Marine Interpretation Message
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000
AGNT40 KWNM 191908
MIMATN

Marine Weather Discussion for N Atlantic Ocean
NWS Ocean Prediction Center Washington DC
208 PM EST THU JAN 19 2017

.FORECAST DISCUSSION...Major features/winds/seas/significant
.weather for the North Atlantic Ocean W of 50W from 30N to 50N.

Over the short term, the new 12Z models remain in reasonably good
agreement with no major forecast problems. The 12Z models remain
consistent in forecasting a weak negatively tilted upper short
wave trough to slide Fri/Fri night with an associated weak surface
low moving off the N Carolina coast Fri night, then passing E
across the central NT2 waters Sat. Overall would favor the similar
and more consistent 12Z GFS/ECMWF solutions (which are well
supported by the 12Z GEFS Mean) for this low. Therefore through
the short term, plan on populating our forecast winds grids with
the representative 12Z GFS 10m/first sigma level winds (with our
smart tool placing 10m winds in stable areas and first sigma level
winds in unstable areas) for tonight through Sat night with some
additional minor edits in deference to the 12Z UKMET/ECMWF.

In the long range, at the upper levels the 12Z models generally
agree that a strong closed upper low will move into the SE conus
late Sun/Sun night, turn NE towards the mid Atlantic coast late
Mon/Mon night...then continue NE across the New England coast
Tue/Tue night. In response at the surface, the 12Z GFS remains
consistent versus its previous respective runs in forecasting a
warm front to drift N from the central to Nrn NT2 waters Sun/Sun
night with strengthening SSW and Ely gradients forecast to develop
S and N of the front, respectively which is line with the other
12Z models. Then the 12Z global models offer differing forecast
tracks for a strong associated attendant surface low to move NE
near, or just off, the mid Atlantic coast Mon/Mon night, then
continue NE across the NT1 waters Tue/Tue night. The 12Z GEFS Mean
indicates that the 12Z GFS forecast track, which is similar to the
12Z global GEM, for this low may be too far E. On the other hand
the 12Z UKMET forecast track looks to progressively become a
western outlier. The 12Z ECMWF track is similar to the 12Z GFS in
regards to timing, but is further NW and closer to the coast Mon
into Tue night. Therefore for now as a compromise, will continue
to populate our forecast winds with our 12Z GFS 10m/first sigma
level wind tool for Sun through Tue night (time shifted 6 hours
faster Mon into Tue night), then will blend these winds 50/50
with the 12Z ECMWF boundary layer winds. So as a result, will be
making some generally minor areal coverage and timing changes to
the previously forecasted gale warnings associated with this
system.

.Seas...The higher 12Z ECMWF WAM has initialized the current seas
better than the lower 12Z Wavewatch III. Therefore will populate
our forecast wave grids with the 12Z ECMWF WAM for tonight. Then
since their associated 12Z GFS/ECMWF solutions become more
similar, and as a compromise, will transition to populating with a
50/50 blend of the 12Z Wavewatch III and 12Z ECMWF WAM for Fri
through Tue night.

.Extratropical Storm Surge Guidance...In the strong Ely gradient
forecast to develop N of the front Sun night into Mon night the
12Z ESTOFS forecasts a more significant surge (up to 3-4 ft) to
develop along the coast from Delaware to Long Island Sound than
forecast by the 12Z ETSS. If the 12Z GFS forecast track for the
associated surface low verifies, would favor the higher surge
forecast by the ESTOFS, but if its too far E with the low then
this surge may be overdone.

.WARNINGS...Preliminary.

.NT1 New England Waters...
.ANZ800...Gulf of Maine...
     Gale Possible Monday into Monday night.
.ANZ805...Georges Bank west of 68W...
     Gale Possible Sunday night into Monday night.
.ANZ900...Georges Bank east of 68W...
     Gale Possible Monday into Monday night.
.ANZ810...South of New England...
     Gale Possible Sunday night into Monday.
.ANZ815...South of Long Island...
     Gale Possible Sunday night into Monday night.

.NT2 Mid-Atlantic Waters...
.ANZ820...Hudson Canyon to Baltimore Canyon...
     Gale Possible Sunday night into Monday.
.ANZ915...Hudson Canyon to the Great South Channel...
     Gale Possible Sunday night into Monday.
.ANZ920...Baltimore Canyon to the Great South Channel...
     Gale Possible Monday.
.ANZ905...The Great South Channel to the Hague Line...
     Gale Possible Monday.
.ANZ910...East of the Great South Channel and south of 39N...
     Gale Possible Monday into Monday night.
.ANZ925...Outer Waters from Baltimore Canyon to Hatteras Canyon...
     Gale Possible Sunday night into Monday.
.ANZ830...Inner Waters from Currituck Beach Light to Cape Hatteras...
     Gale Possible Sunday into Sunday night.
.ANZ833...Inner Waters from Cape Hatteras to Cape Fear...
     Gale Possible Sunday into Sunday night.
.ANZ930...Outer Waters from Hatteras Canyon to Cape Fear...
     Gale Possible Sunday night.
.ANZ835...Inner Waters from Cape Fear to 31N...
     Gale Possible Sunday into Sunday night.
.ANZ935...Outer Waters from Cape Fear to 31N...
     Gale Possible Sunday night.

$$

.Forecaster Vukits. Ocean Prediction Center.


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