Flash Flooding and Hail in Montana, June 26, 2001

Name: Flash Flooding and Hail in Montana, June 26, 2001
Start: 2001-06-26T18:30
End: 2001-06-26T22:30
Location: Montana

June 26, 2001 · NWS BYZ · 23 events in 4 counties and zones

Two severe thunderstorms moved through Yellowstone County Montana on the evening of June 26, 2001. The first storm initiated over northwest Billings in about 15 minutes.

Where it happened

Every event with a place to put it; 6 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: 23

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.

Two severe thunderstorms moved through Yellowstone County Montana on the evening of June 26, 2001. The first storm initiated over northwest Billings in about 15 minutes. The first storm formed a wall cloud and the Billings WSR-88D indicated rotation with this storm which prompted a tornado warning to be issued for the city of Billings. Quarter size hail was reported in the Alkali Creek area (west of Billings) and a 62 mph wind gust was observed at the Billings Airport. Several funnel clouds were reported by the public and law enforcement with this storm. A second storm developed over Park City, Montana. This storm also formed a wall cloud which the Billings WSR-88D indicated as rotating. This storm also produced several funnel clouds, one of which was observed by a NWS meteorologist. Quarter, Golf Ball, and Half Dollar sized hail was reported from Park City through the Laurel, Montana areas. A new Tornado Warning was issued to cover both tornadic thunderstorms. Two additional Tornado Warnings (continuation of previous warnings) were issued for Yellowstone County, Montana. Due to the extremely heavy rain and the slow movement of these thunderstorms, a Flash Flood Warning was issued for Yellowstone County. Rain reports from the Billings Airport was 0.66 inches in about 45 minutes. Huntley, Montana received 1.67 inches of rain in just under 50 minutes. Flash flooding was observed over much of eastern Yellowstone County including downtown Billings. Eventually the two separate supercells merged just east of Billings. A Bow Echo evolved in this area and began moving east. Ten 70 foot (2 foot diameter) power poles were blown down in Huntley, Montana and a semi-trailer was blown over. Several 3 foot diameter trees were also blown down in Shepherd, Montana. A WFO Billings Post-Storm Damage Survey Team assessed this damage and estimated the wind speeds that caused it to be 90 to 100 mph.

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 Jun 26, 1:30 PM MST, 5 hours earlier.

Area forecast discussion, Jun 26, 1:30 PM MST, 5 hours before

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
230 PM MDT TUE JUN 26 2001

.WED AND THU...
MODELS SIMILAR IN KEEPING SURFACE HIGH PRESSURE ACROSS EASTERN MONTANA
TONIGHT. THE HIGH MOVES INTO THE PLAINS WEDNESDAY WITH THE RETURN FLOW
BRINGING WARMER TEMPERATURES  AS WELL AS HIGHER DEW POINTS.  SOUTHWEST
FLOW ALOFT CONTINUE ACROSS THE NORTHERN ROCKIES WITH MIDLEVEL MOISTURE
STREAMING INTO THE BEARTOOTH MOUNTAINS FROM IDAHO. IR SATELLITE PHOTOS
INDICATE OROGRAPHIC CONVECTION OVER YELLOWSTONE PARK THAT SHOULD DRIFT
INTO WESTERN PORTIONS OF THE CWA THIS EVENING FOR SCATTERED HIGH BASED
THUNDERSTORMS. DEWPOINTS WILL SLOWLY INCREASE IN SOUTHERN MONTANA THAT
SHOULD SPREAD NORTH THIS EVENING & TONIGHT THAT COULD PROVIDE MOISTURE
FOR ISOLATED THUNDERSTORMS. A LOW LEVEL CAP WILL HELP KEEP  CONVECTION
TO A MINIMUM IN THE EAST. THE RETURN FLOW WILL HELP BRING WARMER TEMPS
INTO THE CWA WEDNESDAY AND THURSDAY. THORICHT

.FRI...SAT...SUN...MON...TUE...

HOT AND MAINLY DRY WEATHER WILL PREVAIL ACROSS THE AREA FRIDAY AND
SATURDAY AS THE UPPER LEVEL RIDGE AXIS REMAINS OVER MONTANA. WEAK
SHORTWAVES MOVING ACROSS THE AREA FRIDAY WILL ONLY PRODUCE ISOLATED
THUNDERSTORMS. A STRONGER WAVE WILL MOVE ACROSS THE AREA SUNDAY...
BRINGING THE BEST CHANCE FOR THUNDERSTORMS DURING THE EXTENDED PERIOD.
NORTHWEST FLOW PREVAILS MONDAY AND TUESDAY...BRINGING MAINLY DRY
WEATHER MONDAY AND DRY WEATHER TUESDAY. TEMPERATURES WILL BE COOLER
MONDAY AND TUESDAY. MIDDENDORF

    WED     THU     FRI     SAT     SUN     MON     TUE
-----------------------------------------------------------
BIL 062/091 059/090 060/089 062/093 062/093 058/082 053/082
    34/T    21/B    22/B    22/B    23/T    32/B    20/B
LVM 058/086 056/089 054/088 055/090 055/088 055/078 046/078
    34/T    21/B    22/B    22/B    23/T    32/B    20/B
HDN 060/094 057/092 058/091 060/094 060/094 059/085 050/085
    34/T    21/B    22/B    22/B    23/T    32/B    20/B
MLS 063/093 065/090 063/093 063/095 064/095 061/085 054/085
    24/T    31/B    22/B    22/B    23/T    32/B    20/B
4BQ 064/095 064/092 064/093 064/095 063/095 060/083 052/083
    24/T    31/B    22/B    22/B    23/T    32/B    20/B
BHK 061/092 061/092 061/093 061/095 062/093 060/081 050/081
    24/T    31/B    22/B    22/B    23/T    32/B    20/B
SHR 060/091 058/091 055/089 055/092 055/094 055/081 047/081
    34/T    21/B    22/B    22/B    23/T    32/B    20/B

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

10 hail, 7 thunderstorm wind, 6 flash flood. Local standard time, as filed.

Hail, Yellowstone

When: June 26, 6:30 PM MST
Where: Yellowstone County, 10 mi NE of Laurel
Measured: 0.88 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.683, -108.767

Hail, Yellowstone

When: June 26, 6:50 PM MST
Where: Yellowstone County, 10 mi N of Laurel
Measured: 2 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.633, -108.917

Windows smashed and roof damaged

Hail, Yellowstone

When: June 26, 7:20 PM MST
Where: Yellowstone County, Billings Hgts
Measured: 1.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.833, -108.767

Golf ball size hail in western Alkali Creek

Hail, Stillwater

When: June 26, 7:20 PM MST
Where: Stillwater County, Park City
Measured: 1 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.733, -108.583

Hail drifted one foot deep. Windows broken on homes.

Hail, Carbon

When: June 26, 7:25 PM MST
Where: Carbon County, 5 mi SE of Silesia
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.227, -109.028 (the zone’s center; the record gives no point)

Thunderstorm Wind, Yellowstone

When: June 26, 7:25 PM MST
Where: Yellowstone County, Billings Logan Arpt
Measured: 62 kt (71 mph)
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 45.683, -108.733

Hail, Stillwater

When: June 26, 7:30 PM MST
Where: Stillwater County, Park City
Measured: 0.75 in hail
Reported by: LAW ENFORCEMENT
Coordinates: 45.669, -109.395 (the zone’s center; the record gives no point)

Hail, Yellowstone

When: June 26, 7:35 PM MST
Where: Yellowstone County, 7 mi SW of Billings
Measured: 1.75 in hail
Reported by: AMATEUR RADIO
Coordinates: 45.733, -108.000

Golf ball size hail

Hail, Yellowstone

When: June 26, 7:35 PM MST
Where: Yellowstone County, 2 mi E of Laurel
Measured: 1 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.900, -108.317

Hail, Yellowstone

When: June 26, 7:35 PM MST
Where: Yellowstone County, Laurel
Measured: 1.25 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.950, -108.350

Thunderstorm Wind, Yellowstone

When: June 26, 8:10 PM MST
Where: Yellowstone County, Shepherd
Measured: 90 kt (104 mph)
Reported by: NWS STORM SURVEY
Coordinates: 45.937, -108.274 (the zone’s center; the record gives no point)

3 feet diameter trees down

Flash Flood, Yellowstone

When: June 26, 8:18 PM MST
Where: Yellowstone County, 1 mi N of Billings
Reported by: TRAINED SPOTTER
Coordinates: 45.967, -108.233

1-2 miles north of K-Mart

Thunderstorm Wind, Yellowstone

When: June 26, 8:20 PM MST
Where: Yellowstone County, Huntley
Measured: 90 kt (104 mph)
Reported by: NWS STORM SURVEY
Coordinates: 45.500, -108.783

10 power poles knocked down and semi-trailer knocked over

Flash Flood, Yellowstone

When: June 26, 8:25 PM MST
Where: Yellowstone County, Billings
Reported by: TRAINED SPOTTER
Coordinates: 46.000, -107.950

6th Avenue flooded and closed

Hail, Big Horn

When: June 26, 8:30 PM MST
Where: Big Horn County, 17 mi W of Hardin
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 45.424, -107.490 (the zone’s center; the record gives no point)

Flash Flood, Yellowstone

When: June 26, 8:30 PM MST
Where: Yellowstone County, Billings
Reported by: TRAINED SPOTTER
Coordinates: 45.937, -108.274 (the zone’s center; the record gives no point)

Water over the road at 4th and 24th St. North

Flash Flood, Yellowstone

When: June 26, 8:36 PM MST
Where: Yellowstone County, 10 mi W of Billings Logan Arpt
Reported by: TRAINED SPOTTER
Coordinates: 45.950, -108.150

3 feet of water covering Shorey Road

Thunderstorm Wind, Yellowstone

When: June 26, 8:45 PM MST
Where: Yellowstone County, Ballantine
Measured: 70 kt (81 mph)
Reported by: TRAINED SPOTTER
Coordinates: 45.633, -108.917

Road signs and construction debris on I-94

Thunderstorm Wind, Yellowstone

When: June 26, 8:45 PM MST
Where: Yellowstone County, Pompeys Pillar
Measured: 70 kt (81 mph)
Reported by: AMATEUR RADIO
Coordinates: 45.783, -108.617

Construction equipment blown over on I-94

Thunderstorm Wind, Yellowstone

When: June 26, 8:46 PM MST
Where: Yellowstone County, 3 mi W of Worden
Measured: 70 kt (81 mph)
Reported by: TRAINED SPOTTER
Coordinates: 45.817, -108.517

Trees down

Flash Flood, Yellowstone

When: June 26, 9:00 PM MST
Where: Yellowstone County, Billings
Reported by: LAW ENFORCEMENT
Coordinates: 45.800, -108.533

Montana and 1st Avenue South...water covering hoods of cars

Thunderstorm Wind, Big Horn

When: June 26, 9:00 PM MST
Where: Big Horn County, 19 mi W of Hardin
Measured: 80 kt (92 mph)
Reported by: TRAINED SPOTTER
Coordinates: 45.733, -107.950

80 mph thunderstorm wind gust...hay shed destroyed on Fly Creek Road

Flash Flood, Yellowstone

When: June 26, 10:30 PM MST
Where: Yellowstone County, Huntley
Reported by: NWS EMPLOYEE(OFF DUTY)
Coordinates: 45.937, -108.274 (the zone’s center; the record gives no point)

Water covering roadways

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.
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, June 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 2026-09-24. Each event’s entry at NCEI: 5250395, 5250396, 5250392, 5250393, 5249591, 5250394, 5250400, 5250397, 5250398, 5250399, 5249588, 5250292, 5250402, 5250387, 5249590, 5250386, 5250293, 5250389, 5250391, 5250388, 5250390, 5250401, 5249589.