000
AGNT40 KWNM 212045
MIMATN

Marine Weather Discussion for N Atlantic Ocean
NWS Ocean Prediction Center Washington DC
345 PM EST Thu Jan 21 2021

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

At 18Z/1 PM EST a high pressure ridge was along the outer waters
of the mid Atlc and southern New England waters and moves E of
the area through tonight. There was also a warm front extending
SE from inland areas to near Cape Cod. This warm front lifts NE
of the waters this afternoon into early this evening. At 15Z/10
AM EST there was a ASCAT pass across much of the offshore waters
with the exception of the outer N mid Atlc and southern New
England areas. Over much of the mid Atlc waters into the inner S
of New England offshore areas W of Cape Cod winds were SWly to 20
kt. There was an exception over the inner S mid Atlc waters
where max winds were SWly to 25 kt. This area of SWly winds were
slightly less than the OPC GFE grid fields had. Through the rest
of the afternoon into early tonight a trof will move E over the
mid Atlc waters and a cold front will approach from the W and
reach the S New England and mid Atlc coastlines. The cold front
will reach the outer mid Atlc waters later tonight as low
pressure develops along the front and moves E into the outer N
mid Atlc waters. Gales are expected to develop in advance of the
cold front just E of the outer N and central mid Atlc waters
later tonight as a developing low forms along the N mid Atlc
waters and moves E of the area and intensifies. The cold front
moves S and SE into the S mid Atlc waters later tonight and Fri,
then passes S of area Fri night.

On Saturday, an upper short wave moves SE across the New England
waters with a surface trof or a cold front moving SE across the
New England and N and central mid Atlc waters. High pressure
inland builds E and offshore Sat and Sun night with good cold air
advection occurring across the New England and northern areas of
the mid Atlc waters. We have gale headlines in place with
instabilty increasing and cold air advection spreading SE over
this region. The NWly over this area diminishes through Mon. The
next area of concern will be with low pressure that develops and
moves over the outer banks Mon night into Tue. The GFS continues
to be faster with the low pressure than the ECMWF/UKMET
solutions. Preference is for the ECMWF which moves low pressure
offshore Mon night near or N of Cape Hatteras which moves E of
the area by Tue nigh as high pressure builds in from the W.

For the grids will use the GFS through about 00Z Sat, then use a
50/50 blend of the GFS and ECMWF through 12Z Mon. Afterwards will
use the ECMWF through the rest of the forecast period.

.Seas...For the seas the Wave watch and ECMWF wam are in close
agreement and differences are not great. Plan to use a 50/50
blend of these models through 12Z Mon. For Mon and afterwards
will use the ECMWF with few adjustments anticipated.

.EXTRATROPICAL STORM SURGE GUIDANCE...A fairly persistent
offshore flow is expected for the next several days, therefore
no significant positive surge events are expected. Please
monitor products from coastal National Weather Service offices
for detailed water level information.

.WARNINGS...Preliminary.

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

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

$$

.Forecaster Rowland. Ocean Prediction Center.