633
FXUS66 KOTX 071834
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1134 AM PDT Sun Jun 7 2026

.KEY MESSAGES...

- Rain moves in Monday night with an 80% chance of at least a
  tenth of an inch over much of extreme eastern Washington and
  into the Idaho Panhandle. Precipitation turns showery on
  Tuesday with a 10-30% chance for thunderstorms.

- Trending drier Wednesday into next weekend with high
  confidence for above normal temperatures by Friday. There is
  a 30-50% chance for temperatures in the upper 80s to low 90s
  by next Sunday and widespread minor to moderate HeatRisk.

&&

.UPDATE...
Frost advisory in effect has been cancelled early with
temperatures warming into the 40s this morning.

&&

.SYNOPSIS...
Showers and isolated thunderstorms are possible far northeast
Washington and north Idaho Sunday afternoon. Temperatures trend
warmer though pockets of frost expected for northeast Washington
Monday morning. A wetter storm system with widely scattered
light rain across the region late Monday into Tuesday morning.
Breezy with showers Tuesday afternoon with the threat for
isolated thunderstorms. The rest of the week will be drier with
warmer temperatures.

&&

.DISCUSSION...
Sunday: A cold upper-level low will be centered over the
northern Rockies on Sunday with a transient upper-level ridge
over central Washington. The upper-level low will keep showers
and cloud coverage focused over far northeast Washington and
north Idaho on Sunday. Modest instability (100-200 J/kg of
SBCAPE) will support a 10-20% chance of embedded thunderstorms.
Farther west into central Washington, it will be drier and
temperatures will warm by a few degrees compared to Saturday
under the transient ridge with highs in the upper 60s and 70s. A
continued cross-Cascade pressure gradient (+5-6 mb from SEA-
EAT) and effective momentum afternoon mixing will support breezy
winds with gusts up to 25 mph from the lee of the Cascades
through the Spokane area and Palouse. Overnight lows into Monday
morning will be slightly warmer, but pockets of frost across
far northeast Washington (Deer Park to Colville) is possible
with a 60% chance for lows below 36F.

Monday through Wednesday: A surface low and upper-level trough
approaches the Pacific Northwest on Monday. Warm advection ahead
of the low will bring a steadier band of stratiform
precipitation into the Inland Northwest Monday night into
Tuesday morning before transitioning to convective precipitation
later Tuesday morning and afternoon. Initially, low level flow
from the south-southwest should overcome the Cascade rain shadow
with a 50% chance for 0.10 inches of rain across central
Washington. Far eastern Washington and north Idaho have a 90%
chance for greater than 0.10 inches, an 80% chance for greater
than 0.25 inches, and a 40-70% chance for greater than 0.50
inches.

Precipitation transitions to a convective regime later Tuesday
as the upper-level trough moves through the Inland Northwest.
Models show SBCAPE increasing to 200-700 J/kg in the afternoon
across eastern Washington and north Idaho. Given weak wind shear
(0-6 km shear less than 20 knots), the environment will
primarily favor disorganized, slow moving single cell
thunderstorms capable of producing small hail and localized wind
gusts to 40 mph. Simultaneously, tight synoptic gradients (PDX-
GEG gradient reaching +10 to +12 mb) will support widespread
breezy background winds. There is high confidence (80% chance)
for wind gusts exceeding 40 mph along the lee of the Cascades,
the western Columbia Basin, and the Blue Mountains. Showery,
unsettled conditions will persist into Wednesday as another
shortwave trough drops southeastward from the Pacific Northwest
coast, focusing a 20-50% chance of showers over the Cascades,
northeast Washington, and the Idaho Panhandle.

Thursday through Saturday: Models are in good agreement with an
upper-level ridge amplifying off the coast of the Pacific
Northwest, driving a notable warming and drying trend late week
into the weekend. However, significant uncertainty remains
concerning the eastward influence of the ridge. WPC cluster
analysis reveals a split scenario: approximately 50% of the
global ensembles depict the ridge axis farther offshore, keeping
the Inland Northwest cooler and more vulnerable to clipping
shortwaves embedded in the northwest flow. The remaining 50%
shifts the ridge axis farther inland, which would result in much
warmer and drier conditions.

This uncertainty is reflected in a 9-10F spread between the NBM
25th and 75th percentiles by next weekend. Across the Inland
Northwest the 25th percentile max temperatures show daytime
highs in the 75-85F range, while the 75th percentile solutions
are in the 85-95F range. /vmt

&&

.AVIATION...
18Z TAFs: The Inland Northwest will be on the back edge of a
cold upper level trough of lower pressure today. There will be
enough instability across far northeast WA and north Idaho to
support a 15-20% chance of lightning. Showers with towering
cumulus will be spotty around KGEG, KSFF, KCOE with the better
chances and a 30% probability of a passing showers impacting
KCOE this afternoon. Lightning activity is expected to remain
north and east of the Spokane/Coeur d`Alene corridor. Breezy
west-southwest winds into the afternoon with gusts 20 to 25
kts, then decline after 02-04Z.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence VFR conditions at all TAF sites. Low confidence
in shower or thunderstorm developing over a given TAF site. /SVH

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

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        65  41  71  47  64  43 /   0   0   0  90  90  40
Coeur d`Alene  62  41  70  49  59  44 /  10   0   0  80 100  70
Pullman        61  39  69  45  59  41 /   0   0   0  90 100  50
Lewiston       69  45  76  53  68  48 /   0   0   0  80  90  40
Colville       67  35  71  41  64  36 /  10   0   0  80 100  80
Sandpoint      60  39  68  46  57  42 /  30   0   0  70 100  90
Kellogg        59  39  71  48  57  43 /  30   0   0  60 100  90
Moses Lake     72  41  72  45  71  41 /   0   0  20  90  40   0
Wenatchee      71  48  69  52  68  49 /   0   0  30  90  20   0
Omak           72  40  72  48  70  42 /   0   0   0  90  80  10

&&

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

&&

$$