marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 255 PM EDT sun 20 Apr 2014
.Forecast discussion: major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
Over the short term...tho the 12z mdls cont to differ smwht in their fcst tracks for the sfc low now invof 32n76w they fcst smlr ascd fcst gradients. Overall wl favor the 12z GFS fcst gradients ascd with this low and its 30m bl winds...with sm modifications in deference to the 12z UKMET/ECMWF. Per this solution...with a rel high fcst confidence level...wl confine the gales ascd with this system to the cp hat to cp fear wtrs by Mon morning...then fcst winds bcmg subgale thrut by Mon afternoon. So do not plan on making any major chngs to the prev nt2 fcst rgrdg this system nor elswhr thru the short term.
In the long range...the focus shifts further N as a nrn stream upr trof is fcst by all of the 12z mdls to dig into the NE conus Wed...gain negative tilt as its moves ofshr acrs the nrn wtrs Wed nite...then closes off into a closed upr low Thu/Thu nite that drifts E of the ofshr wtrs. At the sfc...vs its prev respective runs...the 12z GFS remains consistent in fcstg an ascd sfc low to move into the Gulf of Maine Tue nite...then drift E of the nt1 wtrs late Wed into Thu whl slowly intensifying. Tho they differ in how they fcst their sfc lows to track ofshr by Thu morning the 12z Gem/UKMET (the 12z Gem moreso than the 12z ukmet) fcst smlrly strong nnwly gradients vs the 12z GFS to dvlp thrut the nt1 and nrn/cntrl nt2 wtrs. The 12z ECMWF tho fcsts a track very smlr to the 12z GFS. Since the 12z gefs mean provides support...and since its in line with the latest wpc medium range guidance and the 12z ECMWF...wl favor the 12z GFS solution for this system. For Tue/Tue nite wl favor the 12z GFS 10m bl winds and then on Wed thru Thu nite wl favor the 12z GFS 30m bl winds in the cold air advection behind the system. Therefore wl cont to fcst psbl gales to dvlp acrs the nt1 and NE nt2 wtrs Wed nite into Thu night.
Seas...an earlier 1041z altimeter pass showed seas up to 19 ft in the Gulf Stream just off cp Hatteras which is sprtd by the 18z obs FM buoy 41025 rprtg 18 ft. The 12z wavewatch iii has initialized these seas rsnbly well and overall wl favor its fcst seas over the short term but wl likely adjust them upward by 10-15 percent invof the Gulf Stream. Then in the long range wl lkly use a 50/50 blend of the 12z wavewatch iii and 12z ECMWF wam as was done prevly.
Extratropical storm surge guidance...in the nnely gradient off the se coast the 12z estofs fcsts a slightly mr sig postive surge than the 12z etss thru Mon which look reasonable. Otherwise the two mdls are smlr.
.Warnings...Preliminary. Any changes will be coordinated through AWIPS 12 planet chat or by telephone:
.Nt1 New England waters... .anz800...Gulf of Maine... gale possible Wed night into Thu. .Anz900...Georges Bank west of 68w... gale possible Wed night into Thu night.
.Nt2 mid Atlc waters... .anz920...Baltimore Canyon to the great South Channel... gale today. .Anz905...The great South Channel to the Hague line... gale possible Wed night into Thu night. .Anz910...East of the great South Channel and south of 39n... gale possible Thu into Thu night. .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 into tonight. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... gale today into Mon. .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. .Anz835...Inner waters from Cape Fear to 31n... gale today into tonight.
.Forecaster vukits. Ocean prediction center.