Flash Flooding and Hail in Montana, July 12, 2001

Name: Flash Flooding and Hail in Montana, July 12, 2001
Start: 2001-07-12T18:29
End: 2001-07-12T23:00
Location: Montana

July 12, 2001 · NWS GGW · 11 events in 2 counties and zones

8 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: $200,000
Events: 11

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 Glasgow, MT wrote its last area forecast discussion before the first event at Jul 12, 1:29 PM MST, 5 hours earlier.

Area forecast discussion, Jul 12, 1:29 PM MST, 5 hours before

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
229 PM MDT THU JUL 12 2001

THIS AFTERNOON A DEW POINT FRONT ACROSS CENTRAL MONTANA. DEW POINTS
ACROSS THE CWFA IN THE MID TO UPPER 60S. CONVECTION FIRING OVER
WESTERN MONTANA WITH A SHORTWAVE MOVING THROUGH THE WESTERN PART OF
THE STATE THIS AFTERNOON. THIS WAVE CONTINUES TO NNE A PIECE OF THIS
WAVE WILL MOVE ACROSS THE WESTERN AREAS THIS EVENING AND TONIGHT.

THIS EVENING...SHRA/TSRA SHOULD MOVING INTO THE REGION MAINLY OVER
THE WESTERN CWFA...ALREADY HAVING AFTERNOON POPCORN CONVECTION OVER
THE SOUTHERN CWFA WITH DAYTIME HEATING. SPC SWODY1 UPDATE PUTS THE
WESTERN ZONES IN A SLGT RISK FOR SVR. TIME HEIGHT SOUNDINGS SHOW A
BETTER SHEAR ENVIRONMENT FOR THIS EVENING ACROSS THE WEST...WET BULB
ZEROS ARE PRETTY HIGH FOR A SIGNIFICANT THREAT OF LARGE
HAIL...HOWEVER STRONG GUSTS CAN BE EXPECTED WITH LARGER STORMS...AND
MOST OF ALL VERY HEAVY RAINFALL. WILL HOLD UP ON A FLASH FLOOD WATCH
FOR THE EASTERN ZONES SINCE THE BEST CHANCE FOR TSRA REMAINS WEST
AND SOUTH.

AFTER THE CONVECTION MOVES OUT LATE THIS EVENING...DO EXPECT ANOTHER
ROUND OF LOWS ST/FG FOR THE EARLY MORNING HOURS FOR THE MISSOURI AND
MILK RIVER VALLEYS. WILL ADD AM FG TO THE ZONES. ETA TRIES TO KEEP
LOW CLOUDS IN ALL DAY ON FRIDAY...HOWEVER DO EXPECT WITH THIS TIME
OF YEAR THE CLOUDS WILL LIFT OUT WITH THE HEATING OF THE DAY.
LOOKING FOR MORE OF THE SAME WITH PM TSRA AGAIN.  SAME PATTERN FOR
SATURDAY CONTINUES.

FOR TEMPS...GOING TO STAY WITH THE STATUS QUO...MODELS ARE TRYING TO
COOL DOWN THE TEMPS SOME ON SATURDAY...HOWEVER NOT BUYING INTO THAT
YET...WILL KEEP THEM UP.                    PROTON

EXTENDED...MODELS SUGGEST AN OMEGA BLOCK DEVELOPING OVER NORTH
AMERICA DURING THE EXTENDED PERIOD. THE UPPER LEVEL RIDGE IS
FORECAST TO REMAIN EAST OF MONTANA WITH A DEEP TROUGH ALONG THE WEST
COAST AND AN UPPER LOW OVER SOUTHWEST CANADA. THIS PATTERN KEEPS
NORTHEAST MONTANA IN SOUTHWEST FLOW ALOFT FOR THE ENTIRE PERIOD.
WILL CONTINUE WITH CHANCE POPS EACH DAY WITH TEMPERATURES REMAINING
NEAR NORMAL.  WATERHOUSE

KGGW 064/088 062/088 062/088 061/087 060/086 060/086 059/085
     TTTTTTT  943232/9933333
KGDV 064/090 064/092 063/090 062/089 061/088 060/087 059/086
     TTTTTTT  943232/9933333

.GGW...NONE.

In the hours before

Local storm report, Jul 12, 5:15 PM MST, 1 hour 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
615 PM MDT THU JUL 12 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0432 PM    10 N EDWARDS              MT   60 MPH TSTM WIND GUST
07/12/01   GARFIELD                       LIFTING SHINGLES OFF ROOF

0445 PM    BRUSSETT                  MT   FLASH FLOODS
07/12/01   GARFIELD                       1 INCH OF RAIN IN LESS
                                          THAN AN HOUR. EXTENSIVE
                                          RUNNING WATER

0445 PM    10 N EDWARDS              MT   1.00 INCH HAIL
07/12/01   GARFIELD                       HAIL COVERING THE GROUND.
                                          VERY HEAVY RAIN.

0505 PM    5 W BRUSSETT              MT   FLASH FLOODS
07/12/01   GARFIELD                       3 INCHES OF RAIN IN LESS
                                          THAN 1 HOUR. 3 FEET OF
                                          WATER IN CULVERTS.

0400 PM    10 NE SAND SPRINGS        MT   1.00 INCH HAIL
07/12/01   GARFIELD                       QUARTER SIZE HAIL FOR 1/2
                                          HOUR. STANDING WATER.

0505 PM    5 W BRUSSETT              MT   1.00 INCH HAIL
07/12/01   GARFIELD

0510 PM    12 W JORDAN               MT   TORNADO
07/12/01   GARFIELD                       ROTATING FUNNEL CLOUD
                                          REPORTED BY SHERIFF

0500 PM    20 W JORDAN               MT   1.75 INCH HAIL
07/12/01   GARFIELD                       HAIL BROKE OUT WINDOWS IN
                                          HOME AND VEHICLES

0500 PM    20 W JORDAN               MT   FLASH FLOODS
07/12/01   GARFIELD                       DEEP WATER RUNNING IN
                                          COULEES

0525 PM    10 N EDWARDS              MT   2.00 INCH HAIL
07/12/01   GARFIELD                       HAIL 4 FEET DEEP IN SOME
                                          SPOTS

WRIGHT

The radar

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

Open the radar archive at this moment

Event by event

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

Hail, Phillips

When: July 12, 6:29 PM MST
Where: Phillips County, 15 mi N of Saco
Measured: 1 in hail
Reported by: TRAINED SPOTTER
Coordinates: 48.683, -107.333

Hail, Phillips

When: July 12, 7:05 PM MST
Where: Phillips County, 30 mi N of Saco
Measured: 1.5 in hail
Reported by: TRAINED SPOTTER
Coordinates: 48.900, -107.333

Hail, Valley

When: July 12, 7:06 PM MST
Where: Valley County, 8 mi NW of Hinsdale
Measured: 1.5 in hail
Crop damage: $150,000
Reported by: TRAINED SPOTTER
Coordinates: 48.483, -107.200

Hail, Phillips

When: July 12, 7:19 PM MST
Where: Phillips County, 10 mi NNE of Saco
Measured: 1.5 in hail
Reported by: TRAINED SPOTTER
Coordinates: 48.600, -107.250

Flash Flood, Phillips

When: July 12, 7:45 PM MST to 10:30 PM MST
Where: Phillips County, East Portion
Reported by: NWS STORM SURVEY
Coordinates: 48.259, -107.913 (the zone’s center; the record gives no point)

Water ran over roadway below the Frenchman Dam, and on the gravel roads east and north of the Bjornberg Bridge.

Flash Flood, Valley

When: July 12, 7:45 PM MST to 11:00 PM MST
Where: Valley County, West Central Portion
Reported by: NWS STORM SURVEY
Coordinates: 48.365, -106.667 (the zone’s center; the record gives no point)

From two to four inches of rainfall caused ditches and coulees to fill up and overtop several gravel roads, blocking several people from returning home just north and east of the Bjornberg Bridge. The rain was at least two feet above one of the gravel roads. The water receded within a few hours, and only puddles were left the next morning when the damage survey was done.

Flash Flood, Phillips

When: July 12, 8:00 PM MST to 11:00 PM MST
Where: Phillips County, South Portion
Reported by: TRAINED SPOTTER
Coordinates: 48.259, -107.913 (the zone’s center; the record gives no point)

Several intense, slow moving thunderstorms dropped from 2-4 inches of rain in an hour, causing many coulees and ditches to overflow onto gravel roads. In some cases, the gravel roads had from 1 to 2 feet of water over them. Water was also up to 10 feet deep in the coulees and overtopped U.S. Highway 191 southwest of Malta.

Hail, Valley

When: July 12, 8:05 PM MST
Where: Valley County, 8 mi NW of Hinsdale
Measured: 1.75 in hail
Crop damage: $50,000
Reported by: TRAINED SPOTTER
Coordinates: 48.483, -107.200

Hail, up to golf ball size were reported as well, and several hundreds of acres of wheat were 100 percent destroyed.

Hail, Valley

When: July 12, 8:08 PM MST
Where: Valley County, 5 mi NE of Beaverton
Measured: 1.5 in hail
Reported by: TRAINED SPOTTER
Coordinates: 48.467, -107.167

Hail, Phillips

When: July 12, 8:30 PM MST
Where: Phillips County, Zortman
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 47.917, -108.533

Hail, Phillips

When: July 12, 8:45 PM MST
Where: Phillips County, 15 mi NE of Zortman
Measured: 0.75 in hail
Reported by: TRAINED SPOTTER
Coordinates: 48.067, -108.300

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 2026-09-24. Each event’s entry at NCEI: 5262088, 5262160, 5262156, 5262157, 5262164, 5262165, 5262163, 5262159, 5262158, 5262161, 5262162.