Montana, 2001

Flash Flooding and Hail in Montana, July 13, 2001

July 13, 2001 · NWS BYZ · 31 events in 7 counties and zones

28 hail, 3 flash flood, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 3 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
31

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 13, 1:17 PM MST, 2 hours 3 minutes earlier.

Area forecast discussion, Jul 13, 1:17 PM MST, 2 hours 3 minutes before
SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
217 PM MDT FRI JUL 13 2001

.SAT AND SUN...

...SEVERE THUNDERSTORM WATCH WILL BE IN EFFECT FOR THE WEST AND CENTRAL
ZONES UNTIL 700 PM MDT...

CONVECTION IS FIRING UP TO THE WEST OF THE CWA AT THIS TIME. SAME OLD
PATTERN IS SEEN ON SATELLITE IMAGERY...IN FACT...LITTLE CHANGE IN THE
OVERALL PATTERN SINCE THE END OF JUNE. HPC HAS NOTED THAT WHENEVER THIS
PATTERN HAS OCCURRED...IT HAS ESSENTIALLY REMAINED THE SAME INTO AUGUST.
RIDGE IS CENTERED OVER THE FOUR CORNERS REGION WITH AN UPPER LOW OFF THE
CALIFORNIA COAST. ANOTHER UPPER LOW IS OVER BAJA CALIFORNIA. ALL THESE
FEATURES ARE COMBINING TO BRING UP MONSOONAL MOISTURE OUT OF MEXICO...
AS WELL AS EMBEDDED SHORTWAVES.

IN GENERAL WILL BE FOLLOWING THE AVN...WHICH HAS A BETTER DEPICTION OF
THE FEATURES. PATTERN REMAINS THE SAME THROUGH THE WEEKEND WITH
EMBEDDED SHORTWAVES AND JET MAXES...WHICH WILL BE HARD TO TIME. AVN
PRECIPITABLE WATER AND BOUNDARY LAYER WIND PROGS INDICATE LOW LEVEL
MOISTURE ADVECTING INTO THE STATE FROM THE GULF OF MEXICO. EXPECT THE
CAP IN THE SOUTHEAST TO BREAK THIS EVENING...FOR THE POSSIBILITY OF
SEVERE THUNDERSTORMS TONIGHT. THERE APPEARS TO BE GOOD DIRECTIONAL
SHEAR...WHICH SHOULD KEEP THE CONVECTION ORGANIZED.

WITH THIS PATTERN...THERE WILL BE THE POSSIBILITY OF SEVERE
THUNDERSTORMS THROUGH THE WEEKEND. THE ONLY QUESTION WILL BE WHERE IN
THE CWA WILL THE CONVECTIVE COMPLEXES BE. IT WILL ALSO REMAIN
UNSEASONABLY HUMID FOR THIS AREA...WITH THE CONTINUED ADVECTION OF THE
LOW LEVEL MOISTURE. STROBIN

.MON...TUE...WED...THU...FRI...
AVN/MRF/UKMET/ECMWF ALL SHOWING THE SAME PATTERN OR A SIMILAR PATTERN
THROUGH WEDNESDAY OF LOW DIGGING ALONG THE WEST COAST WITH ASSOCIATED
TROUGH EXTENDING TOWARD SOUTHERN CALIFORNIA. THIS SCENARIO WOULD KEEP
THE SOUTHWEST FLOW OVER THE REGION WITH WARM TEMPS AND SCATTERED LATE
AFTERNOON SHOWERS/THUNDERSTORMS IN THE FORECAST FOR EACH DAY. BEYOND
WEDNESDAY PER THE MRF...LOW LIFTS OUT INTO CANADA...YET THE SOUTHWEST
FLOW CONTINUES. NO CHANGE IN WEATHER PATTERN BEYOND WEDNESDAY EXPECTED.
SPRINGER

    SAT     SUN     MON     TUE     WED     THU     FRI
-----------------------------------------------------------
BIL 062/090 062/090 061/088 061/085 058/082 058/082 056/082
    44/T    44/T    44/T    44/T    44/T    33/T    33/T
LVM 060/088 052/088 055/086 057/084 057/081 055/081 053/078
    44/T    44/T    44/T    44/T    44/T    33/T    33/T
HDN 060/092 060/092 060/088 060/088 058/085 055/085 055/083
    44/T    44/T    44/T    44/T    44/T    33/T    33/T
MLS 065/095 065/095 065/091 065/088 062/086 059/084 059/084
    44/T    44/T    44/T    44/T    44/T    33/T    33/T
4BQ 063/094 063/094 064/092 064/087 062/085 057/085 057/084
    44/T    44/T    44/T    44/T    44/T    33/T    33/T
BHK 062/093 062/093 064/089 064/087 061/085 058/083 058/083
    44/T    44/T    44/T    44/T    44/T    33/T    33/T
SHR 058/091 058/091 059/089 061/087 059/083 059/083 057/081
    44/T    44/T    44/T    44/T    44/T    33/T    33/T

The radar

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

Open the radar archive at this moment

Event by event

28 hail, 3 flash flood. Local standard time, as filed.

Hail, Sweet Grass

When
July 13, 3:20 PM MST
Where
Sweet Grass County, 7 mi NW of Melville
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.167, -110.050

Hail, Wheatland

When
July 13, 4:13 PM MST
Where
Wheatland County, Harlowton
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.433, -109.817

Hail, Golden Valley

When
July 13, 4:32 PM MST
Where
Golden Valley County, 5 mi S of Ryegate
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.233, -109.250

Hail, Golden Valley

When
July 13, 4:48 PM MST
Where
Golden Valley County, 5 mi S of Ryegate
Measured
2.75 in hail
Reported by
LAW ENFORCEMENT
Coordinates
46.233, -109.250

Broken windows on car and house. Funnel cloud also spotted.

Hail, Golden Valley

When
July 13, 4:50 PM MST
Where
Golden Valley County, Lavina
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.283, -108.933

Hail, Yellowstone

When
July 13, 5:10 PM MST
Where
Yellowstone County, 20 mi NW of Billings
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.000, -108.783

Hail, Stillwater

When
July 13, 5:27 PM MST
Where
Stillwater County, 8 mi NW of Rapelje
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.050, -109.383

Hail, Yellowstone

When
July 13, 5:30 PM MST
Where
Yellowstone County, 5 mi N of Laurel
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.750, -108.767

Hail, Yellowstone

When
July 13, 5:51 PM MST
Where
Yellowstone County, Billings
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Hail, Yellowstone

When
July 13, 5:59 PM MST
Where
Yellowstone County, Billings Hgts
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.817, -108.517

Hail, Golden Valley

When
July 13, 6:00 PM MST
Where
Golden Valley County, Belmont
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.233, -109.000

Hail, Yellowstone

When
July 13, 6:00 PM MST
Where
Yellowstone County, Billings
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Hail, Yellowstone

When
July 13, 6:00 PM MST
Where
Yellowstone County, Billings
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Hail, Yellowstone

When
July 13, 6:00 PM MST
Where
Yellowstone County, Billings
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Hail, Yellowstone

When
July 13, 6:00 PM MST
Where
Yellowstone County, Billings
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Hail, Yellowstone

When
July 13, 6:00 PM MST
Where
Yellowstone County, Billings
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Hail, Yellowstone

When
July 13, 6:05 PM MST
Where
Yellowstone County, Billings
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Hail, Yellowstone

When
July 13, 6:06 PM MST
Where
Yellowstone County, Billings Hgts
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.817, -108.517

Hail, Stillwater

When
July 13, 6:41 PM MST
Where
Stillwater County, 1 mi S of Absarokee
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.483, -109.433

Hail, Musselshell

When
July 13, 7:00 PM MST
Where
Musselshell County, 20 mi S of Roundup
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.167, -108.533

Hail, Yellowstone

When
July 13, 7:30 PM MST
Where
Yellowstone County, 10 mi E of Billings
Measured
2 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.283

Hail, Big Horn

When
July 13, 7:58 PM MST
Where
Big Horn County, Hardin
Measured
0.75 in hail
Reported by
LAW ENFORCEMENT
Coordinates
45.733, -107.600

Flash Flood, Big Horn

When
July 13, 8:02 PM MST
Where
Big Horn County, Hardin
Reported by
LAW ENFORCEMENT
Coordinates
45.424, -107.490 (the zone’s center; the record gives no point)

5 inches of water over I-90

Hail, Big Horn

When
July 13, 8:15 PM MST
Where
Big Horn County, Hardin
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.733, -107.600

Flash Flood, Big Horn

When
July 13, 8:21 PM MST
Where
Big Horn County, Hardin
Reported by
LAW ENFORCEMENT
Coordinates
45.424, -107.490 (the zone’s center; the record gives no point)

3 feet of water covering Custer Street and 7th and 8th Streets. Widespread downtown flooding.

Hail, Yellowstone

When
July 13, 8:28 PM MST
Where
Yellowstone County, 2 mi W of Laurel
Measured
0.75 in hail
Reported by
LAW ENFORCEMENT
Coordinates
45.683, -108.800

Hail, Big Horn

When
July 13, 8:30 PM MST
Where
Big Horn County, 1 mi W of Hardin
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.733, -107.617

Hail, Big Horn

When
July 13, 8:35 PM MST
Where
Big Horn County, Hardin
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.733, -107.600

Hail, Yellowstone

When
July 13, 8:52 PM MST
Where
Yellowstone County, Billings
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.800, -108.483

Flash Flood, Big Horn

When
July 13, 9:00 PM MST
Where
Big Horn County, Hardin
Reported by
LAW ENFORCEMENT
Coordinates
45.424, -107.490 (the zone’s center; the record gives no point)

Flooding in town. 2 to 3 feet of water is common

Hail, Big Horn

When
July 13, 9:40 PM MST
Where
Big Horn County, Crow Agency
Measured
0.75 in hail
Reported by
LAW ENFORCEMENT
Coordinates
45.600, -107.450

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

More

Every storm in Montana in 2001Every state in 2001This day in weather historyWarnings 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 2026-09-24. Each event’s entry at NCEI: 5259116, 5259117, 5259119, 5259118, 5259120, 5259121, 5259122, 5259194, 5259192, 5259193, 5259195, 5259196, 5259197, 5259198, 5259199, 5259200, 5259201, 5259202, 5259203, 5259204, 5259205, 5259206, 5259207, 5259208, 5259209, 5259210, 5259211, 5259212, 5259213, 5259214, 5259215.