863
FXAK69 PAFG 142345
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
345 PM AKDT Sun Jul 14 2024

.SYNOPSIS...
The upper level low over the Y-K Delta is in no hurry to move and
continues to aid in the persistent wet conditions of the West
Coast and Western Interior. Locally heavy rainfall is expected
over the Y-K Delta and Lower Yukon through Monday night, where a
half an inch to an inch and a quarter or expected. The west and
northwest Arctic coast will also see their share of rain as a
front moves across, with half an inch of rain possible from
Utqiagvik west to Point Hope through Monday night.

&&

.DISCUSSION...
Synoptic Analysis and Forecast...
Aloft, at 500 mb, a 531 dam (decameter) low remains parked over
the Y-K Delta this afternoon, with troughing encompassing much of
mainland Alaska. The low center will meander northward Monday to
be near Norton Sound and the drop south through Thursday to be
centered over the northwestern Gulf of Alaska. While this low
drops south, a shortwave drops south out of the high Arctic Monday
afternoon to the offshore Arctic waters and to the Arctic Coast
Tuesday. As this low drops south, it taps into the upper level low
that is heading for the Gulf of Alaska and sets up an elongated
trough from the Pole to the Gulf. Several waves of energy will
work through the flow. Ridging begins to build north across the
Aleutians Tuesday pushing north and east across the Bering Sea,
with the axis stretching across Adak to the Gulf of Anadyr.

At the surface, a 993 mb low is near Kotzebue Sound with a front
extending northeast across the Brooks Range to a 995 mb low south
of Mackenzie Bay. The low near Kotzebue Sound weakens and
dissipates Monday morning as it moves west across Kotzbue Sound.
Meanwhile the front lifts north northwest through Monday, and the
low south of Mackenzie Bay moves north to be 100 NM west of Banks
Island by Tuesday evening. An approaching front diving southeast
out of the high Arctic absorbs the previous front Tuesday and then
tracks east. A 996 mb low near Kotlik this afternoon will meander
slowly and weaken. A 1021 mb high over the East Siberian Sea
extends east across the high Arctic waters. The high weakens to
1013 mb by Tuesday morning as it moves to the northern Chukotsk
Peninsula and weakens.

North Slope and Brooks Range...
A front will push north across the Brooks Range and Arctic Plains
to the Arctic Coast this afternoon and evening, dropping half an
inch to an inch of rain between Utqiagvik and Point Hope through
Monday night. Further east, rainfall amounts will generally be a
quarter of an inch or less. Blustery north to northeast winds will
accompany the rain. 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 frontal system is marching northwest across the Western Interior
this afternoon, maintaining the continued wet conditions for the
area. The heaviest rain will fall over the eastern Y-K Delta where
an additional half an inch to an inch and a quarter of rain is
possible through Monday night. These values are supported by
ensembles, as well as the ECMWF EFI. Across the northern Seward
Peninsula half an inch to an inch of rain is possible through
Monday night, elsewhere, rainfall accumulations will generally be
a quarter of an inch or less.An isolated thunderstorm or two
possible this evening over the Y-K Delta. Another wave of energy
moving over the region will support more showers Tuesday, but rain
chances will diminish by Wednesday. Brisk north winds develop
this afternoon through the Bering Strait, diminishing Monday. High
temperatures in the mid 50s to lower 60s inland and upper 40s to
mid 50s along the coast, with mid 40s on St Lawrence Island.

Central and Eastern Interior...
A rather robust frontal system pushed across the Alaska Range
overnight, overcoming the dry air in place north of the Range and
is producing scattered showers. Expect shower activity to
continue this afternoon as weaker pieces of energy aloft move
over. Latest radar trends support this as does hi-res guidance. An
isolated wet thunderstorm is not out of the question this
afternoon and evening from Eagle to Tanana. A mix of showers and
sun is expected Tuesday and Wednesday as the upper level low
remains over the west, with isolated thunderstorms possible. The
strong southerly winds in the Alaska Range have diminished below
advisory level, so the wind advisory was cancelled. Expect
southerly winds to increase again this afternoon and evening, but
remain below 50 mph, as the winds aloft weaken. High temperatures
largely in the mid 60s to lower 70s.

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 ridging to develop across the northern mainland 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...
Wet conditions persist Monday across the Western Interior, with
rain chances diminishing Tuesday and Wednesday. An isolated
thunderstorm or two possible this evening over the Y-K Delta.
Temperatures in the 50s and 60s. Across the Central and Eastern
Interior expect a mix of rain and sun over the next several days,
accompanied by temperatures in the mid 60s to lower 70s. On
Monday, minimum RH values will drop into the upper 20s to around
30 percent across the Fortymile Country to Dot Lake and Tok.
Expect southerly winds to increase again this afternoon and
evening in the Alaska Range passes, but remain below 50 mph, as
the winds aloft weaken. A few wet thunderstorms possible this
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 and a quarter of rain
through Monday night. The heaviest rain will fall over the eastern
Y-K Delta. No significant issues are anticipated on rivers, but
small streams and creeks are expected to rise.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Small Craft Advisory for PKZ801.
     Small Craft Advisory for PKZ802-850.
     Small Craft Advisory for PKZ803-852.
     Small Craft Advisory for PKZ805.
     Gale Warning for PKZ806-854.
     Gale Warning for PKZ807-856.
     Small Craft Advisory for PKZ810-814.
     Small Craft Advisory for PKZ811-857.
     Small Craft Advisory for PKZ812-813-853-858.
     Small Craft Advisory for PKZ816.
     Small Craft Advisory for PKZ817.
     Brisk Wind Advisory for PKZ859-860.
     Brisk Wind Advisory for PKZ861.
&&

$$