Hail and Heavy Rain in Montana, July 23, 2002

Name: Hail and Heavy Rain in Montana, July 23, 2002
Start: 2002-07-23T14:40
End: 2002-07-23T19:20
Location: Montana

July 23, 2002 · NWS MSO · 4 events in 2 counties and zones

Golfball size hail fell from a thunderstorm over Arlee. 70 inches reported in 30 minutes near Victor, and 1 inch diameter hail reported near Stevensville.

Where it happened

Every event with a place to put it; 1 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

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 4

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 MSO wrote it up.

Golfball size hail fell from a thunderstorm over Arlee. Later in the evening, thunderstorms developed over the Bitterroot Valley, producing heavy rain with 0.70 inches reported in 30 minutes near Victor, and 1 inch diameter hail reported near Stevensville.

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 Missoula, MT wrote its last area forecast discussion before the first event at Jul 23, 1:20 PM MST, 1 hour 20 minutes earlier.

Area forecast discussion, Jul 23, 1:20 PM MST, 1 hour 20 minutes before

WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
220 PM MDT TUE JUL 23 2002

.SHORT TERM...CONVECTION BEGINNING TO DEVELOP ACROSS THE SOUTH THIS
AFTERNOON. STABILITY INDICES SHOW AIR MASS WILL BE PLENTY UNSTABLE
FOR SCATTERED THUNDERSTORM COVERAGE BUT LOW QPF THIS EVENING...WITH
EVEN SOME ISOLATED ACTIVITY OVERNIGHT. WEAK LOW SYSTEM WILL REMAIN
OFF THE WEST COAST TONIGHT...THEN BEGIN TO FILL AS IT MOVES NORTH. AS
A RESULT THE RIDGE SHARPENS OVER THE NORTHERN ROCKIES AND DRYING
EXPECTED REDUCING POPS FOR WED/WED NIGHT. WILL BUMP TEMPS UP FOR WED
IN RESPONSE TO WARMING AIR MASS UNDER RIDGE. MESOETA SUGGESTS A WEAK
DISTURBANCE PUSHING INTO THE RIDGE WED NIGHT FOR SLIGHT CHANCE POPS
ACROSS THE MID-SECTION OF CWA.

THU...PATTERN DE-AMPLIFIES WITH A LOW LEVEL CONV/UPPER LEVEL DIV
COUPLET DEVELOPING ACROSS THE SOUTH LATER. THE AIR MASS CONTINUES
TO BE QUITE UNSTABLE DURING THE HEATING OF THE DAY AND MOISTURE IS
THE MAIN QUESTION MARK...WITH POSSIBLY ANOTHER DRY LIGHTNING EVENT.
CONVECTION WILL CARRY INTO THE EVENING HOURS ACROSS THE SOUTH.

FRI...A DRY WEST-NORTHWESTERLY FLOW EXPECTED WITH COOLER TEMPS. MSJ

.LONG TERM...SATURDAY AND SUNDAY THE TROUGH CROSSES ACROSS THE AREA.
WITH A DRY NORTHWEST FLOW ALOFT. THE CWA SHOULD JUST SEE SOME CLOUDS
FROM THIS.  MONDAY AND TUESDAY THE FLOW GOES WESTERLY WITH A
FLATTENED RIDGE POKING INTO THE AREA. TEMPERATURES WILL RISE
SLIGHTLY THROUGH THE PERIOD REMAINING NEAR NORMAL THROUGHOUT THE
FORECAST. GILCHRIST

.MSO...RFW FOR DRY LIGHTNING TONIGHT IN ZONES 104 105 106 107.

...7-DAY SPOT TEMPS AND POPS...
LIB BBU 055/094 055/090 054/087 35100010
     BBUU 052/084 052/085 053/086 053/087 3300000000
FCA BBB 054/089 052/085 052/083 35100010
     BBUU 050/078 050/080 051/081 051/082 3300000000
POL BBB 062/087 061/084 056/082 35100000
     BBUU 053/077 053/079 053/080 053/081 3300000000
MSO BBB 058/091 058/088 055/086 35101100
     BBUU 052/082 050/082 050/083 050/083 3300000000
HMM BBB 059/090 058/087 054/085 35201100
     BBUU 051/080 048/080 048/082 049/082 3300000000
BTM BBB 053/087 051/085 050/083 35200210
     BBUU 047/078 045/078 046/079 048/080 3300000000
ORO BBU 063/097 062/093 064/091 35100100
     BBUU 060/086 059/088 059/090 059/090 3300000000
GRV BBB 059/092 059/088 056/086 35100100
     BBUU 053/083 051/084 051/085 052/086 3300000000
SMN BBB 056/092 055/087 054/085 35200210
     BBUU 052/082 051/083 050/084 051/085 3300000000

The radar

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

Open the radar archive at this moment

Event by event

3 hail, 1 heavy rain. Local standard time, as filed.

Hail, Lake

When: July 23, 2:40 PM MST to 2:41 PM MST
Where: Lake County, Arlee
Measured: 1.5 in hail
Reported by: TRAINED SPOTTER
Coordinates: 47.150, -114.083

Heavy Rain, Ravalli

When: July 23, 6:35 PM MST
Where: Ravalli County, 5 mi SW of Victor
Reported by: TRAINED SPOTTER
Coordinates: 46.082, -114.121 (the zone’s center; the record gives no point)

Hail, Ravalli

When: July 23, 7:10 PM MST
Where: Ravalli County, 7 mi S of Stevensville
Measured: 1 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.400, -114.083

Hail, Ravalli

When: July 23, 7:20 PM MST
Where: Ravalli County, 8 mi SE of Stevensville
Measured: 1 in hail
Reported by: TRAINED SPOTTER
Coordinates: 46.417, -113.967

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.

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

The same day elsewhere

Every storm in Montana in 2002 Every state in 2002 This day in weather history Warnings in Montana, July 2002

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: 5309194, 5309195, 5309196, 5309197.