.Marine weather discussion for N Atlantic Ocean .NWS ocean prediction center Washington DC 945 PM EDT sun 15 Jul 2018
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
Subtropical Beryl continues to lack convection this evening, although the latest GOES-16 shortwave IR imagery shows a tight low/mid level circulation. Due to the persistent lack of convection, we would not be surprised if NHC declares Beryl Post-tropical. The latest models are in excellent agreement across the west Atlantic for the next few days. However, as was noted below, there are some differences between the models as to how strong the southwest winds will become east of the cold front and associated developing frontal waves Tuesday through Wednesday night. The previous wind grids, which were mostly based on the 12z ECMWF, appear quite reasonable. We will not be making any significant changes to the previous wind and wave height grids with this evenings updates. East to southeast swell continues to impact the mid-Atlantic coast this eveing, and the multi-1 wavewatch appears to be better initialized than the ECMWF wam with this swell. As far as wave heights, both models appear reasonably well initialized across the west Atlantic this evening.
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12z global models in pretty good agreement through most of the forecast period, with some minor timing differences towards the end of the period. For the wind grids, will lean towards the 12z GFS through 18z Tue, then move more towards the 12z ECMWF thereafter.
Subtropical storm Beryl, east of the area, will continue to move ENE and away from the region tonight and Mon. Any tropical storm force winds associated with Beryl will remain east of the area. See latest advisory for more information on Beryl.
Models still in good agreement with timing of front to affect the waters Tue and Tue night. Models continue to differ a bit on strength and timing of waves developing along the front Wed and Wed night, with the ECMWF being slightly weaker than the GFS. Will cap winds at 30 kt in the southerly flow ahead of the front for now, but with the GFS showing a few gales and the ECMWF showing 30 kt, will have to watch to see if models trend stronger with this system, especially in and near the Gulf Stream. Front expected to move across the area Wed and Wed night, then become stationary across the central and southern waters Thu and Thu night. Then on Fri and Fri night, front is expected to begin to lift north as a warm front, with the GFS being the faster of the global models in moving the front further northward. Prefer the slower ECMWF timing of the front, which is more in line with the UKMET and the Canadian.
.Seas...Wave guidance within a foot or two of current observations over the coastal and offshore waters. For the wave grids, will lean towards 12z enp values through 18z Tue, then move towards 12z ecwmfwave values thereafter.
.Extratropical storm surge guidance...No significant extratropical storm surge events are expected during the next few days.
.Nt1 New England waters... None.
.Nt2 mid-Atlantic waters... None.
.Forecaster Clark/achorn. Ocean prediction center.