marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 313 PM EST sun Feb 25 2018
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
Current conditions...the 12z NCEP surface analysis shows a warm front extending roughly W to E across the northern nt2 waters, with high pressure ridges over the offshore waters N and S of the front. Latest available ascat and ascat hi-res passes from a few hours show 20 to 30 kt winds in E flow over zones 815 and 810 in the southern nt1 waters, with 20 to 25 kt winds in SW flow over the central nt2 waters.
Models/forecast...the 12z medium range models are in good overall agreement across the offshore waters for tonight through Wed night, except the GFS is faster with a northern stream low moving se into the nt1 region late Wed and Wed night. The models differ somewhat regarding the timing and strength of the developing low for the late Thu through Fri night timeframe, with the 12z ECMWF looking like a good median solution except it is about six hours faster than the other medium range models. The 12z GFS 10m/30m solution with the stability smart tool will be used for the wind grids for tonight, then will go with the representative 12z ECMWF for Mon through the rest of the forecast period, except the ECMWF will be time shifted six hours slower for Thu through Fri night in deference to the Gem/GFS/UKMET which are slower. Confidence in the gale warnings for the Gulf of Maine and Georges Bank for tonight is average.
Seas...the 12z ECMWF wam and 12z wavewatch both initialized within one or two feet of recent observations over the offshore waters, although the wavewatch is slightly lower with the seas in the central and southern nt2 waters. The models are in good agreement through Wed night, although larger differences develop over the offshore waters starting on Thu, so will go with a 50/50 blend of the 12z ECMWF wam and wavewatch to smooth out the model differences.
Extratropical storm surge guidance...the models indicate E to se flow in the 20 to 30 kt range ahead of a warm front over the nt1 waters tonight. Estofs indicates a positive surge in the 1.0 to 1.5 ft range along the New Jersey and New England coasts, with up to 2.0 ft in Long Island Sound. With most of the models showing 30 to 35 kt winds developing off the mid Atlantic coast around late Thu and Thu night, estofs shows a positive surge in the 1.5 to 2.0 ft range along the New Jersey and Long Island coasts. For both surges, the etss indicates values that are less than half those of estofs, and looks underdone.
.Nt1 New England waters... .anz800...Gulf of Maine... gale possible Friday into Friday night. .Anz805...Georges Bank west of 68w... gale today. Gale possible Friday into Friday night. .Anz900...Georges Bank east of 68w... gale tonight. Gale possible Friday into Friday night. .Anz810...South of New England... gale today. Gale possible Friday night. .Anz815...South of Long Island... gale possible Friday into Friday night.
.Nt2 mid-Atlantic waters... .anz820...Hudson Canyon to Baltimore Canyon... gale possible Friday into Friday night. .Anz915...Hudson Canyon to the great South Channel... gale possible Thursday night. Gale possible Friday night. .Anz920...Baltimore Canyon to the great South Channel... gale possible Thursday night into Friday night. .Anz905...The great South Channel to the Hague line... gale tonight. Gale possible Friday. .Anz910...East of the great South Channel and south of 39n... gale possible Thursday night into Friday night. .Anz825...Inner waters from Baltimore Canyon to Cape Charles Light... gale possible Friday into Friday night. .Anz828...Inner waters from Cape Charles Light to Currituck Beach Light... gale possible Thursday night into Friday night. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... gale possible Thursday into Friday night. .Anz830...Inner waters from Currituck Beach Light to Cape Hatteras... gale possible Thursday into Friday night. .Anz833...Inner waters from Cape Hatteras to Cape Fear... gale possible Thursday night into Friday night. .Anz930...Outer waters from Hatteras Canyon to Cape Fear... gale possible Thursday into Friday night. .Anz835...Inner waters from Cape Fear to 31n... gale possible Thursday night into Friday. .Anz935...Outer waters from Cape Fear to 31n... gale possible Thursday night into Friday night.
.Forecaster Scovil/Scovil. Ocean prediction center.