Winter Weather Advisory 30, NWS Spokane, WA

Area Forecast Discussion
National Weather Service Spokane WA
214 AM PST Mon Nov 15 2021

.SYNOPSIS...
Strong winds to return this afternoon and evening. An incoming
weather system will bring mountain snow and rain showers to the
region through the start of the next week. Snow accumulations will
be limited to the highest mountain peaks through Sunday. Tomorrow
through Tuesday will be mild and windy with moderately strong
wind gusts. Drier and near normal temperatures expected by the
middle of next week.

&&

.DISCUSSION...

...STRONG WIND EVENT TODAY AND TONIGHT...

Today and tonight: Wind will continue to be the primary issue of
concern as a low pressure system moves through the area today and
tonight. A deepening and intensifying surface low will pass
southwest to northeast within proximity of the British Columbia
Border in such a manner as to favor strong southerly winds for a
good part of today. Later this same system will pass a cold front
allowing for the winds to shift and blow more from the southwest. The
expectation is that this cold front passage will bring the strongest
high winds to the area. High wind warnings and wind advisories have
been issued to address this situation. Precipitation will start out
primarily in the form of rain today as most the forecast area starts
out in the warm sector, however after the cold front passage after
00Z Tuesday this evening instability increases and snow levels
lower. Short term high resolution models suggest this airmass change
may allow for a small chance of thunderstorms over parts of extreme
Northeast Washington and North Idaho this evening with another
concern being instability snow showers associated with convergence
zones extending across the cascade crest and impacting Stevens Pass
with intervals of prolonged snow shower activity. A winter weather
advisory will address this. As a side note some record high
temperatures may be broke today due to all the warming brought about
by the strong southerly winds.

Tuesday and Tuesday night: Cold conditionally unstable airmass with
reinforcing cold northwest flow allows for for a widespread rain-
shadow and generally clearing skies between mentions of snow showers
for parts of North Idaho and within proximity of the lee of the
Cascade Crest. Cooling trend in temps bottoming out with the cold
Tuesday night/Wednesday morning low temps with widespread 20s and
teens. /Pelatti

Wednesday - Sunday: With the upper level ridging sitting over the
Pacific Northwest, Wednesday will remain dry ahead of the next
incoming system. Skies will be clear in the morning hours, but cloud
coverage will increase moving later into the day. Temperatures will
be cooler, with high temperatures below normal for the first time in
awhile. The morning lows will be in the upper teens & 20s and
afternoon highs in the 30s to low 40s.

On Thursday, the approaching system will move inland bringing our
next round of precipitation. With lower snow levels, the exact
timing of passage will play a large role in type of precipitation
for areas such as the HWY 2 corridor & some lower elevations. The
Thursday's overnight lows could be cool enough for snow, but
there is still model variation in timing of precip passage. Rain
or snow, the QPF does not look nearly compared to what we've seen
lately. There will be moderate snowfall in the Cascades and ID
high elevations, but elsewhere, snowfall and rain will be light.

The precipitation should be out of the region by mid-day Friday.
Following, the weekend looks like there will be mostly cloudy
skies and near normal temperatures. Unsettled vs. settled weather
is to be determined...little to no consistency amongst the models
as to when our next round of precipitation arrives. JS

&&

.AVIATION...
12Z TAFs: Today will be very turbulent and windy day. Winds will
be hazardous to flight with winds aloft to 50+ kts at 5000 feet
MSL. Those strong winds aloft will translate strong gusts at the
surface especially this afternoon. Southwest winds are expected
again late Monday morning with gusts again in the 30 to 35kt ahead
of a cold front. A sharp wind increase with gusts of 40 to 50kts
will occur along and behind the cold front in the 22z Monday to
06z Tuesday time frame with a line of showers along the front.
Toward the end of the TAF period winds will start to subside at
most TAF sites.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        61  30  43  22  39  27 /  50  50  10   0   0   0
Coeur d'Alene  64  31  42  22  38  25 /  50  70  20   0   0   0
Pullman        61  29  40  21  38  28 /  30  70  20   0   0   0
Lewiston       71  38  48  29  43  31 /  20  50  10   0   0   0
Colville       57  25  44  18  39  22 /  70  50   0   0   0   0
Sandpoint      57  31  40  21  36  23 /  80  80  20   0   0   0
Kellogg        56  30  37  22  37  28 /  40  90  50   0   0   0
Moses Lake     63  32  49  23  43  28 /  20  10   0   0   0   0
Wenatchee      63  35  47  28  40  29 /  70  20  10   0   0   0
Omak           57  29  47  23  39  26 /  80  20   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 2 PM this afternoon to 10 PM PST this evening
     for Northern Panhandle.

     High Wind Warning from 2 PM this afternoon to 10 PM PST this
     evening for Central Panhandle Mountains-Coeur d'Alene Area-
     Idaho Palouse.

     Wind Advisory from 4 PM this afternoon to midnight PST tonight
     for Lewis and Southern Nez Perce Counties-Lewiston Area.

WA...Winter Weather Advisory from 4 PM this afternoon to 10 AM PST
     Tuesday for Western Chelan County.

     Wind Advisory from 3 PM this afternoon to 7 PM PST this evening
     for Central Chelan County-Wenatchee Area-Western Okanogan
     County.

     Wind Advisory from 2 PM this afternoon to 10 PM PST this evening
     for Northeast Mountains-Okanogan Highlands.

     High Wind Warning from 2 PM this afternoon to 10 PM PST this
     evening for Lower Garfield and Asotin Counties-Spokane Area-
     Washington Palouse.

     High Wind Warning from 9 AM this morning to 8 PM PST this
     evening for Upper Columbia Basin.

     Wind Advisory from 9 AM this morning to 7 PM PST this evening
     for Moses Lake Area-Waterville Plateau.

&&