230
FXUS66 KOTX 052248
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
348 PM PDT Sun Oct 5 2025

.KEY MESSAGES...

- Dry Sunday onward with chilly overnight lows falling into the
  upper 20s and 30s.

- Signals point to unsettled weather over the weekend, though
  models still remain uncertain.

&&

.SYNOPSIS...
Drier conditions expected over the weekend into early next week
with chilly overnight lows and areas of frost. Temperatures will
increase slightly through the week. Next weekend brings chances
of unsettled weather and precipitation.

&&

.DISCUSSION...
Today through Wednesday: Now that the surface pressure gradient
across the state has relaxed, winds have started to decrease and
will continue to do so through the night. An upper level ridge just
off the Canadian coast providing northerly flow will result in
continued chilly overnight temperatures and dry conditions. Minimal
cloud cover will promote radiational cooling, which will bring
temperatures down to nearly ten degrees below normal for this time
of year. Sheltered valley areas such as Republic, Deer Park, and
Sandpoint have a 40-60 percent chance of seeing 32 degrees or less,
while Colville has an over 90 percent chance of seeing 32 degrees or
less. Additionally, the Moses Lake and upper Columbia Basin areas
will see temperatures 35 degrees and below, which has prompted the
issuance of a Frost Advisory from midnight tonight through 9am
tomorrow morning. With these chilly temperatures, any sensitive
vegetation could be harmed. Tomorrow, the ridge will begin weakening
and flattening, bringing increasing high temperatures to the area.
With PWATs being only 0.4-0.6" (70-80% of normal), there is no
precipitation anticipated through midweek. This very dry air mass
will bring relative humidity down as well, resulting in poor
relative humidity recovery across the Cascades, Okanogan Highlands,
and Kettle Mountains. This brings some concerns for fire weather,
but not enough to warrant any headlines. Tomorrow, the ridge will
begin flattening, bringing high temperatures up into the 70s and low
temperatures back around normal.

Wednesday through Sunday: Though there is still some disagreement in
the finer details, ensemble models indicate a trough originating off
the Canadian coast impacting the area Wednesday night through the
weekend. While location and track have not been pinned down
completely, models show the trough retrograding to the west and
forming a cut off low that will sit over the PNW coast on Thursday.
By Friday and into next weekend, it will begin moving northeast and
will track right over the state of Washington, bringing
precipitation chances to the forecast area. The variability in
ensemble models is seen in the track and location of where the low
will be on Thursday. If the low pressure sits far enough off the
coast, continued high pressure will be over the forecast area and
conditions will remain mild and dry. If the low sits further east,
lower heights will begin impacting the area sooner in the week. We
will keep an eye on how models continue to render the track of the
low, though it is looking more and more like late next week into
next weekend could see lower temperatures and chances of
precipitation. /AS

&&

.AVIATION...
00Z TAFS: Ceilings will remain in VFR through the next 24
hours. Winds will be light and variable.

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:/weather.gov/otx/avndashboard

&&

.Preliminary Point Temps/PoPs...
Spokane        34  65  38  70  42  72 /   0   0   0   0   0   0
Coeur d`Alene  34  64  41  69  42  72 /   0   0   0   0   0   0
Pullman        33  63  38  69  41  72 /   0   0   0   0   0   0
Lewiston       41  68  43  74  47  75 /   0   0   0   0   0   0
Colville       23  65  29  68  31  69 /   0   0   0   0   0   0
Sandpoint      32  61  40  65  41  68 /   0   0   0   0   0   0
Kellogg        37  63  43  69  46  72 /   0   0   0   0   0   0
Moses Lake     33  67  37  71  38  71 /   0   0   0   0   0   0
Wenatchee      41  65  45  68  45  69 /   0   0   0   0   0   0
Omak           37  67  44  69  44  69 /   0   0   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Frost Advisory from midnight tonight to 9 AM PDT Monday for
     Moses Lake Area-Upper Columbia Basin.
ID...None.

&&

$$