High Wind Watch 2, NWS Anchorage, AK

535 
WWAK72 PAFC 280007
NPWALU

URGENT - WEATHER MESSAGE
National Weather Service Anchorage AK
307 PM AKST Fri Jan 27 2023

AKZ191-281400-
/O.UPG.PAFC.HW.A.0002.230128T2100Z-230129T1800Z/
/O.NEW.PAFC.HW.W.0003.230128T2100Z-230129T2100Z/
Western Aleutians-
Including the city of Shemya and Amchitka
307 PM AKST Fri Jan 27 2023

...HIGH WIND WARNING IN EFFECT FROM NOON SATURDAY TO NOON AKST
SUNDAY...

* WHAT...South winds 50 to 65 mph with gusts up to 75 mph 
  expected.

* WHERE...Western Aleutians.

* WHEN...From noon Saturday to noon AKST Sunday.

* IMPACTS...High winds may move loose debris, damage property, 

* ADDITIONAL DETAILS...A period of strong east to southeasterly 
  winds will accompany a deep North Pacific low as its front 
  pushes across the western Aleutians Saturday afternoon through 
  Sunday morning. Gusts up to 75 mph remain forecast, though 
  expect winds to diminish somewhat Saturday evening as southerly 
  winds along the front shift to southwesterly on the south side 
  of the passing low through early Sunday morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People are urged to secure loose objects that could be blown
around or damaged by the wind.

&&

$$

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

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
420 PM AKST Thu Jan 26 2023

.ANALYSIS AND UPPER LEVELS...

The large upper level ridge is now over Southwest and
Southcentral Alaska and will continue to amplify over
Southcentral into the weekend. An upper level low is centered near
the Kamchatka Peninsula and encompasses most of the Bering Sea.
This is putting a southerly jet streak over the Bering Sea into
Southwest mainland Alaska and a weaker westerly jet streak over
the Interior of the state. Satellite shows a significant southerly
plume of moisture running well south of the Aleutians to the
eastern Aleutians and then curving toward Southwest Alaska which
is correlated to that jet streak.

The central and western Bering Sea are being impacted by a low
complex with the strongest low southwest of Attu this afternoon.
Other waves of rain and snow showers (mostly snow) are rotating
around this low center.

&&

.MODEL DISCUSSION...

Models remain in good synoptic agreement and are in better overall
agreement through the weekend than they have been. The area of
biggest concern is in Southwest mainland Alaska Friday and
Saturday with precipitation-type issues as NAM has been a bit
warmer than basically any of the other models. This is important
as the warmth aloft will determine where the snow/freezing rain
line will set up. The other big factor in this equation is where
the precipitation will fall and the GFS is a little farther west
than NAM, EC or GEM so those parameters are the ones we will
continue to watch closely with subsequent model runs.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist most likely.
There is the possibility for fog or low stratus to develop Friday
morning. Confidence is not currently high that it will form, but
it is a possibility.

&&

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

An upper level ridge will build over Southcentral tonight.
Although this will bring relatively quieter weather and some peeks
of clear skies, all the areas that have warmed enough for snow
melt and rain will freeze overnight. Areas of fog are generally
not expected, but the potential for brief, patchy fog cannot be
ruled out for the upper Cook Inlet locations (Kenai to the
Matanuska Valley).

A couple of embedded shortwaves within this ridge will bring
periods of potentially unsettled weather for the short term
forecast. Warm air aloft looks to advect into Southcentral and
while temperatures at the surface cools tonight, a deep inversion
could spread across Southcentral. That, coupled with a weak
embedded shortwave could bring the return to showers and light QPF
from southwest to northeast. Kodiak Island could see rain by late
Friday morning. Flow will be from the Southwest and could lead to
precipitation type challenges for the Kenai Peninsula up to the
Matanuska Valley Friday night through the weekend. Another
embedded shortwave moves through Saturday morning, helping to
usher in more warm air aloft. Temperatures in the mountains could
be above freezing, where precipitation type could be all rain. In
the valleys, temperatures could be cold enough to be below
freezing and a mix of snow and freezing drizzle/rain is possible.
The probability of precipitation and also the QPF and
accumulations are expected to be light. Further north into the
Susitna Valley, POPs are higher on Saturday morning with weak
upslope enhancement, but temperatures aloft should remain cold
enough to stay snow with little to no accumulations expected.

Warm air advection begins to stall on Sunday, but a ridge will
remain in place. There is enough uncertainty around this timeframe
(Sunday afternoon into Monday) for another shortwave and how
strong that shortwave may be to bring in additional precipitation
to Southcentral. This will affect on how much air aloft will be
allowed to cool, the timing of the trough, and the spatial extent
of precipitation and precipitation type.

&&

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

A highly amplified pattern will continue across Southwest through
the weekend with a ridge of high pressure expanding over the Gulf
of Alaska. This will block the eastward progress of any shortwave
activity and promote strong southerly flow into Southwest
instead. As has been advertised, a warm air mass will accompany
the next upper low into Southwest on Friday afternoon. An initial
wintry mix is expected to transition to freezing rain across the
Lower Kuskokwim Valley, the Kuskokwim Delta, and Bristol Bay
areas, and winter Weather Advisories are in effect for all three
zones. A trace to up to a tenth of an inch of ice will be possible
through Friday night from west of King Salmon, northward, into
the Lower Kuskokwim Valley. Meanwhile, Dillingham into Koliganek
are expected to see the greatest ice accumulations with up to two
tenths of an inch through Friday night. The one exception to the
freezing rain threat will exist from Bethel west, where
temperatures are expected to remain cooler. Thus, the majority of
precipitation should fall as all snow, and Bethel, in particular,
could see anywhere from 3 to 5 inches. Any lingering precipitation
will taper off through the morning hours on Saturday, leaving
Southwest dry and unseasonably warmer through Sunday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

A Bering front stretches from west of Saint Matthew Island,
southeastward, across Nunivak Island, and into the Alaska
Peninsula this evening. Small craft winds and gales will be
possible along the front before it slowly weakens early Friday
morning. A storm force low remains forecast to clip the Western
Aleutians on Saturday with unsettled conditions persisting across
the Western Bering through Saturday night. The front will continue
eastward across the Aleutian Chain through Sunday, albeit, in a
much weaker state. Winds will remain below small craft levels for
most locations though periodic showers can be expected as the
front makes further eastward progress. A second yet weaker front
overspreads the Western Aleutians late Sunday.

&&

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

A relatively active weather pattern is in store for the upcoming
workweek. The long term forecast begins on Monday with an upper-
level ridge slowly exiting the Southern Mainland to the southeast
while an area of high pressure breaks off and heads to the
northwest. An upper trough over the Bering and Aleutians pushes
east and aids in breaking down the ridge. The main forecast
uncertainties lie with how the models decide to handle various
upper-level disturbances embedded within the trough. Nonetheless,
there is general consensus for a Western Bering surface front and
a low near the Alaska Peninsula to spread precipitation across
much of the Bering/Aleutians and Southern Mainland, respectively,
through the week as they track eastward. Southwest Alaska is
expected to experience above normal temperatures roughly through
Tuesday, which would promote the potential for mixed
precipitation across the region. Winds up to gale-force are
anticipated to accompany the Bering front, while winds with the
low should remain at or below small craft. Another low is
advertised to approach the Aleutians from the North Pacific on
Tuesday night into Wednesday. Beyond this time, however,
confidence with the low track decreases significantly.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory: 152 155 161.
MARINE...Gale Warning: 174 178 185 411.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...VR
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...BL
LONG TERM...AF