Heavy Freezing Spray Warning 95, NWS Anchorage, AK

299 
FZAK62 PAFC 232324
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
324 PM AKDT Tue Mar 23 2021

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.

PKZ499-241315-
324 PM AKDT Tue Mar 23 2021

.SYNOPSIS FOR CENTRAL BERING SEA...

There is a 982 mb low at 66N 179E. The front crosses the Aleutians 
and Bering Mon through Wed morning. The front then becomes nearly 
stationary over the southern Bering as it weakens through Thu 
morning. Another front approaches the western Bering by Thu morning.

$$

PKZ411-241315-
Bering Sea Offshore West of 180 and East of the International
Dateline-
324 PM AKDT Tue Mar 23 2021

.TONIGHT...W wind 15 to 30 kt. Seas 12 to 19 ft.
.WED...W wind 10 to 20 kt. Seas 9 to 14 ft.
.WED NIGHT...SW wind 10 to 25 kt. Seas 9 to 14 ft.
.THU...W wind 20 to 30 kt. Seas 11 to 16 ft.
.THU NIGHT...W wind 15 to 30 kt. Seas 12 to 17 ft.
.FRI...W wind 10 to 25 kt. Seas 9 to 14 ft.
.SAT...E wind 15 to 30 kt. Seas 8 to 16 ft.
.SUN...NW wind 10 to 25 kt. Seas 16 to 27 ft.

$$

PKZ412-241315-
Bering Sea Offshore 171W to 180 and North of 56N-
324 PM AKDT Tue Mar 23 2021

.TONIGHT...W wind 15 to 30 kt. Seas 17 to 21 ft.
.WED...W wind 10 to 20 kt. Seas 10 to 16 ft.
.WED NIGHT...W wind 10 to 20 kt. Seas 10 ft.
.THU...SW wind 10 to 25 kt. Seas 8 to 12 ft.
.THU NIGHT...W wind 20 to 30 kt. Seas 10 to 16 ft.
.FRI...W wind 15 to 30 kt. Seas 10 to 17 ft.
.SAT...E wind 10 to 25 kt. Seas 9 to 14 ft.
.SUN...SE wind 10 to 25 kt. Seas 17 to 23 ft.

$$

PKZ413-241315-
Bering Sea Offshore 171W to 180 and South of 56N-
324 PM AKDT Tue Mar 23 2021

...GALE WARNING TONIGHT...

.TONIGHT...SW wind 20 to 35 kt diminishing to 10 to 25 kt after
midnight. Seas 12 to 19 ft. Rain and snow.
.WED...W wind up to 20 kt increasing to 15 to 25 kt in the
afternoon. Seas 10 to 14 ft. Snow and rain.
.WED NIGHT...W wind 15 to 25 kt. Seas 9 ft.
.THU...W wind 15 to 25 kt. Seas 8 to 12 ft.
.THU NIGHT...W wind 25 kt. Seas 9 to 15 ft.
.FRI...SW wind 10 to 25 kt. Seas 10 to 16 ft.
.SAT...SE wind 15 to 30 kt. Seas 9 to 17 ft.
.SUN...S wind 10 to 25 kt. Seas 22 to 31 ft.

$$

PKZ414-241315-
Bering Sea Offshore East of 171W-
324 PM AKDT Tue Mar 23 2021

...GALE WARNING TONIGHT...

.TONIGHT...SW wind 25 to 40 kt diminishing to 20 to 30 kt after
midnight. Seas 9 to 17 ft. Snow and rain.
.WED...SW wind 15 to 30 kt. Seas 10 to 15 ft. Snow and rain.
.WED NIGHT...W wind 10 to 25 kt becoming 15 kt after midnight.
Seas 9 to 14 ft. Rain.
.THU...W wind 10 to 20 kt. Seas 6 to 10 ft.
.THU NIGHT...W wind 10 to 25 kt. Seas 6 to 9 ft.
.FRI THROUGH SAT...W wind 10 to 25 kt. Seas 8 to 13 ft.
.SUN...S wind 15 to 30 kt. Seas 15 to 30 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
504 PM AKDT Mon Mar 22 2021

.ANALYSIS AND UPPER LEVELS...

The weak ridge axis continues to move eastward and now stretches
north across eastern Prince William Sound and the eastern
interior. Under the ridge, conditions are generally clear with
light winds and cold temps.

Farther west, low pressure well south of the eastern Aleutians is
moving northeast toward Kodiak Island. A front associated with
this system is extending into the western Gulf. A secondary trough
is moving east over Southwest Alaska with light snow falling from
interior Bristol Bay into the Kuskokwim Valley.

For the Bering, an amplified ridge of high pressure is keeping
conditions rather tranquil for the western half of the Bering and
the Aleutian Chain. A northerly flow ahead of the ridge is
producing gusty winds and snow showers from the Pribilofs south to
Unalaska and Cold Bay. To the west of the ridge, another strong
low pressure system with an attendant trough is near the
Kamchatka Peninsula and moving east toward the western Bering.

&&

.MODEL DISCUSSION...

Models continue to be in excellent agreement overall for the next
several days. The surface low moving northeast toward the eastern
Aleutians and Kodiak Island will get caught up in the western
Alaska trough as it moves across south central Alaska and PWS
tomorrow. Kodiak and favored portions of eastern Chugach and
wester PWS will see mainly light snow accumulation.

Models also show good agreement for the next front to move quickly
onshore by Tuesday night over the Y-K Delta where there is good
confidence for snow and blowing snow with the frontal passage.
Ahead of the front, this strong storm system will bring Gale to
Storm Force winds to the western Bering overnight tonight.

That front will continue to quickly move east but begin to slow,
affecting the South Central region mainly Wednesday night through
Thursday, bringing another round of snow to the Anchorage area.

&&

.AVIATION...

PANC...Expect predominantly VFR conditions and light north winds
to continue through tonight. A disturbance moving in from the
west may bring a period of very light snow Tuesday morning,
potentially leading to MVFR conditions towards the end of the
period.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:Tonight
through Thursday afternoon)...

An upper level trough over the eastern Bering is in the process
of phasing with a trough and elongated surface low south of the
AKPen. Northeast flow of cold air aloft will help keep
precipitation over Kodiak Island as snow as the low moves into
the central Gulf Tuesday morning. Some light snow is possible
over the western Prince William Sound, western Kenai, Anchorage
Bowl and Mat-Su early Tuesday morning as the trough moves east and
through the area. Weak outflow winds and partly cloudy skies are
expected Tuesday afternoon and into Wednesday as mostly zonal flow
sets up aloft.

By Thursday there is a considerable amount of uncertainty as a
shortwave trough over the eastern Bering interacts with a ridge
over the north Pacific. Model guidance differs in whether or not
flow will remain zonal or become more amplified as the trough
moves towards Southcentral. This will dictate how much moisture
can be advected into the region from the southwest. If the flow
were to remain zonal, most of the moisture would be consumed by
the western Alaska Range before it makes it into the Cook Inlet
Region. If the flow shifts to the southwest, upslope areas of the
western Chugach and Talkeetna Mountains could receive a
considerable amount of snow. This forecast package reflects a
middle ground approach with snow totals ranging from 2 to 7 inches
from Anchorage north to the Mat-Su. Temperatures aloft should
remain cold enough for snow for the mainland, although the snow is
expected to be heavy with surface temperatures hovering around or
slightly above freezing.

&&

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

A blizzard warning for the Kuskokwim Delta coast remains
headlined in the forecast effective Tuesday afternoon at 4 PM
through 1 AM Wednesday. The heaviest snow amount lies in the path
of Y-K coast/delta until the front passes the warned area by
Wednesday morning. Increasing southwesterly winds are also
expected to reduce visibility mainly for Kuskokwim Delta and its
coast until the front passes. This front will also cause low
stratus clouds and fog to linger over Bristol Bay through at least
Wednesday afternoon. The amount of snow will continue to increase
as the front advances eastward the next couple days. Although
warmer westerlies will develop for Bristol Bay and AKPEN through
Thursday morning, precipitation is still expected to fall as snow
across the interior west of the Alaska Range with a rain/snow mix
over Bristol Bay and AKPEN between Wednesday and Thursday. Warm
temperatures will trend upward on Thursday, reaching into the
upper 30s which is also a reflection of the next mid to upper
ridge moving into Southwest AK beginning Thursday morning.

&&

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

A broad frontal system west of Shemya will usher storm force
winds for the western Aleutians tonight. This same frontal system
will elevate seas and wind conditions across the northern Bering
and the Aleutians until it reaches mainland Southwest AK late
Tuesday afternoon. Its trailing front merges to an emerging North
Pacific low, which will shift north past Amchitka Wednesday
morning into the central Bering Sea. Solutions are keeping this
low alive until it enters Bristol Bay area through Wednesday
night. Other interesting features to look out for are the west to
east motion of a couple of shortwaves from the western Bering,
which could bring additional snow over Pribilof and the Bering Sea
on Thursday and Thursday night. Overall, rain/snow mix will
persist over much of the Aleutians and near Pribilof Islands in
the next couple days.

&&

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

Gulf of Alaska: There is a dome of high pressure south of the
Aleutian chain and a glimmer of a ridge axis over the GOA
Thursday. Friday the ridge will get pushed to the south and a
trough will bring a line of showers through the GOA. Saturday a
new organized low will move into the eastern Gulf but this storm
will predominately impact Southeast Alaska.

Bering: There are two weak fronts in the Bering Thursday. One is
between the Y-K Delta to the Pribilof Island to Dutch Harbor.The
other is near Kamchatka with the south edge of the boundary
clipping Attu and Shemya. Both of these boundaries push
southeastward with the leading system rapidly decaying.

&&

.LONG TERM FORECAST (Days 4 through 7: Friday through Monday)...

There is a noticeable amount of model divergence from the Being
to the Gulf Of Alaska. This section of the forecast package
reflects a blend of several models. There are a few items to
gleam past 96 hrs. At the onset of the forecast period, a
relatively amplified pattern on with a trough over the Eastern
Bering and ridge over the Eastern Pacific and the Gulf Of Alaska.
There is a weak frontal boundary over the Western Alaska Range and
portions of Southcentral. The Canadian, GFS and ECMWF have honed
in on another low near Kamchatka and the associated front will
another batch of precipitation from the Western Bering eastward
reaching Bethel by Saturday. The GFS and ECMWF are spinning up a
storm force low in the NW Pacific Saturday. However the past
several model runs the placement of the surface lows are more
than 300 miles apart and the ECMWF is 15 mb deeper with the
surface low by 18z Saturday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Blizzard Warning 155.
MARINE...Storm Warning 178.
		 Gale Warning 130 155 170 172 173 175-177 179-181 185
					  411-414.
		 Heavy Freezing Spray Warning 160 180 185 412 414.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...NR
SOUTHCENTRAL ALASKA...CJ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
MARINE/LONG TERM...PJS