Flash Flooding and Hail in Montana, July 17, 2001

Name: Flash Flooding and Hail in Montana, July 17, 2001
Start: 2001-07-17T12:55
End: 2001-07-17T23:35
Location: Montana

July 17, 2001 · NWS BYZ · 16 events in 10 counties and zones

14 hail, 2 flash flood, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. 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: 16

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 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 17, 8:20 AM MST, 4 hours 35 minutes earlier.

Area forecast discussion, Jul 17, 8:20 AM MST, 4 hours 35 minutes before

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The radar

The Billings radar (KBLX), 122 km away, was scanning. The volume nearest the first event began at 19:55 UTC.

Open the radar archive at this moment

Event by event

14 hail, 2 flash flood. Local standard time, as filed.

Hail, Wheatland

When: July 17, 12:55 PM MST
Where: Wheatland County, 10 mi S of Twodot
Measured: 1 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.267, -110.067

Hail, Wheatland

When: July 17, 1:05 PM MST
Where: Wheatland County, 10 mi S of Twodot
Measured: 1 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.267, -110.067

Hail, Wheatland

When: July 17, 1:20 PM MST
Where: Wheatland County, Harlowton
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.433, -109.817

Hail, Wheatland

When: July 17, 1:30 PM MST
Where: Wheatland County, Harlowton
Measured: 0.88 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.433, -109.817

Hail, Sweet Grass

When: July 17, 2:13 PM MST
Where: Sweet Grass County, 1 mi W of Melville
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.100, -109.967

Hail, Golden Valley

When: July 17, 2:28 PM MST
Where: Golden Valley County, 18 mi NW of Ryegate
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.483, -109.517

Hail, Musselshell

When: July 17, 3:20 PM MST
Where: Musselshell County, 25 mi NW of Roundup
Measured: 0.88 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.700, -108.900

Nickel size hail two feet deep

Hail, Stillwater

When: July 17, 3:30 PM MST
Where: Stillwater County, 3 mi W of Park City
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.633, -108.983

Hail, Carbon

When: July 17, 3:45 PM MST
Where: Carbon County, Boyd
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.467, -109.067

Hail, Yellowstone

When: July 17, 4:32 PM MST
Where: Yellowstone County, 10 mi W of Billings
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.800, -108.683

Flash Flood, Yellowstone

When: July 17, 4:45 PM MST
Where: Yellowstone County, Billings
Reported by: NWS EMPLOYEE(OFF DUTY)
Coordinates: 45.937, -108.274 (the zone’s center; the record gives no point)

Street flooding on the south side of Billings

Hail, Big Horn

When: July 17, 6:00 PM MST
Where: Big Horn County, 10 mi N of Hardin
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.867, -107.600

Hail, Rosebud

When: July 17, 6:00 PM MST
Where: Rosebud County, 15 mi N of Sumatra
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.833, -107.550

Flash Flood, Musselshell

When: July 17, 7:00 PM MST
Where: Musselshell County, Melstone
Reported by: TRAINED SPOTTER
Coordinates: 46.497, -108.398 (the zone’s center; the record gives no point)

3-4 feet of water running over the highway 12. Flooding lasted until 10 pm MDT.

Hail, Custer

When: July 17, 11:00 PM MST
Where: Custer County, 10 mi NE of Miles City
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.500, -105.683

Hail, Custer

When: July 17, 11:35 PM MST
Where: Custer County, 11 mi SE of Miles City
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.283, -105.667

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

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

The same day elsewhere

Every storm in Montana in 2001 Every state in 2001 This day in weather history Warnings in Montana, July 2001

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: 5259590, 5259591, 5259592, 5259593, 5259594, 5259595, 5259596, 5259291, 5259290, 5259292, 5259293, 5259521, 5259597, 5259598, 5259599, 5259600.