Developing severe thunderstorms quickly generated severe downburst wind gusts as they moved into Petroleum 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.
Developing severe thunderstorms quickly generated severe downburst wind gusts as they moved into Petroleum 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 17, 1:31 PM MST, 3 hours 54 minutes earlier.
Area Forecast Discussion National Weather Service Glasgow MT 231 PM MDT Sun Aug 17 2025 .DISCUSSION... KEY MESSAGES: - There is a marginal risk for severe thunderstorms south of the Missouri River tonight. - A building ridge will push temperatures to near 100 or higher Tuesday and Wednesday. WEATHER PATTERN OVERVIEW: Southwest flow aloft streaming into Montana today with building ridge over the Rockies. Dry line feature has moved closer to the North Dakota border with dew points in the 50s across the western portion of the CWA compared to the 60s to the east. Little else in the way of surface features, so convection already over the southwest mountains will rely on midlevel instability to maintain strength over the plains this evening. Still could see some strong wind gusts with collapsing storms, especially with the drier low levels. Storm chances for Monday have decreased with drier airmass. Upper ridge will peak over Montana on Tuesday and Wednesday. Temperature forecast continues to climb in the guidance with some areas near 100 for highs on Tuesday and many areas above 100 for highs on Wednesday. With low temperatures for Tuesday night also remaining in the mid to upper 60s, the likelihood of needing extreme heat products for Tuesday and Wednesday is becoming likely. A cold front Wednesday night and Thursday will bring much cooler temperatures for Thursday and Friday. FORECAST CONFIDENCE & DEVIATIONS: Main forecast deviation from the NBM was pops tonight and Monday for slightly higher probabilities. Confidence is moderate that there will be isolated to scattered showers and thunderstorms at times tonight. Low confidence in thunderstorm chances on Monday. Confidence is high in very hot temperatures on Tuesday and Wednesday which will exceed 100 degrees in some areas. && .AVIATION... VFR. Isolated to scattered showers and thunderstorms possible tonight. Low clouds may develop again over the TAF sides overnight which cloud drop ceilings to MVFR, however there has been some drier air working into the region will could limit clouds to along the North Dakota border. && .GGW WATCHES/WARNINGS/ADVISORIES... None. && weather.gov/glasgow
Special Weather Statement
National Weather Service Glasgow MT
533 PM MDT Sun Aug 17 2025
MTZ024-180030-
Richland MT-
533 PM MDT Sun Aug 17 2025
...A strong thunderstorm will impact portions of east central
Richland County through 630 PM MDT
...
At 532 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles northwest of Sidney, moving southeast at 5 mph.
HAZARD...Wind gusts up to 50 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Sidney, Fairview, East Fairview, and Wooley.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4776 10435 4785 10429 4786 10404 4758 10404
TIME...MOT...LOC 2332Z 300DEG 5KT 4779 10427
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH
ZankerThe Billings radar (KBLX), 144 km away, was scanning. The volume nearest the first event began at 00:24 UTC.
5 thunderstorm wind. Local standard time, as filed.
The War Horse NW HydroMet site (WRHM8) from the Montana Climate Office Mesonet recorded a 59 mph wind gust.
The War Horse NW HydroMet site (WRHM8) from the Montana Climate Office Mesonet recorded a 61 mph wind gust.
The Winnett MT-200 DOT site (MTWIN) recorded a 59 mph wind gust.
The Mosby NW HydroMet site (MOBM8) from the Montana Climate Office Mesonet recorded a 60 mph wind gust.
The Dovetail / Valentine E HydroMet site (VLTM8) from the Montana Climate Office Mesonet recorded a 64 mph wind gust.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2025Every state in 2025This day in weather historyWarnings in Montana, August 2025
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: 1274977, 1274978, 1274979, 1274981, 1274982.