HS 100

marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 225 PM EDT Mon 20 may 2013

.Forecast discussion: major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.

Warm frnt has nearly reached ern edge of new engl waters early this afternoon. Along ern edge of 14z hi res ascat returns were 20 to 25 kt nr 39n69w. Over last coulple of cycles mdls have come into better agreement with dvlpg sfc low just E of new engl waters this evening. 12z GFS 10m winds look OK...and still see some potential for some marginal gales assoc with this low E of offshore waters tngt. Some minor differences exist with where mdls depict the assoc cold front will stall off new engl Tue/Tue ngt. Blend of 12z guidance Sans the 12z Gem global tho looks reasonable with stnry frnt invof Marthas Vineyard/Nantucket se across Georges Bank. 12z mdls in good agreement that frnt shud lift back N as warm frnt Tue ngt into Wed...with increasing SW winds over both mid Atlc and new engl waters later Wed and Wed ngt. 12z GFS trended slower from its previous run with approaching cold front Thu into early Fri. Beginning Wed ngt opc preference switches to more 00z ECMWF as 1/4 deg seems to have been handling the SW winds better than remaining mdls over past couple weeks. That is...better resolving SST/S effect on low lvl stability and resulting winds. GFS 10m winds not indicating any decrease in wind speeds as transition from warmer balt cnyn to Hague line waters to colder shelf or new engl waters N and NW of 1000 FM. 12z GFS has at least backed off somewhat with dvlpg as strong a frntl wave Fri/Sat.

12z multigrid wavewatch iii looks reasonable this afternoon when compared to latest W Atlc ship/buoy obs. For the Thu thru Sat forecast preference continues for a mww3/ECMWF wave mdl blend.

Extratropical storm surge model...N/A.

.Warnings/forecast confidence...Preliminary. Any changes will be coordinated through AWIPS 12 planet chat or by telephone:

.Nt1 New England waters... .Gulf of Maine...none. .Georges Bank...None. .South of New England...None.

.Nt2 mid Atlc waters... .Hudson Canyon to Baltimore Canyon...none. .Baltimore Canyon to Hague line...None. .Baltimore Canyon to Hatteras Canyon...None. .Hatteras Canyon to Cape Fear...None. .Cape Fear to 31n...None. $$

.Forecaster Clark. Ocean prediction center.