Hail and Damaging Winds in Montana, July 21, 2010

Name: Hail and Damaging Winds in Montana, July 21, 2010
Start: 2010-07-21T17:05
End: 2010-07-21T21:55
Location: Montana

July 21, 2010 · NWS BYZ · 9 events in 3 counties and zones

A few severe thunderstorms moved across the central and southern portions of the Billings Forecast Area during the evening hours of the 21st.

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: 9

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 BYZ wrote it up.

A few severe thunderstorms moved across the central and southern portions of the Billings Forecast Area during the evening hours of the 21st.

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 Billings, MT wrote its last area forecast discussion before the first event at Jul 21, 1:56 PM MST, 3 hours 9 minutes earlier.

Area forecast discussion, Jul 21, 1:56 PM MST, 3 hours 9 minutes before

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Hazardous weather outlook, Jul 21, 1:53 PM MST, 3 hours 12 minutes before

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In the hours before

Special weather statement, Jul 21, 1:35 PM MST, 3 hours 30 minutes before

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Special weather statement, Jul 21, 3:08 PM MST, 1 hour 57 minutes before

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Special weather statement, Jul 21, 4:44 PM MST, 21 minutes before

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The radar

The Billings radar (KBLX), 173 km away, was scanning. The volume nearest the first event began at 00:07 UTC.

Open the radar archive at this moment

Event by event

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

Hail, Rosebud

When: July 21, 5:05 PM MST
Where: Rosebud County, Birney
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 45.320, -106.520

Thunderstorm Wind, Rosebud

When: July 21, 5:15 PM MST
Where: Rosebud County, 0.69 mi S of Birney
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 45.310, -106.520

Power was reported out and 4 inch diameter tree limbs were down.

Thunderstorm Wind, Yellowstone

When: July 21, 8:17 PM MST
Where: Yellowstone County, 3.74 mi SSW of (Bil)logan Arpt Bill
Measured: 54 kt (62 mph) measured gust
Reported by: ASOS
Coordinates: 45.750, -108.560

Thunderstorm Wind, Yellowstone

When: July 21, 8:19 PM MST
Where: Yellowstone County, 0.84 mi SW of (Bil)logan Arpt Bill
Measured: 52 kt (60 mph) measured gust
Reported by: ASOS
Coordinates: 45.790, -108.540

Thunderstorm Wind, Yellowstone

When: July 21, 8:36 PM MST
Where: Yellowstone County, 23.42 mi NNW of Pryor
Measured: 50 kt (58 mph) measured gust
Reported by: Trained Spotter
Coordinates: 45.750, -108.690

Thunderstorm Wind, Yellowstone

When: July 21, 8:36 PM MST
Where: Yellowstone County, 13.11 mi SW of Newton Grove
Measured: 50 kt (58 mph) measured gust
Reported by: Trained Spotter
Coordinates: 46.200, -108.000

Thunderstorm Wind, Yellowstone

When: July 21, 8:55 PM MST
Where: Yellowstone County, 3.74 mi NNW of Custer
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 46.180, -107.580

An estimated wind gust of 60 mph was reported 3 miles NNW of Custer.

Thunderstorm Wind, Rosebud

When: July 21, 9:45 PM MST
Where: Rosebud County, 3.98 mi NW of Nichols
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 46.270, -106.810

An estimated wind gust of 60 mph along with crop damage was reported 6 miles west of Forsyth.

Thunderstorm Wind, Big Horn

When: July 21, 9:55 PM MST
Where: Big Horn County, 3 mi WSW of Lodge Grass
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 45.310, -107.410

An estimated wind gust of 60 mph was reported 2 miles west of Lodge Grass.

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 2010 Every state in 2010 This day in weather history Warnings in Montana, July 2010

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 2026-10-01. Each event’s entry at NCEI: 247299, 247301, 247304, 247306, 247311, 247503, 247504, 247506, 247507.