marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 335 PM EDT Mon may 20 2019
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
There was an ascat pass at about 15z with a swath across most areas of the inner Atlc offshore into the southern New England waters. Strongest winds were SW to 20 kt over the inner N mid Atlc offshore waters. Unfortunately did not get a pass over the eastern areas of the New England waters where model guidance is strongest with winds to about 25 kt. There was another pass just along and E of the outer offshore waters at around 1330z which went across the area where NHC has low pressure with potential to be subtropical or tropical cyclone of 70 percent within the next several days. The highest winds were to 30 kt over the N quadrant. There is another area of interest is near 26n72w where there has been persistent convection, but model guidance does not show any surface development.
The warm front has passed NE of the Gulf of ME early this afternoon with a inland cold front approaching from the W. The cold front should be near the N and central areas of the coastline by early tonight. The cold front moves E and se later tonight into Tue, and then crosses into the central and southern areas of the mid Atlc Tue and Tue night, then passing S of the area Wed. There is no change from the models with regards to the track of the low pressure and the potential subtropical or tropical cyclone where it would track to the N and NE tonight and Tue while staying E of the outer mid Atlc offshore waters. As was the case last night will favor a 50/50 blend of the previous grids with the 12z GFS 10/30m winds through about 12z Wed with instability increasing from Tue into early Wed. The greatest instability should be across the northern areas and to lesser degree over the central areas. High pressure builds in from the W Tue night into Wed, then settles across the area late Wed and Wed night. By late Thu through Fri night Gem/UKMET/GFS/ECMWF models are in fairly decent agreement with developing low pressure that moves se into the inner New England and northern mid Atlc offshore waters Thu night, and then S along the outer mid Atlc waters with gale force winds developing Fri and Fri night. Models similar with a weak high pressure ridge building in from the W and NW over the offshore waters Sat and Sat night.
.Seas...The 12z wavewatch and ECMWF wam are in decent agreement through most of the forecast period. The exception is late on Fri into Sat over the northern areas of the mid Atlc where ECMWF wam is noticeably higher with seas. Plan to continue as was done last night to use a 50/50 blend of the wwiii and ECMWF wam through the forecast period.
.Nt1 New England waters... .anz805...Georges Bank west of 68w... gale possible Friday. .Anz900...Georges Bank east of 68w... gale Tuesday night. Gale possible Friday. .Anz810...South of New England... gale possible Friday.
.Nt2 mid-Atlantic waters... .anz915...Hudson Canyon to the great South Channel... gale tonight. Gale possible Friday into Friday night. .Anz920...Baltimore Canyon to the great South Channel... gale possible Friday night. .Anz905...The great South Channel to the Hague line... gale Tuesday night. Gale possible Friday into Friday night. .Anz910...East of the great South Channel and south of 39n... gale possible Friday night.
.Forecaster Rowland. Ocean prediction center.