Hail and Damaging Winds in Montana, August 21, 2025

Name: Hail and Damaging Winds in Montana, August 21, 2025
Start: 2025-08-21T02:53
End: 2025-08-21T03:32
Location: Montana

August 21, 2025 · NWS GGW · 3 events in 2 counties and zones

An advancing cold front became the focus for severe thunderstorms near and south of the Yellowstone River valley in eastern Montana.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 3

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS GGW wrote it up.

An advancing cold front became the focus for severe thunderstorms near and south of the Yellowstone River valley in eastern Montana.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Glasgow, MT wrote its last area forecast discussion before the first event at Aug 21, 1:16 AM MST, 1 hour 37 minutes earlier.

Area forecast discussion, Aug 21, 1:16 AM MST, 1 hour 37 minutes before

Area Forecast Discussion
National Weather Service Glasgow MT
216 AM MDT Thu Aug 21 2025

.DISCUSSION...

KEY MESSAGES:

- Isolated to scattered showers overnight will linger into the
  daylight hours of this morning mainly east of Culbertson and
  Circle before moving to the east by mid morning.

- After this morning, mainly dry weather is expected for several
  days with temperatures between near normal to 10 degrees below
  normal.

WEATHER PATTERN OVERVIEW:

A cold front moved through the forecast area last evening.
Isolated to scattered showers and thunderstorms behind the front
will continue early this morning and move to the east a few hours
after sunrise this morning. High pressure will move into the area
this morning with clearing skies.

NW flow aloft will prevail the next several days with mainly dry
weather and temperatures that will vary from near normal to around
10 degrees below normal.

Tonight and Friday, there will be a wave moving along the MT/WY
border that will bring chances for showers and thunderstorms to
southern Montana. The precipitation from this system is expected
to stay south of the forecast area at this time.

FORECAST CONFIDENCE & DEVIATIONS:

No changes made to the NBM at this time.

&&

.AVIATION...
UPDATED: 0815Z.

FLIGHT CAT RANGE: VFR.

DISCUSSION:

Scattered showers and thunderstorms over the area early this
morning will move to the east by 15z. Skies will clear this
morning and remain mostly clear this afternoon and evening. Mid
and high clouds will move into the areas south of the Missouri
River early Friday morning while skies remain mostly clear to the
north.
WINDS: NW 10-20 knots today and north to NW 5 to 10 knots tonight.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
None.
&&

weather.gov/glasgow

The radar

The Glasgow radar (KGGW), 149 km away, was scanning. The volume nearest the first event began at 09:51 UTC.

Open the radar archive at this moment

Event by event

2 thunderstorm wind, 1 hail. Local standard time, as filed.

Hail, Prairie

When: August 21, 2:53 AM MST
Where: Prairie County, 15.12 mi NNE of Mc Cloud
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 47.110, -105.490

A trained spotter reported quarter size hail.

Thunderstorm Wind, Prairie

When: August 21, 2:53 AM MST
Where: Prairie County, 15.78 mi NNE of Mc Cloud
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 47.120, -105.490

A trained spotter estimated wind gusts of 50 to 60 mph which broke off some tree limbs.

Thunderstorm Wind, Dawson

When: August 21, 3:32 AM MST
Where: Dawson County, 1.17 mi SE of Glendive Dawson Arpt
Measured: 54 kt (62 mph) measured gust
Reported by: AWOS
Coordinates: 47.120, -104.780

The Glendive Airport (AWOS station KGDV) recorded a 62 mph wind gust.

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Montana in 2025 Every state in 2025 This day in weather history Warnings in Montana, August 2025

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1275738, 1275740, 1275739.