWF and the UKMET showing 30 kt in the area, will go ahead and input gales into the forecast for later today in the Gulf of Maine.
Models continue to be in good agreement until around 00z Sunday where models diverge in solutions in regards to a warm front off the mid Atlantic coast and potential lows developing along the front. GFS seems to be the weakest of the models while the ECMWF seems to be the strongest, which is very different than in its previous run. UKMET seems to be a compromise so will lean towards that solution for Saturday night through Sunday night. Forecast confidence for this portion of the forecast is low due to model differences. For Monday and Monday night, will lean more towards the 00z GFS again as the UKMET wants a secondary low to move across the nt1 waters during this time period.
.Seas...Wna within a foot or two of current observations. Will lean towards 00z wna guidance for the wave grids through most of the period. Will use a 50/50 blend of the wna and the ecmwfwave for 00z Sunday through 12z Monday to try and get higher seas in the north quadrant of the low along the frontal boundary over the central nt2 waters as GFS has ligher winds and wna has lighter seas.
.Extratropical storm surge guidance...N/A.
.Nt1 New England waters... .anz800...Gulf of Maine... gale today.
.Nt2 mid-Atlantic waters... .anz920...Baltimore Canyon to the great South Channel... gale today into Friday. .Anz910...East of the great South Channel and south of 39n... gale tonight into Friday. .Anz825...Inner waters from Baltimore Canyon to Cape Charles Light... gale today. .Anz828...Inner waters from Cape Charles Light to Currituck Beach Light... gale today. Gale tonight. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... gale today into Friday. .Anz830...Inner waters from Currituck Beach Light to Cape Hatteras... gale today into tonight. .Anz833...Inner waters from Cape Hatteras to Cape Fear... gale today into tonight. .Anz930...Outer waters from Hatteras Canyon to Cape Fear... gale today into tonight. .Anz835...Inner waters from Cape Fear to 31n... gale today. .Anz935...Outer waters from Cape Fear to 31n... gale today.
.Forecaster achorn. Ocean prediction center.