Winter Weather Advisory 96, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
357 AM AKDT Sat Oct 16 2021

.SYNOPSIS...A strong low moving across the Bering Sea will move to
Bristol Bay tonight, then dive southeast across the Alaska
Peninsula into the Northeast Pacific. A weather front will push
into the Lower Yukon Delta with snow and blowing snow tonight into
Sunday afternoon, mainly south of the Yukon River. Weak high
pressure building into the Interior as the flurries and light snow
taper off today. As the low moves across the Alaska Peninsula the
pressure gradient will strengthen across the Alaska Range and in
the Upper Tanana Valley with gusty winds developing. A low in the
Arctic will produce flurries across the area with some light snow
on the Northwest Arctic Coast.

&&

.DISCUSSION...

Models...The 16/00Z solutions are in good agreement with most of
the elements. The NAM is the outlier with precipitation, so at
this point we will limit its use. Winds in the NAM are also a bit
on the light side with the system approaching the West Coast
Monday so will limit its use there as well. There are some timing
issues with the shortwaves moving through the flow, but the
blending of the solutions should smooth that out. The surface
solutions initialized well against the 16/06Z local analysis.
Will only be making some minor adjustment to the current forecast
temperature database.

Aloft...At 500 hpa...Broad troughing continues of the forecast
area with a 520 dam low near Utqiagvik with troughing extending
south over Anaktuvuk Pass to Tanana to the Kenai Peninsula. Weak
troughing also extends southeast over Ft Yukon and Eagle. A 526
dam low has moved southeast to 400 nm south of Yakutat. Ridging
extending north out of the Pacific has moved over the Eastern
Bering Sea and Gulf of Anadyr. A 510 dam low is moving over the
Western Bering Sea this morning. By Saturday afternoon the low
near Utqiagvik will be 150 nm north of Utqiagvik with troughing
extending west to a 515 dam low over Wrangel Island and continues
west to a 514 dam low 300 nm west of Wrangel Island. Several
shortwave are moving across the state with the strongest shortwave
over Point Lay to Prince William Sound, and a second over Ft
Yukon to Eagle. The ridging has moved over Kodiak Island and
extends northwest over Norton Sound to the Chukotsk Peninsula,
then west. 509 dam low will move over the Central Bering Sea near
the Dateline with a shortwave extending southeast over the
Aleutians just west of Nikolski. Sunday morning weak ridging
over the Gulf of Alaska extends northwest over the Middle Yukon
Valley then west over the Seward Peninsula and the Gulf of Anadyr.
A 515 dam low will be 200 nm north of Utqiagvik and a 513 dam low
will be near Wrangel Island with troughing extending southeast
over Anaktuvuk Pass to Eagle and the Yukon Territory. A 510 dam
low will be 100 nm east of the Pribilofs with a strong shortwave
extending southeast over Sand Point, then south. Ridging will
be pushing north over the Western Bering Sea. Sunday afternoon
troughing will extend across the Arctic with a 512 dam low 300 nm
northwest of Utqiagvik with troughing extending west to a 510 dam
low in the Siberian Arctic, and southeast over the Eastern Arctic
Coast. The low that was near the Dateline will move southeast to
100 nm east of Sand Point at 513 dam. Ridging will lie over the
Southeast Interior to the Middle Tanana Valley, then west over
Norton Sound to St Lawrence Island, then southeast over the
Dateline. At 850 hpa...The -10C isotherm has pushed southeast to
lie from the MacKenzie Delta to Delta Junction to McGrath to
Bethel, then south of St Lawrence Island. The -10C isotherm will
be pushed back to the north today and tonight to lie from
Demarcation Point to Bettles to Nome to Gambell Sunday morning.
Not much change through Monday morning when it will lie from
Demarcation Point to Tanana to Emmonak to St Matthew Island.

Surface...Benign pressure pattern over the mainland with a 1007
mb low 150 nm north of Prudhoe Bay, a 1012 mb low in Norton Sound,
a 967 mb low in the Western Bering Sea with a weather front
approaching the Pribilofs, and a 1008 mb low 100 nm south of
Prince William Sound. Weak trough is north of the Alaska Range
with weak high pressure over the Alaska Range and the Brooks
Range. High pressure is also pushing north across Bristol Bay to a
1018 mb high in the southwest mainland. Saturday afternoon low
pressure will start pushing over the mainland from the west as the
low moves to 100 nm southwest of St Matthew Island and the weather
front moves to Nunivak Island and outer Bristol Bay. Weak high
pressure will continue to push north over the Gulf of Alaska,
Kenai Peninsula, Middle Yukon Valley, and the Northwest Arctic
Coast and Southwest Arctic. The low in the Arctic will be 150 nm
north of Prudhoe Bay. Weak leeside troughing will remain north of
the Alaska and Brooks Ranges. Sunday morning Low pressure will
push over most of the state with only a sliver of high pressure
across the Brooks Range. The low in the Arctic will be 200 nm
north of Utqiagvik at 1005 mb, while the low in the Bering Sea
will be moving east across Bristol Bay with a 972 mb center 100
nm west of King Salmon. The weather front will lie from the North
Pacific to just west of the Shelikof Strait to Bethel to St
Matthew Island. As the low pressure pushes inland the pressure
gradient across the Alaska Range will strengthen with gusty winds
developing near the passes. The pressure gradient will also
tighten between Delta Junction and Tok with the Tanana Valley Jet
developing and gusty winds from Dot Lake to Nenana. Sunday
afternoon the low in Bristol Bay will move across the Alaska
Peninsula and Kodiak Island to be 150 nm southeast of Kodiak City
at 973 mb with the front south of the Alaska Range. Troughing will
persist north of the Alaska Range with the pressure gradient
weakening. Weak high pressure that was over the Brooks Range will
slide north of the Arctic Coast and Plain.

Arctic Coast and Brooks Range...A low north of the coast will
slowly drift northwest with onshore flow from Utqiagvik west, and
offshore flow to the east. Winds 5 to 15 mph. Cloudy conditions
will prevail with light snow from Utqiagvik west and flurries to
the east. No significant accumulation today. Patchy fog along the
coast. Along the coast highs will be in the 20s, with lows in the
teens. Inland and in the Brooks Range highs in the lower teens
and lows in the single digits above.

West Coast and Western Interior...Front moving to the Lower Yukon
Delta coast with snow and blowing snow generally south of the
Yukon River from late this afternoon through Sunday morning with
up to 2 inches of accumulation. Some flurries in the Middle Yukon
Valley this morning tapering off from the south by early
afternoon. Isolated to scattered snow showers in the Norton Sound
region today. Strong gusty northeast and east winds developing
south of the Bering Strait today with winds gusting around 45 mph
on St Lawrence Island. Elevated surf developing this evening will
persist into Sunday evening. East to northeast winds on the coast
will be increasing to 15 to 30 mph with the strongest winds in the
Lower Yukon Delta. Gusts to 40 mph on the outer Capes extending
north to the Bering Strait. Highs in the mid 20s to mid 30s, with
lows in the teens to mid 20s.

Central and Eastern Interior...Some lingering flurries, or
locally light snow north of Fairbanks this morning. Flurries
tapering off from the south this afternoon, but will continue
north of the Yukon River into the evening. Some breaks in the
clouds south of the Yukon River by late afternoon with cloudy
conditions to the north. Winds generally light and variable, but
will be picking up around Delta Junction as the Tanana Valley
Jet kicks in and winds increase to 15 to 25 mph gusting to around
40 mph. Gap winds will also be increasing near the Alaska Range
passes as the pressure gradient across the range tightens up and
winds increase to 20 to 30 mph gusting around 45 mph. Lows 10 to
20 above with highs in the mid 20s to mid 30s.

Coastal Hazard Potential Days 3 and 4...A strong low moving across
the Northern Bering Sea MOnday will produce elevated surf on the
south side of St Lawrence Island Monday night, and the south
facing coastlines of the Seward Peninsula and Bering Strait
beginning early Tuesday morning into Tuesday evening.

Extended forecast for days 4 to 7...A strong 975 mb low will be
near St Lawrence Island as it weakens with broad low pressure over
extending east over mainland Alaska. Strong gusty winds developing
near the Alaska and Brooks Range passes as leeside troughing
develops and the pressure gradient across the ranges strengthens
with high pressure building west into the Copper River Basin and
west along the south slopes of the Brooks Range. Southerly flow
over the state will produce a warming trend across the area with
temperatures slightly above climatological normals.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Heavy Freezing Spray Warning for PKZ230-PKZ235-PKZ240-PKZ245-
PKZ500.

Gale Warning for PKZ210.

Small Craft Advisory for PKZ200-PKZ220.

&&

SDB OCT 21

Special Weather Statement
National Weather Service Fairbanks AK
340 AM AKDT Sat Oct 16 2021

AKZ213-170200-
St Lawrence Island and Bering Strait Coast-
Including Gambell, Savoonga, Brevig Mission, Teller, Wales,
and Diomede
340 AM AKDT Sat Oct 16 2021

...Elevated Surf on St Lawrence Island...

Elevated surf with wave runup of 1 to 1.5 feet above the normal
high tide line is expected Saturday evening through Sunday
evening.

A strong low pressure system moving east across the Bering Sea
will produce the storm surge along with strong easterly winds
around 35 mph gusting near 50 mph by Saturday evening. Winds will
turn from the northeast by Sunday morning and slowly diminish in
the afternoon.

Residents should move boats and other property well above the
normal high tide line in advance of the storm.

For the latest information go to www.weather.gov/fairbanks.