621
FXAK69 PAFG 252204
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
204 PM AKDT Sat May 25 2024

.SYNOPSIS...
Cooler temperatures persist through the weekend before a warming
trend ensues next week. Shower activity diminishes across the
Interior tonight before upper level energy moves across the
southeast Interior bringing another round of wetting rains to that
area Sunday into Monday. On the west coast, precip largely
confined to areas north and northeast of the Seward Peninsula.
Snow continues along the Arctic Coast and Brooks Range, tapering
off Monday. Isolated thunderstorms are possible this afternoon
from Northway to Denali and from McGrath to Russian Mission and
once again on Monday near the Yukon Flats. A Flood Warning remains
in place for Fort Yukon.

&&

.DISCUSSION...
Synoptic Analysis and Forecast...
Aloft, at 500 mb, broad upper level troughing encompasses much of
mainland Alaska. A 531 dam (decameter) low over the northern
Arctic Coast this afternoon dives southwest to be centered near
Selawik by Sunday afternoon moving into the Chukchi Sea north of
Shishmaref by Monday afternoon and then onshore the Chukotsk
Peninsula by Saturday morning. A 534 dam low in Gulf of Alaska
will slowly rotate eastward and weaken through Tuesday. While
these two lows move in opposite directions, weak shortwave energy
will push northwest across the southeast Interior tonight, with a
stronger shortwave trough surging northwest across the northern
Interior, eastern and central Brooks Range, and then the western
Arctic Coast Monday afternoon through Tuesday.

At the surface, a weak trough has moved onshore the Arctic Coast
from Wainwright stretching east, the trough will weaken as a 1006
mb low 225 NM east of Demarcation Point lifts northwest to be 200
NM northeast of Demarcation Point by Sunday morning and weakens to
1013 mb dissipating Sunday night. A 1030 mb high 75 NM northwest
of Wrangel Island moves northeast to be 375 NM northwest of
Utqiagvik Sunday afternoon, continuing northeast through Monday
afternoon to be a 1027 high 100 NM west of Banks Island. A 1010 mb
low develops near Noorvik Sunday night pushing northwest across
Kotzebue sound to be 50 NM northeast of Shishmaref Monday morning,
continuing northwest to be 175 NM west of Point Hope by Tuesday
morning. A thermal trough stretches from Northway to McGrath this
afternoon and will remain in place through Sunday before moving to
Eagle to Fairbanks to McGrath on Monday.

Models...
The 25/12Z models initialized well against the 12Z RAOBS and are in
good agreement with the overall synoptic pattern through Tuesday.
There are some minor differences in placement and timing of
shortwaves moving over the eastern Interior, but the impacts of
the differences are very minimal. Continued the trend of leaning
towards the NAM and hi-res models for winds and a general blend
for QPF and pops. Overall made very few edits to the inherited
forecast package.

North Slope and Brooks Range...
An upper level low moving southwest across the western Arctic
Coast and Brooks Range will bring snow to the Arctic Coast and
Brooks Range through Sunday, tapering off on Monday. An additional
2 to 4 inches of snow is expected through Monday, with the
heaviest amounts falling over the Western Brooks Range. Northerly
winds persist in the Brooks Range passes at 15 to 30 mph producing
areas of low visibility in blowing and drifting snow through
tonight. Winds in the Brooks Range diminish Sunday and Sunday
night. Along the coast northwest winds of 10 to 20 mph persist
through Monday.

West Coast and Western Interior...
Cooler temperatures persist through the weekend as an upper level
low moves across Kotzebue Sound and into the Chukchi Sea. Drier
conditions anticipated through the weekend and into Monday, with
most precip confined to those areas from the northern Seward
Peninsula east to the Upper Kobuk Valley and north. Near gale to
gale force winds expected along the Bering Strait Coast to St
Lawrence Island through tonight diminishing Sunday.

Central and Eastern Interior...
Shower activity persists across the Interior this afternoon but is
expected to push south and diminish through the evening hours.
Isolated thunderstorms are possible this afternoon from Northway
to Denali and from McGrath to Russian Mission. An upper level
disturbance moving across the southeast Interior Sunday and Monday
will bring another round of wetting rains to that area, elsewhere
in the Central and Eastern Interior conditions will be drier
through Monday. A few showers and maybe a thunderstorm or two are
possible Monday afternoon near the Yukon Flats, as a piece of
upper level energy moves over. Highs largely in the 50s today,
warming Sunday, with highs back in the mid 60s.

Extended Forecast Days 4-7...Deterministic and ensemble means
continue to be in good agreement and point to ridging developing
across northern Alaska during the extended forecast periods. This
will lead to warming trend with potentially above normal
temperatures. Scattered showers and isolated thunderstorms not out
of the question at times along the thermal trough.

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

&&

.FIRE WEATHER...
Cooler temperatures persist through the weekend with warmer
temperatures returning early next week. Shower activity diminishes
through the evening hours today. Isolated thunderstorms are
possible this afternoon from Northway to Denali and from McGrath
to Russian Mission. An upper level disturbance moving across the
southeast Interior Sunday and Monday will bring another round of
wetting rains to that area, elsewhere in the Central and Eastern
Interior conditions will be drier through Monday. A few showers
and maybe a thunderstorm or two are possible Monday afternoon near
the Yukon Flats, as a piece of upper level energy moves over. Out
west, drier conditions will prevail, with most precip confined
north and northeast of the Seward Peninsula.

&&

.HYDROLOGY...
A flood warning remains in effect for Fort Yukon until next
Wednesday. Water has poured into low lying areas east of Fort
Yukon and was reported to be rising rapidly today with water 6
inches to 1 ft below impacting low areas of the runway. It is
expected that flooding will be similar to 2023, with water flowing
into low section of Fort Yukon today, cresting on Sunday or
Monday, and then falling very slowly next week.

A flood watch remains for the Yukon Delta near Nunam Iqua and
Kotlik. An ice jam remains in place with high water. Water is over
the bank on the far side and about a foot below bank on the
village side. No flooding has been reported but if the ice shifts
it could push water into town.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Flood Watch for AKZ825.
PK...Small Craft Advisory for PKZ801.
     Small Craft Advisory for PKZ802.
     Small Craft Advisory for PKZ804-852.
     Gale Warning for PKZ806.
     Brisk Wind Advisory for PKZ807-810.
     Small Craft Advisory for PKZ811.
     Small Craft Advisory for PKZ816.
     Small Craft Advisory for PKZ817.
     Small Craft Advisory for PKZ850.
     Small Craft Advisory for PKZ851.
     Small Craft Advisory for PKZ853.
     Gale Warning for PKZ854.
     Gale Warning for PKZ856.
&&

$$