Gale Warning 188, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
407 AM AKST Fri Feb 16 2024

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

A strong blocking ridge remains over the Yukon Territory/British
Columbia border along with a negatively tilted trough from the
eastern Bering southeast into the North Pacific. This has lead to
a stationary front just south of Kodiak Island this morning along
with southeasterly winds aloft. With the exception of Kodiak and
the southern tip of the Kenai Peninsula, the vast majority of
Southcentral remains dry and clear. With the clear skies,
temperatures have cooled a couple more degrees from the previous
morning's lows, making today likely the coolest of the days to
come for many areas.

As we move into Saturday the center of the high will push off to the
the southeast as the broad area of low pressure to our south
pushes slowly north. For most areas this will bring in some high
clouds, which should be enough to warm temperatures again through
the weekend by preventing strong radiative cooling. Generally
speaking, expect highs by Sunday over inland areas to be 5-10
degrees warmer than those observed today. Along the coast, light
upslope flow will lead to some light rain for the Western Prince
William Sound by Saturday morning. Given the warm conditions from
the ridging and strong inversion in place, snow levels will be
around 1500 ft. The upper level features associated with the front
are very weak, so rain should remain very light and near the
immediate coast until Sunday. However, by this time there is
considerable model spread in how southerly shortwaves will
interact with the retreating high over Southeast. Typically models
break down the ridge too quickly, so conditions will likely stay
on the drier side till early next week.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3)...

An active and unsettled pattern over the Bering Sea region and
Southwest Alaska looks to continue through the weekend. A strong
ridge remains firmly in place over Yukon, Canada and extends
westward through the Gulf of Alaska. A deep trough remains firmly
in place over the Bering Sea region. This combination is allowing
for Pacific moisture to get steered northwestward over the Alaska
Peninsula (AKPEN) and mainland Southwest. The combination of this
moisture falling into a cold atmosphere and gusty northwesterly
winds is causing wintry conditions over portions of the Kuskokwim
Delta Coast and Alaska Peninsula. Meanwhile, a storm force
Pacific low moving into the western Bering Sea this weekend and
remaining mostly stationary in the western Bering through Sunday.
This system makes very little progression eastward due the strong
ridge. The western Aleutians could encounter a brief period of
gusty winds and possibly snow or a rain/snow mix.

&&

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

The upper level Canadian ridge extending over Mainland Alaska
slowly edges into the Canadian Provinces through Thursday. The
Bering low loops around the Central Bering, with several
significant shortwaves sliding along the Southern periphery
through the end of the forecast period. Forecast confidence is
overall good as models are well clustered and remain compatible
into the end of the week. However, it becomes chaotically
uncertain locally as the shortwaves along the Southern portions
brings periods of active precipitation and gusty winds. One
shortwave over the Western Aleutians and Bering brings areas of
gale force winds over the Western and Central Aleutians,
diminishing a bit as it moves into part of the Eastern Aleutians.
Afterward, it helps develop a more extensive trough South of the
Eastern Aleutians into the North Pacific by Wednesday. This trough
continues to push into the Gulf of Alaska through Thursday.
Precipitation along the Aleutians, Alaska Peninsula and Southwest
Alaska starts as snow and becomes mixed rain and snow on the
Bering side and all rain along the Pacific side through Wednesday.
Another well developed low approaches the Western Aleutians for
Wednesday, winds increasing to gale force over the Western and
Central Aleutians and locally heavy precipitation in the West
through Thursday.

The Bering shortwaves that continue into the Gulf of Alaska drive
onshore winds all along the Western side of the Mainland ridge.
Surface moisture increases all along the Southern Coasts from the
bottom of the Alaska Peninsula and Kodiak Island into Cook Inlet,
and from the bottom of the Kenai Peninsula to the Canadian Border.
Coastal locations will see rain with the higher amounts from
Prince William Sound East as somewhat warmer than normal
temperatures continue to pump into the Interior through the
forecast period. Gusty gap winds moves across Kodiak Island and
Kenai Peninsula Tuesday, with areas of gale force winds East of
Kodiak Island Wednesday into Thursday.

Kutz

&&

.AVIATION...

PANC...VFR conditions and light northerly winds will persist
through the TAF period. Light winds out of the north to persist
for much of the forecast period. Periods of LLWS possible early
this morning.

&&