marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 255 PM EDT Sat 19 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...the new 12z mdls are in rsnbly good agrmt that the closed upr low now nr the Georgia-Florida border wl drift ofshr tonite then track slowly ENE acrs the srn nt2 wtrs sun into early Mon while wkng into an open wave. At the sfc the 12z mdls also gnrly agree that an ascd nrly vertically stacked sfc low wl follow and smlr fcst track ENE acrs the srn nt2 wtrs tonite into early Mon. Though the mlds differ smwht in their specific fcst tracks...as high pres builds into the nt1 wtrs late sun/sun nite they all fcst a smlrly strong enely gradient acrs the srn/cntrl nt2 wtrs N of the low and its ascd fronts. For this gradient...bearing in mind that it wl mainly running against the Gulf Stream...plan on using the smwhat stronger 12z GFS 30 M bl winds with sm minor modifications per the 12z UKMET/ECMWF. Therefore do not plan on making any major timing and/or areal coverage chngs to the prevly fcstd gale wrngs (wl cont to fcst the gales (max winds up to 35 or 40 kt) to end sun nite). So overall no major short term chngs are planned for the next ofshr fcst package.
In the long range...the 12z mdls grnly agree that the most sig weather feature wl be a nrn stream dvlpg sfc low passing acrs the nt1 wtrs Tue nite into Wed while pulling a moderately strong cold front ofshr. Tho the 12z mdls again differ in their exact fcst tracks of this system...in the wake of the system and its fropa they all fcst a mod strong nnwly gradient to dvlp Wed into Thu. By late Thu/Thu nite...by fcstg less progressive solutions...the 12z GFS/ECMWF are slower than the 12z Gem/UKMET in fcstg the any ascd nnwly gales to end. Since the 12z gefs mean supports the 12z GFS and to be mr in line with the latest wpc medium range guidance...plan on using a blended 12z GFS/ECMWF solution for Thu. Per a blend of the 2consensus of the 12z mdls wl fcst low confidence gales to dvlp acrs the ern nt1 and NE nt2 wtrs Wed nite into Thu.So since the 12z gefs mean supports the 12z GFS and to be mr in line with the latest wpc medium range guidance...plan on using a blended 12z GFS/ECMWF solution for Thu.
Seas...the 12z wavewatch iii has initialized rsnbly well. Tho to account for the counterflow against the Gulf Stream in the short term...as was done prevly...wl lkly blend its fcst seas acrs the srn/cntrl nt2 wtrs with the higher seas fcst by the 12z ECMWF wam mdl. Since a blended 12z GFS/ECMWF solution wl then be used in the long range wl lkly cont to use a 50/50 blend of the 12z wavewatch iii and 12z ECMWF wam.
Extratropical storm surge guidance...in the nely gradient along the se coast through the short term...the 12z estofs fcsts a slightly higher positive surge than the 12z etss...but not sigly so.
.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 Thu. .Anz900...Georges Bank west of 68w... gale possible Thu.
.Nt2 mid Atlc waters... .anz920...Baltimore Canyon to the great South Channel... gale tonight into sun. .Anz905...The great South Channel to the Hague line... gale possible Thu into Thu night. .Anz910...East of the great South Channel and south of 39n... gale possible Thu night. .Anz828...Inner waters from Cape Charles Light to Currituck Beach Light... gale sun into Sun night. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... gale tonight into Sun night. .Anz830...Inner waters from Currituck Beach Light to Cape Hatteras... gale sun into Sun night. .Anz833...Inner waters from Cape Hatteras to Cape Fear... gale today into Sun night. .Anz930...Outer waters from Hatteras Canyon to Cape Fear... gale tonight into Sun night. .Anz835...Inner waters from Cape Fear to 31n... gale today into Sun night. .Anz935...Outer waters from Cape Fear to 31n... gale Sun night.
.Forecaster vukits. Ocean prediction center.