marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 251 am EST Fri Nov 27 2015
.Forecast discussion: major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
00z global models in decent agreement through the fcst period...with only some minor differences noted. Will populate wind grids from 00z GFS through 12z Sat...then 00z ECMWF thereafter.
Frontal boundary E of the area still interacting with high pres to the N and NW causing enhanced NE flow over most of the nt2 waters. Boundary expected to slowly retrograde W towards the offshr waters today and tonight...with conditions persisting at that time. Gradient begins Sat into Sat night as the both the boundary and the ridge to the N and NW weakens. Will continue with the stronger GFS 30m winds in the NE flow thru tonight...then switched to the ECMWF 10m winds for Sat and Sat night due to the GFS still a bit further W with the higher winds than both the ECMWF/UKMET. Did limit winds to 25 kt for Sat and Sat night...as ECMWF a bit high as it is trying to develop a low along the boundary.
To the N...enhanced S to swly flow over the Gulf of Maine today and tonight as a cold front approaches the coast. Latest sfc obs do support using the weaker 10m GFS winds over the cooler waters. Front moves off the coast Sat into Sat night and quickly weakens. Did boost winds by 10 percent over the Gulf of Maine early Sat as the front moves off the coast...but with front weakening quickly as it moves offshore...kept 10m winds later Sat.
Models are coming into more of an agreement for the extended portion of the forecast. Models do show a secondary frontal boundary moving off the NE coast Sun night and moving into the nrn and central nt2 waters Mon before stalling. GFS/ECMWF similar in the position of the front...with the UKMET a bit further S. Models then begin to lift front N as a warm front Tue and Tue night. What complicate matters is that both the GFS and the ECMWF do hint at a weak frontal wave developing along the front E of NC coast Mon night and moving NE along the coast Tue and Tue night. Not ready to buy into the frontal wave just yet and will treat it as just a frontal boundary attm. Continued with ECMWF winds for the grids...although GFS winds are similar.
.Seas...Wna version of wwiii within a ft or two of current obs. Populate wave grids from 00z wna until 12z Sat...then switched to 00z ECMWF wave thereafter.
.Extratropical storm surge guidance...N/A.
.Nt1 New England waters... None.
.Nt2 mid Atlc waters... None.
.Forecaster achorn. Ocean prediction center.