892
FXAK69 PAFG 132241
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
241 PM AKDT Sat Jul 13 2024

.SYNOPSIS...
Persistence is the name of the game for the West Coast and Western
Interior as wet conditions continue through the weekend, with
locally heavy rainfall, especially over the Y-K Delta, where
another inch of rain is possible through Sunday night. Southerly
chinook winds are ongoing in the Alaska Range today and will
continue into Sunday, with gusts of 50 to 60 mph expected through
the Alaska Range passes.

&&

.DISCUSSION...
Synoptic Analysis and Forecast...
Aloft, at 500 mb, broad upper level troughing remains entrenched
over much of mainland Alaska, with a 531 dam (decameter) low
centered near Goodnews Bay. The low center will meander northward
to be near Norton Sound Sunday afternoon before shifting south to
the Y-K Delta Monday afternoon; this will keep the eastern half of
the Interior under southerly flow aloft. The low center will
shift south to be near King Salmon by Wednesday morning as the
influence of an upper level low in the high Arctic starts to push
south towards the Arctic Coast and an upper level low develops
over Chukotka. A series of weak shortwaves will rotate through the
flow.

At the surface, a 994 mb low near St Lawrence Island this
afternoon tracks southeast to be a 996 mb low near Goodnews Bay
Sunday morning and then dissipates. A trough/front will extend
from near Aniak to Shungnak to Chalkyitsik this evening, lifts
northwest Sunday to the West Coast with two 990 mb low centers,
one over Norton Sound and one over Kotzebue Sound. The low over
Kotzebue Sound will weaken Sunday night and become absorbed by the
low over Norton Sound. The low over Norton Sound weakens to 1004
mb Monday afternoon as it moves to be centered over the Y-K Delta.
A 1019 mb high over the East Siberian Sea extends east across the
high Arctic waters. The high weakens to 1015 mb by Tuesday morning
as it moves to the northern Chukotsk Peninsula. A 998 mb low moves
over Mackenzie Bay Monday morning, weakening as it moves northeast
to be 1002 mb to be 100 NM west of Banks Island by Tuesday
morning.

North Slope and Brooks Range...
Little change over the next couple of days as a series of fronts
move across the Brooks Range and North Slope. These fronts will
maintain precip chances across the Brooks Range through early next
week. Blustery northeast winds develop and precip chances ramp up
for the West and Northwest Arctic Coast tonight into Sunday, with
rainfall accumulations near a quarter of an inch from Utqiagvik
to Point Lay and up to half an inch possible in the Brooks Range.
Further east, rainfall amounts will be less. Areas of stratus and
fog will persist into early next week, with visibility dropping
below a mile at times after midnight and through the early morning
hours. High temperatures in the upper 30s to lower 50s along the
coast and 50s and 60s over the Arctic Plains.

West Coast and Western Interior...
A front will push northwest across the West Coast and Western
Interior tonight into Sunday night, maintaining the ongoing wet
conditions across the region. Another half an inch to an inch of
rain is expected through Sunday night, with highest amounts over
the eastern Y-K Delta. Another front will push northwest across
the Alaska Range and into the Western Interior Monday. Troughing
aloft will maintain a mix of rain and sun through at least mid-
week. Brisk north winds develop Sunday through the Bering Strait
diminishing Monday. High temperatures in the mid 50s to lower 60s
inland and lower to mid 50s along the coast, with mid 40s on St
Lawrence Island.

Central and Eastern Interior...
Chinook flow continues in the Alaska Range passes. Winds will be
pulsey with periods of sub advisory level winds this afternoon
and evening. Stronger southerly flow returns late this evening and
overnight, especially across the Eastern Alaska Range. Winds
diminish late Sunday. The ongoing Wind Advisory for the Eastern
Alaska Range may need to be extended and conditions will have to
be monitored. A front pushing northwest across the Interior
tonight into Sunday will increase precip chances across the
Central and Northern Interior. Another weak front will push north
of the Alaska Range late Sunday night into Monday. Once chinook
flow diminishes, precip chances will spread east. High
temperatures largely in the mid 60s to lower 70s. Isolated wet
thunderstorms possible Sunday afternoon and evening from Eagle to
Tanana and Monday from Northway to Eagle and from Minchumina north
to the Central Brooks Range.

Extended Forecast Days 4-7...The upper level low remains the
dominant feature early in the extended period, slowly dropping
south to the Gulf of Alaska. This will allow for an attempt at
weak riding to develop across the Interior from a ridge in the
North Pacific late in the week. This pattern will result in a mix
of sun and clouds across northern Alaska through the week with
moderated temperatures.

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

&&

.FIRE WEATHER...
Little change expected Sunday across the Western Interior, as
widespread wetting rains continue, accompanied by near normal to
slightly below normal temperatures. Gusty southerly winds develop
across the Western Interior Sunday afternoon in the wake of the
front. Rain chances pick up across the Eastern and Northern
Interior tonight into Sunday as a front moves across the region.
Chinook flow in the Alaska Range continues well into Sunday with
southerly winds gusts of 50 to 60 mph. Away from the Alaska Range
winds generally 15 mph or less. High temperatures largely in the
mid 60s to lower 70s. Minimum RH values above 30 percent Sunday.
On Monday, minimum RH values may drop into the upper 20s from Dot
Lake to Tok. Isolated wet thunderstorms possible Sunday afternoon
and evening from Eagle to Tanana and Monday from Northway to Eagle
and from Minchumina north to the Central Brooks Range.

&&

.HYDROLOGY...
More rainfall is expected over the Western Interior this weekend,
with an additional half an inch to an inch of rain. The heaviest
rain will fall over the eastern Y-K Delta. While it is significant
rainfall, no significant issues are anticipated on rivers.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Advisory for AKZ849.
PK...Small Craft Advisory for PKZ802-810>813-853-858.
     Small Craft Advisory for PKZ803-805-852.
     Gale Warning for PKZ806-807-856.
     Small Craft Advisory for PKZ817-850.
     Small Craft Advisory for PKZ851.
     Small Craft Advisory for PKZ854-857.
     Brisk Wind Advisory for PKZ859.
     Brisk Wind Advisory for PKZ860.
     Brisk Wind Advisory for PKZ861.
&&

$$