marine weather discussion for N Atlantic Ocean...corrected NWS ocean prediction center Washington DC 523 PM EDT sun Sep 24 2017
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
Note: warnings below are preliminary, and will be modified based on the next NHC advisory for Hurricane Maria.
Over the short term, the 12z models are in very good agreement over the offshore waters. The models are in agreement calling for dissipation of the remnant low that was Jose over the NE nt2 waters tonight or early Mon. An ascat pass from near 15z showed its center near 38.5n 68w with highest winds down to 20 kt se and NW of the center. Otherwise all eyes will be focused on Hurricane Maria as it lifts north and northwestward into the se nt2 waters tonight into Mon and then the central nt2 waters by midweek. A 15z ascat-a overpass went over Maria and indicated that tropical storm force winds already extended into the far southern zone anz935. Also of note, Tropical Storm Lee became a hurricane last night and intensified during the day as the latest satellite imagery shows that Lee has clearly formed an eye. Lee was located near 31.3n 49.7w per the 21z advisory from NHC. It is forecast to drift se and then turn to the W and then N over the next several days, and remain well E of the offshore waters. For more information on Lee please refer to the latest advisory from the National Hurricane Center.
Over the medium range, we will once again follow the latest NHC advisory for Maria. Compared to 24 hours ago, the 12z models today are in better agreement until Thu and then afterwards they diverge and by 120 hours show a spread of up to 600 nm. In general, they bring Maria north and northwestward over the southern nt2 waters Mon and Mon night, and then to E of Cape Hatteras by Wed. An upper level trough and associated cold front is then expected to cross se Canada and New England Wed night through Thu night, with Maria turning toward the E and NE at that time, and beginning to accelerate ahead of the trough and front. High pressure should build E over the waters in the wake of the trough/front and departing Maria later in the week into next weekend. The 12z GFS is used for background grids except time- shifted 6 hours slower after 06z Thu to form a closer fit to NHC track.
Please continue to closely monitor the latest NHC advisory, WFO forecasts, and opc forecasts over the next few days.
As far as sea heights are concerned, it appears as if both the 00z wavewatch iii and 00z ECMWF wam have initialized within a foot or so of the latest observations and altimeter data across the offshore waters early this afternoon. Sea heights range from near 19 feet over far se nt2 waters to 3-4 feet over the Gulf of Maine per the 18z ra1 opc sea state analysis. For the afternoon package we will once again attempt to align the sea heights forecast with the latest NHC advisory for Hurricane Maria as swells associated with Maria will impact all of the offshore waters during the next several days. Conditions will deteriorate into the middle of the week as Maria lifts northward over the nt2 waters, with slowly improving conditions later in the week as Maria turns to the E and NE, and moves away from the region.
1. Maria is forecast to continue moving northward, paralleling the U.S. East Coast, and it is likely that some direct impacts will occur along portions of the coast beginning Tuesday, and a tropical storm watch has been issued for a portion of the coast of North Carolina.
2. Storm surge flooding especially along the sound side of the North Carolina Outer Banks is possible beginning Tuesday, and a storm surge watch has been issued for a portion of the North Carolina Outer Banks.
3. Swells from Maria are increasing along the coast of the southeastern United States and are expected to reach the mid- Atlantic coast today. These swells will likely cause dangerous surf and rip currents at beaches in these areas through much of the week. For more information, please monitor information from your local National Weather Service office at www.Weather.Gov.
.Extratropical storm surge guidance...For surge information related to Maria please see the latest information provided by NHC and local WFO coastal offices.
.Nt1 New England waters... None.
.Nt2 mid-Atlantic waters... .anz920...Baltimore Canyon to the great South Channel... tropical storm possible Wednesday into Thursday night. .Anz910...East of the great South Channel and south of 39n... tropical storm possible Thursday into Friday. .Anz825...Inner waters from Baltimore Canyon to Cape Charles Light... tropical storm possible Wednesday into Wednesday night. .Anz828...Inner waters from Cape Charles Light to Currituck Beach Light... tropical storm Tuesday. Tropical storm possible Tuesday night into Wednesday night. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... tropical storm Monday night into Tuesday. Tropical storm possible Tuesday night. Hurricane possible Wednesday into Thursday. Tropical storm possible Thursday night. .Anz830...Inner waters from Currituck Beach Light to Cape Hatteras... tropical storm Monday night into Tuesday. Hurricane possible Tuesday night into Wednesday. Tropical storm possible Wednesday night into Thursday. .Anz833...Inner waters from Cape Hatteras to Cape Fear... tropical storm Monday night into Tuesday. Hurricane possible Tuesday night. Tropical storm possible Wednesday into Wednesday night. .Anz930...Outer waters from Hatteras Canyon to Cape Fear... tropical storm today into tonight. Hurricane Monday into Tuesday. Hurricane possible Tuesday night into Wednesday night. Tropical storm possible Thursday. .Anz835...Inner waters from Cape Fear to 31n... tropical storm Monday night into Tuesday. Tropical storm possible Tuesday night. .Anz935...Outer waters from Cape Fear to 31n... tropical storm today. Hurricane tonight into Tuesday. Tropical storm possible Tuesday night into Wednesday.
.Forecaster Bancroft. Ocean prediction center.