marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 356 PM EDT Tue Sep 1 2015
.Forecast discussion: major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
At 18z opc sfc analysis showed a cold front over the NE nt2 waters while 1017 mb low was roughly 115 nm E of Cape Hatteras. A warm front extended E from the center of the low across the anz925 waters. A 1502z asctb hires pass indicated winds 15 kt and under over the nt1 waters. Over the nt2 waters 25 kt winds were noted the srn and nrn anz925 and anz930 waters respectively while 20 kt winds were present over the se anz833 waters. Winds 15 kt or less were noted throughout the rest of the nt2 waters where asct data was available.
12z guidance looks reasonable through day 3 W/some differences arising day 4 and 5 in regards to low pres expected E of waters. Though these differences at the moment dont have a huge impact on conditions over the nt1/nt2 offshore waters. Low pres over the nt2 waters slides se tonight into Wed as weak high pres over the nt1 waters also slides se. A cold front is still anticipated to move into then cross the nt1 and nrn nt2 waters late Wed/thurs into late thurs/early Fri...W/increasing N/NE-ly flow behind it as high pres builds in. Current thinking of winds up to 25 kt or so as the high builds in remains reasonable.
The high remains centered in in the vicinity of the mid-Atlantic coast/waters W/its ridge extending over the nt1 and nt2 waters through the end of the period. However some uncertainty develops in regards to the development and track of low pres E of the waters. While differences are noted day 4 and part of day 5 between the 12z GFS/UKMET/ECMWF...W/the GFS being farthest E and the ECMWF farthest W...by the end of day 5 the models place the low roughly 200 to 300 nm E/NE of Bermuda. Will continue to monitor the evolution of the low later in the period.
.Seas...Will generally favor the 12z nww3 over the period with some tweaks to seas during the period of increased winds as high pres builds in behind the front.
.Extratropical storm surge guidance...N/A.
.Nt1 New England waters... None.
.Nt2 mid Atlc waters... None.
.Forecaster Holley. Ocean prediction center.