Damaging Wind and High Wind in Montana, June 13, 2020

Name: Damaging Wind and High Wind in Montana, June 13, 2020
Start: 2020-06-13T11:02
End: 2020-06-13T17:43
Location: Montana

June 13, 2020 · NWS GGW · 2 events in 2 counties and zones

A trough of low pressure at the surface combined with seasonally hot temperatures, an unstable atmosphere, and enough shear to generate and sustain strong thunderstorms across portions of eastern Montana - a few of which produced severe wind gusts in Valley and Dawson Counties.

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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 2

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 Jun 13, 4:38 AM MST, 6 hours 24 minutes earlier.

Area forecast discussion, Jun 13, 4:38 AM MST, 6 hours 24 minutes before

Area Forecast Discussion
National Weather Service Glasgow MT
538 AM MDT Sat Jun 13 2020

.DISCUSSION...
The upper ridge over the state will be moving east today while an
upper low pushes into the Pacific Northwest. A surface low will
develop along the lee trof and lift north-northeast through east-
central Montana today. This will shift the lee trof into the area
and provide the focal point for afternoon and evening
thunderstorm development.

Relative humidity behind this surface trof will plummet to the
teens and temperatures may rise to near 100 across portions of
Garfield County. With winds around 20 mph, this will lead to
elevated fire weather conditions, particularly across Garfield,
Petroleum, and southern Phillips Counties.

On the other side of the surface trof, isolated to scattered
thunderstorms are expected to develop. These will likely begin to
develop along a line from near Malta to southwest Valley County to
eastern Garfield County sometime between 2 to 4 PM. Any storms
that develop may rapidly become severe and move north- northeast.
Due to such hot temperatures and marginal moisture, large
inverted-V soundings with moderate instability suggest damaging
winds in excess of 70 mph and large hail will be the severe
threats.

Strong southeast winds will continue ahead of the surface trough
today, so the Lake Wind Advisory remains in effect until the
evening.

Cooler air moves into the region on Sunday with scattered showers
and thunderstorms behind the surface trof as the upper low pushes
into the northern Rockies. This broad trof will linger through
next week, providing temperatures close to normal. Occasional
showers or thunderstorms are also possible as shortwaves rotate
through the area.

&&

.AVIATION...
VFR conditions through this afternoon with gusty southeast winds
through tonight.

Isolated storms will develop after 20-22Z today and may become
severe with large hail and damaging winds. This would mainly
impact GGW and OLF, though all TAF locations may see a
thunderstorm.

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 9 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 Glasgow radar (KGGW), 166 km away, was scanning. The volume nearest the first event began at 00:29 UTC.

Open the radar archive at this moment

Event by event

1 high wind, 1 thunderstorm wind. Local standard time, as filed.

High Wind, Dawson

When: June 13, 11:02 AM MST to 5:43 PM MST
Where: Dawson forecast zone
Measured: 62 kt (71 mph) measured gust
Reported by: Department of Highways
Coordinates: 47.266, -104.899 (the zone’s center; the record gives no point)

At the Beaver Hill I-94 DOT site (MTBVR), the first severe wind gust of 60 mph was recorded at 11:02 AM MST. Sustained winds speeds well above 40 mph and wind gusts well above 60 mph continued over the next 6 hours. The peak wind gust of 71 mph was recorded at 12:32 PM MST. The last severe wind gust of 58 mph was recorded at 5:43 PM MST.

Thunderstorm Wind, Valley

When: June 13, 5:30 PM MST
Where: Valley County, King Coulee Raws
Measured: 50 kt (58 mph) measured gust
Reported by: RAWS
Coordinates: 47.800, -107.020

At the King Coulee RAWS site (KIGM8), a 58 mph wind gust was recorded at 5:30 PM MST. Time estimated by radar.

What these are

High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
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

Every storm in Montana in 2020 Every state in 2020 This day in weather history Warnings in Montana, June 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: 899304, 899287.