Extreme Cold in Washington, December 27, 2021

Area Forecast Discussion
National Weather Service Spokane WA
954 PM PST Sun Dec 26 2021

.SYNOPSIS...
Look for periodic snow showers, with the potential for localized
heavy snow through Sunday night. The weather will turn
significantly colder Monday, continuing through this week, with
some of the coldest values we've seen in 10 years or more.

&&

.DISCUSSION...
A couple updates to ongoing winter weather highlights. Arctic air
continued to push down the Okanogan Valley into the Moses Lake
area. Conditions are downright brutal in the Okanogan Valley with
temperatures in most areas between 0-5F, with winds gusting 30-45
MPH producing wind chills in many areas near -20F to -25F with
local readings to -30F. Have upgraded the Wind Chill Advisory to a
warning. The Waterville Plateau given the high exposed area to the
wind will likely achieve similar wind chill readings into Monday
morning. Most sensors are showing winds lighter in the Okanogan
Highlands so have kept this as an advisory. Although the lighter
winds have allowed air temperatures to plummet, with a WSDOT
sensor in Wauconda already down to -10F.

Now regarding the snow. Most of the more intense snow showers have
been focused from the palouse into the Idaho Panhandle, clipping
eastern Spokane county at times. With drier arctic air now moving
into portions of Stevens counties, and radar trends show little
activity over northern WA, have cancelled the Winter Storm Warning
for the NE Washington mountains. For the North Idaho Panhandle,
additional accumulations will be possible under the heavier
showers. After the arctic front passage overnight snow showers
should diminish. With most locations likely getting less than 2
inches of additional snow have downgraded this warning to an
advisory. JW

&&

.AVIATION...
06Z TAFS: Snow showers will persist into Monday morning mainly
from the Spokane/Coeur d'Alene areas down through the Palouse as a
low pressure system interacts with an arctic boundary dropping
over the area. CIGS will be mainly MVFR with localized IFR
conditions possible especially under heavier snow showers. Strong
north winds down the Okanogan Valley through 18z Monday will lead
to areas of drifting snow around Omak. Drier air pushing into
Central WA should keep CIGS mainly VFR. Models aren't taking this
drying very far east on Monday, suggesting stratus could linger
over the Idaho Panhandle and eastern third of Washington, with
flurries likely over the region. JW

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane         8  15   3  14  -1   8 /  60  20  10  10  10  10
Coeur d'Alene  10  17   6  15   3  10 /  90  20  20  20  20  10
Pullman        11  17   6  18   5  13 /  60  30  10  30  30  20
Lewiston       19  24  15  23  15  20 /  50  20  10  20  30  20
Colville       -1  13  -5  11  -8   9 /  30  10   0  10  10   0
Sandpoint       8  15   7  13   5  10 /  70  20  10  20  20  10
Kellogg        12  18   9  16   7  12 /  80  40  30  40  40  20
Moses Lake      4  15   2  17   3  15 /  30   0   0  10  10   0
Wenatchee       3  14   3  13   2  12 /  40   0   0  10  10  10
Omak           -2   9   0  13   0  10 /  10   0   0   0  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 8 AM PST Monday for Central
     Panhandle Mountains-Coeur d'Alene Area-Idaho Palouse.

     Winter Weather Advisory until 4 AM PST Monday for Northern
     Panhandle.

WA...Wind Chill Warning until noon PST Monday for Okanogan Valley-
     Waterville Plateau.

     Winter Weather Advisory until 8 AM PST Monday for Spokane Area-
     Washington Palouse.

     Wind Chill Advisory until noon PST Monday for Moses Lake Area-
     Okanogan Highlands.

     Wind Chill Advisory from 10 PM this evening to noon PST Monday
     for Upper Columbia Basin.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
1029 PM PST SUN DEC 26 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1026 PM     HEAVY SNOW       5 ESE MOYIE SPRINGS     48.71N 116.09W
12/26/2021  M14.0 INCH       BOUNDARY           ID   TRAINED SPOTTER

            SEVERAL DAY ACCUMULATION. 18F DEGREES.

&&

CD