834
FXAK69 PAFG 091025 AAA
AFDAFG

Northern Alaska Forecast Discussion...UPDATED
National Weather Service Fairbanks AK
225 AM AKDT Thu May 9 2024

SYNOPSIS...
Generally unsettled weather conditions persist throughout the next
several days with showery conditions remaining. Strong southerly
gap flow winds in the Alaska Range diminish this morning with a
wind advisory out until 10 am. A flood watch remains in effect for
the Yukon River at circle.

DISCUSSION...
Model Analysis...
Aloft, at 500 mb, a 515 dam (decameter) low near the Alaska
Peninsula will weaken as it moves east over Kodiak Island and
becomes an open wave near Cordova by Friday morning before
lifting north across the Interior and into Canada Friday evening
through Saturday. This will push at the ridging allowing
temperatures to cool slightly in the Interior today and Friday.
Models initialized 1 to 2 dam too low on this ridge which will
limit the impact of this low as it moves through. Models are in
relatively good agreement through Friday with differences
increasing Saturday, although general pattern of ridging along the
Alcan border and troughing along the West Coast remains. Models
indicate that a roughly 527 dam low will enter the Gulf of Alaska
Saturday night and weaken through Sunday possibly pushing the
ridging east again early next week.

At the surface a low follows the progression of that upper level
low as it fills in. A 1000 mb low in the Northwest territories
will move fill in and move east today. Troughing across most of
northern Alaska that was stretched between these two lows will
weaken and fill in as these surface lows weaken. A 980 low in the
Bering Sea this morning will move east along the Aleutians, slowly
weakening as it meanders into the Gulf of Alaska by Saturday
afternoon. This low is associated with the 527 dam low mentioned
previously and sees similar model differences in its exact
strength and position with models averaging about 999mb by
Saturday afternoon. Weak surface lows and small disturbances will
persist across Northern Alaska as that trough weakens and is then
reinforced by the second low.

North Slope and Brooks Range...
A round of snow this morning for the western North Slope as a
surface low tracks west across the North Slope. This same low was
responsible for overnight snowfall along the central and eastern
Arctic Coast and is expected to move off shore tonight. North
winds 15 to 20 mph are expected west of this low with no blowing
or drifting snow concerns. Winds elsewhere are expected to remain
under 15 mph. 1 to 2 inches of snowfall is expected along the
Western North Slope this morning with this system. Conditions
remain calm and dry after the passage of this low through the
weekend. Areas of fog and stratus are expected to persist. Highs
in the 20s to low 30s.

West Coast and Western Interior...
Some northern winds in the 15 to 25 mph range along coastal areas
from Point Hope to Kivalina and south through the Bering Strait
will strengthen slightly today as the low along the North Slope
moves westward further squeezing the pressure gradient through
this area, but then weaken as the low fills in. Winds under 15 mph
expected elsewhere. Small disturbances and the general troughing
will provide support for continued showers through Friday with
some isolated to scattered on this weekend. Highs in the 40s to
low 50s in the Western Interior and from 25 to 40 along the West
Coast.

Central and Eastern Interior...
Showery activity persists as disturbances aloft continue to
propagate. A mix of rain, snow, and rain-snow mix is expected
with most low lying areas getting rain. Slight chance of
thunderstorms from Huslia to the Yukon Flats this afternoon along
with showers. Strong southerly gap flow in the eastern Alaska
Range will weaken today. Winds elsewhere will generally be less
than 15 mph with winds being slightly higher and gusty near
showers. Highs in the 50s to low 60s becoming slightly warmer
Saturday as ridging builds back up again.

Extended Forecast Days 4-7...
Model Guidance continues to indicate persistent broad upper level
troughing over most of the forecast area throughout the extended
forecast period. Periodic intrusions of ridging from Canada into
the eastern Interior are also suggested. This pattern will
continue to support scattered showers across much of northern
Alaska.

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

FIRE WEATHER...
Strong southerly gap flow winds in the eastern Alaska Range will
weaken this morning. These winds have helped dry out the area
north of Isabel Pass to Delta Junction. Winds will have diminished
significantly by the time of peak heating this afternoon so Red
Flag conditions are not anticipated. However near red flag
conditions are possible from Delta Junction to Donnelly Dome early
this afternoon. Minimum relative humidity values of 20 to 25
percent are expected in this area this afternoon with values in
the 25 to 30 percent range along the rest of the Tanana Valley and
near Eagle with 30 percent and higher expected elsewhere in the
Interior. High temperatures in the 50s to near 60 through Friday.
Scattered to Numerous showers expected today throughout the
Interior as a disturbance moves through today. SLight chance of
thunderstorms this afternoon north of the White Mountains from
Huslia east to the Yukon Flats. Isolated to scattered showers will
remain throughout the weekend as more disturbances move through
the area.

HYDROLOGY...
The breakup front on the Yukon river is approaching Circle and
expected to reach Circle in the near future. As of 7 pm Wednesday,
an ice jam was in place 12 miles upriver from Circle with some
overbank flooding of low areas with no water over higher banks.
Downstream of circle, small sloughs and streams are clearing of
ice, but the main channel of the Yukon still has ice in-place.

The Tanana and Upper Kuskokwim River are mostly open.

Rivers north of the Yukon River have mostly intact ice.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Advisory for AKZ849.
     Flood Watch for AKZ833.
PK...Small Craft Advisory for PKZ806.
     Heavy Freezing Spray Warning for PKZ806.
&&

$$