705
AGNT40 KWNM 140806
MIMATN

Marine Weather Discussion for N Atlantic Ocean
NWS Ocean Prediction Center Washington DC
306 AM EST Wed Nov 14 2018

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

Ascat wind retrievals from 0040 UTC last night indicated a cold
front across the outer offshore waters with gales in the cold
advection behind the front over the Gulf of Maine. Current
surface reports still indicate strong W to NW flow over the
northern zones, and the 00Z GFS/ECMWF/ARW all show an increase in
the winds in the cold advection as the associated low center
moves NE of the area while rapidly intensifying. The models show
the gales continuing across the Gulf of Maine into early tonight,
and with the good agreement on the intensity of the winds the
confidence in the gales is well above average. In addition, the
00Z models all show low pressure developing SW of the area along
the tail end of the same front today, then moving it NE into the
area tonight and Thu while intensifying. The GFS/ARW indicate
gales developing along the SE coast late this afternoon into
tonight ahead of associated warm front as it interacts with
strong high pressure building over New England. The models then
indicate continued strong development as a shortwave approaches
the Mid Atlc coast Thu night into Fri. The GFS has been showing
widespread gales with a few storm force areas mainly near the
Gulf Stream in NT2. The 00Z ECMWF is in generally good agreement
with the 00Z GFS on the track and development of the system,
though is weaker with the winds and seems a little underdone
considering the upper level support. The previous forecast
favored the stronger solution, and at this time am inclined to
favor it as well with the upper levels supporting a stronger
solution. As a result, confidence in the widespread gales and
smaller area of storm near the Gulf Stream is above average for
Thu night into Fri, so planning on making only minor adjustments
to the short term headlines in the next forecast. Will also start
out with the 00Z ARW winds as they seem representative, then
transition to the 00Z GFS late Thu into Thu night while using
first sigma winds over unstable areas to account for the deeper
mixing.

Into the medium range period, the 00Z GFS and ECMWF remain in
decent agreement into Sun with high pressure building across the
W Atlc behind the aforementioned frontal system. The GFS then
becomes a bit stronger with the next cold front moving into the
region late Sun, and has been fairly inconsistent on the overall
timing. In contrast, the 00Z ECMWF has been more consistent on
this feature, and is in decent agreement with the 00Z UKMET. As a
result of the marginally better support, am planning on
transitioning to the 00Z ECMWF on Sun and continuing with it
through the remainder of the forecast period.

.SEAS...The 00Z Wavewatch and ECMWF WAM are initialized within a
ft or two of each other, and agree somewhat well into Sun. Will
use an even blend of the two up to that point while making
adjustments to account for the current data. Will then stay
closer to the 00Z ECMWF WAM Sun through the end of the forecast
period to better match the preferred winds of the 00Z ECMWF.

.EXTRATROPICAL STORM SURGE GUIDANCE...The 00Z ESTOFS and ETSS
are both showing a strong signal for a positive surge along the
Mid Atlc and New England coasts late Thu into Fri with the strong
coastal low expected to develop in that time frame. The ESTOFS
continues to show values greater than 2 ft in NY Bight and Long
Island Sound, and is roughly 50 percent higher than the ETSS
which seems a little underdone. Please continue to closely
monitor the latest OPC and coastal WFO forecasts over the next
few days, and refer to the coastal National Weather Service
offices for more information.

.WARNINGS...Preliminary.

.NT1 New England Waters...
.ANZ800...Gulf of Maine...
Gale today into tonight.
Gale Thursday night.
Gale Possible Friday.
.ANZ805...Georges Bank west of 68W...
Gale today.
Storm Thursday night.
Gale Possible Friday.
.ANZ900...Georges Bank east of 68W...
Gale today into tonight.
Gale Thursday night.
Gale Possible Friday into Friday night.
.ANZ810...South of New England...
Gale Thursday night.
Gale Possible Friday.
.ANZ815...South of Long Island...
Gale Thursday night.
Gale Possible Friday.

.NT2 Mid-Atlantic Waters...
.ANZ820...Hudson Canyon to Baltimore Canyon...
Gale Thursday.
Storm Thursday night.
Gale Possible Friday.
.ANZ915...Hudson Canyon to the Great South Channel...
Gale Thursday.
Storm Thursday night.
Gale Possible Friday.
.ANZ920...Baltimore Canyon to the Great South Channel...
Gale Thursday.
Storm Thursday night.
Gale Possible Friday.
.ANZ905...The Great South Channel to the Hague Line...
Gale today into tonight.
Storm Thursday night.
Gale Possible Friday into Friday night.
.ANZ910...East of the Great South Channel and south of 39N...
Storm Thursday night.
Gale Possible Friday into Friday night.
.ANZ825...Inner Waters from Baltimore Canyon to Cape Charles Light...
Gale Thursday into Thursday night.
Gale Possible Friday.
.ANZ828...Inner Waters from Cape Charles Light to Currituck Beach Light...
Gale tonight into Thursday night.
.ANZ925...Outer Waters from Baltimore Canyon to Hatteras Canyon...
Gale tonight into Thursday night.
Gale Possible Friday.
.ANZ830...Inner Waters from Currituck Beach Light to Cape Hatteras...
Gale tonight into Thursday night.
.ANZ833...Inner Waters from Cape Hatteras to Cape Fear...
Gale tonight into Thursday.
.ANZ930...Outer Waters from Hatteras Canyon to Cape Fear...
Gale tonight into Thursday.
.ANZ835...Inner Waters from Cape Fear to 31N...
Gale today into Thursday.
.ANZ935...Outer Waters from Cape Fear to 31N...
Gale tonight into Thursday.

$$

.Forecaster Kells. Ocean Prediction Center.