Gale Warning 811, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
422 PM AKST Sun Nov 10 2024

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

The large low that has brought heavy rains and gusty winds to the
Gulf continues to exit eastward across the Gulf. Kodiak Airport
has received 1.35 in of rainfall in the last 24 hours with peak
winds of around 58 mph. At this moment, most of the precipitation
has moved east of Kodiak Island. Looking at the Southcentral
coast, precipitation chances have diminished as the low continues
to move to the east and any precipitation chances will be
relegated to the eastern coastline. As for winds, gale force winds
will slowly diminish and will drop to below small craft criteria
by Monday. Small craft winds in Shelikof Strait and Southern Cook
Inlet will linger until Monday night. Looking further inland,
conditions will remain as they have been, dry and calm with the
Copper River Basin temperatures hovering close to 0F in the
nighttime hours.

Once the low completely moves out and dissipates to the east,
calm conditions will prevail in Southcentral by Monday afternoon.
A weak trough will pass through the region, but with a lack of
moisture, no precipitation is expected to accompany it. There is
a small risk of fog in Cook Inlet, especially around Homer, on
Monday night but recent soundings reveal a lower chance of that
occurring than before. With continued cold air advection,
temperatures across the board will diminish day-by-day with highs
in the upper 20s expected in Anchorage by Tuesday. Also starting
Tuesday, the cold air advection interacts with a trough to the
west and will stir up some gale force winds in the Western Gulf
through the short term period.

The aforementioned trough will arrive in Southcentral by Wednesday
and will have impacts in the Copper River Basin and areas east of
the Copper River Delta along the coast. The Copper River Basin
will see snowfall with the best chances southeast of Glennallen.
The coastal regions east of the Copper River Delta will see mainly
snowfall, with a period of rain/snow mix possible.

-JR

&&

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

A shortwave ridge is the main weather feature for the next 24
hours over most areas. Otherwise, the region is surrounded by
three low pressure systems, one southeast of Kodiak, another south
of Adak, and the third near the Gulf of Anadyr. The two southern
lows will mainly influence the wind field, keeping things mostly
northerly from the Alaska Peninsula through the eastern Aleutians.
The front associated with the Anadyr low will dissipate as it
moves east from the central Bering into the Kuskokwim Delta
early Tuesday morning. The main impact will be some very light
snow from the Pribilofs east towards Nunivak Island.

A stronger front will enter the western Aleutians/Bering Monday
and sweep east into Southwest through Wednesday. The parent low
will remain off of the Russian Coast, resulting in a quickly
weakening occluded front as it moves east. Temperatures aloft are
quite cool along the front, which would support snow, however the
broad southerly surface winds are most likely going to produce
rain or a mix in the lower levels for the Pribilofs on Tuesday.
As the system reaches the Southwest Coast late Tuesday and into
Wednesday night, wind will be fairly weak, with temperatures aloft
supporting mostly snow. Some warmer air in the lowest level may
yield to a rain/snow mix along the immediate coast due to the
southerly winds. The most likely areas to get an inch or two will
be from Dillingham north and west into the Kuskokwim Delta.
Otherwise the front will not have enough support to bring
precipitation into the interior. An additional system will reach
the central Aleutians on Wednesday, and will become the focus
quickly as it will likely bring a slug of moisture and warm air
into Southwest later in the week.

&&

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

An emerging North Pacific low will make its way into the central
Bering early Thursday before moving towards the southwestern
Alaska coastline by Friday morning. Recent trends in deterministic
and ensemble model guidance has suggested a slightly deeper
surface low by the time the low reaches southwest Alaska, dropping
below 980 mb. In addition, guidance has focused on a solution
where the low center will make its landfall over Nunivak Island
and the Kuskokwim River Delta. The potential for widespread
precipitation and some gale-force winds still exists with this
low as it progresses over Southwest.

As additional shortwave energy moves ahead of the low, a triple
point low is expected to form along its front on Friday near
Kodiak Island. The triple point low is currently expected to
become the dominant feature by Saturday as it moves towards Prince
William Sound. Widespread precipitation, mainly in the form of
snow, will take place over most of Southcentral, with heavier
precipitation occurring along the coastal mountain ranges. Behind
the low, cold Arctic air will be carried southward due to the
support of the upper level trough that will situate itself over
mainland Alaska by Saturday. Though the coldest stretch of
temperatures won't occur until after the end of the extended
forecast period, Sunday lows for many inland locations could get
into the single digits, with potential subzero lows in the days
following.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist.

&&