320
FXAK69 PAFG 081144
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
344 AM AKDT Wed May 8 2024

.SYNOPSIS...
Little in the way of change is anticipated over the next several
days as generally unsettled weather conditions persist. Snow and
rain chances continue as a series of disturbances push across the
state. Strong southerly gap flow develops in the Alaska Range
tonight into early Thursday morning and a Wind Advisory has been
issued for the eastern Alaska Range north of Trims Camp. A Flood
Watch remains in effect for the Yukon River at Circle.

&&

.DISCUSSION...
Synoptic Analysis and Forecast...
Aloft, at 500 mb, a 512 dam (decameter) low near the Pribilofs
weakens as it moves southeast to Sand Point Thursday morning,
weakening further into an open wave near Cordova Friday morning
before lifting north across the Alaska Range and Interior through
Saturday. A shortwave stretches east from Lake Minchumina to Eagle
to a 537 dam low in the central Northwest Territories. This
shortwave lifts northwest across the Interior today with a closed
533 dam low developing near Allakaket this afternoon. The new low
continues northwest to be centered over the Western Brooks Range
Thursday morning to near Kotzebue Sound Friday morning, and then
the western Seward Peninsula by Friday afternoon. Meanwhile, the
low over the Northwest Territories lifts northeast to the
northeastern Northwest Territories Thursday afternoon and
weakening through Friday. As this low tracks northeast, it pushes
weak ridging over the Arctic waters north with a 549 dam ridge
developing near Banks Island this afternoon that slowly moves
south southwest through Friday. A 525 dam low over the southern
Kamchatka Peninsula this afternoon dives southeast quickly to be
near Adak Thursday afternoon to near Sand Point Friday afternoon.

At the surface, a 996 mb low 150 NM northwest of the Pribilofs
weakens to 1000 mb and moves to be 150 NM southeast of the
Pribilofs this afternoon, and over Sand Point Thursday morning at
1004 mb, the low then weakens as it moves east across the Alaska
Peninsula. A trough extends northwest along the Arctic Coast from
a 1000 mb low over the central Northwest Territories to a 1010 mb
low 25 NM north of Prudhoe Bay. The low north of Prudhoe Bay moves
west to be 25 NM north of Nuiqsut by this afternoon, to 50 NM
south of Utqiagvik Thursday morning, and then weakens. A thermal
low pressure trough over the Tanana Valley will remain in place
through tonight then shift north over the northeast Interior on
Thursday.

North Slope and Brooks Range...
Areas of fog and stratus persist along the Arctic coast this
morning. Gradient tightens over the northwest Arctic coast this
afternoon into Thursday, resulting in northwest winds of 15 to 20
mph. Elsewhere, winds of less than 15 mph are expected. A series
of disturbances moving across the Brooks Range through Friday
continue snow chances. 1 to 2 inches of snow expected through
Thursday with an additional inch possible Thursday night into
Friday. Temperatures trend upwards the next few days with highs
for most areas in the 20s and 30s in the eastern Arctic Plains and
Brooks Range.

West Coast and Western Interior...
Winds pick up a bit between Point Hope and St Lawrence Island
today and Thursday as a low tracks along the Aleutians. Expect
winds in the 15 to 25 mph range in this area today and Thursday.
Elsewhere, winds will be less than 15 mph. General troughing aloft
and energy moving through the trough will continue to support
rain and snow showers through the week. Highest precip chances
will be south of Galena and in the Brooks Range this afternoon and
tonight, with lower chances Thursday into Friday. The best precip
chances today and Wednesday will be south of Galena and in the
Brooks Range, where up to 2 inches of snow accumulation is
possible. High temperatures in the 40s to lower 50s across the
Western Interior with temperatures in the mid 20s to near 40 along
the coast.

Central and Eastern Interior...
Unsettled weather continues across the Interior the next several
days as disturbances aloft support shower activity. A mix of
snow, rain, and a rain-snow mix is expected. For valley locations,
including Fairbanks, mostly rain is expected, through rain could
transition to snow overnight Thursday into early Friday morning.
Snowfall amounts generally an inch or less through Thursday,
primarily over the higher elevations, with up to 2 inches near the
Brooks Range. Thursday night into Friday snowfall amounts am inch
or less, except in higher elevations where up to 2 inches are
possible. Weak southerly gap flow is ongoing in the Alaska Range
passes and is expected to increase tonight into early Thursday
morning, especially over the eastern Alaska Range where winds of
30 to 40 mph with gusts to 60 mph are expected. Issued a Wind
Advisory for the eastern Alaska Range north of Trims Camp from 10
pm tonight through 10 am Thursday. Winds will diminish in the
Alaska Range through the day Thursday. Elsewhere, winds will
generally be less than 15 mph. High temperatures largely in the
50s to near 60 today and Thursday with cooler temperatures at
higher elevations.

Extended Forecast Days 4-7...Deterministic and ensemble guidance
continue to indicate persistent broad upper level troughing over
much of the forecast area through the extended forecast. Guidance
also suggests periodic intrusions of upper level ridging from
Canada into the Eastern Interior. This pattern supports scattered
shower activity across northern Alaska and energy moves through
the trough.

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

&&

.FIRE WEATHER...
A series of disturbances will lift northwest across the Interior
through the end of the work supporting isolated to scattered
showers each day. High temperatures largely in the 50s to near 60
through Friday. Minimum relative humidity values will drop to 20
to 25 percent this afternoon from Healy to Fairbanks and east to
near Delta Junction. Lower relative humidity values also expected
today near Eagle and portions of the Upper Tanana Valley. On
Thursday minimum relative humidity values of 20 to 25 percent will
be confined from Donnelly Dome to Eielson to near Dot Lake. Winds
generally less than 15 mph. Southerly gap flow in the Alaska
Range increases tonight, especially over the eastern Alaska Range,
where wind gusts to 60 mph are expected through early Thursday
morning. Winds will diminish through the day Thursday. At this
time it looks like the strongest winds will be tonight and early
Thursday morning and not during the driest part of the day,so not
anticipating Red Flag conditions at this time. However, near Red
Flag conditions from Delta Junction to Donnelly Dome are possible
early Thursday afternoon.

&&

.HYDROLOGY...
As of 2 pm Tuesday, ice was moving past Circle and the break up
front with high water is upstream but approaching Circle. No
overbank flooding has been reported yet. As the breakup front
moves downstream, it is likely that small jams may form and
release, leading to fluctuating water levels and potential minor
or moderate flooding at Circle today into tonight.

The break up front on the Yukon River will approach Ft Yukon on
Wednesday or Thursday. Downstream of Ft Yukon most ice remains in
place on the Yukon River at this time.

The Tanana and Upper Kuskokwim River are mostly open.

Rivers north of of the Yukon River have mostly intact ice.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Advisory for AKZ849.
     Flood Watch for AKZ833.
PK...Heavy Freezing Spray Warning for PKZ850.
&&

$$