Storm Warning 127, NWS Anchorage, AK

503 
FZAK62 PAFC 221301
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
401 AM AKST Wed Nov 22 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.

PKZ499-230215-
401 AM AKST Wed Nov 22 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 983 mb low at 58N 180E moves to 60N 164W at 968 mb Thu morning then
shifts south and moves to 55N 147W at 978 mb. The associated 
front pushes across the Bering and over the Alaska Peninsula by 
Thu afternoon.

$$

PKZ411-230215-
Bering Sea Offshore West of 180 and East of the International
Dateline-
401 AM AKST Wed Nov 22 2017

...GALE WARNING THROUGH TONIGHT...

.TODAY...NW wind 30 to 45 kt. Seas 14 to 22 ft.
.TONIGHT...NW wind 30 to 45 kt becoming W 20 to 35 kt after
midnight. Seas 13 to 21 ft.
.THU...SW wind 15 to 30 kt. Seas 9 to 15 ft.
.THU NIGHT...S wind 20 to 30 kt. Seas 8 to 12 ft.
.FRI THROUGH SAT...W wind 25 to 40 kt. Seas 10 to 18 ft.
.SUN...S wind 10 to 25 kt. Seas 9 to 14 ft.

$$

PKZ412-230215-
Bering Sea Offshore 171W to 180 and North of 56N-
401 AM AKST Wed Nov 22 2017

...STORM WARNING THROUGH THURSDAY...

.TODAY...W wind 35 to 50 kt. Gusts to 65 kt. Seas 14 to 21 ft 
building to 20 to 27 ft in the afternoon. Snow showers.
.TONIGHT...NW wind 40 to 55 kt. Gusts to 70 kt. Seas 23 to 34 ft. 
Snow showers.
.THU...NW wind 35 to 50 kt becoming W 25 to 35 kt in the
afternoon. Gusts to 65 kt in the morning. Seas 16 to 31 ft.
.THU NIGHT...W wind 20 to 30 kt. Seas 11 to 18 ft.
.FRI...SW wind 20 to 35 kt. Seas 8 to 13 ft.
.SAT...W wind 15 to 30 kt. Seas 9 to 15 ft.
.SUN...NE wind up to 15 kt. Seas 6 to 11 ft.

$$

PKZ413-230215-
Bering Sea Offshore 171W to 180 and South of 56N-
401 AM AKST Wed Nov 22 2017

...STORM WARNING TONIGHT...

.TODAY...W wind 35 to 45 kt. Seas 16 to 23 ft.
.TONIGHT...NW wind 35 to 50 kt. Gusts to 65 kt. Seas 18 to 29 ft. 
Snow showers.
.THU...NW wind 30 to 45 kt becoming W 15 to 30 kt in the
afternoon. Seas 15 to 30 ft.
.THU NIGHT...W wind 15 to 30 kt. Seas 9 to 17 ft.
.FRI...S wind 25 to 40 kt. Seas 8 to 13 ft.
.SAT...W wind 20 to 35 kt. Seas 7 to 12 ft.
.SUN...N wind up to 20 kt. Seas 5 to 10 ft.

$$

PKZ414-230215-
Bering Sea Offshore East of 171W-
401 AM AKST Wed Nov 22 2017

...STORM WARNING TONIGHT AND THURSDAY...

.TODAY...SW wind 30 to 45 kt. Seas 13 to 21 ft. Rain.
.TONIGHT...W wind 45 to 60 kt. Gusts to 75 kt. Seas 20 to 34 ft. 
Rain showers and snow showers.
.THU...NW wind 45 to 60 kt. Seas 21 to 36 ft. Rain showers.
.THU NIGHT...NW wind 30 to 45 kt. Seas 15 to 23 ft.
.FRI...W wind 15 to 30 kt. Seas 7 to 12 ft.
.SAT...S wind 15 to 30 kt. Seas 7 to 12 ft.
.SUN...N wind 15 kt. Seas 9 to 15 ft.

$$

091 
FZAK62 PAFC 230023
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
323 PM AKST Wed Nov 22 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.

PKZ499-231345-
323 PM AKST Wed Nov 22 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 969 mb low at 61N 171W dives to 52N 151W at 983 mb Thu night 
then merges with a 978 mb low in the Southern Gulf of Alaska for 
Fri afternoon. The associated front pushes across the Alaska 
Peninsula through Fri afternoon. A new front edges over the 
Western Aleutians by Fri afternoon. 

$$

PKZ411-231345-
Bering Sea Offshore West of 180 and East of the International
Dateline-
323 PM AKST Wed Nov 22 2017

...GALE WARNING TONIGHT...

.TONIGHT...NW wind 30 to 45 kt becoming W 20 to 35 kt after
midnight. Seas 13 to 21 ft.
.THU...SW wind 15 to 30 kt. Seas 9 to 15 ft.
.THU NIGHT...S wind 20 to 30 kt. Seas 8 to 12 ft.
.FRI...S wind 25 to 40 kt. Seas 10 to 15 ft.
.FRI NIGHT...W wind 20 to 35 kt. Seas 9 to 15 ft.
.SAT THROUGH SUN...NW wind 20 to 35 kt. Seas 9 to 14 ft.
.MON...E wind 20 to 35 kt. Seas 11 to 19 ft.

$$

PKZ412-231345-
Bering Sea Offshore 171W to 180 and North of 56N-
323 PM AKST Wed Nov 22 2017

...STORM WARNING THROUGH THURSDAY...

.TONIGHT...NW wind 40 to 55 kt. Seas 23 to 34 ft. Snow showers.
.THU...NW wind 35 to 50 kt becoming W 25 to 35 kt in the
afternoon. Seas 17 to 32 ft subsiding to 14 to 22 ft in the 
afternoon.
.THU NIGHT...W wind 20 to 30 kt. Seas 11 to 17 ft.
.FRI...SW wind 20 to 35 kt. Seas 11 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 9 to 12 ft.
.SAT THROUGH SUN...N wind 25 to 40 kt. Seas 9 to 14 ft.
.MON...E wind 15 to 30 kt. Seas 8 to 13 ft.

$$

PKZ413-231345-
Bering Sea Offshore 171W to 180 and South of 56N-
323 PM AKST Wed Nov 22 2017

...STORM WARNING TONIGHT...

.TONIGHT...NW wind 35 to 50 kt. Seas 17 to 29 ft. Snow showers.
.THU...NW wind 30 to 45 kt becoming W 15 to 30 kt in the
afternoon. Seas 14 to 29 ft.
.THU NIGHT...W wind 15 to 30 kt becoming SW after midnight. Seas
9 to 17 ft.
.FRI...S wind 25 to 40 kt. Seas 8 to 12 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 8 to 13 ft.
.SAT...NW wind 20 to 35 kt. Seas 6 to 11 ft.
.SUN...NW wind 25 to 40 kt. Seas 12 to 19 ft.
.MON...S wind 20 to 35 kt. Seas 10 to 18 ft.

$$

PKZ414-231345-
Bering Sea Offshore East of 171W-
323 PM AKST Wed Nov 22 2017

...STORM WARNING THROUGH THURSDAY...

.TONIGHT...W wind 45 to 60 kt. Seas 20 to 35 ft. Rain showers and
snow showers.
.THU...NW wind 45 to 60 kt. Seas 22 to 37 ft.  and rain showers.
.THU NIGHT...NW wind 30 to 45 kt diminishing to 20 to 30 kt after
midnight. Seas 14 to 22 ft.
.FRI...NW wind 15 to 30 kt. Seas 9 to 13 ft.
.FRI NIGHT...SW wind 15 to 30 kt. Seas 6 to 11 ft.
.SAT...SE wind 15 to 30 kt. Seas 6 to 11 ft.
.SUN...S wind 20 to 35 kt. Seas 12 to 19 ft.
.MON...NW wind 20 to 35 kt. Seas 9 to 17 ft.

$$

474 
FZAK62 PAFC 231243
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
343 AM AKST Thu Nov 23 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.

PKZ499-240200-
343 AM AKST Thu Nov 23 2017
.SYNOPSIS FOR CENTRAL BERING SEA...
A 969 mb low at 60N 162W will move to 57N 158W at 979 mb by this
afternoon, then it will move into the western Gulf at 984 mb this 
evening. A front pushing into the western Aleutians Fri morning 
will continue east to arrive in the eastern Aleutians by Sat 
morning.

$$

PKZ411-240200-
Bering Sea Offshore West of 180 and East of the International
Dateline-
343 AM AKST Thu Nov 23 2017

...GALE WARNING FRIDAY...

.TODAY...SW wind 15 to 25 kt. Seas 9 to 15 ft.
.TONIGHT...S wind 20 to 30 kt. Seas 8 to 12 ft.
.FRI...S wind 25 to 35 kt. Seas 10 to 14 ft. Rain.
.FRI NIGHT...W wind 15 to 30 kt. Seas 9 to 14 ft.
.SAT THROUGH SUN...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.MON...NE wind up to 20 kt. Seas 8 to 16 ft.

$$

PKZ412-240200-
Bering Sea Offshore 171W to 180 and North of 56N-
343 AM AKST Thu Nov 23 2017

...STORM WARNING TODAY...

.TODAY...NW wind 35 to 50 kt becoming W 25 to 35 kt in the
afternoon. Seas 15 to 30 ft.
.TONIGHT...W wind 25 kt. Seas 9 to 17 ft.
.FRI...SW wind 25 kt becoming 15 to 30 kt in the afternoon. 
Seas 10 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 9 to 13 ft.
.SAT THROUGH SUN...N wind 25 to 40 kt. Seas 10 to 18 ft.
.MON...N wind 10 to 25 kt. Seas 7 to 12 ft.

$$

PKZ413-240200-
Bering Sea Offshore 171W to 180 and South of 56N-
343 AM AKST Thu Nov 23 2017

...GALE WARNING TODAY AND FRIDAY...

.TODAY...NW wind 30 to 45 kt becoming W 15 to 30 kt in the
afternoon. Seas 14 to 29 ft.
.TONIGHT...SW wind 15 to 25 kt. Seas 10 to 18 ft subsiding to 7 to
12 ft after midnight.
.FRI...SW wind 15 to 25 kt becoming S 20 to 35 kt in the
afternoon. Seas 7 to 11 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 8 to 13 ft.
.SAT THROUGH SUN...NW wind 30 to 45 kt. Seas 13 to 21 ft.
.MON...N wind 10 to 25 kt. Seas 8 to 13 ft.

$$

PKZ414-240200-
Bering Sea Offshore East of 171W-
343 AM AKST Thu Nov 23 2017

...STORM WARNING TODAY...

.TODAY...NW wind 45 to 55 kt diminishing to 35 to 50 kt in the
afternoon. Gusts to 75 kt through this morning. Seas 21 to 36 ft.
.TONIGHT...NW wind 25 to 40 kt. Seas 14 to 22 ft.
.FRI...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.FRI NIGHT...S wind 15 to 30 kt. Seas 6 to 10 ft.
.SAT...SE wind 20 to 35 kt. Seas 8 to 13 ft.
.SUN...NE wind 20 to 35 kt. Seas 9 to 17 ft.
.MON...NW wind 15 to 30 kt. Seas 9 to 14 ft.

$$

187 
FZAK62 PAFC 240034
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
334 PM AKST Thu Nov 23 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.

PKZ499-241400-
334 PM AKST Thu Nov 23 2017
.SYNOPSIS FOR CENTRAL BERING SEA...

A 986 mb low at 55N 157W swings across the Northern Pacific 
through Sat afternoon. High pressure moves to the Eastern Bering 
by Sat morning. A 977 mb Russian Far East low extends a front 
over the Bering to a 984 mb low near 56N 171W and a 987 mb low 
around 50N 178W that form Sat afternoon.

$$

PKZ411-241400-
Bering Sea Offshore West of 180 and East of the International
Dateline-
334 PM AKST Thu Nov 23 2017

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...S wind 20 to 30 kt. Seas 8 to 12 ft.
.FRI...S wind 35 kt. Seas 9 to 15 ft. Rain.
.FRI NIGHT...W wind 20 to 35 kt. Seas 10 to 17 ft. Rain.
.SAT...W wind 10 to 25 kt. Seas 8 to 13 ft.
.SAT NIGHT...NW wind 10 to 25 kt. Seas 8 ft.
.SUN...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.MON...NE wind up to 20 kt. Seas 8 to 16 ft.
.TUE...NW wind 15 to 25 kt. Seas 13 to 21 ft.

$$

PKZ412-241400-
Bering Sea Offshore 171W to 180 and North of 56N-
334 PM AKST Thu Nov 23 2017

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 10 to 17 ft subsiding to 11 ft after
midnight.
.FRI...SW wind 25 kt becoming 15 to 30 kt in the afternoon. Seas
8 to 11 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 9 to 14 ft. Rain.
.SAT...NW wind 15 to 30 kt. Seas 9 to 15 ft.
.SAT NIGHT...N wind 30 to 45 kt. Seas 10 to 18 ft.
.SUN...N wind 25 to 40 kt. Seas 13 to 21 ft.
.MON THROUGH TUE...N wind 10 to 25 kt. Seas 7 to 12 ft.

$$

PKZ413-241400-
Bering Sea Offshore 171W to 180 and South of 56N-
334 PM AKST Thu Nov 23 2017

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 15 to 25 kt. Seas 10 to 18 ft subsiding to 8 to
12 ft after midnight.
.FRI...S wind 15 to 30 kt. Seas 7 to 10 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 8 to 13 ft. Rain.
.SAT...N wind 15 to 30 kt. Seas 7 to 12 ft.
.SAT NIGHT...NW wind 30 to 45 kt. Seas 10 to 18 ft.
.SUN...NW wind 30 to 45 kt. Seas 14 to 28 ft.
.MON THROUGH TUE...N wind 10 to 25 kt. Seas 9 to 17 ft.

$$

PKZ414-241400-
Bering Sea Offshore East of 171W-
334 PM AKST Thu Nov 23 2017

...GALE WARNING TONIGHT...

.TONIGHT...NW wind 25 to 40 kt. Seas 13 to 21 ft.
.FRI...W wind 15 to 30 kt. Seas 8 to 13 ft.
.FRI NIGHT...W wind up to 20 kt becoming SE 15 to 30 kt after
midnight. Seas 7 to 10 ft.
.SAT...SE wind 15 to 30 kt. Seas 6 to 10 ft.
.SAT NIGHT...SE wind 25 to 40 kt. Seas 9 to 17 ft.
.SUN...NE wind 25 to 40 kt. Seas 11 to 19 ft.
.MON...NW wind 15 to 30 kt. Seas 9 to 14 ft.
.TUE...NE wind up to 15 kt. Seas 4 to 8 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
549 AM AKST Tue Nov 21 2017

.ANALYSIS AND UPPER LEVELS...
A frontal system is currently pushing onshore across the Kuskokwim
Delta and into Southwest Alaska early this morning. Along the
coast temperatures behind the front have warmed into the mid 30s,
but inland temperatures remain cooler with snow the prevailing
precipitation type. Over Southcentral Alaska, offshore flow
weakens as a flat upper level ridge shifts east. Flat ridging also
persists across the Aleutians and much of the Bering with the
next developing frontal system still well to the southwest of the
western Aleutians.

&&

.MODEL DISCUSSION...
Models continue to be in good agreement with the front crossing
Southwest Alaska today and continuing east as a trough moving
into Southcentral Alaska this afternoon and evening. With regards
to the powerful low approaching the Southwest Alaska coast
Wednesday afternoon and evening, the 00Z GFS and EC have come in
to very good agreement on the strength and depth of the low
center. The 00Z NAM and Canadian track the low further south and
roughly 10 mb shallower, which while still windy would lead to a
colder solution. The stronger and more northerly solution was
preferred and is consistent with the strong thermal gradient
present across the Bering. Additionally the 06Z NAM came in in
better agreement with the GFS and EC, further favoring the more
northerly solution and potential for stronger southerly flow and
more warming along the coast ahead of the front.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist through the day
with the potential for brief periods of MVFR conditions in light
snow showers this evening.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 2)...

Dry offshore flow is quickly weakening this morning as shortwave
ridging builds over the region ahead of a weakening shortwave
trough which is currently moving inland along the west coast of
Alaska. Clouds will increase through the day with light snow
moving into inland Southcentral as the shortwave trough moves
eastward in the late afternoon and evening. Moisture is going to
be rather meager given the recent offshore flow, but there should
be enough forcing for ascent and low level southwest flow up Cook
Inlet to support light snow (generally an inch or less).

The shortwave trough will continue east overnight and Wednesday,
bringing another shot of cold air advection and rapidly
intensifying offshore winds. With the movement from west to east,
this event will tend to favor gaps along western Prince William
Sound and through Thompson Pass/Valdez. Westerly/northwest winds
will also ramp up to near storm force across the Barren Islands
over the marine waters. Another front will quickly move into the
western Gulf of Alaska Wednesday evening and overnight, bringing
rain and snow to Kodiak and the southern Kenai coastline.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...

The calm before the storm aptly sums up the weather for Southwest
Alaska. Currently a weak cold front is crossing the region at 5
am, with the front stretching from Bethel to Goodnews Bay. Ahead
of this feature, widespread areas of light snow have developed
with some reduced visibilities observed. This will continue to
spread eastward through the day, with drier conditions returning
briefly.

Our attention then turns to a rapidly deepening storm that is
expected to affect the region as a ~965 mb low tracks from near
Nunivak Island Wednesday afternoon towards Bristol Bay Thursday
morning. An attendant cold front will surge eastward, before
stalling across central portions of southwest Alaska. A pretty
stout low-level jet of 55 to 70 knots will develop ahead of it,
with some of this energy mixing down to the surface, where
sustained southerly winds of 30 to 50 mph are expected. With the
waters still ice free and a decent fetch seen in the model data,
some high surf and beach erosion issues may develop, mainly from
Kipnuk south towards Goodnews Bay. Additionally, widespread
snowfall will develop along and ahead of the front, with perhaps 4
to 8 inches possible east of a Bethel to King Salmon line. This
is near where the front is expected to stall, with good surface
convergence and and strong ascent aloft, some mesoscale banding
will probably develop, enhancing the snowfall intensity. Closer to
the coast, temperatures will likely warm for the snow to turn to
mainly a rain snow mix with minor accumulations possible.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

Another strong Bering Sea storm will bring more strong winds to
the eastern Bering Sea, Akpen, and eastern Aleutians. Generally
quiet weather is expected through the next 12 to 18 hours before
things begin to change, as a ~993 mb low north of Shemya Tuesday
evening heads towards Saint Matthews Island while rapidly
deepening to ~965 mb by early Wednesday afternoon, with an
attendant cold front sweeping east. This low is forecast to then
strengthen a few more millibars as it treks east towards Nunivak
island, before dropping southeast into Bristol bay Thursday
morning. Widespread precipitation and storm force winds will
develop along and ahead of the front.

As the low moves along the coast of Southwest Alaska, a PV
anomaly will dive southeast on the backside of the low, with
heights lowering to below 450mb. This will help compress the area
while interacting with strong cold and dry advection. This type
of setup is similar to a storm last week, albeit stronger in all
aspects. As such, some hurricane force wind gusts may develop
cross the eastern Bering and portions of the AKPEN/eastern
Aleutians. However, this is currently forecast to occur 3 to 4
periods out and given some uncertainty in strength and positioning
of the surface low among the various models, we decided to hold
off on a high wind watch for now. However, a special weather
statement was issued to cover these concerns.

Further west, once the storm force winds associated with the
front shift off to the east, wrap-around cold advection will
still maintain high-end gales to low-end storm force winds for
the western Bering, with lighter winds farther south across the
chain, and precipitation becoming more showery in nature.

&&

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

A ridge of high pressure enters from the west, meaning that
Thursday through Saturday should be clear and cold for most of the
state. The next system to impact the Alaska region is a low that
is forecast to move northward along the Kamchatka peninsula,
pushing a front through the Aleutians on Sunday. After the Sunday
time frame, model uncertainty becomes much higher, but for now, it
looks like a ridge will push storms approaching from the west
away from the mainland and into the Gulf of AK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 120 127 130-132 136 138 150 155 160 165 170 172-180
         181 185 351 352.
         Storm 411 412.

&&

SYNOPSIS AND MODEL DISCUSSION...JR
SOUTHCENTRAL ALASKA...Ahsenmacher
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...P Doll
LONG TERM...LF