149
FXAK69 PAFG 160923
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
123 AM AKDT Mon Sep 16 2024

.SYNOPSIS...
A coastal low is moving inland across the Yukon Valley this
morning, and will shift east today along with more showers. A very
strong low in the Bering Sea develops Tuesday, although the track
will be over Bristol Bay, keeping any coastal storm impacts well
south of the Yukon Delta. This storm will bring rain and gales to
the YK Delta, and more chances for rainfall to the Interior
Wednesday and Thursday.

&&

.DISCUSSION...

Upper Levels and Analysis...
A weakening occluded low is moving inland over the Yukon Valley,
with the low currently situated over Galena, with a central
pressure around 989 mb. The upper low center is dominating the
flow over Alaska, with the height of that low center around 528
dam. A subtropical jet stream persists over the Bering Sea, with
another developing low over the W Aleutians. Widespread moderate
rain showers are wrapping around the low, with the heaviest
rainfall falling over the YK Delta as expected, with 24 hour
rainfall totals in excess of 1.0 inches. The associated occluded
front is moving over the Brooks Range, bringing rain mixed with
snow above 4000 feet.

Forecast and Model Discussion...
Numerical models are fairly locked into the pattern as the strong
low moving inland over the Yukon Valley shifts east through
Tuesday, and another strong low moves into Bristol Bay. The latter
will bring offshore winds to the YK Delta and more rainfall, with
light rainfall chances for the remainder of the Interior Wednesday
and Thursday. This forecast prefers a blended NBM and NAM nest.

Central and Eastern Interior...
Rain showers move through the Interior today as the low out west
shifts east. An isolated thunderstorm is possible again today
across the Fortymile and Yukon-Tanana Uplands, including Eagle.
Showers continue into Tuesday then things dry out as a low over
Bristol Bay induces downslope drying. The low dives into the Gulf
and more rain/showers will move through the Interior Wednesday and
Thursday. With the clouds and showers temps over the Interior will
be running a few degrees below seasonal norms.

West Coast and Western Interior...
Showers will continue into Tuesday as the low currently over the
Yukon Valley shifts eastward. Gusty west-northwest winds will move
onshore into E Norton Sound behind that low. A strong low will
move into Bristol Bay Tuesday, and this will bring strong
northeast offshore winds to the YK Delta along with more rainfall
of 0.5 to 0.75 inches from the Yukon Valley southward. Rain tapers
off Tuesday night and turns more showery as northwest winds move
in behind that low.

North Slope and Brooks Range...
Snow levels are falling to 2500 feet by Wednesday, with continued
chances for rain/snow showers over the Brooks Range. Rain and
snow showers with some drizzle will also continue over the Arctic
Coast. Extensive fog over the E Arctic continues this morning and
will be possible into midweek with a weak area of low pressure
persisting along the immediate coast.

Extended Forecast Days 4-7...
A building ridge over the Bering Sea will induce some upper
troughing over the Mainland Thursday through the weekend, which
likely means it will be getting colder as the main storm track is
shunted south. Rain showers mixed with higher elevation snows will
be possible through Friday night with a drying trend noted for the
weekend.

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

&&

.HYDROLOGY...
0.5 to 1.0 inches of rainfall fell over the Lower Yukon watershed
and down to the Delta. More rainfall is expected for Tuesday and
Wednesday with another 0.5 to 0.75 inches over the same area.
River rises are likely, but will not be significant. Elsewhere, no
concerns as rivers are running low due to fairly low snow levels.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...High Surf Advisory for AKZ825.
PK...Small Craft Advisory for PKZ801-817-850.
     Small Craft Advisory for PKZ802-806-807-853-854-856.
     Small Craft Advisory for PKZ803.
     Small Craft Advisory for PKZ804.
     Small Craft Advisory for PKZ805.
     Small Craft Advisory for PKZ852.
&&

$$

Ahsenmacher