Montana, 2001

Hail and Damaging Wind in Montana, July 23, 2001

July 23, 2001 · NWS BYZ · 27 events in 9 counties and zones

26 hail, 1 thunderstorm wind, as filed by the National Weather Service.

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
27

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 23, 12:59 PM MST, 3 hours 13 minutes earlier.

Area forecast discussion, Jul 23, 12:59 PM MST, 3 hours 13 minutes before
SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
159 PM MDT MON JUL 23 2001

.TUE AND WED...
AVN SEEMS TO HAVE A BETTER HANDLE ON THE SHORT WAVE GOING INTO WESTERN
MONTANA...KICKING OFF SHOWERS AND THUNDERSTORMS...LOOKING HOW BOTH
MODELS LINED UP WITH THE 18Z WATER VAPOR IMAGERY. DIFFICULT TO TELL ON
THEIR ALIGNMENT WITH THE SURFACE FEATURES AT 18Z. BOTH MODELS BASICALLY
TELL THE SAME STORY...NAMELY THE SLOW EAST PROGRESSION OF THE UPPER
TROUGH. THEY DIFFER IN STRENGTH AND TIMING OF THE SHORT WAVES.

THE MAIN THETA E MAXIMA REMAINS SOUTH OF MONTANA IN WYOMING THROUGHOUT
THE PERIOD. AVN AND ETA DIFFER IN PUSHING UP RIDGES INTO MONTANA...BUT
BOTH SOLUTIONS POINT TO A CONTINUING CHANCE OF THUNDERSTORMS WITH THE
BETTER POSSIBILITIES BEING OVER WYOMING INTO SOUTHEAST MONTANA. CAPES
NOT THAT BAD FOR THE REST OF TODAY...BUT THEY LOOK PROMISING FOR
TUESDAY OVER ABOUT THE EAST HALF OF THE COUNTY WARNING AREA. THEY ALSO
BECOME RATHER HIGH WEDNESDAY OVER EXTREME SOUTHEAST MONTANA AND
SHERIDAN COUNTY. AS THE UPPER TROUGH ADVANCES...MOISTURE BEGINS
DROPPING. IT SEEMS REASONABLE TO LOWER POPS TO ISOLATED ON WEDNESDAY
OVER MOST AREAS...BUT TO KEEP SCATTERED POPS GOING FOR EXTREME SOUTHEAST
MONTANA INTO SHERIDAN COUNTY WYOMING. AM HAVING PROBLEMS WITH AVN ON
WEDNESDAY WITH A VERY STRONG DIVERGENCE PATTERN DEVELOPING OVER ROUGHLY
CENTRAL MONTANA. THIS WOULD AID IN THUNDERSTORM DEVELOPMENT AND THE
SITUATION WILL HAVE TO BE WATCHED. WILL SEE WHAT OTHER MODEL RUNS
INDICATE. CHB

.THU...FRI...SAT...SUN...MON...
AFTER WAVE PASSES WEDNESDAY MORE OF A WESTERLY FLOW BUILDS INTO AREA...
HOWEVER FLOW CONTINUES TO HAVE SOMEWHAT A CYCLONIC FLOW TO IT THURSDAY
AND FRIDAY. WOULD EXPECT A FEW WAVES TO MOVE ACROSS AREA THURSDAY AND
FRIDAY IN THIS FLOW. WESTERLY FLOW...SHOULD...DRY LOWER ATMOSPHERE TO
KEEP CONVECTION THAT DOES OCCUR LESS WIDE SPREAD...BUT ENOUGH TO KEEP
MENTION OF THUNDERSTORMS IN THURSDAY AND FRIDAY. SATURDAY...MODELS BEGIN
TO DIVERGE A BIT. MRF/UKMET DRIVE ENERGY SOUTH FROM GULF OF ALASKA INTO
PACIFIC NORTHWEST WITH DEEPENING SOUTHWEST FLOW OVER MONTANA...THEN
MOVE TROUGH ACROSS AREA...WITH WESTERLY FLOW BY MONDAY. ECMWF MORE
PROGRESSIVE WITH THIS ENERGY SLIDING IT ACROSS MONTANA SATURDAY WITH
RIDGING BY LATE SUNDAY. NEW AVN ON THE OTHER HAND HAS TROUGH MUCH DEEPER
ON WEST COAST THAN 00Z MRF...WHICH COULD OPEN US UP TO DEEPER MOISTURE
AGAIN SATURDAY AND SUNDAY...THUS WILL CONTINUE CHANCE OF THUNDERSTORMS
SATURDAY AND SUNDAY. RASCH

    TUE     WED     THU     FRI     SAT     SUN     MON
-----------------------------------------------------------
BIL 056/088 057/088 060/088 062/090 063/090 059/087 057/084
    33/T    32/T    33/T    33/T    33/T    33/T    11/B
LVM 049/084 048/084 055/085 057/086 058/087 055/085 053/080
    32/T    22/T    33/T    33/T    33/T    33/T    11/B
HDN 053/092 054/092 058/090 060/092 061/092 057/089 055/086
    43/T    42/T    33/T    33/T    33/T    33/T    11/B
MLS 058/088 059/092 062/087 063/088 064/090 060/088 057/085
    33/T    32/T    33/T    33/T    33/T    33/T    11/B
4BQ 059/086 058/091 060/086 061/087 062/089 058/087 055/084
    44/T    43/T    33/T    33/T    33/T    33/T    11/B
BHK 056/084 057/089 059/085 060/086 060/088 056/086 054/083
    33/T    32/T    33/T    33/T    33/T    33/T    11/B
SHR 055/087 055/090 057/088 058/090 058/090 -056/087 054/084
    44/T    43/T    33/T    33/T    33/T    33/T    11/B

The radar

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

Open the radar archive at this moment

Event by event

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

Hail, Golden Valley

When
July 23, 4:12 PM MST
Where
Golden Valley County, 15 mi NW of Lavina
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.433, -109.150

Hail, Golden Valley

When
July 23, 4:20 PM MST
Where
Golden Valley County, 11 mi NW of Lavina
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.400, -109.100

Hail, Musselshell

When
July 23, 4:45 PM MST
Where
Musselshell County, 7 mi WSW of Roundup
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.417, -108.667

Hail, Musselshell

When
July 23, 4:50 PM MST
Where
Musselshell County, 5 mi W of Roundup
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.450, -108.633

Hail, Big Horn

When
July 23, 4:52 PM MST
Where
Big Horn County, 5 mi W of Busby
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.533, -108.033

Hail, Musselshell

When
July 23, 5:03 PM MST
Where
Musselshell County, Roundup
Measured
1.25 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.450, -108.533

Hail, Musselshell

When
July 23, 5:05 PM MST
Where
Musselshell County, Roundup
Measured
0.88 in hail
Reported by
LAW ENFORCEMENT
Coordinates
46.450, -108.533

Hail, Musselshell

When
July 23, 5:20 PM MST
Where
Musselshell County, Delphia
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.500, -108.217

Hail, Musselshell

When
July 23, 5:30 PM MST
Where
Musselshell County, Musselshell
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.517, -108.083

Hail, Musselshell

When
July 23, 5:45 PM MST
Where
Musselshell County, 4 mi S of Melstone
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.550, -107.883

Hail, Yellowstone

When
July 23, 5:59 PM MST
Where
Yellowstone County, 3 mi NE of Custer
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.167, -107.500

Thunderstorm Wind, Big Horn

When
July 23, 6:00 PM MST
Where
Big Horn County, 10 mi N of Decker
Measured
60 kt (69 mph)
Reported by
TRAINED SPOTTER
Coordinates
45.150, -106.800

Hail, Rosebud

When
July 23, 6:05 PM MST
Where
Rosebud County, 6 mi S of Sumatra
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.533, -107.550

Hail, Treasure

When
July 23, 6:08 PM MST
Where
Treasure County, 20 mi NW of Hysham
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.500, -107.533

Hail, Treasure

When
July 23, 6:10 PM MST
Where
Treasure County, 15 mi NW of Hysham
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.450, -107.450

Hail, Rosebud

When
July 23, 6:27 PM MST
Where
Rosebud County, 5 mi W of Forsyth
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.267, -106.767

Hail, Powder River

When
July 23, 6:30 PM MST
Where
Powder River County, 10 mi W of Biddle
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.100, -105.550

Hail, Rosebud

When
July 23, 7:02 PM MST
Where
Rosebud County, 3 mi N of Vananda
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
46.383, -107.000

Hail, Powder River

When
July 23, 7:08 PM MST
Where
Powder River County, 10 mi S of Biddle
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
44.950, -105.350

Hail, Stillwater

When
July 23, 7:15 PM MST
Where
Stillwater County, 20 mi SE of Columbus
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.433, -108.950

Hail, Carbon

When
July 23, 7:30 PM MST
Where
Carbon County, 5 mi W of Joliet
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.483, -109.083

Hail, Yellowstone

When
July 23, 7:35 PM MST
Where
Yellowstone County, 6 mi S of Laurel
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.600, -108.767

Hail covered the ground

Hail, Yellowstone

When
July 23, 7:45 PM MST
Where
Yellowstone County, Billings
Measured
0.75 in hail
Reported by
AMATEUR RADIO
Coordinates
45.800, -108.483

Hail, Carbon

When
July 23, 8:00 PM MST
Where
Carbon County, Boyd
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.467, -109.067

Hail, Carbon

When
July 23, 8:30 PM MST
Where
Carbon County, Silesia
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.550, -108.850

Hail, Stillwater

When
July 23, 9:30 PM MST
Where
Stillwater County, 5 mi W of Columbus
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.633, -109.350

Hail, Carbon

When
July 23, 9:42 PM MST
Where
Carbon County, 3 mi S of Joliet
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
45.433, -108.983

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

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 2026-09-30. Each event’s entry at NCEI: 5259387, 5259388, 5259389, 5259390, 5259405, 5259391, 5259394, 5259392, 5259393, 5259395, 5259407, 5259399, 5259396, 5259397, 5259398, 5259408, 5259406, 5259409, 5259410, 5259411, 5259400, 5259401, 5259402, 5259403, 5259404, 5259413, 5259412.