Moscow, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

576
FXUS66 KOTX 232238
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
238 PM PST Mon Dec 23 2024

.SYNOPSIS...
Unsettled weather will continue for much of this week. Check
mountain pass forecasts and conditions often before traveling.
Periods of heavy mountain snow are likely Wednesday night with an
incoming winter storm. Snowfall will continue at the Cascade
mountain passes through the weekend.


&&

.DISCUSSION...
Today through Tuesday Night: The shortwave trough that was over
the region today providing dry conditions is quickly heading east
as a vertically stacked low heads towards southern BC.
Precipitation will spread west to east through central WA and
north ID beginning late this evening and continuing through
Tuesday. Snow levels will rise through the night for most of
eastern WA and north ID bringing rain to most locations. The
exception is the Cascade valleys and northern WA valleys where
temperatures will remain cooler for snow or a rain/snow mix. For
locations like Leavenworth and Colville have an inch or less of
snow. Republic and Winthrop will see 2-3 inches.

For the passes, the following statistics are for 2, 4 and 6
inches of snow through Tuesday afternoon:

Stevens Pass: 65%, 40%, 15%
Blewett pass: 65%, 20%, 5%
Loup Loup Pass: 60%, 10%, 0%
Sherman Pass: 80%, 15%, 5%
Lookout Pass: 15%, 5%, 0%

Tuesday evening and night precipitation will decrease with the
exception of the Cascade crest and N ID mountains where light snow
will continue. Accumulations for Stevens and Lookout Pass look to
be an inch or less.

Temperatures will remain quite warm for the week of Christmas.
/Nisbet

*** Winter storm expected to bring heavy mountain snow to the
Cascade passes starting Christmas night and lasting through at least
Friday morning ***

Wednesday through Friday: Overall, not much change to the forecast as
the ensemble guidance has not wavered much over the last day with
the Christmas night storm. An atmospheric river aimed at the Pacific
NW will send a warm front through our region Wednesday night.
Current guidance supports snow down to the valley floors in the
Cascade valleys Wednesday night. There is still some uncertainty on
the position of the moisture plume today. If the AR plume goes south
of us, there could be a larger threat for lowland snow as upper air
temperatures would be cooler (advertised by 30% of the global
ensembles) supporting widespread lowland snow around 2-5 inches in
eastern Washington and north Idaho. The other 70% of the models have
the AR plume aimed at us which would favor a bit warmer of a
solution where the snow is confined to US-2 and northward. Either
way, Stevens Pass will be hit hard starting Wednesday afternoon (55%
chance of 18+" of snow from Wednesday afternoon to Friday morning).
With a cold front passage bringing down snow levels substantially in
central Washington, there is high confidence that places like
Winthrop and Leavenworth will be snow through much of the event. The
Wenatchee area carries greater uncertainty as far as snow goes but
model soundings suggest accumulating snowfall is possible to the
valley floors.

Friday through Monday: An active storm track will continue bringing
primarily mountain snow to the region through the weekend. From now
until the new year, Stevens pass could see 50+" of snow. This goes
to show how active of a pattern it is.  DB



&&

.AVIATION...
00Z TAFS: -RA will move into the region aft 06-08Z for EAT/MWH,
and 10-12Z for GEG/SFF/COE/PUW.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence of VFR conditions for PUW/LWS. Once -ra begins at
EAT, have moderate confidence they will see deteriorating
conditions to MVFR.

-----------------------

Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https:/www.weather.gov/otx/avndashboard

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        36  42  31  38  33  40 /  40  80  10   0  90  90
Coeur d`Alene  35  41  33  37  31  39 /  30  90  30  10  80  90
Pullman        37  42  31  38  35  41 /  40  90  50   0  80  90
Lewiston       40  47  35  44  37  48 /  10  90  40   0  60  80
Colville       31  39  28  34  31  36 /  70 100   0  30 100  90
Sandpoint      33  38  33  35  31  36 /  10  90  30  40  80 100
Kellogg        35  42  33  37  32  39 /  10  90  60  20  70 100
Moses Lake     39  45  28  37  33  43 /  60  50   0  20  90  70
Wenatchee      37  42  30  35  31  35 /  90  60   0  40 100  70
Omak           34  41  28  34  31  35 /  80  70   0  40 100  80

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Storm Watch from Wednesday afternoon through Friday
     morning for Western Chelan County.

&&

$$