Gale Warning 23, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
459 PM AKST Sat Jan 28 2023

.ANALYSIS AND UPPER LEVELS...

A sharp ridge aloft, nosing over Southcentral Alaska is
controlling the flow pattern. The high pressure is causing an
amplification of the pattern and broad southwesterly flow aloft over
the mainland. The previous warm front that brought freezing rain
to southwest Alaska has stalled, currently very stationary over
the southern Mainland. There are two main upper level low
pressure, the stronger feature is over the far western Aleutians,
where a high wind warning is in effect. The second is a complex,
much less organized area of low pressure in the northeastern
Pacific with multiple circulations embedded within it. How those
features phase into the broader westerly flow aloft will shape the
forecast in coming days.

&&

.MODEL DISCUSSION...

Large scale features are well agreed upon through the short term.
The large western Aleutians system is at a point where guidance is
locked into a solution, high confidence as it decays and moves
northwestward. The less organized small-scale features have more
opportunity to not be handled well, however, guidance is in good
agreement with the northeastern Pacific circulation to eventually
consolidate into a broad and weak circulation in the Gulf of
Alaska. There is also good agreement with the progression of the
Bering Sea front as it moves over and across the mainland. The
forecast for this package is higher confidence.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist, however, there
remains an opportunity for areas of low stratus around Cook Inlet.
High pressure, weak surface winds, and a surface inversion could
lead to patchy low clouds.

Sunday late afternoon and evening, chances for light snow
increase, however, the thermal profile is right on the border of
freezing drizzle as well, something to keep an eye on between now
and then.

&&

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

An upper level ridge over Southcentral will continue over the
next couple days. Warmer air aloft has kept a lot of locations
under party to mostly cloudy skies. Fog reported last night in
Kodiak has gotten more dense during the later part of this
morning. Areas of fog will likely continue for the rest of tonight
until tomorrow morning. For Sunday, a trough will push against
the western side of the ridge and under southwesterly flow, move
right into Southcentral. The additional moisture will begin to
saturate the column from the top and attempt to eat away at the
inversion Sunday morning. Mid layers that remain dry with the
onset of precipitation will likely fall as freezing drizzle.
Portions of the western Kenai Peninsula could be saturated with a
warm nose and could fall as freezing rain. Snow could briefly be
mixed into the freezing rain and drizzle at first, especially as
overall flow moves up Cook Inlet. The onset and transition of
precipitation type will be mainly based upon the sequence and
timing of atmospheric saturation. Slight differences in regards to
timing the cooler air across the area. Overall though,
precipitation amounts are expected to be light through most of the
short term.

The upper ridge will break down further on Sunday night through
Monday as a weak low moves into the Gulf. Winds at the surface
will become more northerly and temperatures aloft will continue to
cool down to the surface. Chance of precipitation remain likely
for the Kodiak Island and southern Kenai Peninsula Monday through
Tuesday morning. Any precipitation lingering near Kenai north into
the Susitna Valley will become snow. Southward, precipitation
types transition towards rain and or snow. The Copper River Basin
appears to be drier Tuesday and Wednesday. Snow may even mix into
Kodiak city Tuesday night into Wednesday morning before the next
potential ridge builds in from the west mid to late week.

&&

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

Southwest Alaska was plagued by areas of drizzle, low stratus,
and fog through much of the day on Saturday. However, satellite
imagery shows things are finally beginning to clear out across
Bristol Bay into the Lower Kuskokwim Valley as a weak front lifts
out of the region. While overcast skies continue to persist over
over the Kuskokwim Delta, visibility is finally improving for
locations such as Bethel. Unfortunately, Sunday will see somewhat
of a repeat for the region as increased moisture from the next
passing low and front promotes renewed areas of showers and low
stratus. Fog development may also prove to be a nuisance during
the overnight hours from Bethel down into Dillingham Saturday
night into the morning hours on Sunday.

Perhaps the best news for the region is that, while brief periods
of light freezing rain remain possible early Sunday morning, the
chance for impactful accumulations remain low as temperatures
across Southwest continue to warm. Any nighttime temperature dips
below freezing tonight should quickly rebound to above freezing
during the morning hours on Sunday with continued southerly flow
into Southwest. A front moves into Southwest Monday into Tuesday
with continued showery conditions anticipated for the region. A
cooling trend, however, will see the threat for freezing rain come
to an end, with rain to transition over snow by Monday afternoon
if not sooner.

&&

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

A hurricane force low continues to lift northward into the
western Bering this evening. While the strongest winds are
expected to remain west of the Western Aleutians, storm force
winds of 50 to 60 knots and gusts to 70 knots are forecast through
tonight. Initial gusts will be out of the southeast and along the
leading edge of the low's front. Winds may briefly subside with
the front's departure, but renewed winds gusting to hurricane
force out of the southwest are expected as the low continues
northward. Strong cold air advection and the possible development
of a stinger jet will both aid in enhancing the southwesterly
winds, likely after midnight. Winds will then gradually taper off
through the early morning hours on Sunday. A high wind warning
remains in effect for the Western Aleutians and is set to expire
Sunday morning at 6AM. Not surprisingly, resulting seas will range
from 20 to 30 feet across the western Bering through Sunday
night.

Showery conditions over much of the Bering are forecast Sunday
into early next week as what remains of the front makes its way
eastward into the eastern Bering. The front should move into
Southwest Alaska over the latter half of the day on Monday leaving
drier conditions in place over the eastern Bering. By Tuesday, a
developing low south of the Alaska Peninsula may promote small
craft to gale force northwesterly winds through the Eastern
Aleutians.

&&

.LONG TERM FORECAST (Days 4 through 7: Wednesday through
Saturday)...

The long term forecast begins on Wednesday with a broad upper-
level trough, and multiple embedded shortwaves, over the Bering
and Aleutians and a shortwave ridge near Mainland Alaska. As the
trough shifts to the east, the ridge flattens and various surface
lows are advertised to traverse the Bering/Aleutians before
approaching the Mainland on Thursday. The deterministic models
depict more variability with the lows in regards to track, timing
and evolution, however there is general consensus for these
surface features to dissipate earlier on Saturday as the next
system unfolds. Also, an upper trough and surface low near the
Panhandle looks to extend northward to Southcentral through at
least Thursday afternoon, however beyond this time, model
agreement diverges significantly with this system.

On Friday, there is good agreement for a large, deep upper-level
low to approach the western domain from the Northwest Pacific.
Its attendant surface low will extend its front across the
Western/Central Aleutians Friday morning before pushing
northeastward across the Bering and the rest of the Aleutians by
Saturday morning. The front is expected to reach Southwest Alaska
around Saturday afternoon, however model agreement weakens beyond
this time. Nonetheless, expect a generally active weather pattern
to continue for the long term period.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning 191.
MARINE...Storm Warning 177 178 411.
		 Gale Warning 175 176 413.
FIRE WEATHER...NONE.

&&

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1019 PM AKST SAT JAN 28 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0555 PM     NON-TSTM WND GST SHEMYA, AK              52.72N 174.11E
01/28/2023  M82 MPH          ALEUTIANS WEST     AK   MESONET

            MESONET REPORTED GUSTS TO 82 MPH.

&&

ED