964
FXAK69 PAFG 160118
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
518 PM AKDT Wed May 15 2024


.SYNOPSIS...
A ridge of high pressure aloft over the Eastern Interior of Alaska
will persist into the weekend. This will keep conditions generally
clear, warm and dry into the weekend across the Eastern Interior.

A strong storm just west of the Bering Strait is causing strong
south winds over most of the West Coast, with near blizzard
conditions in the Bering Strait over Northwest Alaska. These
winds and near Blizzard conditions will taper off late tonight
and early Thu as the storm moves northwest.

A cold front with this system that lies along the West Coast of
Alaska will move over the Far Western Interior and Western North
Slope tonight and to just east of Utqiagvik south over the
Western Interior on Thu and then remain in place through Fri and
weaken on Sat. This will bring light rain to the far Western
Interior tonight and to much of the Western Interior on Thu, with
isolated to scattered showers on Fri that will diminish to
isolated showers on Sat. The North Slope will see little if any
precip. The North Slope is warm with areas of fog today into
Thu, then cool closer to normal and get cloudier and more foggy
Fri into the weekend.

A thermal low pressure trough stretching from Tanana to Chicken
will move to Coldfoot to Chicken by 4pm Thu, then remain in place
and strengthen Fri through Sat. This is causing southerly winds of
15 mph gusting to 30 mph to blow through Alaska Range Passes
today and causing near Red Flag conditions between Delta Junction
and Donnelly Dome this afternoon. This winds will decrease Thu as
the trough moves further north of the Alaska Range.

Isolated thunderstorms are possible this afternoon/evening southeast
of Chicken. No convection is expected Thu. There will be isolated
showers and a very slight chance of thunderstorms along the
thermal trough Fri and Sat PM.


Surface...
A 975 mb low 120 NM west of Point Hope will move to 100 NM north
of Wrangel Island as a 985 mb low by 4pm Thu, then slowly weaken
in place. A weather front stretching from this low to Kotzebue
south to Bristol Bay will move east to Utqiagvik to McGrath by
4pm Thu, and to Nuiqsut to McGrath by 4pm Fri and then dissipate
on Fri night and Sat.

A thermal low pressure trough stretching from Tanana to Chicken
will move to Coldfoot to Chicken by 4pm Thu, then remain in place
and strengthen Fri through Sat.

High pressure will build over the Beaufort Sea Thu into Fri.

A low will move east across the Bering Sea Thu night and Fri and
into Bristol Bay on Sat.

&&

.DISCUSSION...
Models initialize well aloft at 12Z and show similar solutions
aloft through Sat. Will use a blend of models for features aloft
through Sat.

The long wave pattern consists of a strong ridge of high pressure
aloft over the Eastern Interior with a deep trough over the Bering
Sea and NE Russia. This pattern will persist into the weekend,
with the ridge building slightly Fri into Sat, then building west
across most over Northern AK on Sun. This will keep conditions
generally clear, warm and dry into the weekend across the Eastern
Interior. The North Slope is warm with area of fog today into
Thu, then cools closer to normal and gets cloudier and more foggy
Fri into the weekend. The West Coast is very stormy and cold but
winds and snow will decrease late tonight into Thu, then warm
towards normal and become drier from Fri into Sat. The far
Western Interior tonight will see rain tonight, with rain and
cooler temps spreading to much of the Western Interior on Thu,
with isolated to scattered showers on Fri, then warming and
drying to isolated showers on Sat.

850 mb temperatures are near +4C over the SE Interior, above 0C
east of McGrath and Utqiagvik and -6C along the West Coast.
Temps will cool over Western Alaska through Thu, then remain
steady on Fri before warming on Sat. The Eastern portion of
Alaska will see little change in temps through Fri then warming on
Sat.

Models have similar precip patterns and will use a blend of
models for precip. It looks like we have precip moving to far east
over Central Brooks Range tonight and Thu, and following shifts
will probably want to trim that back.

At the surface at 18Z, models None.all verify 6-8 mb too weak on
the low over the Chukotsk Peninsula. The NAM is the deepest with
this system so will use the NAM for surface features and winds,
but will keep the central pressure of this system 5 mb deeper than
the NAM through Fri and bump up winds over the Bering Strait and
NW AK above model winds by 5kt now through Thu AM.

Coastal Hazard Potential Days 3 and 4... Elevated water levels
3-5 ft above normal high tides occuring today from the Bering
Strait south. This has pushed water on top of ice near shore, but
wave action low due to limited fetch length and water on top of
ice appears to be only issue.

&&

.FIRE WEATHER...
A ridge of high pressure aloft over the Eastern Interior of Alaska
will persist into the weekend. This will keep conditions generally
clear, warm and dry into the weekend across the Eastern Interior.
A thermal low pressure trough stretching from Tanana to Chicken
will move to Coldfoot to Chicken by 4pm Thu, then remain in place
and strengthen Fri through Sat. This is causing southerly winds of
15 mph gusting to 30 mph to blow through Alaska Range Passes
today and causing near Red Flag conditions between Delta Junction
and Donnelly Dome this afternoon. This winds will decrease Thu as
the trough moves further north of the Alaska Range.

Isolated thunderstorms are possible this afternoon/evening
southeast of Chicken.  No convection is expected Thu.
There will be isolated showers and a very slight chance of
thunderstorms along the thermal trough Fri and Sat PM.

&&

.HYDROLOGY...
Rivers north of the Yukon are starting to see some break up, but
with warming temperatures through this weekend that could start
to change by the weekend. The Yukon River upstream of Pilot
Station is partially open with mainly weak and rotting ice left
which lessens the chances of ice jams.

There was a report from Emmonak Tuesday evening stating that
river levels have been rising. There was still about 8 inches of
snow on top of the ice and people are still snow machining across
the river with about 3 feet of ice at Nunam Iqua last week. The
ice has not moved or broken in any way from Emmonak to Mountain
Village. Due to this strong ice in place, this will be an area of
ice jam concern once temperatures warm late this week and more
water flows into the river.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Blizzard Warning for AKZ801-820-821.
     Winter Weather Advisory for AKZ814.
     High Wind Warning for AKZ815.
     High Wind Warning for AKZ817.
     Winter Weather Advisory for AKZ823.
PK...Small Craft Advisory for PKZ801.
     Small Craft Advisory for PKZ802-804-816.
     Brisk Wind Advisory for PKZ803-813.
     Gale Warning for PKZ806-807-854-856.
     Brisk Wind Advisory for PKZ808-859.
     Gale Warning for PKZ810.
     Gale Warning for PKZ811.
     Brisk Wind Advisory for PKZ812.
     Brisk Wind Advisory for PKZ817.
     Brisk Wind Advisory for PKZ850.
     Small Craft Advisory for PKZ851.
     Heavy Freezing Spray Warning for PKZ851.
     Gale Warning for PKZ857.
     Gale Warning for PKZ858.
&&

$$

JB