639
FXUS66 KOTX 011821
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1021 AM PST Sun Nov 1 2026

.KEY MESSAGES...

- Cool temperatures, light winds, and 20-50% chance of light
  rain Sunday morning in southeast Washington and southern Idaho
  Panhandle. Light rain accumulations up to a tenth of an inch.

- Dry conditions Sunday evening through Wednesday.

&&

.SYNOPSIS...
Mid and high clouds bring a small chance of sprinkles and
showers to southeastern Washington and north Idaho through
Sunday morning. Drier air arrives Sunday afternoon and
conditions remain seasonal and dry through Wednesday. Mountain
snow showers return mid to late week.

&&

.DISCUSSION...
Sunday through Wednesday: The upper level that was offshore finally
moves into northern California tonight, bringing clouds and
light rain to southeast Washington and the southern Idaho
Panhandle. Because the best dynamics are shifting south, the
chance for substantial rain tonight is decreasing. There is a
10-30% chance of 0.10 or more of rain through Sunday afternoon
for the Palouse, foothills of the Blue Mountains, L-C valley,
and Camas Prairie. Dry air filters in from the west during the
day behind the base of the shortwave trough, which will lead to
very sunny skies filtering into most of the region except
lingering low stratus in southeast Washington and the central
and southern ID Panhandle. There will be a risk for fog Sunday
night with clear skies across the region. Forecasting fog is a
low confidence endeavor but high resolution models are hinting
at fog development on the northern Palouse and chances
increasing to the north and west overnight. Monday through
Wednesday afternoon remains quiet and dry with near normal
temperatures in the upper 40s to mid 50s.

Wednesday night through Sunday: A couple of waves will move
through the region mid to late week, bringing the potential for
rain and mountain snow. From 4 AM Thursday to 4 AM Saturday,
there is a 5-10% chance of 4+ inches of snow for Stevens Pass
and Lookout Pass and a 30% chance for Washington Pass. The Gulf
of Alaska longwave trough remains firmly anchored into next
weekend with shortwaves pivoting around it, favoring ridging
building into our area which would favor drier conditions in 70%
of the global ensemble. This does not mean it would be
completely dry, especially the Cascades. 30% of the global
ensemble resembles a dirty ridge with deeper troughing in the
northeast Pacific and displaced further east towards the Pacific
northwest. Overall, the next week is drier than we would like
to see for the start of November. /DB

&&

.AVIATION...
18Z TAFS: Light rain showers sitting over eastern Washington
are continuing to impact GEG/SFF, but are slowly fizzling out
on radar and are expected to dissipate over the next couple
hours. Through the day, clouds will clear to the west. PUW and
LWS are the two TAF sites not at VFR. PUW is at LIFR and is not
expected to break out of LIFR until at least 00Z, if not a bit
longer, as this coincides with when clouds will begin clearing.
LWS is at MVFR, and timing is similar to PUW for improvement to
VFR.

With clearing skies, saturated profiles, and light winds
overnight, fog development is possible Monday morning.
Confidence is highest at GEG/SFF, where guidance indicates a 50%
chance of LIFR conditions, with the potential for fog beginning
around 09Z and continuing into the next forecast period. This
area with higher confidence extends from Spokane down into the
Ritzville area. COE and PUW have a chance for IFR/LIFR ceilings
and reduced visibilities, but they are around 20-30 percent and
will occur later in the period, around 12-14Z. There is a 20
percent chance for MVFR conditions at LWS and as far east as
MWH, but since confidence is lower, low cloud decks were put in
as FEW/SCT rather than BKN/OVC. EAT is not expected to see
reduced visibilities and is expected to stay at VFR through the
forecast period.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in PUW staying LIFR through at least 00Z, with some soundings
indicating LIFR conditions lasting through 01-02Z. High
confidence in LWS being MVFR through 00Z. Moderate chance of
LIFR ceilings/fog formation for GEG and SFF starting around 09Z
Monday, and low chance of IFR/LIFR conditions at COE and PUW a
little later, around 12-1Z. Low confidence of LWS/MWH dropping
to MVFR around 15Z. The most impactful alternate scenario will
be if ceilings/visibilities at GEG, SFF, COE, PUW, LWS, and MWH
drop earlier than anticipated, could require amendments. /AS

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

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        51  33  51  35  53  34 /  10   0   0   0   0   0
Coeur d`Alene  52  33  51  34  53  35 /  10   0   0   0   0   0
Pullman        43  32  51  35  53  33 /  20   0   0   0   0   0
Lewiston       53  38  55  39  57  39 /  30   0   0   0   0   0
Colville       51  27  50  26  53  27 /   0   0   0   0   0   0
Sandpoint      50  32  48  31  52  32 /  10   0   0   0   0   0
Kellogg        51  34  51  34  55  36 /  10   0   0   0   0   0
Moses Lake     54  29  55  35  57  28 /   0   0   0   0   0   0
Wenatchee      52  34  52  40  55  37 /   0   0   0   0   0   0
Omak           51  31  52  34  54  32 /   0   0   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...None.
ID...None.

&&

$$