Storm Warning 172, NWS Anchorage, AK

958 
FZAK62 PAFC 221204
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
304 AM AKST Sun Dec 22 2019

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.

PKZ499-230145-
304 AM AKST Sun Dec 22 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A 962 mb low at 55N 176W Sun morning will move to 56N 170W Sun 
afternoon. The low then moves over Bristol Bay at 970 mb Mon 
afternoon. A second 992 mb North Pacific Low at 50N 177W Sun 
afternoon will move to 51N 174W Sun night. This low will then 
become absorbed into the low over Bristol Bay Mon afternoon. 

$$

PKZ411-230145-
Bering Sea Offshore West of 180 and East of the International
Dateline-
304 AM AKST Sun Dec 22 2019

...STORM WARNING TODAY...

.TODAY...NW wind 45 to 60 kt diminishing to 35 to 50 kt in the
afternoon. Seas 20 to 34 ft. Freezing spray. Snow showers and rain
showers.
.TONIGHT...NW wind 30 to 45 kt. Seas 18 to 25 ft. Freezing spray.
Snow showers.
.MON...NW wind 30 to 45 kt diminishing to 15 to 30 kt in the
afternoon. Seas 14 to 22 ft. Freezing spray.
.MON NIGHT...N wind 10 to 25 kt. Seas 9 to 14 ft.
.TUE...N wind 10 to 25 kt. Seas 6 to 11 ft.
.WED...E wind 10 to 25 kt. Seas 7 ft.
.THU...E wind 15 to 30 kt. Seas 9 to 17 ft.

$$

PKZ412-230145-
Bering Sea Offshore 171W to 180 and North of 56N-
304 AM AKST Sun Dec 22 2019

...STORM WARNING TODAY...

.TODAY...NE wind 35 to 50 kt. Seas 17 to 25 ft. Rain showers and
snow showers.
.TONIGHT...NE wind 25 to 40 kt diminishing to 20 to 30 kt after
midnight. Seas 18 to 25 ft. Snow showers and rain showers.
.MON...NE wind 15 to 30 kt. Seas 13 to 19 ft.
.MON NIGHT...N wind 10 to 20 kt. Seas 10 to 14 ft.
.TUE THROUGH WED...N wind up to 20 kt. Seas 6 to 11 ft.
.THU...NE wind 10 to 25 kt. Seas 5 to 10 ft.

$$

PKZ413-230145-
Bering Sea Offshore 171W to 180 and South of 56N-
304 AM AKST Sun Dec 22 2019

...HURRICANE FORCE WIND WARNING TODAY...

.TODAY...W wind 50 to 65 kt. Gusts to 85 kt. Seas 26 to 41 ft. Rain 
showers and snow showers.
.TONIGHT...W wind 35 to 50 kt. Seas 24 to 38 ft subsiding to 24 to
28 ft after midnight.  and rain showers.
.MON...NW wind 30 to 45 kt. Seas 16 to 27 ft. Snow showers.
.MON NIGHT...N wind up to 20 kt. Seas 12 to 18 ft.
.TUE THROUGH WED...N wind up to 20 kt. Seas 7 to 12 ft.
.THU...E wind 15 to 30 kt. Seas 7 to 12 ft.

$$

PKZ414-230145-
Bering Sea Offshore East of 171W-
304 AM AKST Sun Dec 22 2019

...STORM WARNING TONIGHT...

.TODAY...SE wind 30 to 45 kt. Seas 14 to 29 ft. Rain showers and
snow showers.
.TONIGHT...NE wind 35 to 50 kt becoming NW 25 to 40 kt after
midnight. Seas 19 to 34 ft. Rain showers with snow showers.
.MON...NW wind 20 to 30 kt. Seas 15 to 23 ft. Freezing spray.
.MON NIGHT...NW wind 15 to 30 kt. Seas 12 to 18 ft.
.TUE THROUGH THU...N wind 10 to 25 kt. Seas 6 to 11 ft.

$$

824 
FZAK62 PAFC 230021
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
321 PM AKST Sun Dec 22 2019

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.

PKZ499-231400-
321 PM AKST Sun Dec 22 2019
.SYNOPSIS FOR CENTRAL BERING SEA...

A 967 mb low at 56N 168W Sun afternoon moves to 58N 157W at 976 
mb Mon afternoon. A 989 mb low at 46N 179E Mon afternoon moves to
51N 169W at 973 mb Tue afternoon.

$$

PKZ411-231400-
Bering Sea Offshore West of 180 and East of the International
Dateline-
321 PM AKST Sun Dec 22 2019

...GALE WARNING THROUGH MONDAY...

.TONIGHT...NW wind 30 to 45 kt. Seas 16 to 23 ft. Freezing spray.
Snow.
.MON...NW wind 25 to 40 kt diminishing to 15 to 25 kt in the
afternoon. Seas 12 to 17 ft. Freezing spray.
.MON NIGHT...NW wind 10 to 25 kt. Seas 9 to 14 ft. Freezing spray.
.TUE AND TUE NIGHT...NW wind 10 to 25 kt. Seas 7 to 10 ft.
.WED THROUGH FRI...E wind 20 to 35 kt. Seas 9 to 14 ft.

$$

PKZ412-231400-
Bering Sea Offshore 171W to 180 and North of 56N-
321 PM AKST Sun Dec 22 2019

...GALE WARNING TONIGHT...

.TONIGHT...NE wind 20 to 35 kt. Seas 17 to 24 ft. Snow.
.MON...NE wind 10 to 25 kt. Seas 11 to 17 ft.
.MON NIGHT...NE wind 15 kt. Seas 10 to 13 ft. Freezing spray.
.TUE...NE wind up to 15 kt. Seas 8 ft.
.TUE NIGHT THROUGH WED...N wind up to 20 kt. Seas 7 ft.
.THU THROUGH FRI...NE wind 10 to 25 kt. Seas 6 to 11 ft.

$$

PKZ413-231400-
Bering Sea Offshore 171W to 180 and South of 56N-
321 PM AKST Sun Dec 22 2019

...STORM WARNING TONIGHT...

.TONIGHT...W wind 35 to 50 kt. Seas 20 to 34 ft. Rain with snow.
.MON...W wind 30 to 45 kt becoming NW 15 to 30 kt in the
afternoon. Seas 16 to 24 ft.
.MON NIGHT...N wind 10 to 25 kt. Seas 11 to 15 ft.
.TUE...NE wind 10 to 25 kt. Seas 9 ft.
.TUE NIGHT...N wind 10 to 25 kt. Seas 7 to 10 ft.
.WED...N wind up to 15 kt. Seas 7 ft.
.THU THROUGH FRI...E wind 10 to 25 kt. Seas 8 to 13 ft.

$$

PKZ414-231400-
Bering Sea Offshore East of 171W-
321 PM AKST Sun Dec 22 2019

...GALE WARNING TONIGHT...

.TONIGHT...N wind 30 to 45 kt. Seas 15 to 30 ft. Rain and snow
showers.
.MON...N wind 15 to 30 kt becoming 25 kt in the afternoon. 
Seas 12 to 20 ft. Snow and rain showers.
.MON NIGHT...NW wind 10 to 25 kt. Seas 9 to 14 ft. Freezing spray.
.TUE...N wind 10 to 25 kt. Seas 7 to 10 ft.
.TUE NIGHT...N wind 15 to 25 kt. Seas 6 to 9 ft.
.WED THROUGH FRI...NE wind 10 to 25 kt. Seas 5 to 10 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
500 AM AKST Sat Dec 21 2019

.ANALYSIS AND UPPER LEVELS...
Arctic air continues to drain southward. However, the bulk of the
coldest air remains locked north of the Alaska Range. Where the
skies were clear over night, radiational cooling occurred and a
number of locations in southcentral dipped into single digits and
below zero. On satellite imagery, there is a decaying frontal
boundary in western Alaska and a mature low in the North Pacific
with the leading edge of the cloud shield approaching Unalaska.
ASCAT/advanced scatterometer has detected gale and storm force
winds in the north Pacific associated with this low pressure
system. The jet core that is driving the Pacific storm was pegged
at 160 knots.

&&

.MODEL DISCUSSION...
Models remain in good synoptic agreement through Monday morning
from the Gulf Of Alaska to the North Pacific. Monday problems
emerge with a low near Bristol Bay. This low is headed eastward
but there is no consensus with the precise track yet. Overall,
next week looks more active with the potential snow for the
Anchorage Bowl.

&&

.AVIATION...

PANC...VFR conditions and light winds are anticipated this TAF
package.

&&

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

A weakening frontal system moving east across the mainland will
bring some clouds, but generally dry conditions with offshore flow
in the lower levels will prevail through today. Some light snow
with an upper wave and surface low over the eastern Gulf will
bring a little snow to the eastern Copper River Basin tonight.
Strong outflow gap winds across coastal locations in the northern
Gulf and NW gales across the Barren Islands will slowly diminish
through this evening. A triple point low develops along an
eastward moving front near Kodiak Island Sunday morning. This low
then heads slowly northeast and intensifies as the front moves to
the North Gulf Coast Sunday evening. These systems will initially
bring snow to Kodiak early Sunday morning which should then
transition to rain fairly quickly. Overrunning snow heads north
into Southcentral during the afternoon and evening hours on
Sunday. The brunt of precipitation(mainly snow) through Sunday
will likely be over the southern and eastern Kenai Peninsula and
Gulf Coastal locations. The deep cold airmass to the lee of the
Chugach/Kenai mountains will allow light snow to move inland as
moist southeast flow rides over the cold air.

&&

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

Southwest Alaska starts out with cold and dry weather in place.
Lows in interior areas of southwest AK will drop to the minus
teens tonight, with light flow from the Interior in place. This
will begin to change Sunday with the approach of a powerful low
pressure system in the Bering. This low will send a frontal system
into the southwest coast Sunday, bringing snow and increased wind
speeds, mainly for areas near Bristol Bay. This will cause blowing
snow with some visibility reduction possible. Interior areas of
southwest Alaska will still remain cold, with some increase in
cloud cover and light snow. Additionally, we are still looking
into elevated water levels along the coast, however the potential
looks low as of now for any surge.

&&

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

The powerful low anticipated for the Bering and Aleutians has made
its arrival, with the low center just now approaching the western
Aleutians from the southwest. It is well defined on satellite as a
mature, well wrapped low. As this low progresses east, it will
bring strong winds will cold air advection behind it. This is
where the main weather threat will be, with Hurricane Force winds
forecasted. The main core of these winds will remain over the
central Bering and are not expected to impact the Aleutian Islands
themselves. However, winds do look strong enough to keep the High
Wind Warning in effect for the Central Aleutians. We decided to
cancel the high wind watch for the Eastern Aleutians though, as
it looks like the low will be weakening by the time it reaches
there and the strongest winds will stay north of the islands.
Models were speeding the low up a bit and satellite does show it
moving pretty quick, so progressed it a touch quicker in the
forecast tonight. Otherwise, the forecast is on track with this
system.

&&

.MARINE (Days 3 through 5)...

Beginning the extended period marine forecast on Monday afternoon,
a weakening and departing gale force low in Bristol Bay will fall
apart by Tuesday morning. The Pacific storm track will shift
south of the Aleutian Chain through Thursday and move into the
Gulf of Alaska as a series of lows moves into the Gulf. Currently
the first will move into the Gulf by Tue and last through
Wednesday, possibly as a gale force low as it tracks north to the
Gulf Coast. A second low, possibly stronger, moves in sometimes
Wednesday/Wednesday night. Over the Bering, this pattern will
keep a cold, northerly or northeast flow over that area with areas
of freezing spray.

&&

.LONG TERM FORECAST (Days 4 through 7)...

The long term will kick off Tuesday with a deep pool of cold air
over the majority of mainland Alaska. A Bering low looks to track
across the northern Gulf Tuesday along the boundary of cold arctic
air spilling out of the state. Model guidance suggests a winter
precipitation event along the southern coast as the low moves
east. Another low in the Western Aleutians Tuesday is expected to
track across the Aleutian chain and into the northern Gulf on
Wednesday through Thursday, adding reinforcements with another
round of winter precipitation. Guidance is mixed on the exact
track of these two storms, but model guidance suggests that we
will be covered in cold air and odds for some wintry weather are
strong.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning 185.
MARINE...Heavy Freezing Spray 129 140 180 181. Hurricane Force 413
173 175 177. Storm 411 412 165 170 171 172 174 176 178. Gale 120
121 130 131 132 185 138 139 351 352 414 150 155 160 179 180 181.

&&

SYNOPSIS AND MODEL DISCUSSION...PJS
SOUTHCENTRAL ALASKA...RC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BJB
MARINE/LONG TERM...JA/LB