marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 316 am EST Thu Nov 15 2018
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
The current GOES infrared satellite imagery shows an intense low pressure system in the central Atlc this morning with the low center to the E of the Newfoundland. In addition, the imagery also reveals cold cumulus streaming across the Gulf of Maine in the strong cold advection in the wake of the system, although current surface observations indicate the gales previously over nt1 last night have moved E of the offshore waters. An ascat overpass from 00z also indicated gales just E of the offshore waters with winds as high as 45 kt off the coast of Nova Scotia, but the system has moved quickly E since the time of the pass taking the higher winds with it. The 00z GFS/ECMWF winds are initialized fairly well when compared with the data, and the models indicate that the winds will continue decreasing over nt1 today as high pressure builds over nt1.
Further S, observations along the se coast show sustained winds right along the coast to 30 kt overnight with several buoys off the South Carolina coast gusting to as high as 40 kt with a warm front over the far srn waters tightening the pressure gradient between the high building to the N. In addition, ascat from 03z indicated a few gales along the se coast. The latest NCEP surface analysis also shows low pressure along the W coast of Florida, and the 00z models all indicate the low will strengthen while moving NE along the se coast today before moving offshore near the Virginia CAPES late today into tonight while pulling a strong cold front offshore. The GFS is about the strongest with the winds associated with this feature, and indicates widespread gales across the offshore waters with a few smaller areas with storm force winds mainly near the low. The 00z ECMWF/UKMET/Gem are all weaker with the winds and show no more than 40 kt. However, all of the models show a strong shortwave moving offshore tonight which should act to increase the forcing with the associated surface feature. Previous preference was with the intensity of the GFS, and this still makes sense since the upper levels suggest strong development. As a result, confidence with the previous storm and gale headlines is above average, so planning on staying near the previous grids with this system.
On Sat, the 00z models indicate high pressure building over the W Atlc, before a weak front moves across nrn nt1 Sat night. The models then show the high moving slowly across the area into sun, before another weak front moves offshore Mon. The GFS has been an outlier solution with the front on Mon, while the 00z ECMWF has been consistently in somewhat decent agreement with the UKMET. In addition, the wpc medium range guidance is favoring the ECMWF solution, so planning on using the 00z ECMWF from Sat through the end of the forecast period as a result of the better support from the rest of the guidance.
.Seas...Will be making minor adjustments to the previous wave height grids to account for current data, as the previous grids seem reasonable. Will then transition to the 00z ECMWF wam on Sat to match the preferred winds of the 00z ECMWF while making minor adjustments to match up with the adjacent coastal zones.
.Extratropical storm surge guidance...The 00z estofs and etss are both showing a positive surge along the mid Atlc and New England coasts this afternoon into Fri with the strong coastal low expected to develop. The estofs continues to show values greater than 2 ft from the Virginia CAPES to Long Island Sound tonight, and up to 1 ft along the New England coast Fri. The estofs is roughly 50 percent higher than the etss which seems a little underdone. Please continue to closely monitor the latest coastal WFO forecasts over the next few days for more information.
.Nt1 New England waters... .anz800...Gulf of Maine... gale tonight into Friday. .Anz805...Georges Bank west of 68w... gale tonight. Storm Friday. .Anz900...Georges Bank east of 68w... gale tonight. Storm Friday. Gale Friday night. .Anz810...South of New England... gale tonight. Storm Friday. .Anz815...South of Long Island... gale today into Friday.
.Nt2 mid-Atlantic waters... .anz820...Hudson Canyon to Baltimore Canyon... gale today into Friday. .Anz915...Hudson Canyon to the great South Channel... gale today. Storm tonight into Friday. .Anz920...Baltimore Canyon to the great South Channel... gale today. Storm tonight. Gale Friday. .Anz905...The great South Channel to the Hague line... storm tonight into Friday. Gale Friday night. .Anz910...East of the great South Channel and south of 39n... storm tonight. Gale Friday. .Anz825...Inner waters from Baltimore Canyon to Cape Charles Light... gale today into Friday. .Anz828...Inner waters from Cape Charles Light to Currituck Beach Light... gale today into Friday. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... gale today. Storm tonight. Gale 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. .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 Kells. Ocean prediction center.