marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 337 am EDT Tue Jul 25 2017
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
Summary...the 00z NCEP surface analysis shows a 1007 mb low centered just E of Cape Cod, with a warm front extending E from the low across the Georges Bank waters, and a cold front extending SW from the low to the Delaware coast. The analysis also indicates a high pres ridge building E into the central and southern nt2 waters, with a low pres trough approaching the mid Atlantic and Carolina coasts. Latest available ascat hi-res and ascat passes from a few hours show 25 to 30 kt winds in the nt1 waters N of the low, and 25 to 30 kt winds in SW flow over the central and northern nt2 waters E of the 1000 fathoms curve. Lightning density product data at 0720z indicates scattered showers and tstms in the outer zones of the nt2 area ahead of the cold front, and also over the inner zones near the mid Atlantic coast.
Models...the 00z medium range models are in good overall agreement across the offshore waters for today through Thu night, and the 00z ecwmf appears to be the most representative model for this timeframe and will be used for the wind grids. The 00z UKMET is a strong and slow outlyer solution with the low moving across the nrn nt2 and nt1 waters on Fri and Sat, while the 00z ECMWF and 00z GFS 10m have come into good agreement for that period. A 50/50 blend of the 00z ECMWF/GFS 10m will be used for Fri through the end of the forecast period.
Seas...the 00z wna wavewatch and 00z ECMWF wam both initialized well over the offshore waters. Since am favoring the 00z ECMWF through Thu night, will use the 00z ECMWF wam for the sea height grids over this timeframe in order to be consistent. Then will switch to using a 50/50 blend of the 00z wna wavewatch/ECMWF wam for Fri through the end of the forecast period for consistency purposes.
.Extratropical storm surge guidance...N/A.
.Nt1 New England waters... None.
.Nt2 mid-Atlantic waters... None.
.Forecaster Scovil. Ocean prediction center.