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000
AGNT40 KWNM 260727
MIMATN

Marine Weather Discussion for N Atlantic Ocean
NWS Ocean Prediction Center Washington DC
327 AM EDT Tue Sep 26 2017

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

Note: Warnings below are preliminary, and will be modified based
on the next NHC advisory for Hurricane Maria.

Buoy 41002 reported 37 kt with gusts to 47 kt in the srn NT2
offshore waters to the W of Hurricane Maria at 0600 UTC, and
buoy 41048 to the E of Maria reported 27 kt with gusts to 35 kt.
Ascat again largely missed the highest winds associated with
Maria overnight, though the overpasses between 01Z and 03Z
indicated tropical storm force winds in srn and central NT2 with
up to 50 kt in the far outer waters. The 00Z GFS 10m winds
indicated up to 65 kt in zone ANZ930 at 0600 UTC while the
normally conservative 00Z ECMWF surface winds indicated up to 55
kt. The 00Z GFS/ECMWF/UKMET/GEM models all forecast Maria to move
slowly N over the next few days and take the center of Maria to
roughly 120 NM to the E of Cape Hatteras tonight into Wed. The
models then indicate an upper trough moving off the New England
coast will steer the tropical system off to the E. The models
agree well on the track into Wed night, then start diverging on
the timing of the trough and the associated eastward turn of
Maria. The 00Z ECMWF has trended slower with the trough and the
subsequent track of Maria, and is a bit of a slow outlier
solution. The 00Z GFS agrees somewhat well with the timing of
the 00Z UKMET/GEM/NAM while Maria is in the W Atlc, so planning
on starting out with the 00Z GFS 10m winds for the background
wind grids in next forecast, and continuing with it into Fri.
However, will need to adjust the timing of it to match the next
official forecast from NHC.

The 00Z GFS also indicates a cold front will pass SE over the
waters in the medium range, and takes it SE through the NT2 by
the end of the forecast period. The 00Z ECMWF is a bit slower
than the overall consensus of the 00Z GFS/UKMET, mainly due to
the aforementioned slower trough associated with steering Maria
off to the E. As a result of the better model support, am
planning on continuing with the 00Z GFS through the remainder of
the forecast period.

Seas...the 00Z Wavewatch and ECMWF are initialized within a ft or
two of the current data, and are in reasonably good agreement in
the short range mainly due to the good agreement of the
associated weather models. The Wavewatch then becomes faster with
taking the seas associated with Hurricane Maria off to the E in
conjunction with the faster GFS solution. However, with the 00Z
ECMWF becoming a slow outlier, planning on starting out with the
00Z Wavewatch and make timing adjustments based on the next NHC
advisory.

.Extratropical Storm Surge Guidance...For surge information
related to Maria please see the latest information provided by
NHC and local WFO coastal offices.

KEY MESSAGES:

1. Maria is forecast to continue moving northward, paralleling the
U.S. east coast, and it is likely that some direct impacts will
occur along portions of the North Carolina coast beginning today,
where a Tropical Storm Warning is in effect.

2. Storm surge flooding, especially along the sound side of the
North Carolina Outer Banks, is expected beginning today, and a
Storm Surge Watch has been issued for portions of eastern North
Carolina.

3. Swells generated by Maria are affecting much of the
east coast of the United States from Florida through southern New
England.  These swells are also affecting Bermuda, Puerto Rico, the
northern coast of Hispaniola, the Turks and Caicos Islands, and
the Bahamas.  These swells are likely to cause life-threatening surf
and rip current conditions.  Please consult products from your local
weather office for more information.

.WARNINGS...Preliminary.

.NT1 New England Waters...
     None.

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

$$

.Forecaster Kells. Ocean Prediction Center.



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