Alert archive / Montana / Flash Flood Warnings in 2026

Flash Flood Warning 4, NWS Missoula, MT

July 17, 2026Missoula County, Powell County, Montana

NWS Missoula, MT issued this flash flood warning at Jul 17, 2026, 5:09 PM MDT for Missoula County, Powell County, Montana. It was in force for 93 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 17, 2026, 5:09 PM MDT (23:09 UTC)
Expired
Jul 17, 2026, 6:42 PM MDT
In force
93 min
Issued by
NWS Missoula, MT
Area
Storm-based polygon
Flood severity
None

Counties Missoula County, MT, Powell County, MT

The radar

The Missoula radar (KMSX), 50 km from the middle of the area, began a volume at 23:13 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The text

As transmitted.

797 
WGUS55 KMSO 172309
FFWMSO
MTC063-077-180115-
/O.NEW.KMSO.FF.W.0004.260717T2309Z-260718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Missoula MT
509 PM MDT Fri Jul 17 2026

The National Weather Service in Missoula has issued a

* Flash Flood Warning for...
  East Central Missoula County in west central Montana...
  West Central Powell County in west central Montana...

* Until 715 PM MDT.

* At 509 PM MDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is ongoing or
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flash flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Clearwater and Greenough.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 4683 11335 4686 11342 4700 11346 4704 11337
      4697 11329 4687 11325 4683 11334

FLASH FLOOD...RADAR INDICATED

$$
1 follow-up statement
079 
WGUS75 KMSO 180042
FFSMSO

Flash Flood Statement
National Weather Service Missoula MT
642 PM MDT Fri Jul 17 2026

MTC063-077-180052-
/O.CAN.KMSO.FF.W.0004.000000T0000Z-260718T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Missoula MT-Powell MT-
642 PM MDT Fri Jul 17 2026

...FLASH FLOOD WARNING IS CANCELLED FOR EAST CENTRAL MISSOULA AND
WEST CENTRAL POWELL COUNTIES...

The heavy rain has ending. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

A Flood Watch remains in effect until 900 PM MDT for a portion of
west central Montana.

&&

LAT...LON 4683 11335 4686 11342 4700 11346 4704 11337
      4697 11329 4687 11325 4683 11334

$$

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Missoula, MT wrote its last area forecast discussion before this flash flood warning went out at Jul 17, 1:39 PM MDT, 3 hours 30 minutes earlier.

Area forecast discussion, Jul 17, 1:39 PM MDT, 3 hours 30 minutes before
Area Forecast Discussion
National Weather Service Missoula MT
139 PM MDT Fri Jul 17 2026

.DISCUSSION...

KEY MESSAGES:

- Strong to severe thunderstorms this afternoon and evening,
  bringing the threat of strong winds, large hail, and heavy rain.

- Trending drier and breezy this weekend. Elevated fire weather by
  Sunday from hot, dry, and breezy conditions, especially in
  northwest Montana

- Thunderstorms return by Tuesday next week with the next Monsoon
  moisture surge.

Monsoonal moisture has peaked over the region, with atmospheric
moisture content running at 200 percent of normal and precipitable
water values over 1 inch. Impressive instability along with an
incoming wave of energy currently moving through central Idaho
sets the stage for widespread thunderstorm development this
afternoon. High resolution models show convection forming over the
southern Bitterroot mountains around 2 to 3pm, moving northwards
and potentially forming into a line of storms that could hold
together into northwest Montana this evening. Gusty winds will be
the main concern with this convection, with gusts 40 to 50 mph
anticipated with stronger storms. It should be noted that a few
of our high resolution models are showing the potential for gusts
over 60 mph through the Missoula valley northwards into the
Mission valley early this evening. While not a likely scenario (10
to 20 percent chance) it is something that will be monitored
closely moving forwards. Further north, in northwest Montana, hail
becomes more of a concern due to increased shear values. It
should also be noted that thunderstorms could linger across
northwest Montana through early Saturday morning.

Storms will also be capable of very heavy rainfall rates of 0.75"
or more per hour. fortunately storm motion should keep cells
moving fairly rapidly which overall decreases the flash flooding
risk. However, sensitive flood prone areas and recent burn scars,
particularly in Lemhi County and southwest Montana, could have
flood concerns if they take a direct hit from thunderstorms.

On Saturday, the low pressure system that has been sitting off the
Pacific Northwest coast slowly moves through southern British
Columbia and Alberta, flattening the ridge of high pressure and
bringing more westerly flow aloft. This will shift thunderstorm
potential primarily to locations south of Interstate 90. Never
the less, a few storms still could become strong in these areas
with gusty winds, and brief heavy rain the main threats. Further
north across northwest Montana, breezy westerly winds will
develop. This coupled with much drier air could enhance fire
weather concerns. By Sunday, much drier air moves over all of
western Montana and north central Idaho, with hot, dry and breezy
conditions anticipated.

Global ensembles suggest the next surge of monsoon moisture will
arrive by the middle of next week (Tuesday into Thursday). Chances
for showers and thunderstorms will trend higher each day as
precipitable water values reach over one inch.

&&

.AVIATION...The atmosphere over the Northern Rockies airspace is
unstable and thunderstorms have begun to develop. Any thunderstorm
will be capable of gusty outflow winds 40 to 50 mph, but this
threat is higher probability at KMSO and KHRF between 17/2200 and
18/0200z. Additionally, hail 0.25 to 1.00" is possible at all
terminals along with brief but heavy rainfall degrading
visibility 2-4 statute miles. Thunderstorm threat decreases after
18/0300z but showers and embedded thunderstorms will remain a
threat in northwest MT overnight.

&&

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

In the hours before

Special weather statement, Jul 17, 3:54 PM MDT, 1 hour 15 minutes before
Special Weather Statement
National Weather Service Missoula MT
354 PM MDT Fri Jul 17 2026

MTZ005-172230-
Missoula/Bitterroot Valleys MT-
354 PM MDT Fri Jul 17 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL RAVALLI COUNTY
UNTIL 430 PM MDT...

At 354 PM MDT, Doppler radar was tracking a strong thunderstorm over
Victor, or 10 miles north of Hamilton, moving north at 10 mph.

HAZARD...Wind gusts up to 30 mph and penny size hail. Heavy rainfall
         0.50 to 0.75" per hour possible.

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...
  Stevensville, Victor, Pinesdale and Bell Crossing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4632 11402 4634 11424 4643 11424 4647 11422
      4651 11419 4658 11416 4657 11396
TIME...MOT...LOC 2153Z 184DEG 8KT 4638 11413

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH
Local storm report, Jul 17, 4:01 PM MDT, 1 hour 8 minutes before
Preliminary Local Storm Report
National Weather Service Missoula MT
401 PM MDT Fri Jul 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0330 PM     Rain             5 WNW West Valley       46.19N 113.12W
07/17/2026  M1.29 Inch       Deer Lodge         MT   Trained Spotter

            Spotter reported lots of hail, with a few up
            to 1 inch.

&&

BEC
Special weather statement, Jul 17, 4:08 PM MDT, 1 hour 1 minute before
Special Weather Statement
National Weather Service Missoula MT
408 PM MDT Fri Jul 17 2026

MTZ007-172230-
Butte/Blackfoot Region MT-
408 PM MDT Fri Jul 17 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN DEER LODGE...
NORTHERN SILVER BOW AND SOUTH CENTRAL POWELL COUNTIES UNTIL 430 PM
MDT...

At 408 PM MDT, Doppler radar was tracking a strong thunderstorm near
Galen, or 7 miles south of Deer Lodge, moving northeast at 20 mph.

HAZARD...Wind gusts up to 30 mph and nickel size hail. Heavy rain
         rates 0.50 to 0.75 inches per hour are possible.

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...
  Deer Lodge, Galen and Racetrack.

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 4620 11284 4628 11294 4649 11270 4634 11245
      4633 11245 4633 11247 4634 11247 4634 11249
      4633 11250 4633 11253 4631 11256 4630 11257
      4628 11256 4626 11256 4624 11258 4624 11260
      4621 11257 4620 11258 4618 11257 4617 11258
TIME...MOT...LOC 2208Z 237DEG 15KT 4629 11278

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...30 MPH
Local storm report, Jul 17, 4:28 PM MDT, 41 minutes before
Preliminary Local Storm Report
National Weather Service Missoula MT
428 PM MDT Fri Jul 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0328 PM     Hail             5 WNW West Valley       46.18N 113.11W
07/17/2026  M1.00 Inch       Deer Lodge         MT   Trained Spotter

            Heavy rain of 1.29 inch in less than an
            hour.

&&

BEC
Special weather statement, Jul 17, 4:51 PM MDT, 18 minutes before
Special Weather Statement
National Weather Service Missoula MT
451 PM MDT Fri Jul 17 2026

MTZ007-043-172315-
Potomac/Seeley Lake Region MT-Butte/Blackfoot Region MT-
451 PM MDT Fri Jul 17 2026

...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL POWELL AND EAST
CENTRAL MISSOULA COUNTIES UNTIL 515 PM MDT...

At 451 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Ovando, or 26 miles north of Drummond, moving northeast
at 20 mph.

HAZARD...Wind gusts up to 30 mph and penny size hail. Rainfall rates
         of 0.50 to 0.75 inches are possible.

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...
  Ovando, Woodworth and Clearwater.

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 4690 11335 4701 11353 4723 11331 4709 11304
TIME...MOT...LOC 2250Z 216DEG 15KT 4702 11333

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH
Local storm report, Jul 17, 5:03 PM MDT, 6 minutes before
Preliminary Local Storm Report
National Weather Service Missoula MT
503 PM MDT Fri Jul 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     Flash Flood      1 SE Drummond           46.66N 113.13W
07/17/2026                   Granite            MT   Emergency Mngr

            Flooding across I-90 WB lane between mile
            marker 155-156, east of Drummond MT.

&&

BEC

The office that day

Everything else NWS Missoula, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 16, 6:02 PM MDTSpecial Weather StatementMSOSanders58 min
Jul 16, 6:05 PM MDTSpecial Weather StatementMSOLincoln55 min
Jul 16, 6:19 PM MDTAreal Flood AdvisoryMSOSilver Bow56 min
Jul 16, 6:41 PM MDTSpecial Weather StatementMSOSilver Bow34 min
Jul 17, 5:29 AM MDTSpecial Weather StatementMSOLincoln31 min
Jul 17, 2:59 PM MDTSpecial Weather StatementMSODeer Lodge31 min
Jul 17, 3:18 PM MDTSpecial Weather StatementMSOPowell27 min
Jul 17, 3:19 PM MDTSpecial Weather StatementMSOGranite26 min
Jul 17, 3:50 PM MDTAreal Flood AdvisoryMSODeer Lodge55 min
Jul 17, 3:54 PM MDTSpecial Weather StatementMSORavalli36 min
Jul 17, 4:08 PM MDTSpecial Weather StatementMSODeer Lodge22 min
Jul 17, 4:14 PM MDTFlash Flood WarningMSOGranite2 hr
Jul 17, 4:15 PM MDTFlash Flood WarningMSOGranite2 hr
Jul 17, 4:17 PM MDTFlood WatchMSODeer Lodge, Granite, Missoula, Powell, Ravalli, Silver Bow3 hr
Jul 17, 4:27 PM MDTAreal Flood AdvisoryMSOGranite3 hr
Jul 17, 4:37 PM MDTFlash Flood WarningMSOGranite2 hr
Jul 17, 4:51 PM MDTSpecial Weather StatementMSOPowell24 min

Nearby

Flash Flood Warnings in Montana, 2026Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.