Gale Warning 306, NWS Anchorage, AK

324 
FZAK62 PAFC 162335
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
335 PM AKDT TUE MAY 16 2017

OFFSHORE WATERS FORECAST FOR THE BERING SEA

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT AN AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WIND WAVE AND SWELL HEIGHT.

PKZ499-171330-
335 PM AKDT TUE MAY 16 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 991 MB LOW CENTERED NEAR 54N 170W WILL MOVE TO 53N 165W AT 996 MB WED
AFTERNOON BEFORE DISSIPATING THU AFTERNOON. HIGH PRESSURE WILL REMAIN
OVER THE WESTERN BERING THROUGH THU AFTERNOON.

$$

PKZ411-171330-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
335 PM AKDT TUE MAY 16 2017

...GALE WARNING TONIGHT...

.TONIGHT...N WIND 20 TO 35 KT DIMINISHING TO 10 TO 20 KT AFTER
MIDNIGHT. SEAS 6 TO 11 FT.
.WED...N WIND 10 TO 20 KT. SEAS 6 FT. PATCHY FOG.
.WED NIGHT...NE WIND 10 KT. SEAS 5 FT. PATCHY FOG.
.THU...NE WIND UP TO 15 KT. SEAS 4 FT.
.THU NIGHT...NE WIND UP TO 15 KT. SEAS 3 FT.
.FRI...E WIND UP TO 10 KT. SEAS 3 TO 5 FT.
.SAT THROUGH SUN...S WIND UP TO 20 KT. SEAS 4 FT.

$$

PKZ412-171330-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
335 PM AKDT TUE MAY 16 2017

.TONIGHT...NE WIND 20 TO 30 KT. SEAS 6 TO 10 FT.
.WED...N WIND 20 KT. SEAS 7 FT.
.WED NIGHT...N WIND 10 TO 20 KT. SEAS 6 FT. PATCHY FOG.
.THU...NE WIND 10 TO 20 KT. SEAS 3 TO 6 FT.
.THU NIGHT...NE WIND UP TO 15 KT. SEAS 3 FT.
.FRI THROUGH SUN...E WIND 15 KT. SEAS 4 FT.

$$

PKZ413-171330-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
335 PM AKDT TUE MAY 16 2017

.TONIGHT...N WIND 15 TO 30 KT. SEAS 5 TO 9 FT. PATCHY FOG.
.WED...N WIND 15 TO 25 KT. SEAS 5 TO 8 FT.
.WED NIGHT...N WIND 20 KT. SEAS 7 FT. PATCHY FOG.
.THU...NE WIND 15 KT. SEAS 5 FT.
.THU NIGHT...NE WIND 15 KT. SEAS 4 FT.
.FRI THROUGH SAT...NE WIND 15 KT. SEAS 4 FT.
.SUN...SE WIND 15 KT. SEAS 3 TO 6 FT.

$$

PKZ414-171330-
BERING SEA OFFSHORE EAST OF 171W-
335 PM AKDT TUE MAY 16 2017

.TONIGHT...NE WIND 15 KT. SEAS 5 FT. PATCHY FOG.
.WED...NE WIND 10 TO 20 KT. SEAS 5 FT.
.WED NIGHT...NE WIND 10 TO 20 KT. SEAS 4 FT.
.THU...E WIND UP TO 15 KT. SEAS 3 FT.
.THU NIGHT...E WIND UP TO 15 KT. SEAS 3 FT.
.FRI THROUGH SUN...E WIND UP TO 20 KT. SEAS 3 TO 6 FT.

$$

754 
FZAK62 PAFC 171149
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
349 AM AKDT WED MAY 17 2017

OFFSHORE WATERS FORECAST FOR THE BERING SEA

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT AN AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WIND WAVE AND SWELL HEIGHT.

PKZ499-180115-
349 AM AKDT WED MAY 17 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A BROAD 995 MB LOW CENTERED NEAR 54N 166W MOVES TO 50N 164W AT
999 MB THU MORNING BEFORE DISSIPATING BY THU AFTERNOON. HIGH 
PRESSURE REMAINS OVER THE WESTERN BERING THROUGH FRI AFTERNOON.


$$

PKZ411-180115-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
349 AM AKDT WED MAY 17 2017

.TODAY...N WIND 10 TO 20 KT. SEAS 6 FT. PATCHY FOG.
.TONIGHT...NE WIND 10 KT. SEAS 5 FT. PATCHY FOG.
.THU...NE WIND 10 TO 15 KT. SEAS 4 FT. PATCHY FOG.
.THU NIGHT...NE WIND UP TO 15 KT. SEAS 3 FT.
.FRI...E WIND UP TO 20 KT. SEAS 3 FT.
.SAT THROUGH SUN...S WIND UP TO 20 KT. SEAS 4 FT.

$$

PKZ412-180115-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
349 AM AKDT WED MAY 17 2017

.TODAY...N WIND 20 KT. SEAS 7 FT. PATCHY FOG.
.TONIGHT...N WIND 10 TO 20 KT. SEAS 6 FT. PATCHY FOG.
.THU...NE WIND 10 TO 20 KT. SEAS 4 FT. PATCHY FOG.
.THU NIGHT...NE WIND UP TO 15 KT. SEAS 3 FT.
.FRI...E WIND 10 KT. SEAS 3 FT.
.SAT THROUGH SUN...SE WIND UP TO 15 KT. SEAS 4 FT.

$$

PKZ413-180115-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
349 AM AKDT WED MAY 17 2017

.TODAY...N WIND 15 TO 25 KT. SEAS 5 TO 8 FT. PATCHY FOG.
.TONIGHT...N WIND 20 KT. SEAS 6 FT. PATCHY FOG.
.THU...NE WIND 15 KT. SEAS 5 FT. PATCHY FOG.
.THU NIGHT...NE WIND 15 KT. SEAS 4 FT.
.FRI...NE WIND UP TO 15 KT. SEAS 4 FT.
.SAT...E WIND UP TO 15 KT. SEAS 4 FT.
.SUN...S WIND UP TO 15 KT. SEAS 3 TO 6 FT.

$$

PKZ414-180115-
BERING SEA OFFSHORE EAST OF 171W-
349 AM AKDT WED MAY 17 2017

.TODAY...NE WIND 10 TO 20 KT. SEAS 5 FT.
.TONIGHT...NE WIND 10 TO 20 KT. SEAS 4 FT. PATCHY FOG.
.THU...E WIND 10 TO 15 KT. SEAS 4 FT.
.THU NIGHT...E WIND UP TO 15 KT. SEAS 3 FT.
.FRI THROUGH SUN...E WIND UP TO 15 KT. SEAS 3 TO 6 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion...CORRECTED
National Weather Service Anchorage AK
729 PM AKDT Mon May 15 2017

UPDATE TO LONGTERM

.ANALYSIS AND UPPER LEVELS...
An upper level ridge extends over most of mainland Alaska today
and a double-centered upper level low over the Bering Sea.

The surface low in the Bering Sea is still being supported by the
upper level low and bringing in some areas of heavier rainfall to
the region as well as gusty winds. The front associated with the
low will make it into the southwest Gulf of Alaska by early
tomorrow morning.

There is still a little bit of instability in the Susitna Valley
and Copper River Basin which could bring in some showers...especially
over higher terrain.

&&

.MODEL DISCUSSION...
Models are is very good synoptic agreement today. The differences
in the Bering Sea region in regards to where the triple point
would develop look to be resolved with the NAM solution from
yesterday the one they converged around.

High resolution models are detecting the developing gap flow over
Southcentral Alaska tomorrow well and are used for some of the
details for gap winds.

&&

.AVIATION...
PANC...VFR conditions will persist through Tuesday. The potential
for afternoon or evening southeast winds is the only question to
address. While the Turnagain Arm winds will increase some this
afternoon, it looks like the strongest area will remain west of
the airport. Tomorrow will be a different story with SE Turnagain
Arm winds expected to impact the airport in the afternoon.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
High pressure will continue to build over Southcentral Alaska,
keeping dry and clear conditions over the area through Tuesday
morning. The only exception remains the Copper River Basin, where
some residual moisture will keep some cloudy and showery
conditions over the area before clearing out this evening. A front
will track over Kodiak Island Tuesday morning, and continue
tracking northward over the Northern Gulf and Cook Inlet region by
early Wednesday morning. Rain and gusty winds are expected with
this system as it progresses northward. As the pressure gradient
tightens over the Turnagain Arm/Knik River Valley area and
Northern gulf coast, increased gap winds are expected through
Turnagain Arm/Knik River Valley and along the Copper River Tuesday
afternoon into Wednesday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2...Tue and Wed)...
A quiet weather day today will give way to a more active pattern
for the next couple of days. A warm front is pushing through the
Central Aleutians and will make its way into Bristol Bay by early
Tue morning. Light rain will track up the Alaska Peninsula and
into King Salmon/Dillingham around daybreak. A strengthening
coastal ridge will push against this front, forcing it to take on
a more west to east orientation and start to fall apart through
Tue. However, the ridge will help to produce gusty southeast
winds through much of the southwest, especially through favored
gaps.

Wed will see the front fall apart as it slowly tracks
inland. This will allow the synoptic forced gusts to diminish
with more diurnally enhanced winds dominating. Models all indicate
a potent vort max rotating through the area near the Kuskokwim
Mountains on Wed afternoon. If there are a few breaks in the
clouds and some instability can build into the area, there should
be a decent shot from some isolated thunderstorms. Held off on
introducing those into the forecast at this point as it still 48
hours out in time.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2...Tue and
Wed)...
The pattern remains much the same with a broad trough over the
Bering and weak pieces of energy rotating counter-clockwise
through it. The biggest changes today were to increase some of
the winds associated with the front lifting through the Central
Aleutians and increase precipitation potential over the Western
Bering with a shortwave dropping south. The winds should peak
tonight near the Alaska Peninsula and as the front gets squeezed
up against the west coast of the mainland. The shortwave dropping
through the Western Bering will bring another round of rain and
keep the small-craft winds blowing.
On Wed, a ridge tries to build in over the Western Aleutians. This
should bring a drying trend to the area. Winds will also be on a
downward trend as the surface low in the base of the trough drifts
east and weakens.

&&

.LONG TERM FORECAST (Days 3 through 7...Tues through Sat)...

The forecast period commences with two closed lows influencing the
Aleutians...one south of Kiska Island and the other west of
Kodiak. Both the GFS ensemble mean and the ECMWF are tightly
clustered at 500 MB with both features... while the Canadian GEM
pings into the lead storm but continues to have run to run
continuity issues with the second storm. Due to the handling of
the overall pattern...have better confidence in the ECMWF and GFS.
The coastal ridge will set up over SE AK and block the first
system. Expect the surface low to fill but definitely ushering
moisture into the AK Peninsula and Kodiak Island. While the second
pushes into the Gulf of Alaska robust easterly winds and an
impulse will get ejected from the system bringing the next wave
of moisture to the region. This is looking to be a pretty wet
period for the AK Peninsula and Kodiak...with ridging over the
Bering and ridging over the SE AK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 160.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...TP
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...PS