High Wind Warning 6, NWS Anchorage, AK

240 
WWAK72 PAFC 260056
NPWALU

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
356 PM AKST Sat Feb 25 2023

AKZ181-260600-
/O.CON.PAFC.HW.W.0006.000000T0000Z-230226T0600Z/
Alaska Peninsula-
Including the cities of Cold Bay and Sand Point
356 PM AKST Sat Feb 25 2023

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 9 PM AKST THIS
EVENING...

* WHAT...West northwest winds 35 to 55 mph with gusts up to 80 mph.

* WHERE...Alaska Peninsula.

* WHEN...Until 9 PM AKST this evening.

* IMPACTS...High winds may move loose debris, damage property, 
  and cause power outages. Travel will be difficult.

* ADDITIONAL DETAILS...Winds will peak during the mid to late 
  afternoon hours, then gradually diminish this evening into the 
  overnight hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People are urged to secure loose objects that could be blown
around or damaged by the wind. Prepare for the possibility of
widespread power outages. Use caution if you must drive.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/afc

861 
WWAK72 PAFC 260557
NPWALU

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
857 PM AKST Sat Feb 25 2023

AKZ181-260700-
/O.EXP.PAFC.HW.W.0006.000000T0000Z-230226T0600Z/
Alaska Peninsula-
Including the cities of Cold Bay and Sand Point
857 PM AKST Sat Feb 25 2023

...HIGH WIND WARNING WILL EXPIRE AT 9 PM AKST THIS EVENING...

Winds will continue to come down through the evening.

$$

For more information from the National Weather Service visit
https://weather.gov/afc

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
533 AM AKST Sat Feb 25 2023

.ANALYSIS AND UPPER LEVELS...

Upper-level flow is returning to a more amplified pattern as a
trough, and its associated low located over the Bering, are
beginning to dig southeastward towards the Alaska Peninsula. The
aforementioned low is noticed beautifully on Nighttime
Microphysics Satellite Imagery just north of Amchitka this morning
with its front stretching across the central Bering. Low ceilings
and fog are being observed across much of Southcentral this
morning with reduced visibilities being reported in some regions,
especially the western Kenai Peninsula. As a result, a Dense Fog
Advisory has been issued for the Western Kenai Peninsula through
9 AM AKST.

&&

.MODEL DISCUSSION...

Models are in good agreement through Saturday, but are struggling
with the timing and strength an approaching low pressure system
moving into the Bering Sunday and then towards the Southwest
Monday and Tuesday. The main challenges with this system will be
determining precipitation types across the Southwest and timing of
the snow across Southcentral early next week. Otherwise, the near
term challenge will be the threat of fog across parts of the
southern mainland.

&&

.AVIATION...
PANC...Mainly MVFR conditions are expected through the morning
hours, but a chance that ceilings and visibility could drop to
IFR is possible. VFR conditions are expected by this afternoon as
northerly flow dries out the atmosphere. Fog/ low ceilings may
redevelop over the terminal late tonight into early tomorrow
morning, but confidence levels are low.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Saturday through Monday night)...

The upper-level longwave trough axis will move from Southcentral
to Southeast Alaska today. As it does, the flow aloft will become
northwesterly, ushering in a colder and drier airmass. At the
surface, the pressure gradient will begin to tighten due to a
trough of low pressure extending from Yakutat to Prince William
Sound and high pressure building from Southwest Alaska across the
interior to the Yukon. The increasing gradient, coupled with cold
air advection, will result in an increase in outflow winds through
favored gaps and passes. Multiple upper-level shortwaves will move
across Southcentral, embedded in the northwesterly flow, through
the weekend, each helping to reinforce the cold air advection and
increase the gust factor of these winds.

The first of these features will move from the Susitna Valley
to the northern Gulf this morning with a second, weaker wave
moving through the region later this afternoon. The first wave may
bring a period of scattered snow showers across the Chugach and
Kenai Mountains through early afternoon, with flurries possible
for Anchorage and Palmer. The second wave will bring the first
round of colder air aloft, as temperatures at 850 mb drop to
around -16C. A third wave will move through for Sunday, with
colder air (850 mb temps to -20C) filtering in from the interior.
This wave will also help enhance the gusty winds along the coast
through the first half of Monday.

The colder airmass will result in well below normal temperatures
across inland areas through the next couple of days. The biggest
challenge to the temperature forecast will be whether any residual
low-level moisture lingers across Cook Inlet and the Copper River
Basin. Radiational cooling, in conjunction with any moisture near
the surface, could result in areas of fog for these location
during the overnight hours, keeping these locations warmer than
expected. For most locations, through, expect generally clear
skies through the start of the work week.

&&

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

A potent low moving across the Bering Sea this morning is
expected to eventually dive southward across the Alaska Peninsula
this afternoon and evening. While the low will avoid moving into
Southwest Alaska, an associated front will kindly graze the coast
of the Kuskokwim Delta and Bristol Bay with light snow showers
over the latter half of the day, potentially lingering into the
overnight hours. However, snow accumulations will be on the meager
side, especially further inland. Bethel is expected to only see
perhaps an inch of total snow and the Lower Kuskokwim Valley and
interior Bristol Bay missing out entirely. Coastal locations will
fair better from Kipnuk to Cape Newenham to Togiak to see upwards
of 2 to 3 inches of total snow.

The bigger story across Southwest Alaska over the next couple of
days will continue to entail a much colder air mass moving into
the region through the weekend into early next week. Saturday
morning temperatures are in the teens across the Kuskokwim Delta
and Bristol Bay with single digit temperatures noted across the
Lower Kuskokwim Valley. As more cold air spills into Southwest,
Sunday morning temperatures will quickly drop to below zero across
the Kuskokwim Delta and Lower Kuskokwim Valley with Bristol Bay
seeing single digit temperatures. Cool temperatures will linger
into early Monday before the next Bering low brings warmer
temperatures back into Southwest Alaska. This will mean the
potential for freezing rain in some area, though uncertainty
remains high during the day three period.

&&

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

An upper low located over the Central Bering this morning is
bringing elevated winds, seas, and areas of snow showers to the
region. This activity will persist through the afternoon and
evening hours as the low eventually dips southward across the
Alaska Peninsula. Currently, snow showers and winds gusting to 35+
knots are promoting low visibility across the Pribilof Islands.
Conditions will gradually improve this afternoon as the low begins
a southward descent into the Alaska Peninsula. Winds are expected
to increase and decrease in intensity with the arrival and
passage of the front through the Aleutians over the course of the
day. Winds are only now beginning to increase out of the southwest
across Dutch Harbor. Strong cold air advection wrapping around
the backside of the low will promote widespread gale and storm
force winds south of the Pribilof Island to the Eastern Aleutians
through the morning hours, with gusts to as high as 60 knots
possible for Unalaska. Similarly, by this afternoon, gusts to as
high as 60 knots will also be possible for Cold Bay and King Cove.
A swath of 20+ foot seas will accompany the higher winds from
north of the Western Aleutians all the way through the Alaska
Peninsula later today. The Bering low and its front finally should
depart into the North pacific by tonight, leaving a temporary
calm over the region.

Further west, the next North Pacific low will begin to lift
across the Western and Central Aleutians late Saturday into
Sunday. Southwesterly flow south of the low will usher warming
temperatures and renewed gusty conditions across the region as a
warm front tracks across the Aleutian Chain and through the
Pribilof Islands by Monday morning. Any snow showers ahead of the
front should quickly transition to rain. Across the Western
Aleutians, the warm-up will be short-lived as cold air immediately
begins to wrap around the backside of the low through the latter
half of the day.

&&

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

Starting Tuesday morning, agreement between the 12Z deterministic
model runs is weak, with stark discrepancies regarding synoptic
features. Namely, a low in the Bering Tuesday morning is
positioned by the GFS in the Central Bering, with a front having
just pushed inland into Southwest Alaska. The Euro model suggests
that the low is positioned slightly more to the south, with the
front just offshore of Southwest Alaska. The Canadian model is
much more progressive and the outlier, positioning the low over
the Southwestern coastline, and the front having already pushed
significantly inland, reaching Southcentral already by Tuesday
morning. These differences erode initial forecast confidence. The
lows then look to push inland, with the GFS showing a slower,
heavier precipitation event for Southwest and Southcentral as the
low makes its way east. By Wednesday morning, the GFS shows a
strong precipitation event for the Greater Bristol Bay area to the
Prince William Sound and Eastern Kenai. Wednesday morning the
Euro advertises the low moving into Prince William Sound just with
significantly less of a precipitation signature. The low
represented by the Canadian model has since departed Southcentral
by Wednesday morning, leaving some remnant showers behind.

Solutions appear to converge more by Wednesday afternoon, as
showers across Southern Alaska dissipate by Thursday morning.
Winds associated with these events do show decent agreement, with
the GFS and Euro solutions suggesting gusty winds through the gaps
and passes of the Eastern Aleutians Wednesday afternoon.
Additionally, as the low moves east, strong winds through the
Barren Islands are currently expected between Thursday morning and
that afternoon. A weak low looks to enter the Western Bering by
late Wednesday night moving across the Chain, exiting to the south
upon reaching the AKPen Thursday afternoon. Southwest and
Southcentral Alaska look to enjoy a reprieve from activity through
Thursday into Friday evening as high pressure moves to build in.
Friday afternoon, the GFS solution shows a front from a Kamchatka
low approaching Southwest Alaska, however the Euro solution mostly
disregards this front and instead builds a North Pacific low to
approach the southern edge of the Central Aleutians by Friday
afternoon instead. Given time, disagreements between the solutions
will diminish, so stay tuned to our latest forecast to keep up-
to-date on this potentially active pattern next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Dense Fog Advisory: 121.
MARINE...Gale Warning: 130-132, 136, 150, 155, 165, 171-179, 351-352,
					   412, 414.
	     Storm Warning: 170, 413.
		 Heavy Freezing Spray Warning: 121, 127, 129, 160, 180, 185,
									   414.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...NSC
SOUTHCENTRAL ALASKA...TM
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BL
LONG TERM...CL

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
514 AM AKST Sat Feb 25 2023

AKZ181-185-260200-
Alaska Peninsula-Eastern Aleutians-
Including the cities of Cold Bay, Sand Point, Unalaska,
and Nikolski
514 AM AKST Sat Feb 25 2023

...STRONG WESTERLY WIND GUSTS TO IMPACT THE EASTERN ALEUTIANS AND
SOUTHERN ALASKA PENINSULA SATURDAY...

A strong Bering Sea low and associated front will move from west
of Saint Paul Island this morning to the Alaska Peninsula by
Saturday evening. Cold, unstable air wrapping around the back
side of the low in the wake of the front will promote widespread
gale and storm-force winds. The strong winds are expected to
impact the eastern Aleutians through the morning hours and the
southern Alaska Peninsula later this afternoon and evening. Winds
of 30 to 45 mph with gusts approaching 70 mph are possible from
Unalaska to Cold Bay and King Cove with this system.