Severe Thunderstorm Warning 10, NWS Missoula, MT

Area Forecast Discussion
National Weather Service Missoula MT
1213 PM MDT Thu Jul 16 2026

.DISCUSSION...

KEY MESSAGES:

- Scattered strong to severe thunderstorms this afternoon and
  evening, with strong winds, large hail, and heavy rain.

- Another round of scattered strong to severe storms possible
  Friday afternoon and evening

- Trending drier and breezy this weekend, thunderstorms returning
  by Tuesday next week

The concern for strong to severe thunderstorms remains this
afternoon and evening across much of western Montana and north
central Idaho. High resolution models show two main areas of
thunderstorms with slightly different timing and threats.

Thunderstorms in southwest and west-central Montana will likely
form on the earlier side, as early as 1pm, and linger through
roughly 10pm. These storms will largely form on the terrain
initially but may spread into valley locations towards early
evening. The bigger threat with these storms will be large hail
(quarter sized or bigger) and heavy rainfall. Severe wind gusts
can't be completely ruled out, but lack of strong forcing aloft
and overall slower storm motions favors gusts more in the 40 to 50
mph range.

Thunderstorms in northwest Montana and north central Idaho will
likely form later in the evening and continue into the overnight
timeframe, generally 7pm and 1am MDT. These storms will be driven
by better forcing aloft, with lightning already occurring
upstream in eastern Washington/Oregon. These storms may pose more
of a wind threat with the potential for upstream convection to
form into more of a line as it moves into northwest Montana,
meaning wind threats could be more widespread. Wind gusts 58 mph
or higher are possible with the stronger storms. Heavy rain and
hail will also be a concern.

Friday, the upper level pattern changes very little. An additional
surge of monsoonal moisture brings already elevated atmospheric
moisture values even higher (precipitable water values greater
than 1 inch). High resolution models are again favoring strong to
severe storms developing in this environment. Some questions
remain however in terms of cloud cover and how that may impact
heating and thus instability by the afternoon. If cloud cover does
not fill in tomorrow morning, thunderstorms threats of strong
outflow winds, hail and very heavy rainfall will again be a
concern. Debris flow in flood prone areas or recent burn scars
will be a larger concern as well due to the higher moisture
content and location of stronger convection closer to regional
flood prone areas in southwest Montana and north central Idaho.

Looking ahead to the weekend, the focus for showers and
thunderstorms shifts into Lemhi County, ID and southwest Montana.
The rest of the area will remain warm and dry. This change will
be driven by a westerly flow aloft, with atmospheric instability
decreasing for many areas. Breezy winds will develop as well,
particularly across northwest Montana.

&&

.AVIATION...A monsoon surge from the south-southwest has atmospheric
moisture running well above normal across the region. Plenty of
atmospheric instability will lead to thunderstorms initiating off
the terrain of central Idaho and northeast Oregon. between
16/1800-2000Z, with storms moving northeastward through the
evening. Increasing south-southwest winds aloft will provide
sufficient wind shear to organize thunderstorms, with a 5-15%
chance for severe thunderstorms across the region. Primary storm
threats include large hail (1 inch in diameter or greater), strong
winds (50-60kts), and heavy rain. High resolution models continue
to hint at storms congealing into a line this evening across
northwest Montana which could bring more widespread strong winds.

Elevated instability remains across the region overnight with
some forcing across northwest Montana, thus a few thunderstorms
may pop up during the early morning hours. Valley locations that
experience rain today will have the potential for patchy fog on
Friday morning.

There is some concern with cloud cover limiting instability on
Friday but most guidance shows enough clearing on Friday morning
to allow for another round of thunderstorms on Friday afternoon
and evening. Gusty outflow winds are a concern once again with
high resolution models trending toward a wave of strong outflow
winds originating in the Bitterroot Valley mid afternoon, then
spreading northward through the evening hours.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

Special Weather Statement
National Weather Service Missoula MT
115 PM MDT Thu Jul 16 2026

MTZ007-162000-
Butte/Blackfoot Region MT-
115 PM MDT Thu Jul 16 2026

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL SILVER BOW COUNTY UNTIL
2 PM MDT...

At 115 PM MDT, Doppler radar was tracking a strong thunderstorm 6
miles west of Divide, or 22 miles southwest of Butte, moving
northeast at 15 mph.

HAZARD...Wind gusts up to 40 mph and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
  Butte, Silver Bow, Walkerville, Divide, Nissler, Newcomb and
  Janney.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4581 11299 4582 11301 4611 11250 4609 11247
      4604 11247 4603 11244 4600 11244 4596 11243
      4594 11244 4592 11242 4591 11242 4589 11240
      4586 11243 4572 11275 4575 11276 4576 11278
      4576 11280 4579 11289 4578 11291 4580 11293
TIME...MOT...LOC 1915Z 231DEG 11KT 4578 11287

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

Special Weather Statement
National Weather Service Missoula MT
504 PM MDT Thu Jul 16 2026

MTZ001-004-162330-
Lower Clark Fork Region MT-Kootenai/Cabinet Region MT-
504 PM MDT Thu Jul 16 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHERN LINCOLN AND
NORTHWESTERN SANDERS COUNTIES UNTIL 530 PM MDT...

At 504 PM MDT, Doppler radar was tracking a strong thunderstorm 12
miles south of Noxon, or 24 miles northwest of Thompson Falls, moving
northeast at 30 mph.

HAZARD...Penny size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

Locations impacted include...
  Tuscor and Trout Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 4784 11588 4809 11562 4795 11536 4772 11567
      4782 11585 4783 11585 4783 11587
TIME...MOT...LOC 2304Z 218DEG 26KT 4782 11574

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...<30 MPH