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000
AGNT40 KWNM 191237
MIMATN

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.

-----------------------------------------------------------------
 PREVIOUS DISCUSSION...

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.

KEY MESSAGES:

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.

.WARNINGS...Preliminary.

.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.


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