Clayton, Washington Weather Forecast Discussion

437
FXUS66 KOTX 100749
AFDOTX
Area Forecast Discussion
National Weather Service Spokane WA
1249 AM PDT Wed Sep 10 2025
.KEY MESSAGES...
- Showers and thunderstorms expanding across the region through
  Thursday.
- Areas of smoke and haze through the week, especially near
  wildfires.
&&
.SYNOPSIS...
The chance for showers and thunderstorms across the region will
increase through Thursday. While some areas have seen an
improvement in air quality, areas of smoke and haze is expected
to continue through the week, especially near wildfires.
&&
.DISCUSSION...
Today through Saturday: As the low tracks further inland and
pushes a series of shortwaves through the area, the chance for
daily afternoon, evening, and overnight showers and
thunderstorms continue for eastern Washington and the Idaho
Panhandle. These precipitation amounts will overall be very
light and less than a tenth of an inch, but isolated heavy
rainfall rates may occur within stronger thunderstorms. PWATs
from now through midday tomorrow are at 100-150 percent of
normal, but Thursday night through Saturday rise to 150-200
percent of normal. This will give the best chance of wetting
rains to the area on Thursday night, where chances (40-60
percent) are confined to far southeast Washington and central
Idaho. Highest chances for rain are outside of the area and
across eastern Oregon. With this increased surge of moisture
combined with the lift from shortwaves moving into the area
also comes the chance for wetter thunderstorms, and therefore
higher chances for locally heavy rainfall rates within
thunderstorms. Should any of these thunderstorms pass over
sensitive burn scars, there is a chance of some flash flooding.
Overall thunderstorm chances each day are 10-20 percent, with
localized chances of 30 percent near the areas receiving the
most rainfall. Though the overall area is focused on eastern
Oregon, higher PWATs and the chance for stronger thunderstorms
has led the Weather Prediction Center to include far southeast
Washington and central Idaho in Excessive Rainfall Outlook for
today and tomorrow with a marginal chance for flash flooding,
especially near burn scars. By Saturday, chances for showers
lower to around 10-20 percent. Temperatures will remain in the
low to mid 80s through Saturday, but will cool slightly each
day. These temperatures are slightly higher than normal for this
time of year.
Sunday through Wednesday: Right now, models are indicating that as
this low fills and moves out of the area, another low pressure
system will move in right behind it, bringing further chances for
precipitation. This low will not bring as many small waves of
energy into the area, so chances for thunderstorms lower to
1-5%. The strength of the low is still in question, but overall
is indicating more widespread precipitation. Chances for wetting
rains, however, remain low. By Tuesday, cluster analysis shows
less confidence in continued wet conditions, and shows high
heights moving over the area, indicating a possible return to
warmer and drier conditions. However, there is disagreement on
the strength of the higher heights and the location, so signals
right now are low.
Smoke and haze: Smoke from wildfires continues to drift through the
area, with areas of smoke and haze being heaviest near ongoing
wildfires. An Air Quality Alert has been issued for areas in
Washington through 11am tomorrow. /AS
&&
.AVIATION...
06Z TAFS: GEG/SFF/COE is experiencing smoke from wildfires being
moved through the area. They are mentioned in the TAFs until
10Z, but there is the chance of smoke through the TAF period,
though there is less of a chance it will impact ceilings. Main
impacts in the TAFs are chances of showers and thunderstorms
through the night and tomorrow night. From 12-18Z, GEG/SFF/COE
have a chance of rain with embedded thunderstorms, though
chances of thunderstorms are higher earlier. PUW/LWS have a
chance of showers and thunderstorms during these times as well,
but then have showers near the end of the TAF period, with LWS
specifically having a chance of seeing showers from 00-06Z
tomorrow. MWH/EAT have chances of showers and thunderstorms now
through roughly 18Z. Chances of heavy enough showers to briefly
drop to MVFR are possible near the end of the forecast period,
but confidence is low enough that they`re not mentioned in the
TAFs directly.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate
confidence in smoke for GEG/SFF/COE through 10Z, and low
confidence of smoke thick enough to lower visibilities for all
TAF sites through the period. Low confidence in timing and
location of thunderstorms tonight into Wednesday morning but
moderate confidence that showers will expand through the day.
Low confidence that heavier showers might briefly drop ceilings
to MVFR. /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:/weather.gov/otx/avndashboard
&&
.Preliminary Point Temps/PoPs...
Spokane        86  58  81  57  81  56 /  10  20  20  30  20  20
Coeur d`Alene  86  59  81  57  79  57 /  10  20  30  40  30  20
Pullman        81  53  76  52  75  52 /  10  50  50  50  40  20
Lewiston       86  63  81  62  81  61 /  10  60  60  60  50  20
Colville       86  46  84  47  83  47 /   0  10  20  20  20  20
Sandpoint      84  54  81  52  78  52 /  10  20  40  40  40  40
Kellogg        84  58  79  57  74  58 /  10  40  60  70  60  40
Moses Lake     86  58  83  56  83  54 /  10  10  20  10  10   0
Wenatchee      86  63  86  62  85  61 /  20  10  20  10   0   0
Omak           89  60  89  59  86  58 /  10  10  10  10   0   0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Air Quality Alert until noon PDT Thursday for Central Chelan
     County-Northeast Mountains-Okanogan Highlands-Wenatchee
     Area-Western Chelan County.
ID...None.
&&
$$

NWS OTX Office Area Forecast Discussion