marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 906 am EST Mon Dec 22 2014
.Forecast discussion: major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
Warm front over the far sthrn waters is slowly moving N. Isoltd cnvctn conts over the waters S of Cape Fear near and just S of the front. At 12z a 1014 mb low was loc just se of Cape Romain and is slowly mvng NE. Highest winds this mrng are ESE 15 to 25 kt just ahead of the warm front btwn Cape Romain and httrs cnyn. N of balt cnyn...winds AR lgt NE. Highest seas are 8 ft...off the coast of NC where the wave watch is 1 to 3 ft underdone. Will adjust the grids for the updated fcst for this but otw...little change. Trimmed back the sthrly winds ahd of the front Wed night...which delayed on onset of srly gales until Thu 12z.
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The Sat img show more convctn ovr the srn wtrs asctd with a wrm frnt and lightng strikes concentrated to the far S-wrn portion. The radar has tstms cells ovr the far S-wrn wtrs too. At 06z low pres 1011 mb ovr edge of the srn wtrs has a wrm frnt strtchng E acrs the far srn portions. Inland hgh pres ovr Quebec xtnds a ridge SW thru NY and the mid Atlc states into the S-ern states. The pres grdnt is quite slack and the Max obs winds are 25 kt ovr the srn wtrs. The latst rapid-scat pass ovr the region at 0140z had 30 kt winds ovr the srn wtrs along the wrm frnt.
There are a few spots of locally generated enrgy in a fairly wk ridge aloft. Upplvl difflence ovr Canada will allow more energy to spill back into the trof to the W and that energy will combine with the one streaming frm the W and dvlp a fairly deep upprlvrl trof that wil result into a clsd low that will push a strng frnt into the region in the xtndd prd. Hence the curr wrngs in the frct in the xtndd prd wil be retained.
The glbl mdls hv intialized well and they are in decent agrmnt in the short term. There are some mnr diffs in the xtndd prd which are mainly in timing of the low pres that will be moving NE and pulling a cld frnt acrs the region and the strength of the winds ovr the region. CMC ecmwfhr and GFS hv hgr gale force winds compared to UKMET and so wil stay with GFS 30 M winds and will retain all the wrngs. In the short term the hgh pres ovr Canada wil mv se while the low pres ovr the srn wtrs will move NE and lift the wrm frnt acrs the srn wtrs into the nrn wtrs. In the xtndd prd low pres will pass inland in the NE dir as it pulls a strng frnt acrs the wtrs. The pres grdnt wil become tight and gale force winds will be genrtaed. The gale force winds will subside to below gale force as a ridge moves in just before end of fcst prd.
.Seas...The seas range btwn 2 and 6 ft ovr most of the region xcpt the srn wtrs where they peak at 8 ft. The nww3 multi grid WV mdl fits fairly well with the seas pattern and so is the ecmwfwave and both WV mdls are in agrmnt. The seas wil remain below 8 ft in the short term but will build to 17 ft peaks ovr the nrn wtrs in the gale force areas.
.Extratropical storm surge guidance...N/A.
.Nt1 New England waters... .anz800...Gulf of Maine... gale possible Thu into Fri. .Anz805...Georges Bank west of 68w... gale possible Thu into Fri. .Anz900...Georges Bank east of 68w... gale possible Thu into Fri. .Anz810...South of New England... gale possible Thu into Thu night. .Anz815...South of Long Island... gale possible Thu into Thu night.
.Nt2 mid Atlc waters... .anz820...Hudson Canyon to Baltimore Canyon... gale possible Thu into Thu night. .Anz915...Hudson Canyon to the great South Channel... gale possible Thu into Thu night. .Anz920...Baltimore Canyon to the great South Channel... gale possible Thu into Thu night. .Anz905...The great South Channel to the Hague line... gale possible Thu into Fri. .Anz910...East of the great South Channel and south of 39n... gale possible Thu into Thu night. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... gale possible Thu. .Anz830...Inner waters from Currituck Beach Light to Cape Hatteras... gale possible Thu. .Anz930...Outer waters from Hatteras Canyon to Cape Fear... gale possible Thu.
.Forecaster prosise/musonda. Ocean prediction center.