A weak stalled surface front, ahead of an advancing low pressure system, combined with strong heating to produce a severe thunderstorms which moved from Garfield County through Prairie County.
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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.
The episode as NWS GGW wrote it up.
A weak stalled surface front, ahead of an advancing low pressure system, combined with strong heating to produce a severe thunderstorms which moved from Garfield County through Prairie County.
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 Aug 4, 1:17 PM MST, 3 hours 30 minutes earlier.
Area Forecast Discussion National Weather Service Glasgow MT 217 PM MDT Sun Aug 4 2019 .DISCUSSION... Afternoon Update: Kept much of the morning update forecast relatively the same. Refreshed much of the grids with the latest model solutions and blends, but the forecast remains relatively intact from previous iterations. Bigelbach PREVIOUS DISCUSSION: Upper ridge flattening as an upper trof moves through central Canada today. With the flat ridge, Canadian high pressure will slip some cooler air south of the border for temperatures more in the 80s instead of 90s. A boundary lingers across southern Montana and will provide a focus for convection through the day. In general storms are expected to remain south of the cwa but a few could develop northward. As the trough moving across Canada digs toward the Great Lakes, the upper ridge shifts slightly westward as it rebounds. This will push the hottest air westward, keeping temperatures more in the 80s for much of next week. By late in the week, more widespread thunderstorms may return as shortwaves again move through the ridge. Ebert && .AVIATION... Expected Flight Category: VFR Synopsis: Hot and dry remains the predominant weather pattern over the region. Some showers and thunderstorms will be possible in the SDY and GDV areas through this evening. Winds: Winds are expected to be out of the northeast at 7-12 kts through this evening then will calm to light and variable through Monday. Bigelbach && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && weather.gov/glasgow
Special Weather Statement National Weather Service Glasgow MT 514 PM MDT Sun Aug 4 2019 MTZ025-026-050000- Dawson MT-Prairie MT- 514 PM MDT Sun Aug 4 2019 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL PRAIRIE AND SOUTHWESTERN DAWSON COUNTIES UNTIL 600 PM MDT... At 513 PM MDT, Doppler radar was tracking a strong thunderstorm 14 miles northwest of Terry, moving east at 40 mph. Nickel size hail will be possible with this storm. Locations impacted include... Fallon, Hoyt and Marsh. PRECAUTIONARY/PREPAREDNESS ACTIONS... This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 4687 10559 4705 10559 4708 10471 4681 10472 TIME...MOT...LOC 2313Z 271DEG 34KT 4697 10548 Jamba
The Glasgow radar (KGGW), 201 km away, was scanning. The volume nearest the first event began at 23:47 UTC.
1 thunderstorm wind. Local standard time, as filed.
Public reported a car port blown across a street where it damaged a pickup truck. vehicles moved and damaged by wind gusts. Penny size hail was also reported with damage to some crops. Wind gust speed estimated. Time estimated by radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2019Every state in 2019This day in weather historyWarnings in Montana, August 2019
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: 842411.