493
FXUS66 KOTX 260845
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
145 AM PDT Sat Sep 26 2026

.KEY MESSAGES...

- Possible frost Sunday and Monday mornings over eastern
  Washington and Idaho Panhandle mountain valleys, as well the
  outlying areas around the Spokane area and Palouse.

&&

.SYNOPSIS...
Condtions will calm overnight as the system exits the region. A
dry, fall like pattern expected for start of next week. Some
patchy frost is possible this weekend into early next week.

&&

.DISCUSSION...
Saturday through Sunday night: Weather trends cooler and drier for
Saturday as the Inland Northwest lies in the wake of Fridays cold
front passage and exiting upper-level trough. 850mb temperatures on
Saturday cool to 1-4C, translating to high temperatures in the upper
50s to mid 60s. These temperatures are about 5-10 degrees below
average for this time of year.  A dry air mass combined with light
winds on Saturday brings moderate to high confidence for the
northern valleys, the Palouse, and the central Idaho Panhandle
valleys to see frost Sunday morning, however increasing middle and
high level clouds associated with an upper-level low digging into
California may help moderate low temperatures a bit. The air mass
slightly warms on Sunday with less cloud cover. Despite warmer high
temperatures, clearer skies and light winds brings another night of
frost/freeze conditions Monday morning.

Monday through Friday: The flow aloft becomes more zonal across the
Pacific Northwest early next week, allowing temperatures to warm to
near seasonal averages (highs in the 60s to low 70s). An moisture
plume associated with weather frontal systems moving into western
Canada will bring cloud cover and a chance for precipitation to the
mountains on Tuesday. This precipitation will be mostly
orographically enhanced under this zonal flow regime with limited
dynamic forcing to support precipitation across the lowlands. The
latest National Blend of Models (NBM) guidance highlights a 70 to 80
percent chance for precipitation amounts greater than 0.50 inches
and a 10 to 20 percent chance for north Idaho.

Considerable model spread emerges in the ensemble guidance from
Wednesday through Friday, leading to lower confidence in the
forecast for this period. Around 60% of ensembles favor the building
of an upper-level ridge over the Pacific Northwest, which would
promote dry conditions and temperatures near or slightly above
average. Conversely, the remaining 40 percent maintain a cooler,
zonal pattern with the potential for a trough to traverse the
region. This alternate solution would keep temperatures cooler with
light precipitation, primarily focused over the mountains. /vmt


.AVIATION...
06Z TAFS: Winds will gradually decline over the next couple of
hours, decreasing to below 10kts at the TAF sites between
11-13Z. Widespread VFR conditions with light winds are expected
on Saturday. Middle and high level clouds will increase
Saturday afternoon.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in VFR conditions.

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

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

&&

.AVIATION...
06Z TAFS: Winds will gradually decline over the next couple of
hours, decreasing to below 10kts at the TAF sites between
11-13Z. Widespread VFR conditions with light winds are expected
on Saturday. Middle and high level clouds will increase
Saturday afternoon.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in VFR conditions.

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

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        60  38  66  37  68  44 /   0   0   0   0   0   0
Coeur d`Alene  59  39  66  39  66  43 /   0   0   0   0   0   0
Pullman        59  35  65  39  65  41 /   0   0   0   0   0   0
Lewiston       65  41  68  44  71  46 /   0   0   0   0   0   0
Colville       63  32  68  32  69  36 /   0   0   0   0   0   0
Sandpoint      57  34  63  35  64  39 /   0   0   0   0   0   0
Kellogg        56  35  64  39  64  43 /   0   0   0   0   0   0
Moses Lake     66  40  69  38  70  44 /   0   0   0   0   0   0
Wenatchee      65  46  67  46  70  52 /   0   0   0   0   0   0
Omak           66  40  68  40  69  45 /   0   0   0   0   0   0

&&

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

&&

$$