Tumtum, Washington Weather Forecast Discussion

432
FXUS66 KOTX 080748
AFDOTX
Area Forecast Discussion
National Weather Service Spokane WA
1248 AM PDT Mon Sep 8 2025
.KEY MESSAGES...
- Cooler and unsettled weather returning to the region next week
  with increasing threat for showers and afternoon thunderstorms.
- Improving air quality expected with pattern change.
&&
.SYNOPSIS...
Smoke and haze is expected into early next week though we have
seen some improvement in areas. Temperatures will be cooling
into the 70s by next week. Today through Friday, there are
chances of precipitation and afternoon and evening
thunderstorms.
&&
.DISCUSSION...
Today: Lingering convection from the shortwave that moved through
the area yesterday evening exists in far southeast Washington and
into central Idaho, with some isolated thunderstorms in the northern
Idaho Panhandle. This convection looks to move out of the area by
late morning. Temperatures today start a cooldown into temperatures
closer to normal than they have been recently. Today, temperatures
will be in the low 80s, only a few degrees higher than normal this
time of year. A low pressure system sitting off the PNW coast will
begin moving inland. This low pressure system will bring scattered
light rain showers and chances of thunderstorms to the area this
evening, a trend that will continue through the week. Thunderstorms
tonight will be mostly confined to the northern Idaho Panhandle,
northern Mountains, Okanogan Valley and Highlands, Cascades, and the
Blues.
Tomorrow through Friday: As that low pressure system moves further
inland, the trend of showers and afternoon thunderstorms continue
through Friday. Days that look to be wettest include tomorrow, where
the Cascades have a 50 percent chance and higher of seeing a
wetting rain (0.10 inches of rain or more), and Wednesday,
where chances of a wetting rain move southeastward into far
southeast Washington, Central Idaho, and the Camas Prairie.
While afternoon and evening chances for thunderstorms will be
widespread at 10-20 percent, places that will see the highest
percentages for thunderstorms (25 percent chance and above) will
be the areas mentioned above that could see wetting rains. With
this very welcome cooler and wetter system moving through,
relative humidities will steadily begin improving beginning
today and continuing through the week. Temperatures will drop
down to right around normal, in the mid 70s, and lows will be in
the mid 50s, so a hint of fall seems to be moving through the
area this week.
Next weekend: Wetting rain chances decrease as we get into next
weekend, but high temperatures will remain in the mid-70s.
Current long range guidance shows good agreement of lower
heights continuing through Saturday. While cluster analysis
shows further lowering heights moving in Sunday, there is less
agreement on if we see some higher heights and a slight warm up
first, but temperatures look to stay below 80 for most areas.
All in all, at the moment it looks like continued lower heights,
lower temperatures, and wetter conditions will continue at
least through the weekend, maybe even into early next week if
the clusters and long range models continue their current trends.
Enjoy our first taste of fall! /AS
&&
.AVIATION...
06Z TAFS: Smoke and haze will continue to bring degraded vis
but locations are expected to remain VFR. Thunderstorm chances
will increase around 00-03z Tuesday for the Columbia Basin and
southeast Washington (KMWH-KPUW-KLWS).
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Low confidence on MVFR 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        82  56  79  56  81  56 /  10  20  30  20  20  40
Coeur d`Alene  83  57  81  57  81  56 /  10  10  20  30  30  50
Pullman        81  51  74  51  74  52 /  10  40  30  40  40  60
Lewiston       87  61  81  61  80  60 /  10  40  40  40  50  60
Colville       82  46  80  46  82  47 /  30  20  40  30  30  30
Sandpoint      80  52  80  53  80  52 /  10  10  30  40  40  50
Kellogg        80  57  78  58  78  57 /  10  20  40  50  40  70
Moses Lake     82  57  78  54  80  55 /  10  20  60  20  30  30
Wenatchee      82  61  76  60  80  62 /  10  40  70  30  30  30
Omak           85  59  81  58  84  59 /  20  30  50  30  20  20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Air Quality Alert until noon PDT today for Central Chelan
     County-Lower Garfield and Asotin Counties-Moses Lake Area-
     Northeast Blue Mountains-Northeast Mountains-Okanogan
     Highlands-Okanogan Valley-Spokane Area-Upper Columbia
     Basin-Washington Palouse-Waterville Plateau-Wenatchee
     Area-Western Chelan County-Western Okanogan County.
ID...Air Quality Alert until noon PDT today for Central Panhandle
     Mountains-Coeur d`Alene Area-Idaho Palouse-Lewis and
     Southern Nez Perce Counties-Lewiston Area-Northern
     Panhandle.
&&
$$

NWS OTX Office Area Forecast Discussion