744
FXUS66 KOTX 070719
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1219 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.

&&

.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...
06Z TAFs: A cold upper-level low will move through the Inland
Northwest Sunday with shower chances retreating to far northeast
Washington and the Idaho Panhandle. The boundary layer remains
dry with widespread VFR conditions expected through the period.
Primarily flat cumulus development is anticipated Sunday
afternoon with cloud bases above 7k feet. There will be enough
instability across far northeast WA and north Idaho to support a
15-20% chance of lightning. KCOE has a 10% chance Sunday
afternoon, which was too low to include in the TAF. Winds will
become breezy in the afternoon from the west to southwest with
gusts 20 to 25 knots.

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

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

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  69  46  64  43 /  10   0  10  70  90  50
Coeur d`Alene  62  41  68  48  60  44 /  20   0  10  70 100  80
Pullman        61  39  67  44  62  41 /   0   0   0  70  90  60
Lewiston       69  46  74  52  70  48 /  20   0   0  70  90  60
Colville       67  35  69  41  65  37 /  20   0   0  70 100  80
Sandpoint      60  39  67  46  58  42 /  40   0   0  60 100  90
Kellogg        59  39  69  47  58  43 /  30   0   0  60 100  90
Moses Lake     72  43  71  44  72  42 /   0   0  20  50  30   0
Wenatchee      71  49  69  51  69  49 /   0   0  30  60  30   0
Omak           72  41  71  47  71  42 /   0   0  10  60  80  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Frost Advisory until 11 AM PDT this morning for Northeast
     Mountains-Okanogan Highlands-Okanogan Valley-Western
     Okanogan County.
ID...Frost Advisory until 11 AM PDT this morning for Northern
     Panhandle.

&&

$$