120
FXAK69 PAFG 042223
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
223 PM AKDT Fri Oct 4 2024

.SYNOPSIS...Improving conditions are expected along the West Coast
as the strong low pressure system moves to Bristol Bay and
weakens. Northerly flow on the back side of the system will bring
a resurgence of winds through the Bering Strait, this time from
the north, with gusts to 50 mph possible at St. Lawrence Island
on Saturday. With cold air advection and open water, expect snow
showers beginning Sunday morning over western capes and St.
Lawrence Island. Southerly gap winds persist through Alaska Range
Passes through Sunday morning. Partly cloudy to mostly clear
conditions will continue through Sunday in the Interior before a
weak shortwave bring clouds and a chance of light snow from Tok
east. Very quiet conditions with mostly clear skies, light winds,
and above normal temperatures will continue through the Monday for
the North Slope.

&&

.DISCUSSION...

Analysis and Forecast Discussion...A 960 mb surface low continues
to weaken in Bristol Bay as it moves southeast, eventually
reaching Sand Point at 979 mb Sunday morning. This feature is
vertically stacked and dominating the weather pattern across
northern Alaska. Southerly flow is in place over the central and
eastern Interior and the North Slope, with seasonable
temperatures, mostly clear skies, and southerly gap winds through
Alaska Range passes. Expect these winds to weaken Saturday as flow
turns southeast. A weak shortwave could bring very light snow to
the far eastern Interior on Monday, otherwise the Interior looks
to remain very dry with northerly flow developing across the West
Coast behind the strong low. This will cause snow showers to
develop over western capes and St. Lawrence Island. The North
Slope will see south flow weaken Saturday and a return to
troughing by Monday.

The only significant forecast change we will make today is
decreasing overnight interior valley temperatures by a couple of
degrees. This is matching up with observations from the past
couple nights. With dwindling daylight hours and insolation, we
are quickly approaching the time of year when models begin to
struggle to resolve the strength of inversions in Interior Alaska,
hence the need to decrease low temperatures from guidance on
mostly clear nights. Otherwise, we will use a blend of models to
make small updates to the forecast based off observational trends.

West Coast and Western Interior...Winds will continue to diminish
over most of the West Coast as the strong low pressure system
track further southeast into Bristol Bay and weakens. Northerly
flow on the back side of the system will bring increased north
winds through the Bering Strait, with gusts to 50 mph possible at
St. Lawrence Island on Saturday. With cold air advection and open
water, expect snow showers beginning Sunday morning over western
capes and St. Lawrence Island. Dry conditions are expected in the
Interior. High temperatures will follow a cooling trend to be
mostly in the 30s and low 40s by Monday. Lows will be in the low
30s along the coast and in the 20s inland.

Central and Eastern Interior...Partly cloudy to mostly clear
conditions will continue through Sunday before a weak shortwave
bring clouds and a chance of light snow from Tok east. High
temperatures will remain well above normal; in the 40s to near 50
in the Tanana Valley with lows in the teens and 20s. Northeast
winds over Interior summits will diminish Saturday evening, though
gap winds through Alaska Range passes look to remain near advisory
level through early Sunday morning. Wind Advisories are in effect
until Saturday afternoon.

North Slope and Brooks Range...Very quiet conditions with mostly
clear skies, light winds, and above normal temperatures will
continue through the Monday. Some fog and light snow is likely
west of Nuiqsut beginning Sunday. Temperatures will be in the 20s
and 30s with teens and 20s in higher elevations of the Brooks
Range.

Coastal Hazard Potential Days 3 and 4...None.

Extended Forecast For Days 4 Through 7...Drier and warmer than
normal conditions look to persist across the area through the
extended forecast period. A weak frontal system looks to move to
the West Coast late Tuesday/early Wednesday. Periods of strong
southerly flow and gap winds through Alaska Range passes are
expected across the central and eastern Interior. Models are in
agreement for a strong low to move into the Gulf of Alaska next
Saturday. A lot of uncertainty remains in the track of the low. A
more easterly track may yield some snow wrapping into the eastern
Interior, while a more westerly track would bring Chinook winds
and dry conditions.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Advisory for AKZ847-849.
     High Surf Advisory for AKZ827.
PK...Small Craft Advisory for PKZ801-804.
     Small Craft Advisory for PKZ802.
     Gale Warning for PKZ803-853.
     Gale Warning for PKZ805-852.
     Small Craft Advisory for PKZ806-807-810-850-857.
     Small Craft Advisory for PKZ808-809-855.
     Small Craft Advisory for PKZ811.
     Small Craft Advisory for PKZ815.
     Gale Warning for PKZ816-817.
     Gale Warning for PKZ851-854.
     Gale Warning for PKZ856.
     Small Craft Advisory for PKZ860.
     Small Craft Advisory for PKZ861.
&&

$$

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