A stagnant pattern kept warm and unusually humid air anchored across the area which caused the development of a couple severe storms, including one that developed a landspout tornado.
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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 stagnant pattern kept warm and unusually humid air anchored across the area which caused the development of a couple severe storms, including one that developed a landspout tornado.
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 1, 2:14 PM MST, 4 hours 42 minutes earlier.
Area Forecast Discussion National Weather Service Glasgow MT 314 PM MDT Thu Jun 1 2023 .DISCUSSION... The stage is set for a multi-day heavy rain event (or series of events) to impact most of northeast Montana tonight through Saturday morning. An overall stagnant flow pattern with higher pressure to the east and lower pressure to our west will both combine to draw in moisture transport from the Pacific Ocean AND the Gulf of Mexico. These moisture sources will travel our directions and converge and wrap up into NE and NC Montana, producing mulitple waves of heavy rain amid scattered general thunderstorms. Given the lack of shear in this environment, the main threat obviously with any of these storms will be heavy rain and flooding. Minor threats would be lightning and gusty winds. Following the best model consensus for timing and amount of rainfall, I felt it was best to update/expand the area of the flood watch to now include another tier of zones eastward. For more information, refer to the Hydrology discussion below. From Saturday night moving forward, the stagnant flow pattern remains, as we continued to be sandwiched between low pressure from the west and high pressure from the east. Unusually humid air will remain over our region for the foreseeable future. Models show showers and thunderstorms nearly every day, but confidence is average to below average for details on timing and amounts. ----BMickelson && .AVIATION... VFR mostly, with isolated MVFR directly in a thunderstorm later this evening and through the remainder of the TAF cycle tomorrow. After a day of mostly sunny skies today, more widespread and intense rain showers with scattered thunderstorms will move into the area from the south beginning this evening. Heavy rain will become even more intense through the day on Friday. Expect amendments and erratic gusty winds near the stronger storms. Ahead of the storms, winds will be from the southeast at 10 to 15 kts. ----BMickelson && .HYDROLOGY... The stagnant weather pattern and moisture laden atmosphere will lend itself to efficient heavy rainstorms and scattered thunderstorms, especially this evening through all day Friday. Models are beginning to fall in line, showing heavy rainfall accumulations most locations near and west of MT-Highway 13. When the low pressure circulation strengthens over Wyoming this evening, storm are expected to ramp up. Near and west of a line from Scobey through Wolf Point through McCloud, 2-day rainfall accumulations will be between 1 and 2 inches. Locally higher amounts may be possible. Near and east of that line, expect less than 1 inch of rainfall. Anyone planning outdoor activities should closely monitor the latest forecasts and any possible flood warning that may be issued. Alternate plans will need to be considered in order to address public safety concerns. ----BMickelson && .GLASGOW WATCHES/WARNINGS/ADVISORIES... Flood Watch through late Friday night for Central and Southeast Phillips...Central and Southern Valley...Daniels...Garfield... McCone...Northern Phillips...Northern Valley...Petroleum... Prairie...Southwest Phillips...Western Roosevelt. && weather.gov/glasgow
The Glasgow radar (KGGW), 63 km away, was scanning. The volume nearest the first event began at 01:56 UTC.
1 tornado. Local standard time, as filed.
Law enforcement and the public reported a landspout tornado near 8 SW West Fork. The tornado lasted about 10 minutes, with no visible damage to properties or fields. With no|visible indicators, the length of path and path width were estimated.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2023Every state in 2023This day in weather historyThe tornado archive for Montana, 2023Warnings in Montana, June 2023
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: 1093668.