marine weather discussion for N Atlantic Ocean NWS ocean prediction center Washington DC 837 am EDT Tue Sep 19 2017
.Forecast discussion...Major features/winds/seas/significant .Weather for the North Atlantic ocean W of 50w from 30n to 50n.
Note: warnings are preliminary, and will be modified based on the next NHC advisory for Hurricane Jose.
Current conditions...the 06z NCEP surface analysis shows Hurricane Jose centered about 200 nm E of Cape Hatteras, with a stationary front meandering across the southern nt1 waters, and a high pres ridge over the Gulf of Maine. Latest available ascat and ascat hi-res passes from last night show 30 to 45 kt winds in zones 910 and 920 of the northern nt2 waters, with 20 to 30 kt winds in zones 905 and 915 of the northern nt2 waters. Lightning density product data at 1110z shows isolated showers and tstms over the northern nt2 waters E of 1000 fathoms.
Models/forecast...the medium range models are in good overall agreement across the offshore waters for today into Wed, so the representative GFS 10m solution will be used for the wind grids during this timeframe. The UKMET is W of the other models with Jose for late Wed through Sat night, while the Gem is E of the other models. The ECMWF/GFS are in good agreement for today through Fri, with the ECMWF stronger and SW of the GFS for Fri night through the rest of the forecast period. However, the ECMWF looks like a good comprimise between the GFS and the UKMET, so it will be used for late Wed through the rest of the forecast period. Am not planning to make any significant changes to the current forecast trend.
Seas...the wna wavewatch and ECMWF wam still initialized a bit low with the wave heights around Hurricane Jose, so am planning to go with the previous official wave height grids for today into Sat, with adjustments possible based on the next NHC advisory. Will then blend in the ECMWF wam for late Sat through the rest of the forecast period, in order to be consistent with the preferred ECMWF winds.
Extratropical storm surge guidance...please refer to the latest NHC advisory and local NWS WFO guidance in reference to any potential tropical storm surge.
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The GOES-E infrared satellite imagery indicates Hurricane Jose over the outer offshore waters in central nt2, and the water vapor imagery indicates dry air wrapping around the center. The imagery also indicates cloud tops have been warming over the past few hours, and convection near the center has been not quite as strong as a result of the drier air. In addition, the imagery indicates that the upper level winds are increasing in intensity, so the increasing shear is also helping to limit convection. However, the 00z model guidance indicates that the center is still very strong, so hurricane winds are still expected near the center. The ascat wind retrievals from 02z UTC last night largely missed the system, though indicated up to 50 kt to the E of the center. Also, current surface observations indicate up to 45 kt along the coast. The 00z models all indicate that Jose will move slowly N over the next 36 to 48 hours as the upper level steering is somewhat weak with an upper trough passing well to the N of Jose. On Thu and Fri, the models start to differ on the track. The 00z GFS has trended to the E of the 18z run and indicates a little more steering to the E from the trough to the N. The 00z ECMWF also trended E, but not quite as much as the GFS and is more consistent on the track by Sat night while keeping the low well W of the 00z GFS solution. In contrast, the 00z UKMET is now W of all other solutions, while the 00z Gem continues to take Jose off to the E as it indicates more steering by the upper trough. At this time am preferring the 00z ECMWF solution, but will adjust grids based on the next NHC advisory. Otherwise, the 00z models agree somewhat well over the remainder of the forecast period, though some differences start appearing in the srn zones with the next tropical system, Maria, moving into the area. The 00z ECMWF/GFS have come into somewhat decent agreement on this low, so planning on using the 00z ECMWF winds through the remainder of the forecast period. However, will again make adjustments based on the next NHC advisory for Maria.
Seas...the 00z wavewatch and ECMWF wam are still initialized a little low with the wave heights around Hurricane Jose, so planning on using the previous official wave height grids while making adjustments based on the next advisory. Will then blend in the 00z ECMWF wam from late Sat Onward to match the preferred winds of the 00z ECMWF.
.Extratropical storm surge guidance...Please refer to the latest NHC advisory and local NWS WFO guidance in reference to any potential tropical storm surge.
1. While the center of Jose is currently forecast to remain offshore of the U.S. Coast, the large cyclone is expected to cause some direct impacts in portions of New England, and a Tropical Storm Warning is in effect for the coast of Rhode Island and a part of the Massachusetts coast, including Cape Cod. Any deviation to the left of the NHC forecast track would increase the likelihood and magnitude of impacts elsewhere along the U.S. East Coast from Delaware to southern New England.
2. Minor to moderate coastal flooding is possible from Delaware to southern New England during the next several days. Please see products issued by local National Weather Service forecast offices.
3. Swells generated by Jose are affecting Bermuda, the Bahamas, and much of the U.S. East Coast. These swells are likely to cause dangerous surf and rip current conditions for the next several days in these areas.
4. Jose will produce heavy rain over a small part of southern New England and eastern Long Island as it passes offshore of these locations on Tuesday and Wednesday. Total accumulations of 3 to 5 inches are expected over eastern Long Island, southeast Connecticut, southern Rhode Island, and southeast Massachusetts, including Martha's Vineyard and Nantucket. This rainfall could cause isolate flooding. Elsewhere Jose is expected to produce light rainfall with little risk of flooding over the majority of the mid-Atlantic coast and the northeast states.
.Nt1 New England waters... .anz805...Georges Bank west of 68w... tropical storm tonight into Wednesday night. Tropical storm possible Wednesday night into Thursday night. Gale possible Friday. .Anz900...Georges Bank east of 68w... tropical storm tonight into Wednesday night. Tropical storm possible Wednesday night into Thursday night. Gale possible Friday. .Anz810...South of New England... tropical storm today into Wednesday night. Tropical storm possible Wednesday night into Thursday night. Gale possible Friday. .Anz815...South of Long Island... tropical storm today into Wednesday night.
.Nt2 mid-Atlantic waters... .anz820...Hudson Canyon to Baltimore Canyon... tropical storm today into Wednesday. .Anz915...Hudson Canyon to the great South Channel... tropical storm today into Wednesday night. Tropical storm possible Wednesday night into Thursday night. Gale possible Friday. .Anz920...Baltimore Canyon to the great South Channel... tropical storm today. Hurricane today. Tropical storm tonight into Wednesday night. Tropical storm possible Wednesday night into Thursday. .Anz905...The great South Channel to the Hague line... tropical storm today into Wednesday night. Tropical storm possible Wednesday night into Thursday night. Gale possible Friday into Saturday night. .Anz910...East of the great South Channel and south of 39n... tropical storm today into Wednesday night. Tropical storm possible Wednesday night into Thursday night. Gale possible Friday into Saturday night. .Anz825...Inner waters from Baltimore Canyon to Cape Charles Light... tropical storm today into tonight. .Anz828...Inner waters from Cape Charles Light to Currituck Beach Light... tropical storm today. .Anz925...Outer waters from Baltimore Canyon to Hatteras Canyon... hurricane today. Tropical storm tonight. .Anz930...Outer waters from Hatteras Canyon to Cape Fear... tropical storm today.
.Forecaster Scovil/Kells. Ocean prediction center.