702
FXUS66 KOTX 062100
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
200 PM PDT Sun Sep 6 2026

.KEY MESSAGES...

- Cool and showery weather expected through Monday with
  isolated thunderstorms. Locally heavy rain will bring flooding
  concerns over recently burned areas and steep terrain late
  Sunday afternoon into Monday.

- A warming and drying trend returns around the middle of next
  week.

&&

.SYNOPSIS...
Active weather sticks around through Labor Day Weekend with
scattered showers, isolated thunderstorms, and cooler than
normal temperatures. A warming and drying trend commences around
the middle of next week as higher pressure returns to the
region.

&&

.DISCUSSION...
Tonight through Tuesday: A broad low near Redmond, Oregon
Sunday afternoon, migrates to the southern Panhandle of Idaho
early Monday and Montana by Monday afternoon. At the same time a
secondary upper low on its heels is drawn over the Cascades
Monday before that too shifts into western Montana by Tuesday
morning. A deformation axis/boundary sits around the eastern CWA
and the southerly flow ahead of the main low will continue
drawing on PWAT fetch (140-160% of normal).

For this afternoon and tonight the lift with the low, the
moisture and an area of 400-900 J/kg of MUCAPE over eastern WA
and ID will lead to increasing rain showers and a chance for
thunderstorms. The best chances from this development will be
over southeast WA/lower ID and could expand somewhat rapidly
north through the late afternoon to evening. Locally heavy rain,
gusty winds and lightning will be possible. Farther west a
chance for showers will linger over the Cascades and central WA,
with the better chances pushing back against the Cascades and
north-central WA.

Then heading into Monday the lingering deformation axis and
secondary low coming on the heels of the first will keep rain
showers going across the eastern third of WA and Idaho with PoPs
around 50-90%. The highest chances will be around Idaho. Other
chances will re-emerge near the Cascades and central WA through
the afternoon and evening Monday too, but PoPs will remain
around 20-30% there. Heading into Monday evening into overnight
the secondary low migrates east and starts to draw the higher
PoPs closer to the ID/MT border, but the proximity of the low
and modest moisture with will keep chances going into Tuesday
morning. Then by Tuesday afternoon the risk for showers retreats
to north Idaho.

The WPC continues to have a marginal excessive rainfall threat
for the far eastern reaches of WA and all of ID today and
tonight and mainly Idaho Monday, where steadier rain may allow
some modest rain amounts. This will bring a risk for burn scar
debris flows, rock slides and some rises on small creeks and
streams. Rain amounts around the eastern third of WA and ID are
forecast to range between 0.10 to 0.30 inches and around 0.25
to 0.75 inches across Idaho, with locally over 1 inch possible
around the some of the higher terrain across the north and
central ID Panhandle mountains. Meanwhile, central WA and the
Cascades could see trace amounts to 0.05 inches. Any
thunderstorms could produce locally higher rain amounts.

Winds will increase some Monday. West winds of 10-15 mph with
gusts of 15 to 25 mph will be possible, especially the Upper
Columbia Basin, Palouse and the Spokane/CdA area. Highs Monday
will be in the upper 50s and 60s over the east third of WA and
ID, while central WA will see upper 60s and 70s. Tuesday will
see upper 60s and 70s. Lows will be in the 40s to low 50s.

Wednesday to Sunday: The middle part of the work week turns
drier and warm, before the next low approaches toward the later
part of the week and weekend. Guidance starts to differ in the
evolution of that low but the general trend is there. Wednesday
and Thursday remain dry, but winds are forecast to increase
Thursday out of the west. Right now models support 10-20 mph
winds with gusts of 20-25 mph locally near 30-35 mph around the
Waterville Plateau. Highs will be in the 70s and 80s, with a few
areas possibly approaching 90 in the deeper basin. Region RH
values drop some, though they generally remain above critical
values. Still if the forecast holds there could be some locally
elevated fire weather conditions Thursday.

Then Thursday night into Sunday the low moves into area,
increasing shower chances around the region. There could be some
embedded t-storms, but the risk is too low to include in the
official forecast. Locally breezy conditions are possible around
central WA and the Cascades gaps. Highs are forecast to be in
the upper 60s and 70s, with lows in the 40s to low 50s and
locally some upper 30s in the sheltered valleys on the weekend.
/Solveig


&&

.AVIATION...
18Z TAFS: An upper-level low continues to linger over the
Pacific Northwest. A band of showers from Yakima to Moses Lake
will move northwest into Wenatchee through the early afternoon.
Showers then begin to increase across far eastern Washington
and the Idaho Panhandle by mid afternoon with steadier rain
expected Sunday evening into early Monday morning. Embedded
thunderstorms will be possible Sunday evening. For the TAF
sites, conditions will remain VFR through 06z Monday, before
ceilings lower overnight into Monday morning with areas of MVFR
conditions across the Idaho Panhandle and eastern third of
Washington including KGEG/KSFF/KCOE/KPUW.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: There is high
confidence for rain showers to move into extreme eastern
Washington and the Idaho Panhandle Sunday afternoon and then
becoming steadier in the evening. However, there is low
confidence for thunderstorms to impact TAF sites. Between 12-18z
Monday, HREF probability range from 50-70% for MVFR conditions
for KGEG/KSFF/KCOE with 30% chance for IFR conditions at
KGEG/KCOE. JW

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

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        50  68  49  72  49  79 /  70  50  30  20   0   0
Coeur d`Alene  49  64  48  70  48  77 /  80  70  40  20   0   0
Pullman        46  64  41  69  43  77 /  80  50  20   0   0   0
Lewiston       55  71  50  76  52  83 /  80  60  20   0   0   0
Colville       44  69  41  75  41  80 /  50  30  30  10   0   0
Sandpoint      48  59  44  67  44  74 /  90  90  70  20   0   0
Kellogg        48  58  46  66  47  74 / 100  90  50  20   0   0
Moses Lake     50  75  47  77  49  83 /  10  20  10   0   0   0
Wenatchee      57  76  53  79  58  85 /  20  20  10   0   0   0
Omak           50  76  50  79  52  83 /  30  20  20   0   0   0

&&

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

&&

$$