marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 942 am EDT Thu Jun 22 2017
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
At 8 am a cold front has moved into the nrn mid Atlantic waters and should stall stall over this area later this morning and then gradually returns N as a warm front this afternoon and tonight. Over the mid Atlantic offshore waters a high pressure ridge extends W into the srn areas. There were scattered showers along and se of the Gulf Stream this morning and should persist into tonight. Model guidance has winds to 15 kt with the stronger winds along a se of the Gulf Stream today.
Model guidance looks similar through the forecast period. A cold front approaches the New England and mid Atlc coast by late Fri night into Sat. Models have winds of at least 25 kt or 30 kt during this period of time. GFS/UKMET are showing the potential for gales by Sat night in advance of cold front over the innner and outer waters of nrn mid Atlantic which seems overdone. Will await 12z model guidance before considering any changes later this afternoon. The cold front pushes further offshore before weakening sun. Another cold front moves se into New England waters Sun night into Mon.
For the updated forecast will be making few changes to previous gfe grids which look good.
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Summary...the 00z NCEP surface analysis shows a cold front arcing NE to SW across the Gulf of Maine and srn New England, with a high pres ridge across the nt2 waters. Latest available ascat and ascat hi-res passes from a few hours ago show 15 to 20 kt winds over the nt1 and nrn nt2 waters, with prevailing winds in the 5 to 15 kt range over most of the central and srn nt2 waters.
Models...the 00z medium range models are all in good overall agreement across the offshore waters during the forecast period, although some timing differences appear for Mon and Mon night. However, the 00z GFS has strong support from the 00z UKMET through Mon night. Since the 00z GFS 10m solution looks like the most representative model solution, it will be used for the wind grids through the entire forecast period. Am not planning to make any significant changes to the current forecast trend.
Seas...the 00z wna wavewatch and 00z ECMWF wam both initialized reasonably well over the coastal/offshore waters, and are in good overall agreement during the forecast period with only minor differences noted. A representative 50/50 blend of the 00z wna wavewatch/ECMWF wam will be used for the sea height grids during the forecast period.
.Extratropical storm surge guidance...N/A.
.Nt1 New England waters... None.
.Nt2 mid-Atlantic waters... None.
.Forecaster Rowland/Scovil. Ocean prediction center.