Alert archive / Montana / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 21, NWS Missoula, MT

August 22, 2026Flathead County, Lincoln County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Aug 22, 2026, 5:27 PM MDT for Flathead County, Lincoln County, Montana. It was in force for 48 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 22, 2026, 5:27 PM MDT (23:27 UTC)
Expired
Aug 22, 2026, 6:15 PM MDT
In force
48 min
Issued by
NWS Missoula, MT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Flathead County, MT, Lincoln County, MT

The radar

The Missoula radar (KMSX), 150 km from the middle of the area, began a volume at 23:27 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.

What was reported inside it

TimeReportWhereRemark
Aug 22, 6:00 PM MDTTSTM WND GST 54La Salle, MTASOS station KGPI Kalispell.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.5 hours before the alert went out and 317 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Great_falls, MT at 12:00Z on 2026-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 22 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 2026-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
22 J/kg
Mixed-layer CIN
-584 J/kg
Mixed-layer LCL
2213 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

569 
WUUS55 KMSO 222327
SVRMSO
MTC029-053-230015-
/O.NEW.KMSO.SV.W.0021.260822T2327Z-260823T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Missoula MT
527 PM MDT Sat Aug 22 2026

The National Weather Service in Missoula has issued a

* Severe Thunderstorm Warning for...
  West Central Flathead County in northwestern Montana...
  East Central Lincoln County in northwestern Montana...

* Until 615 PM MDT.

* At 527 PM MDT, a severe thunderstorm was located 17 miles southwest
  of Whitefish, or 17 miles west of Kalispell, moving northeast at 40
  mph.

  HAZARD...60 mph wind gusts and small hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Whitefish, Columbia Falls, Lupfer, Olney, Marion and La Salle.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds.

&&

LAT...LON 4823 11487 4831 11498 4868 11447 4835 11406
      4809 11469
TIME...MOT...LOC 2327Z 235DEG 36KT 4829 11466

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
2 follow-up statements
581 
WWUS55 KMSO 222354
SVSMSO

Severe Weather Statement
National Weather Service Missoula MT
554 PM MDT Sat Aug 22 2026

MTC053-230004-
/O.CAN.KMSO.SV.W.0021.000000T0000Z-260823T0015Z/
Lincoln MT-
554 PM MDT Sat Aug 22 2026

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR EAST CENTRAL LINCOLN
COUNTY...

A Severe Thunderstorm Warning still remains in effect for a portion
of Flathead County until 615 PM MDT.

&&

LAT...LON 4829 11470 4840 11485 4868 11447 4835 11406
      4819 11444
TIME...MOT...LOC 2327Z 235DEG 36KT 4829 11465

$$


MTC029-230015-
/O.CON.KMSO.SV.W.0021.000000T0000Z-260823T0015Z/
Flathead MT-
554 PM MDT Sat Aug 22 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM MDT FOR
WEST CENTRAL FLATHEAD COUNTY...

At 554 PM MDT, a severe thunderstorm was located over Whitefish, or
14 miles north of Evergreen, moving northeast at 40 mph.

HAZARD...60 mph wind gusts and small hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Whitefish, Columbia Falls, Lupfer, Olney and La Salle.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds.

&&

LAT...LON 4829 11470 4840 11485 4868 11447 4835 11406
      4819 11444
TIME...MOT...LOC 2327Z 235DEG 36KT 4829 11465

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
210 
WWUS55 KMSO 230011
SVSMSO

Severe Weather Statement
National Weather Service Missoula MT
611 PM MDT Sat Aug 22 2026

MTC029-230021-
/O.EXP.KMSO.SV.W.0021.000000T0000Z-260823T0015Z/
Flathead MT-
611 PM MDT Sat Aug 22 2026

...SEVERE THUNDERSTORM WARNING WILL EXPIRE AT 615 PM MDT FOR WEST
CENTRAL FLATHEAD COUNTY...

&&

LAT...LON 4829 11470 4840 11485 4868 11447 4835 11406
      4819 11444
TIME...MOT...LOC 2354Z 236DEG 36KT 4845 11431

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 9:59 PM MDTSpecial Weather StatementMSO31 min
Aug 22, 9:08 AM MDTRed Flag WarningMSOBeaverhead, Deer Lodge, Granite, Jefferson, Powell, Silver Bow35 hr
Aug 22, 9:08 AM MDTRed Flag WarningMSOFlathead, Lincoln, Mineral, Missoula, Sanders21 hr
Aug 22, 2:45 PM MDTSpecial Weather StatementMSORavalli45 min
Aug 22, 3:39 PM MDTSpecial Weather StatementMSOSanders36 min
Aug 22, 4:09 PM MDTSpecial Weather StatementMSOSanders66 min
Aug 22, 4:12 PM MDTSpecial Weather StatementMSOMissoula48 min
Aug 22, 4:30 PM MDTSpecial Weather StatementMSOLincoln60 min
Aug 22, 5:09 PM MDTSpecial Weather StatementMSOLincoln66 min

Nearby

Severe Thunderstorm Warnings in Montana, 2026Every severe thunderstorm 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.