Flooding in Alaska, June 1 to 2, 2023

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
217 PM AKDT Wed May 31 2023

.SYNOPSIS... A cool pattern will continue across most of northern
and central Alaska through Friday, with a front bringing a round of
rain and snow showers across the Interior Thursday through Thursday
night. Another low will bring more rain and snow showers across
northwest Alaska Friday night into Saturday. Weak high pressure will
build into the Interior over the weekend with a low deepening near
Bristol Bay. An overall drier pattern with a gradual warm up is
expected early next week.

&&

.DISCUSSION...
Upper Levels and Analysis...
A series of shortwave troughs will continue to rotate thru
northern AK around a persistent upper low over the Chukchi Sea.
The first trough will usher in some cooler conditions well into
the Interior, with an area of showers advancing west to east. Some
clearing in the interior will allow temps to approach freezing in
the lower elevations tonight. Patchy frost will be possible as
well.

Model Discussion...
The 12z guidance is in decent agreement on their depictions of
the tonight's trough pushing to the eastern Interior, and the
second trough that pushes thru Thursday night into Friday. The
models are a little warm along the Seward Peninsula compared to
latest obs around Nome, and so snow amounts for tonight into
Thursday were bumped up a little.

Central and Eastern Interior...
Lingering light rain continues over 224, but rivers are falling
and the flood threat has waned. So the Flood Watch was canceled.
Pronounced clearing can be seen on satellite across the central
Interior, and this clearing will help with radiational cooling
tonight. Guidance continues to trend cooler with min temps, so
plenty of low to mid 30s are now expected across 221 and 222. An
SPS will be issued for tonight to talk about the cold temps. Some
locations may get a light freeze. Confidence has increased on
solid categorical PoPs with the next front that pushes thru the
Interior late Thursday thru Friday morning. Snow levels will fall,
so some of the highest elevations of the central Interior may see
some snowflakes, while the eastern Alaska Range could see a few
inches of snow. Minor snow accum and winds approaching 50 mph is
possible in the Isabell Pass Thursday night.

North Slope and Brooks Range...
A cold front will bring snow to the north slope and Eastern
Brooks range tonight then another front will push through Thursday
night into Friday. There could be 2 to 4 inches of snow in the
lower elevations, with up to 6 inches near Atigun Pass by Friday
night. Blowing snow could reduce visibility at times. This could
make travel difficult over the Brooks Range Passes.

Western Interior and West Coast...
A band of mainly snow, mixing in with rain along the coast, is
expected to produce some light snow accums across much of the
Seward Peninsula. Nome may get a couple inches of accums tonight
thru Thursday morning. Rain showers expected in the western
Interior, with snow possible in the higher elevations. Precip will
generally taper off by Thursday night, with fog and low stratus
likely returning Friday and continuing into the weekend.

Days 4 through 7...
Decent model agreement continues behind the passage of the upper
shortwave rotating NE of the North Slope, with gradual upper
ridging over Interior AK over the weekend. A warmup to slightly
above normal temps and generally drier conditions expected early
next week.

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

&&

.FIRE WEATHER...
Another round of showers is expected to cross the Interior Thursday
aftn thru Friday morning, but no lightning is expected with this
activity. RH values will drop into the 30s Thursday with breezy W to
SW winds. Generally warmer and drier conditions expected over the
weekend.

&&

.HYDROLOGY...
Flood warnings for Stevens Village and the Yukon River Delta, as
waters continue to recede. The Flood Watch for the Salcha River was
also canceled, as the heavy rain threat ends. There is still Flood
Advisory along the lower Yukon that continues thru at least
Thursday. People along rivers and streams should prepare for
elevated water levels through this week. River access points and
gravel bars will likely be covered with water along with increased
debris in rivers.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Small Craft Advisory for PKZ801.
     Heavy Freezing Spray Warning for PKZ812.
     Brisk Wind Advisory for PKZ815.
     Small Craft Advisory for PKZ850.
     Small Craft Advisory for PKZ851.
     Brisk Wind Advisory for PKZ861.
&&

ARK