575
FXUS66 KOTX 122127
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
227 PM PDT Sat Sep 12 2026

.KEY MESSAGES...

- Widespread rain returns late Saturday night through Sunday.
  Most of the Inland Northwest has a 50-90% chance of receiving
  half an inch or more of rain with this system.

- Risk for debris flows and rock slides in Central Washington
  near sensitive burn scars and steep terrain.

- Isolated thunderstorms Saturday night into Sunday, especially
  for Eastern Washington and North Idaho.

- Warming and drying trend Monday through Friday with
  temperatures rebounding into the 70s-80s by the end of the week.

&&

.SYNOPSIS...
Saturday will be dry through the afternoon, then rain will
begin moving in from the southwest late Saturday night,
spreading across the region by Sunday morning. Widespread rain
chances persist through the day Sunday, accompanied by isolated
thunderstorm chances and gusty winds. Conditions trend warmer
Monday through Friday as a ridge of high pressure builds over
the Inland Northwest.

&&

.DISCUSSION...
Today and tomorrow: An upper level low offshore Oregon this
afternoon will slowly move inland tonight, bringing widespread rains
and a small chance (10-15%) of thunderstorms starting around 11 PM
this evening in southern Chelan and Grant County and spreading
northeast through the night hours. An occluded front will pass
through the region in the late morning, leaving eastern WA and north
ID in a showery regime while north central WA stays in a stable
precipitation regime in the wraparound region. Weak surface
based instability (50-300 J/kg) rebuilds in Sunday afternoon in
eastern WA and north ID as day time heating occurs, bringing an
additional 15% chance of thunderstorms. There has been an
undeniable trend towards less precipitation amounts in southeast
WA and the southern ID Panhandle and more precipitation amounts
in the Cascades due to the nature of showery precipitation
versus stratiform. The upper low departs in northwest MT Sunday
night, bringing additional light wraparound rain to eastern WA
and north ID overnight into Monday. The National Blend of Models
has struggled badly with this system, but the probabilities of
1+ inch of rain through 5 AM Monday appear more trustworthy at
this point as there is more ingestion of high resolution models:

Wenatchee: 81%
Chelan: 57%
Omak: 39%
Colville: 31%
Moses Lake: 21%
Pullman: 16%
Spokane: 14%
Lewiston: 13%
Sandpoint: 13%

Monday through Saturday: Monday will be mostly dry as the trough
shifts into the north central US. Temperatures will be cool in the
upper 50s through low 70s. There will be some lingering showers in
the ID Panhandle in the early afternoon with upslope flow into the
mountains. Another trough sweeps through southwestern British
Columbia Tuesday, bringing another round of light showers to the
northern mountains and Cascades. The remainder of next week is
dominated by high pressure in the northern Pacific shifting eastward
into the Pacific NW. Temperatures will rebound into the 70s and 80s
with lots of sunshine. Will need to monitor for frost potential in
the sheltered northern valleys. /Butler

&&

.AVIATION...
18Z TAFS: VFR conditions are expected through 07Z. A blanket of
mid and high level clouds will spread across the region. Winds
will be breezy from the north-northeast through much of the day.
After 07z, an incoming system will bring increasing low-mid
clouds with precip chances increasing west to east through the
end of the TAF period. Winds will also shift from North to
South-Southwest tonight. Chances for MVFR ceilings increase
after 07z as rain increases. There is a 15% chance of embedded
thunderstorms for KGEG-KSFF-KCOE-KPUW-KLWS.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
for VFR conditions through much of the day. Confidence drops to
moderate after 07Z with MVFR ceilings.


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

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        49  58  45  66  45  67 /  90 100  80   0   0   0
Coeur d`Alene  49  57  45  62  44  65 /  60 100  90  10   0   0
Pullman        48  59  47  64  41  66 / 100 100  90   0   0   0
Lewiston       56  67  48  72  49  72 /  90  90  70   0   0   0
Colville       50  58  46  67  40  69 /  50 100  60   0  10  20
Sandpoint      48  55  46  59  41  63 /  40 100  90  40   0  10
Kellogg        46  55  43  58  44  63 /  50 100 100  60   0   0
Moses Lake     54  59  44  68  45  70 / 100  90  40   0   0   0
Wenatchee      55  61  49  70  53  71 / 100 100  20   0   0  10
Omak           54  63  47  71  48  72 /  60 100  50   0  10  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Flood Watch from 1 AM PDT Sunday through Sunday evening for
     Central Chelan County-Okanogan Highlands-Okanogan Valley-
     Upper Columbia Basin-Waterville Plateau-Wenatchee Area-
     Western Chelan County-Western Okanogan County.
ID...None.

&&

$$