000
AGNT40 KWNM 230200
MIMATN

Marine Weather Discussion for N Atlantic Ocean
NWS Ocean Prediction Center Washington DC
900 PM EST FRI 22 FEB 2019

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

NOAA Frying Pan Shoals buoy 41013 has been conistently gusting
to near 30 kt since this afternoon, and reporting significant
wave heights to 8 ft. The higher resolution WRF/ARW and NAMNest
appear somewhat better initialized with these stronger winds
this evening. We updated the near term wind grids across these
southern NT2 zones with heavily weighted WRF/ARW blend which
results in some limited areas to 30 kt tonight. The latest
models then remained quite consistent with the developing
coastal surface low and strong cold front expected to impact the
NT2/NT1 offshore waters this weekend and early next week. The
previous OPC wind grids appear reasonable with widespread gales
developing Sun and persisting across the northern outer zones at
least through Tue night. Our confidence remains above average
that the west winds will then increase to storm force in the
cold air advection over these northern outer zones Mon into Mon
night. The 12Z/18Z runs of the GFS remained slightly stronger
with these winds versus the latest ECMWF/UKMET. The higher ECMWF
WAM is better initialized than the Wavewatch off the North
Carolina coast this evening. We then adjusted these wave heights
higher by about 15 percent or so to better match the buoy
observations.

---------------------------------------------------------------
...Previous Discussion...

Per the 18Z NCEP surface analysis a stationary front was located
across the southern NT2 waters, while a high pressure ridge was
located over the rest of the NT2 and NT1 waters. The latest
ASCAT hires data revealed 10-20 kt winds over the inner northern
and southern NT2 waters, with 20-30 kt winds over the inner
central NT2 waters.

The 12Z guidance remains in good agreement over most of the
period, though models begin to diverge some from overnight
Tuesday into Wednesday through the remainder of the forecast
period. Hence, will populate the grids with a 50/50 blend of the
12Z GFS/ECMWF through Sunday 12Z, then allow the ongoing grids
to remain in place through the remainder of the period with
tweaks needed here and there. Overall, no changes will be made
to the warning headlines in place. High pressure ridging is
expected to slide SE across the waters through Saturday night,
with the stationary front over the S NT2 waters lifting N
through the NT2 and eventually NT1 waters tomorrow into Sunday.

A strong cold front, associated with a strong low moving E
across eastern Canada, is expected to move E across the waters
Sunday into Sunday night, with a period of strong cold air
advection in it`s wake persisting into roughly Tuesday night.
Gales are expected to develop over the offshore waters ahead of
the front Sunday, with gales persisting over the NT1 and NE NT2
waters into early Wednesday. Per guidance, continuing with storm
force winds over parts of the NE NT2 waters Monday into
overnight Monday into early Tuesday is very reasonable. This is
due to the 12Z GFS/ECMWF/UKMET/NAM showing a wide area of 40 kt
winds in the cold air advection over the NE NT2 waters, in the
vicinity of the Gulf Stream as well, with the 12Z GEM/NAVGEM
actually showing winds in the 45-50 kt range. Additionally the
12Z GFS/ECMWF continue to indicate 50-60 kt winds at the 925 mb
level for the same region and time frame. With the continued
agreement among the guidance, confidence concerning the strength
and timing of these various features and warning level winds is
above average.

Beyond that conditions generally ease across the waters heading
into Wednesday as the low continues to slowly move away to the
NE, while high pressure builds in from the W. Where differences
being to arise in the guidance, is in regards to the end of the
period and whether or not low pressure develops somewhere over
the NT1 and NT2 waters. The 12Z GFS/UKMET/GEM all move a low E
across the waters, or into the waters by Wed night, while the
12Z ECMWF/NAVGEM show only high pressure ridging over the waters
through the end of the period. Because of that feel using a
persistence forecast for Wednesday day 5 is reasonable.

.SEAS...Populated the wave grids with a 50/50 blend of the 12Z
WaveWatch III/ECMWF WAM through Sunday, allowing the prior wave
grids to remain in place after given the choice to continue with
the old wind grids, with only few tweaks made.

.EXTRATROPICAL STORM SURGE GUIDANCE...The 12Z ESTOFS shows surge
values around 1 foot over the southern and northern New England
coasts Sun into Sun night as the onshore flow north of the warm
front increases. The 12Z ETSS is well below 1 ft and does appear
too low. For more details please monitor the latest forecast and
information from your local National Weather Service office.

.WARNINGS...Preliminary.

.NT1 New England Waters...
.ANZ800...Gulf of Maine...
Gale Sunday.
Gale Possible Sunday night into Wednesday.
.ANZ805...Georges Bank west of 68W...
Gale Sunday.
Gale Possible Sunday night.
Storm Possible Monday.
Gale Possible Monday night into Tuesday night.
.ANZ900...Georges Bank east of 68W...
Gale Sunday.
Gale Possible Sunday night.
Storm Possible Monday into Monday night.
Gale Possible Tuesday into Wednesday.
.ANZ810...South of New England...
Gale Possible Sunday night into Tuesday.
.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 night.
.ANZ915...Hudson Canyon to the Great South Channel...
Gale Sunday.
Gale Possible Sunday night.
Storm Possible Monday.
Gale Possible Monday night into Tuesday.
.ANZ920...Baltimore Canyon to the Great South Channel...
Gale Sunday.
Gale Possible Sunday night into Tuesday.
.ANZ905...The Great South Channel to the Hague Line...
Gale Sunday.
Gale Possible Sunday night.
Storm Possible Monday into Monday night.
Gale Possible Tuesday into Wednesday.
.ANZ910...East of the Great South Channel and south of 39N...
Gale Sunday.
Gale Possible Sunday night.
Storm Possible Monday into Monday night.
Gale Possible Tuesday into Tuesday night.
.ANZ825...Inner Waters from Baltimore Canyon to Cape Charles
Light...
Gale Sunday.
Gale Possible Sunday night into Monday.
.ANZ828...Inner Waters from Cape Charles Light to Currituck
Beach Light...
Gale Sunday.
Gale Possible Sunday night.
.ANZ925...Outer Waters from Baltimore Canyon to Hatteras
Canyon...
Gale Sunday.
Gale Possible Sunday night into Monday night.
.ANZ830...Inner Waters from Currituck Beach Light to Cape
Hatteras...
Gale Sunday.
Gale Possible Sunday night.
.ANZ833...Inner Waters from Cape Hatteras to Cape Fear...
Gale Sunday.
Gale Possible Sunday night.
.ANZ930...Outer Waters from Hatteras Canyon to Cape Fear...
Gale Sunday.
Gale Possible Sunday night.

$$

.Forecaster Clark/Holley. Ocean Prediction Center.