Tornadoes and Hail in Montana, July 7, 2020

Name: Tornadoes and Hail in Montana, July 7, 2020
Start: 2020-07-07T14:58
End: 2020-07-07T19:01
Location: Montana

July 7, 2020 · NWS GGW · 37 events in 7 counties and zones

A very unstable atmosphere combined with warm moist air from the southeast and a cold front from the west, to easily form and support multiple severe thunderstorms which merged into a bowing squall line and resulted in a tornado and a gustnado.

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: 37

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 GGW wrote it up.

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 7, 12:15 PM MST, 2 hours 43 minutes earlier.

Area forecast discussion, Jul 7, 12:15 PM MST, 2 hours 43 minutes before

Area Forecast Discussion
National Weather Service Glasgow MT
115 PM MDT Tue Jul 7 2020

.DISCUSSION...
A widespread severe weather event is on track for all of
Northeast Montana from late afternoon through the evening hours.
Storms are forming across the higher terrain in central and
southwest Montana and will progress eastward into Northeast
Montana. Storms may be semi-discrete initially as they enter
Phillips and Petroleum Counties. If they are able to remain
discrete then very large hail to the size of baseballs, damaging
winds in excess of 70 mph, and an isolated tornado will be
possible.

Once the storms merge into one or more line segments destructive
wind gusts in excess of 70 to 80 mph will become the primary
threat. Look for this main line of storms to arrive in Phillips
and Petroleum Counties around 4 or 5 PM, Opheim to Glasgow to
Jordan around 6 to 7 PM, and the ND border by 9 to 10 PM or so.

It is possible a few isolated storms could enter the Yellowstone
River Valley ahead of this primary line of storms during the early
evening hours. If this were to happen, all severe modes would be
possible.

An upper trough moves across the state on Wednesday with slightly
cooler and generally drier weather. A few storms are possible
near the Canadian border with the proximity of a stacked low
pressure system moving from Saskatchewan into Manitoba.

Ridge then builds north from the Desert Southwest for hot and dry
weather for the remainder of the week. Could see a few
thunderstorms on Friday as a shortwave pushes through the top of
the ridge.

-Mottice/RAE

&&

.AVIATION...
A line of severe storms should reach KGGW around 00-01Z, KOLF
01-02z, and KGDV and KSDY between 02 and 03z this evening. This
line of storms will bring intense and erratic winds as well as
hail, heavy rain, and brief IFR conditions.

Skies should be clearing out by 06z for much of the region.

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 10 PM MDT this evening For Fort Peck
Lake for Central and Southeast Phillips...Central and Southern
Valley...Garfield...McCone...Petroleum.

&&

weather.gov/glasgow

The radar

The Billings radar (KBLX), 126 km away, was scanning. The volume nearest the first event began at 21:59 UTC.

Open the radar archive at this moment

Event by event

34 thunderstorm wind, 2 tornado, 1 hail. Local standard time, as filed.

Tornado, Petroleum

When: July 7, 2:58 PM MST to 3:12 PM MST
Where: Petroleum County, 2.06 mi SW of Winnett to 1.94 mi SW of Winnett
Rating: EF0
Path length: 0.14 mi
Path width: 20 yd
Reported by: Public
Coordinates: 46.977, -108.378

Petroleum County dispatch relayed a public report of a brief, weak gustnado spun up out of severe thunderstorm outflow winds southwest of Winnett. Time estimated from radar.

Thunderstorm Wind, Phillips

When: July 7, 3:04 PM MST
Where: Phillips County, Manning Corral Raws
Measured: 62 kt (71 mph) measured gust
Reported by: RAWS
Coordinates: 47.700, -108.480

At the Manning Corral Dogtown RAWS site (MCDM8), at 71 mph wind gust was recorded.

Tornado, Petroleum

When: July 7, 3:10 PM MST to 3:15 PM MST
Where: Petroleum County, 7.98 mi WSW of Dry Blood Creek Raws to 7.83 mi WSW of Dry Blood Creek Raws
Rating: EF0
Path length: 0.15 mi
Path width: 50 yd
Reported by: Law Enforcement
Coordinates: 47.177, -108.522

Petroleum County dispatch and Emergency Manager relayed a public report of a brief, rain-wrapped, weak tornado northwest of Winnett. No damage was found.

Thunderstorm Wind, Phillips

When: July 7, 3:16 PM MST
Where: Phillips County, Zortman
Measured: 62 kt (71 mph) measured gust
Reported by: Social Media
Coordinates: 47.920, -108.530

Public reported, via Facebook, that a 71 mph wind gust blew a tree down in Zortman.

Thunderstorm Wind, Petroleum

When: July 7, 3:22 PM MST
Where: Petroleum County, 10.18 mi SW of Chain Buttes Raws
Measured: 54 kt (62 mph) measured gust
Reported by: Mesonet
Coordinates: 47.430, -108.210

At the Lewsotwn Port #1 RAWS site (TR464), a 62 mph wind gust was recorded.

Hail, Petroleum

When: July 7, 3:25 PM MST
Where: Petroleum County, 2.13 mi SSW of Winnett
Measured: 1.25 in hail
Reported by: Emergency Manager
Coordinates: 46.970, -108.360

Petroleum County Emergency Manager reported hail up to the size of half dollars.

Thunderstorm Wind, Phillips

When: July 7, 3:30 PM MST
Where: Phillips County, 0.83 mi SE of Malta South Dot
Measured: 55 kt (63 mph) measured gust
Reported by: Department of Highways
Coordinates: 47.960, -108.310

At the Malta South US-191 DOT site (MTMAL), a 63 mph wind gust was recorded.

Thunderstorm Wind, Phillips

When: July 7, 3:35 PM MST
Where: Phillips County, 1.55 mi ESE of Zortman
Measured: 56 kt (64 mph) measured gust
Reported by: RAWS
Coordinates: 47.910, -108.500

At the Zortman BLM RAWS site (ALDM8) a 64 mph wind gust was recorded.

Thunderstorm Wind, Phillips

When: July 7, 3:40 PM MST
Where: Phillips County, 0.46 mi E of Malta
Measured: 61 kt (70 mph) estimated gust
Reported by: Social Media
Coordinates: 48.350, -107.860

Public reported, via Facebook, several trees blown over in the Malta Cemetery.

Thunderstorm Wind, Phillips

When: July 7, 3:41 PM MST
Where: Phillips County, 3.28 mi WNW of Dodson
Measured: 65 kt (75 mph) measured gust
Reported by: Public
Coordinates: 48.410, -108.300

Public reported at 75 mph wind gust at their personal home weather station.

Thunderstorm Wind, Phillips

When: July 7, 3:55 PM MST
Where: Phillips County, 8.4 mi N of Malta Arpt
Measured: 61 kt (70 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 48.470, -107.910

Trained spotter reported extensive roof, fence, and barn damage from severe winds, including a thirty-foot pine tree being up-rooted. Heavy rain also caused water to flow up some drains. Time estimated from radar.

Thunderstorm Wind, Phillips

When: July 7, 3:55 PM MST
Where: Phillips County, 2.3 mi NW of Malta Arpt
Measured: 77 kt (89 mph) measured gust
Reported by: Mesonet
Coordinates: 48.370, -107.920

At the Malta airport AWOS site (KM75), an 89 mph wind gust was recorded.

Thunderstorm Wind, Phillips

When: July 7, 3:55 PM MST
Where: Phillips County, 8.4 mi N of Malta Arpt
Measured: 76 kt (87 mph) measured gust
Reported by: Trained Spotter
Coordinates: 48.470, -107.910

Trained spotter 8 N Malta recorded an 88 mph wind gust on their personal home weather station.

Thunderstorm Wind, Phillips

When: July 7, 3:55 PM MST
Where: Phillips County, 8.4 mi N of Malta Arpt
Measured: 76 kt (87 mph) measured gust
Reported by: Trained Spotter
Coordinates: 48.470, -107.910

Trained spotter 8 N Malta reported extensive straight-line wind damage to their property.

Thunderstorm Wind, Garfield

When: July 7, 4:06 PM MST
Where: Garfield County, 0.69 mi S of South Sawmill Raws
Measured: 74 kt (85 mph) measured gust
Reported by: RAWS
Coordinates: 47.560, -107.530

At the South Sawmill Creek RAWS site (SSMM8), an 85 mph wind gust was recorded.

Thunderstorm Wind, Phillips

When: July 7, 4:15 PM MST
Where: Phillips County, 0.92 mi W of Saco
Measured: 52 kt (60 mph) estimated gust
Reported by: COOP Observer
Coordinates: 48.470, -107.350

Cooperative observer reported downed tree branches, two inches in diameter.

Thunderstorm Wind, Phillips

When: July 7, 4:18 PM MST
Where: Phillips County, 1.95 mi SE of Saco
Measured: 55 kt (63 mph) measured gust
Reported by: Department of Highways
Coordinates: 48.450, -107.300

At the Saco US-2 DOT site (MTSCO), a 63 mph wind gust was recorded.

Thunderstorm Wind, Phillips

When: July 7, 4:24 PM MST
Where: Phillips County, 0.46 mi W of Saco
Measured: 61 kt (70 mph) estimated gust
Reported by: Public
Coordinates: 48.470, -107.340

Public reported extensive roof, siding, gutter, and tree damage from severe winds. In addition, a harrow was pushed a distance of 200 feet; a grain bin was lofted up and over a wind break; some other buildings, a few bulls, and a junk pile were all carried a distance of 300 yards to a nearby lake.

Thunderstorm Wind, Phillips

When: July 7, 4:25 PM MST
Where: Phillips County, 17.08 mi NNE of Saco
Measured: 61 kt (70 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 48.710, -107.240

Trained spotter reported siding and shingles peeled off a house.

Thunderstorm Wind, Valley

When: July 7, 4:30 PM MST
Where: Valley County, 15.36 mi NNW of Hinsdale
Measured: 61 kt (70 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 48.610, -107.190

Trained spotter reported a 30 by 60 foot shed destroyed. Wind speed estimated.

Thunderstorm Wind, Roosevelt

When: July 7, 4:30 PM MST
Where: Roosevelt County, 5.56 mi NNW of Volt
Measured: 53 kt (61 mph) measured gust
Reported by: Trained Spotter
Coordinates: 48.450, -105.780

A trained spotter reported a 61 mph wind gust.

Thunderstorm Wind, Roosevelt

When: July 7, 4:30 PM MST
Where: Roosevelt County, 5.56 mi NNW of Volt
Measured: 53 kt (61 mph) measured gust
Reported by: Trained Spotter
Coordinates: 48.454, -105.766

Trained spotter reported multiple tree limbs downed.

Thunderstorm Wind, Valley

When: July 7, 4:37 PM MST
Where: Valley County, 1.38 mi W of Glasgow Intl Airport (Kggw)
Measured: 50 kt (58 mph) measured gust
Reported by: Public
Coordinates: 48.220, -106.650

Public reported a 58 mph wind gust from their personal home weather station.

Thunderstorm Wind, Valley

When: July 7, 4:39 PM MST
Where: Valley County, 2.27 mi NNW of Glasgow Intl Airport (Kggw)
Measured: 55 kt (63 mph) measured gust
Reported by: Mesonet
Coordinates: 48.250, -106.640

Public reported a 63 mph wind gust from their personal home weather station.

Thunderstorm Wind, Valley

When: July 7, 4:40 PM MST
Where: Valley County, 13.14 mi N of Hinsdale
Measured: 61 kt (70 mph) measured gust
Reported by: Public
Coordinates: 48.590, -107.090

Public recorded a 70 mph wind gust on their personal home weather station, and measured 0.7 inch of rain.

Thunderstorm Wind, Valley

When: July 7, 4:45 PM MST
Where: Valley County, 1.39 mi W of Duck Creek
Measured: 58 kt (67 mph) measured gust
Reported by: Trained Spotter
Coordinates: 47.980, -106.550

Trained spotter at the Duck Creek Recreation Area measured a 67 mph wind gust. | Time estimated from radar.

Thunderstorm Wind, Valley

When: July 7, 4:46 PM MST
Where: Valley County, Bluff Creek Raws
Measured: 65 kt (75 mph) measured gust
Reported by: RAWS
Coordinates: 48.870, -106.950

At the Bluff Creek RAWS site (BLUM8), a 75 mph wind gust was recorded.

Thunderstorm Wind, Valley

When: July 7, 4:50 PM MST
Where: Valley County, 0.93 mi W of Duck Creek
Measured: 61 kt (70 mph) estimated gust
Reported by: Social Media
Coordinates: 47.980, -106.540

Public reported, via Facebook, a roof was completely torn off a house near the Duck Creek Recreation Area.

Thunderstorm Wind, Valley

When: July 7, 4:50 PM MST
Where: Valley County, 3.9 mi WNW of Baylor
Measured: 52 kt (60 mph) measured gust
Reported by: Public
Coordinates: 48.670, -106.480

Public recorded a 60 mph wind gust on their personal home weather station.

Thunderstorm Wind, Valley

When: July 7, 4:53 PM MST
Where: Valley County, 0.69 mi S of Saint Marie
Measured: 72 kt (83 mph) measured gust
Reported by: Mesonet
Coordinates: 48.410, -106.520

At the Saint Marie MARCO mesonet site (07MT), an 82 mph wind gust was recorded.

Thunderstorm Wind, Valley

When: July 7, 5:03 PM MST
Where: Valley County, 5.03 mi NE of Baylor
Measured: 50 kt (58 mph) measured gust
Reported by: Public
Coordinates: 48.700, -106.320

Public reported a 58 mph wind gust.

Thunderstorm Wind, Roosevelt

When: July 7, 5:28 PM MST
Where: Roosevelt County, 5.56 mi NNW of Volt
Measured: 53 kt (61 mph) measured gust
Reported by: Mesonet
Coordinates: 48.450, -105.780

At the Lustre mesonet site (FW0464), a 61 mph wind gust was recorded.

Thunderstorm Wind, McCone

When: July 7, 5:51 PM MST
Where: McCone County, 0.83 mi NW of Cow Creek Dot
Measured: 53 kt (61 mph) measured gust
Reported by: Department of Highways
Coordinates: 47.690, -105.490

At the Cow Creek MT-13 DOT site (MTCOW), a 61 mph wind gust was recorded.

Thunderstorm Wind, Garfield

When: July 7, 5:54 PM MST
Where: Garfield County, 21.04 mi SE of Cohagen
Measured: 50 kt (58 mph) estimated gust
Reported by: Department of Highways
Coordinates: 46.860, -106.230

At the Hillside MT-59 DOT site (MTHIL), a 58 mph wind gust was recorded.

Thunderstorm Wind, Sheridan

When: July 7, 6:30 PM MST
Where: Sheridan County, 0.83 mi NNW of Reserve
Measured: 65 kt (75 mph) estimated gust
Reported by: Social Media
Coordinates: 48.610, -104.460

Public reported, via Facebook, a hopper bottom fertilizer bin was blown over. Wind speed estimated.

Thunderstorm Wind, Roosevelt

When: July 7, 6:41 PM MST
Where: Roosevelt County, 3.45 mi N of Froid
Measured: 52 kt (60 mph) estimated gust
Reported by: Social Media
Coordinates: 48.380, -104.500

Public reported, via Facebook, damage to an outdoor shed and loss of power. Wind speed is estimated.

Thunderstorm Wind, Sheridan

When: July 7, 7:01 PM MST
Where: Sheridan County, 0.91 mi E of Comertown Dot
Measured: 65 kt (75 mph) measured gust
Reported by: Department of Highways
Coordinates: 48.800, -104.270

At the Commertown Turn-Off MT-5 DOT site (MTCOM), a 75 mph wind gust was recorded.

What these are

Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
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.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.

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

The same day elsewhere

Every storm in Montana in 2020 Every state in 2020 This day in weather history The tornado archive for Montana, 2020 Warnings in Montana, July 2020

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: 905193, 905578, 905149, 905581, 909683, 905141, 909684, 909685, 905228, 909687, 905416, 909689, 909691, 909692, 909693, 905422, 909694, 905444, 905450, 905480, 909695, 909696, 909700, 909701, 909703, 909704, 909705, 905533, 909707, 909708, 909711, 909712, 909713, 909714, 905556, 909716, 909717.