Severe Thunderstorm Warning 1, NWS Spokane, WA

Area Forecast Discussion
National Weather Service Spokane WA
208 PM PDT Thu May 28 2026

.KEY MESSAGES...

- Scattered severe thunderstorms this afternoon and evening
  (Thursday). Some storms will be capable of producing damaging
  outflow winds, large hail, and heavy downpours. Some storms
  will continue into Friday over the northern mountains and
  Idaho Panhandle.

- Very warm this afternoon with minor to moderate HeatRisk.
  Heat related impacts possible to those that are sensitive to
  the heat especially to those without adequate cooling and/or
  hydration.

- Gusty winds through the Cascade gaps into the Wenatchee Area,
  Waterville Plateau, and Moses Lake Area Friday afternoon and
  evening with a 40-50% chance for gusts of greater than 40 mph.

&&

.SYNOPSIS...
Warm and muggy conditions today will give way to thunderstorms in
the late afternoon and evening. Some thunderstorms will be strong to
severe and capable of producing damaging outflow winds, hail, and
heavy downpours. Breezy to windy conditions on Friday especially
through the Cascade gaps. The weekend will be drier and occasionally
breezy.

&&

.DISCUSSION...

Rest of this afternoon through Friday: A vigorous shortwave is
rounding a deep upper level low pressure system off to our south.
The center of the low is situated over central California and the
shortwave is currently pushing across northern Nevada. A highly
diffluent flow pattern aloft and a strong vorticity maximum in the
northeast quadrant of the this low pressure system will be the
kicker that initiates convection across the Inland Northwest today.
Strong to severe thunderstorms are already being observed in western
Idaho to eastern Oregon. The potential for severe thunderstorms will
initially favor the southern Idaho Panhandle into southeast
Washington by 3-4 pm. Thunderstorms are then progged to develop
north to northwest with time through the rest of the afternoon into
the evening. Thunderstorms will initially favor supercell
development with the potential for hail of 1.5-2.0 inches and along
with damaging outflow winds. There is a non-zero chance for
tornadoes with supercells over the southeast portion of the forecast
area; a very low chance of 2-4 percent within a 25 mile radius, but
not of the question this afternoon.

Thunderstorms are then expected to organize along a line and
transition to favoring damaging winds over producing large hail as
this line progresses across the Columbia Basin into the Spokane-
Coeur d'Alene Area. The amount of CAPE in the 1000-3000 J/kg range
with 20-30 kts of 0-6 km bulk shear is enough for the potential of
damaging wind gusts along the leading edge of the line of
thunderstorms. As the cold pool gets established, we could see winds
in the 60-70 mph range. This will not only bring the potential for
down trees and power lines, but also bring the potential for blowing
dust across the Columbia Basin, into the Palouse and northward
along the Highway 2 corridor. Blowing dust may be enough to
reduce visibility down to a mile or less and result in rapid
changes to visibility.

The line of thunderstorms is expected to push north of the Canadian
border between midnight to 2AM. A shortwave pushing in off of the
eastern Pacific will bring additional convection on Friday primarily
across the northern mountains, but also across the southern Idaho
Panhandle. We won't be nearly as unstable as today, but there is
still the potential for a few stronger thunderstorms that brings
small hail, gusty outflow winds, and brief heavy downpours. The
shortwave will also tighten the westerly gradient with gusty winds
of 35-45 mph through the Cascade gaps into the Wenatchee Area,
Waterville Plateau, and into the western Columbia Basin.

Friday night through Thursday: The disturbance that moves
across on Friday looks to push much of the moisture and
instability east of the region by Saturday. It also will bring
temperatures down a bit with temperatures back down to near
normal in the 60s to low 70s. Overall a much drier forecast for
the weekend and occasionally breezy. Showers and isolated
thunderstorms may hang on over the Idaho Panhandle into the
Northeast Mountains through the weekend into Monday as the
shortwave looks to stall over the northern Rocky Mountains and
possibly form a closed low circulation. Temperatures warm back
up above normal next week into the mid to upper 70s by Tuesday
into Wednesday. Models are indicating a shortwave disturbance
around the Wednesday into Thursday time frame that would bring
the potential for breezy winds and also a threat for showers and
thunderstorms particularly over Northeast Washington and into
the Idaho Panhandle. /SVH

&&

.AVIATION...
18Z TAFs:

WIDELY SCATTERED THUNDERSTORMS TODAY WITH A THREAT OF SEVERE
WEATHER INCLUDING DAMAGING WINDS, BLOWING DUST AND LARGE HAIL

There is good model agreement that strong to severe
thunderstorms will threaten all TAF sites picking initiating
between 22-01Z moving northward across the eastern Washington
and the Idaho Panhandle through 08Z. Main impacts with these
thunderstorms will be for severe wind gusts up to 70+ kts,
torrential rainfall, and hail. For hail, there is the potential
for isolated storms to produce up to ping pong to baseball
sized hail with KLWS and KPUW carrying the higher threat.
Another potential impact will come from models supporting
damaging winds developing at the leading edge of the
thunderstorms, which will also have the potential to pick up
significant blowing dust across the Columbia Basin (KEPH/KMWH)
prior to heavy rain. It's possible some of this dust could
briefly lower visibility at KGEG, KSFF, KCOE, and KPUW, but
confidence in BLDU too low to include for these TAF sites.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
There is high confidence of impactful thunderstorms over all TAF
sites from 22Z Thursday through 08Z Friday. Models support with
moderate confidence of 50-60kt gusts with thunderstorms and
localized 70kt wind gusts with severe thunderstorms.

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

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        54  74  47  65  45  67 /  70  10  20   0  10  20
Coeur d'Alene  57  74  49  62  46  62 /  70  10  20   0  30  30
Pullman        50  69  43  59  41  62 /  70  10  10   0   0  10
Lewiston       56  76  52  65  48  69 /  60  40  30  10   0   0
Colville       50  76  43  69  41  70 /  80  50  60  20  10  30
Sandpoint      54  75  48  63  44  61 /  60  30  30  10  40  60
Kellogg        56  75  48  61  45  60 /  70  10  10  20  40  40
Moses Lake     55  77  44  72  42  75 /  80  20   0   0   0   0
Wenatchee      62  73  49  70  48  75 /  70  40  10   0   0   0
Omak           59  76  48  73  48  75 /  80  80  30  10   0   0

&&

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

&&

Special Weather Statement
National Weather Service Spokane WA
334 PM PDT Thu May 28 2026

IDZ004-282330-
Central Panhandle Mountains ID-
334 PM PDT Thu May 28 2026

...A strong thunderstorm will impact portions of southwestern
Shoshone County through 430 PM PDT...

At 333 PM PDT, Doppler radar was tracking a strong thunderstorm 20
miles south of Wallace, moving northwest at 10 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to outdoor objects is
         possible.

Locations impacted include...
Calder and Huckleberry Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until midnight PDT for
the Panhandle of Idaho.

&&

LAT...LON 4716 11597 4713 11610 4727 11626 4732 11600
TIME...MOT...LOC 2233Z 157DEG 7KT 4720 11606

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

Butler