Storm Warning 24, NWS Anchorage, AK

096 
FZAK62 PAFC 121247
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
347 AM AKST Wed Feb 12 2020

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.

PKZ499-130200-
347 AM AKST Wed Feb 12 2020
.SYNOPSIS FOR CENTRAL BERING SEA...

A 984 mb low at 54N 168E will weaken and move to 55N 166E 
Wednesday afternoon. Wed morning a 972 mb low at 45N 175E 
deepens to 955mb and moves to 48 N 177E Wed night. This low will 
move 52N 179W Thursday night with a pressure of 960mb. 

$$

PKZ411-130200-
Bering Sea Offshore West of 180 and East of the International
Dateline-
347 AM AKST Wed Feb 12 2020

...STORM WARNING TONIGHT...

.TODAY...SE wind 15 to 30 kt becoming E 25 to 40 kt in the
afternoon. Seas 12 to 15 ft.
.TONIGHT...E wind 35 to 50 kt. Seas 14 to 22 ft. 
Rain showers and snow.
.THU...NE wind 25 to 40 kt. Seas 19 to 27 ft. 
Rain showers and snow.
.THU NIGHT...NE wind 20 to 35 kt. Seas 13 to 21 ft.
.FRI THROUGH SAT...NW wind 25 to 40 kt. Seas 11 to 19 ft.
.SUN...N wind 15 to 30 kt. Seas 11 to 19 ft.

$$

PKZ412-130200-
Bering Sea Offshore 171W to 180 and North of 56N-
347 AM AKST Wed Feb 12 2020

...GALE WARNING TONIGHT AND THURSDAY...
...HEAVY FREEZING SPRAY WARNING THURSDAY...

.TODAY...SE wind 10 to 20 kt. Seas 8 to 13 ft. Freezing spray.
.TONIGHT...E wind 20 to 35 kt increasing to 30 to 45 kt after
midnight. Seas 8 to 12 ft building to 10 to 18 ft after midnight.
Freezing spray. Snow.
.THU...E wind 25 to 40 kt. Seas 12 to 20 ft. Heavy freezing spray
near ice edge. Snow.
.THU NIGHT...E wind 20 to 35 kt. Seas 12 to 20 ft.
.FRI THROUGH SAT...S wind 20 to 35 kt. Seas 10 to 18 ft.
.SUN...E wind 10 to 25 kt. Seas 9 ft.

$$

PKZ413-130200-
Bering Sea Offshore 171W to 180 and South of 56N-
347 AM AKST Wed Feb 12 2020

...STORM WARNING TONIGHT...

.TODAY...S wind 10 to 25 kt becoming SE 25 to 40 kt in the
afternoon. Seas 8 to 13 ft.
.TONIGHT...E wind 35 to 50 kt. Seas 13 to 21 ft. Rain.
.THU...SE wind 30 to 45 kt. Seas 15 to 23 ft.
.THU NIGHT...S wind 30 to 40 kt. Seas 16 to 23 ft.
.FRI THROUGH SAT...SW wind 25 to 40 kt. Seas 12 to 20 ft.
.SUN...E wind 10 to 25 kt. Seas 7 to 11 ft.

$$

PKZ414-130200-
Bering Sea Offshore East of 171W-
347 AM AKST Wed Feb 12 2020

...GALE WARNING TONIGHT AND THURSDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH THURSDAY...

.TODAY...N wind 10 to 20 kt. Seas 3 to 7 ft. Heavy freezing spray
near ice edge.
.TONIGHT...NE wind 10 to 25 kt becoming E 20 to 35 kt after
midnight. Seas 3 to 8 ft. Heavy freezing spray near ice edge. Rain.
.THU...SE wind 20 to 35 kt. Seas 4 to 9 ft. Heavy freezing spray near
ice edge. Snow showers.
.THU NIGHT...S wind 15 to 30 kt. Seas 4 to 9 ft.
.FRI THROUGH SAT...S wind 15 to 30 kt. Seas 6 to 11 ft.
.SUN...SE wind 10 to 25 kt. Seas 3 to 8 ft.

$$

758 
FZAK62 PAFC 130022
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
322 PM AKST Wed Feb 12 2020

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.

PKZ499-131400-
322 PM AKST Wed Feb 12 2020
.SYNOPSIS FOR CENTRAL BERING SEA...

A 957 mb low near 49N 179E will move to 57N 176W at 972 mb Fri
afternoon. 

$$

PKZ411-131400-
Bering Sea Offshore West of 180 and East of the International
Dateline-
322 PM AKST Wed Feb 12 2020

...GALE WARNING THROUGH THURSDAY...

.TONIGHT...E wind 30 to 45 kt. Seas 13 to 21 ft. Rain showers and
snow.
.THU...NE wind 30 to 40 kt diminishing to 20 to 35 kt in the
afternoon. Seas 18 to 22 ft. Rain showers and snow.
.THU NIGHT...NE wind 15 to 30 kt. Seas 12 to 19 ft. Snow showers
and
rain showers.
.FRI...N wind 15 to 30 kt. Seas 10 to 17 ft.
.FRI NIGHT...N wind 10 to 25 kt. Seas 10 to 15 ft.
.SAT THROUGH MON...N wind 15 to 30 kt. Seas 10 to 18 ft.

$$

PKZ412-131400-
Bering Sea Offshore 171W to 180 and North of 56N-
322 PM AKST Wed Feb 12 2020

...GALE WARNING THROUGH THURSDAY...
...HEAVY FREEZING SPRAY WARNING THURSDAY...

.TONIGHT...E wind 20 to 35 kt increasing to 30 to 40 kt after
midnight. Seas 9 to 17 ft. Freezing spray. Snow.
.THU...E wind 25 to 40 kt. Seas 11 to 18 ft. Heavy freezing spray.
Snow.
.THU NIGHT...E wind 30 kt. Seas 11 to 18 ft. Freezing spray.
.FRI...E wind 15 to 30 kt. Seas 12 to 17 ft.
.FRI NIGHT...N wind 15 to 30 kt. Seas 9 to 14 ft.
.SAT...NW wind 10 to 25 kt. Seas 8 to 12 ft.
.SUN...E wind 10 to 25 kt. Seas 9 ft.
.MON...N wind 15 to 25 kt. Seas 8 to 11 ft.

$$

PKZ413-131400-
Bering Sea Offshore 171W to 180 and South of 56N-
322 PM AKST Wed Feb 12 2020

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...E wind 30 to 45 kt. Seas 11 to 19 ft. Rain.
.THU...SE wind 25 to 40 kt. Seas 13 to 21 ft.
.THU NIGHT...S wind 20 to 35 kt. Seas 12 to 20 ft. Rain showers
and
snow showers.
.FRI...SW wind 20 to 35 kt. Seas 10 to 18 ft.
.FRI NIGHT...W wind 20 to 35 kt. Seas 10 to 18 ft.
.SAT...SW wind 15 to 30 kt. Seas 10 to 18 ft.
.SUN...E wind 10 to 25 kt. Seas 7 to 11 ft.
.MON...NW wind 10 to 25 kt. Seas 9 to 12 ft.

$$

PKZ414-131400-
Bering Sea Offshore East of 171W-
322 PM AKST Wed Feb 12 2020

...GALE WARNING TONIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...E wind 10 to 25 kt increasing to 20 to 35 kt after
midnight. Seas 3 to 8 ft. Heavy freezing spray.
.THU...SE wind 15 to 30 kt. Seas 3 to 8 ft. Heavy freezing spray.
Snow showers.
.THU NIGHT...SE wind 15 to 30 kt. Seas 6 to 11 ft. Heavy freezing
spray. Snow.
.FRI...S wind 20 to 30 kt. Seas 7 to 12 ft.
.FRI NIGHT...S wind 20 to 35 kt. Seas 7 to 12 ft.
.SAT...SW wind 15 to 30 kt. Seas 7 to 12 ft.
.SUN...SE wind 10 to 25 kt. Seas 3 to 8 ft.
.MON...N wind 15 to 30 kt. Seas 5 to 10 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
427 AM AKST Tue Feb 11 2020

.ANALYSIS AND UPPER LEVELS...

On satellite imagery there is a frontal boundary over the central
Aleutians with a new wave developing near Atka. The original low
that anchored the occlusion is filling and is near Attu Island.
Remnants of the occlusion span from the Western Aleutians to NE
Russia and into portions of western Alaska. There is another low
spinning up east of Japan. Most of the Gulf Of Alaska and
Southcentral is under clear skies. There is a jet core east of
Cordova and a second jet core well south of the chain associated
with the system east of Japan. The latest ASCAT (advanced
scatterometer) pass has detected gale force winds over the Barren
Islands and a few gales associated with the front in the Central
Aleutians.

&&

.MODEL DISCUSSION...

The ensemble members of the GFS are tightly grouped through 24
hrs and beyond that problems emerge in the North Pacific. The
ensembles and the operational runs all show a progressive pattern
with back to back lows impacting the Aleutians and the Gulf Of
Alaska but the timing of the low tracks is clearly out of sync.
Since these storms have modified tropical moisture associated
with them the differences will ultimately impacted the level of
precision with identifying which locations will get a wintry mix
(rain/snow combo). The areas of concern will be the Central
Aleutians, AKPEN, Kodiak and Prince William Sound. The models all
ping into arctic air banked up against the Alaska Range with some
of the arctic air seeping into Southcentral.

&&

.AVIATION...

PANC...VFR conditions are expected this TAF package. There is a
low pressure system that is moving towards Southcentral, however
the leading edge of the precipitation shield is not expected to
reach the aerodrome this TAF package. "Down Inlet" flow will
continue and northerly wind will continue over PANC through 6z
Thursday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
High pressure at the surface and aloft will remain over the
Southcentral mainland today. Offshore winds will diminish during
the day as the surface gradient relaxes. A fairly strong system
will move into the Gulf of Alaska from the south today.
Precipitation and increasing winds will reach Kodiak Island this
afternoon and increase this evening. The precipitation will start
as snow on Kodiak, with some blowing snow. This will mix with or
change to rain later in the night through Wednesday morning.
Precipitation will reach the Kenai Peninsula Tuesday evening, and
move inland Tuesday night and Wednesday. The best chances for snow
are along the Gulf Coast, and Inland through the Copper River
Basin. Areas from northern Cook Inlet through the Susitna valley
have a chance of snow, but accumulations look unlikely at this
time.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...

Weak low pressure is currently pushing into Southwest Alaska. The
cirrus shield of this system can be well seen on satellite. This
low is mostly a mid to upper level low and is not being reflected
at the surface. In fact, winds in southwest Alaska are generally
northeasterly as the mid level cloud cover of this low rides over
the top of cold air. So not much will amount from current weather,
save for a slight warm-up...therefore little adjustment was made
to the forecast tonight.

Later today into Wednesday a second low pressure will slide east
across the AKPEN. This should bring a shot of snow to the Bristol
Bay area. More importantly, winds wrapping around the backside of
the low will strengthen northeasterly flow for all of Southwest
AK, especially Wednesday night into Thursday. Temperatures will
drop as well as they are drawn south from the Interior. Right now
we do not expect wind chill to meet advisory criteria, but be
prepared for it to get cold again.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...

Low pressure in the far Western Bering continues to hang a weak
front across the Western Bering/Aleutians. Some gale force winds
are still expected from it today though. This low will drift
northwest and decay through Wednesday. Meanwhile, strong
northeasterly flow will begin to setup late today in the eastern
Bering and be in full force Wednesday. This will make for an
interesting wind pattern in the central Bering as this northeasterly
flow collides with the front out west. This amounts to sharply
shifting wind and some areas of gale force in the central Bering
as these two air masses compete for real estate in the Bering.

Wednesday into Thursday a more powerful low pressure system is
expected to work its way north out of the north Pacific and across
the western Aleutians into the Bering. As of now, we have it to
bring storm force winds with it. However, models are hinting at
some stronger winds, so we will continue to hone the wind forecast
with this system. This low will be the next big weather maker for
the Bering Sea, so stay tuned to the forecast.

&&

.MARINE (Days 3 through 5: Thursday through Saturday)...

A strong storm will be moving across the central Aleutians into
the central Bering Sea Thursday and Friday then weaken Sunday.
Gale force wind can be expected north of the low and in advance of
it's front Thursday and Friday. Gale force west and southwest wind
is likely south of this low as it crosses the Aleutians Friday.

Over the Gulf of Alaska, winds will remain below gale force
Thursday through Saturday.

&&

.LONG TERM FORECAST (Days 3 through 7: Thursday through Monday)...

A strong ~960mb storm crosses the central Aleutians Thursday,
moving into the central Bering Sea as it weakens. This storm will
push a front through the Aleutians and Alaska Peninsula that will
then elongate to the east as a triple point low forms along it
near Kodiak Thursday night. The main low over the Bering Sea will
gradually weaken through Friday and Saturday. The models diverge
on the location of the center Friday and Saturday and also begin
to diverge significantly Saturday night and Sunday with respect to
the remnants of this storm and the approach of the next strong
Aleutian and Bering Sea storm Sunday. The latest model runs
support a much stronger storm than the previous solutions, but
also diverge on the location of the storm center. Confidence in
the extended forecast beyond Saturday is low due to the varied and
significantly differing solutions. The approach will be to
maintain the current forecast solutions with adjustments trending
toward the ECMWF solution.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 119 120 130 131 132 136 137 138 139 351 352 411 412
413 414 150 155 160 170 172 173 174 175 176 177 178 179. Heavy
Freezing Spray 121 129 139 414 412 160 155 150.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...PJS
SOUTHCENTRAL ALASKA...BL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BJB
MARINE/LONG TERM...SA