Gale Warning 437, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
504 PM AKDT Wed Aug 3 2022

.ANALYSIS AND UPPER LEVELS...

An occluding low with plenty of moisture is located in the western
Bering. Its warm front is extending along the Southwestern Alaska
coast. Rainfall this morning has been primarily confined to that
coastline, across Bristol Bay and the AKPen around Pilot Point to
King Salmon. The cold front for this low is moving towards the
eastern Aleutians with west to southwesterly gale force winds
and additional rainfall. To the east, temperatures are already
touching 70 degrees by around noon in the Susitna Valley. Cumulus
clouds are beginning to form over the Copper River Basin, Alaska
and Talkeetna mountains. Some high clouds ahead of the warm front
are filtering over Kodiak Island and the Kenai Peninsula.

&&

.MODEL DISCUSSION...

Models are in overall good agreement through the weekend. The low
currently over the Bering moving through mainland the last half
of the week is on track with good agreement. Going into next week,
an upper low is expected to drop through the Bering Strait into
Southwest Alaska. Some divergence becomes more apparent with its
strength as it is in the Strait and then quickly diverges by
Tuesday with GFS moving more quickly and the Canadian model much
slower and stretching further south into the Bering.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist. Lowering
cloud bases and southerly winds are anticipated Thursday evening
with precipitation beginning by Friday morning.

&&

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

Enjoy the sun while you can! A large frontal boundary remains on
track and is moving towards Southcentral. Numerous locations can
expect showers and bands of rain Thursday and Friday. On satellite
imagery, this system is a classic mature cyclone with an occlusion
over the Bering and the leading edge of the warm front pushing
across the Alaska Peninsula and Kodiak. Looking at CIMSS MIMIC
Layer PW a large portion of the system has PWs (Total Precipitable
Water) over 1.5 inches. And at the tail end of the front the PW
is actually over 2 inches. This juicy airmass is coming to
Anchorage and the Mat-Su Valleys.

&&

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

A cloudy and wet pattern is expected across Southwest Alaska over
the next few days as a low from the Bering moves into the region.
This low will begin to bring rain across the Kuskokwim Delta and
Bristol Bay this evening and tonight. The rain will then become
more widespread on Thursday and then taper off from west to east
on Friday. Rainfall totals will generally range between 0.20" and
0.40".

&&

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

A low pressure system in the central Bering will continue to
produce areas of gale force winds this evening and tonight. The
low will gradually weaken over the next several hours and the
winds will gradually weaken along with the low. Winds will then
remain below gale force Thursday morning through the rest of the
forecast period.

&&

.MARINE (Days 3 through 5 - Saturday through Monday)...

Gulf of Alaska: An elongated area of low pressure with its front
has weakening upper level support over the Northern Gulf through
Monday. Forecast confidence is fair due to the timing of changes.
Widespread rain, briefly heavy rain locally spreads across the
region. Gusty West winds increase to gales for late Saturday from
Kamishak Bay and the Barren Islands and near Sitkinak into the
Gulf, diminishing Sunday. Areas of gusty Southwest winds linger
through Monday. Seas to 10 feet, subsiding.

Bering: High pressure over the Southern Bering and Aleutians
weakens by Monday. A series of weak lows move over the Northern
Bering through Monday. A moderately strong low approaches the
Western Aleutians for Monday. Forecast confidence is fair with the
movement of the lows. Gusty Westerly winds move across the Bering
diminishing Monday. Gusty Southeast winds ahead of the Aleutian
low increase to areas of gales late Sunday, diminishing. Seas to
10 feet over the Bering, and building to 12 feet near the Western
Aleutians through Monday.

&&

.LONG TERM FORECAST (Days 4 through 7 - Sunday through Wednesday)...

Gusty westerly winds accelerating through the gaps in the western
Gulf should begin to decrease Sunday. The next system to move
into the area begins near the Bering Strait Sunday night towards
Southwest Monday morning. Models quickly diverge around this
timeframe onwards, but cool air and precipitation is expected with
this low as it moves into Southwest Alaska sometime on Monday.
The main question with this is the strength of this air mass and
how far south it will go before moving eastward. Meanwhile, high
pressure will build over the Bering Sea Monday into Tuesday.
Easterly winds are expected across the Aleutians early in the week
and a North Pacific low will approach, then move along the Aleutians
through Wednesday afternoon. This low could remain south just
enough to keep precipitation minimal due to the strengthening high
over the Bering.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale Warning 179.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...VR
SOUTHCENTRAL ALASKA...PS
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ED
MARINE/LONG TERM...MK/VR