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FXAK69 PAFG 081325 AAA
AFDAFG

Northern Alaska Forecast Discussion...UPDATED
National Weather Service Fairbanks AK
525 AM AKDT Sat May 8 2021

.SYNOPSIS...
An upper level over the NE Interior will move north over the Ern
North Slope today and bring several inches of snow to the NE
Interior and Eastern North Slope today, with east winds 20-30 mph
and periods of low visibility in blowing snow over the Eastern
North Slope today.

A weather front over the AKPen and Gulf of Alaska will move north
to the YK Delta and Alaska Range late tonight, to the Bering
Strait to the SE INterior on Sun, and from Point Hope to the SE
INterior on Mon. This will bring numerous rain showers to the West
Coast south of the Bering Strait tonight and Sun, and scattered
to isolated showers to the Interior and north of the Bering Strait
on Sun. Isolated thunderstorms are possible over zone 224 on Mon.

A second weather front will move north over Bristol Bay on Sun,
and then north over the West Coast of Alaska Sun night and Mon.
This will bring another round of showers to the West Coast south
of the Bering Strait on Sun night and Mon.

Temperatures will rise several degrees today and Sun over the
area south of the Brooks Range bringing temperatures above normal
this weekend, and remaining above normal through next week.

Aloft...
The long wave pattern consists of broad ridge over Western Canada
and Northern Alaska, with a long wave trough over the Bering Sea
and Western Gulf of Alaska. This pattern will persist through the
middle of next week. Several weak short waves will make their way
north over Alaska through the weekend, with the ridge and heights
building slightly over Northern Alaska through Sun.

A strong short wave trough that lies from Arctic Village east will
move to Barter Island east by 4pm Sat, then moving east on Sat
night. Moderate snow showers with this feature will cause 1-4
inches of snow with this feature between Arctic Village and Barter
Island today, with the snow diminishing south of the trough.

With the building ridge aloft, due not expect any thunderstorms
today or Sun, with a slight chance Mon PM over zone 224 with the
next short wave.

A second short wave trough in the AKPen and Gulf of AK will move
north to Norton Sound to Yakutat by 4pm Sun, to the Bering Strait
to Northway by 4am Mon, and to Point Hope to Northway by 4pm Mon.
Will see scattered to isolated showers along this trough, with
thunderstorms possible over zone 224 on Mon.


Surface...
Strong high pressure north of the Arctic Coast of Alaska will
persist into the middle of next week. NE winds 15-25 mph will
persist along the Arctic Coast through Mon, with higher gusts over
the Ern Arctic today as the strong low aloft approaches from the
south. The high will keep stratus and fog along the North Slope
into Mon, and likely longer.

A surface thermal low pressure trough that lies from the YK Delta
to Fairbanks to Eagle will persist through tonight, then move to
Galena to Northway by 4pm Sun, and persist into Mon, and likely
through the middle of next week.

Weak high pressure south of the AK Range will persist into Mon.
This will cause south winds 15 mph gusting to 25 mph through AK
Range Passes through Mon.

A weather front over the AKPen and Gulf of Alaska will move north
to the YK Delta and Alaska Range late tonight, to the Bering
Strait to the SE Interior on Sun, and from Point Hope to the SE
Interior on Mon, merging with the thermal trough. This will bring
numerous rain showers to the West Coast south of the Bering
Strait tonight and Sun, and scattered to isolated showers to the
Interior and north of the Bering Strait on Sun and Mon. Isolated
thunderstorms are possible over zone 224 on Mon.

A second weather front will move north over Bristol Bay on Sun,
and then north over the West Coast of Alaska Sun night and Mon.
This will bring another round of showers to the West Coast south
of the Bering Strait on Sun night and Mon.

&&

.DISCUSSION...
At 00Z Fri, models initialized well aloft. Models show similar
solutions aloft with just slight differences in the timing and
strength of shorts waves moving north over Northern Alaska.

With precipitation, the NAM and ECMF models show precipitation
over much of Zone 220 now, while the precip is now mainly just
north of Ft Yukon, which is what the GFS shows. Given the better
depiction of the current area of precip shown by the GFS, prefer
the GFS for today. For Sun through Mon, models differ slightly
with showering precip associate with the thermal trough. Since
this is convective and low probability, will use a blend of models
to depict showery precip along the thermal trough Sun and Mon.

At the surface at 06Z, models are a few mb too weak with the
trough in the Eastern Interior and a few mb too weak with the
ridge over the Copper Basin. Result is that winds will be 3-5 kt
stronger today through AK Range passes than models indicate, and
3-5 kt stronger than models indicate over the Ern North SLope
today.

Bottom line for models is that we will use a blend of models for
winds, temps, clouds through Mon. We will use the GFS for precip
location today, then a blend of models for precip location Sun and
Mon. We will bump up winds 3-5 kt today for AK Range Passes and
Ern North Slope. Surface temps will slowly increase through Sun.

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

&&

.FIRE WEATHER...
Expect Min RH less than 30% over the Tanana Valley each afternoon
from today through Mon, with rh 15-25% on the north side of the
Alaska Range from Healy to Delta to Tok today and Sun. South winds
Gusting 25 mph through Alaska Range passes will continue through
Mon.

&&

.HYDROLOGY...
There is a flood watch for the Yukon River at Eagle that will
continue into Sun, and possible Mon. Ice moved at Eagle but is
now jammed in place. The break up front with higher water near
Dawson should move through Eagle in the next day or two, causing
the ice to either move or jam further at Eagle. The Yukon near
Eagle needs to be watched closely.

The rest of the Yukon River and rivers north of the Yukon remain
frozen, but are starting to have ice lift and shift in a few
places. Melting will increase next week along and north of the
Yukon River as temps warm.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Flood Watch for AKZ224.

Winter Weather Advisory for AKZ204.

Small Craft Advisory for PKZ210.

Brisk Wind Advisory for PKZ225-PKZ230-PKZ240-PKZ245.
&&

$$

JB MAY 21