The low-level inversion weakened enough during the night-time hours to allow the stronger winds from aloft reach all the way down to the surface for the higher elevations of southwest Phillips County.
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The episode as NWS GGW wrote it up.
The low-level inversion weakened enough during the night-time hours to allow the stronger winds from aloft reach all the way down to the surface for the higher elevations of southwest Phillips 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 Jan 19, 8:49 PM MST, 43 minutes earlier.
Area Forecast Discussion National Weather Service Glasgow MT 849 PM MST Tue Jan 19 2021 .DISCUSSION... With clouds and chinook winds blowing through the night, temperatures look to hold up a bit more than previously expected. Besides the temperature tweak, the going forecast looked good. TFJ Previous Discussion... No precipitation of any significance is in sight for Northeast Montana over the next week. We will, however, see colder weather arrive for the latter half of this week into the weekend. One more day of above normal temperatures is in store for Wednesday with highs in the 30s and 40s. It will also be a bit windy with westerly winds increasing tonight through tomorrow. By Wednesday afternoon we could see gusts to around 40 mph out of the northwest with the passage of a cold front. Another cold front drops south Wednesday Night which will usher in the colder temperatures the remainder of the week as an upper trough moves into the area. Temperatures by the weekend will be near normal for late January but will be much colder than they have been the last several weeks. A system moving across southern Montana Friday and Saturday could bring a chance of light snow into the southern zones of the forecast area. -Mottice && .AVIATION... VFR conditions with westerly winds increasing to 15 to 20 knots tonight. Winds become more northwesterly Wednesday afternoon with gusts 30 to 35 knots as skies clear. && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && weather.gov/glasgow
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Wind gusts of at least 58 mph began during the night of the 19th, and intermittently lasted through the overnight hours into the 20th. The peak wind gust of 67 mph was recorded at the Zortman RAWS site (ALDM8) at 12:32 AM MST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2021Every state in 2021This day in weather historyWarnings in Montana, January 2021
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: 940571.