Gusty winds started initially along the Rocky Mountain Front the evening of the 3rd associated with increasing mid level flow and mountain waves. Gusty winds then spread onto the remaining North-central Montana plains, primarily behind terrain features.
Every event with a place to put it; 12 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 TFX wrote it up.
Gusty winds started initially along the Rocky Mountain Front the evening of the 3rd associated with increasing mid level flow and mountain waves. Gusty winds then spread onto the remaining North-central Montana plains, primarily behind terrain features.
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 Great Falls, MT wrote its last area forecast discussion before the first event at Feb 3, 8:17 PM MST, 1 hour 4 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 817 PM MST Fri Feb 3 2023 .UPDATE... The main update was to decrease temperatures in the Milk River area east of Chinook through midnight. The gusty southwest winds have not scoured out the cold air yet in the town of Harlem, so have lowered lows there into the upper teens, which is the current temperature there. Winds should continue to spread east after midnight, which will help moderate temperatures there. Overall, though, the current overnight forecast period appears to be mostly on track, keeping precipitation on the Continental Divide in the mountains of Southwest Montana. Will therefore continue the Winter Weather Advisory for the East Glacier Park area, including Marias Pass. A passing shortwave will continue to increase winds over the plains of North Central and Central Montana through and after midnight. Winds will then gradually decrease during the late morning and afternoon hours as the shortwaves starts to exit the area. Model guidance continues to indicate that winds will likely become strong at times across portions of the area, so will continue the High Wind Warnings as is, and the strong winds will also cause near whiteout conditions at times in the Winter Weather Advisory area. -Coulston && .SYNOPSIS... A Pacific weather system brings windy conditions to the plains and light snow along the Northern Divide tonight into Saturday. Another system arrives late Sunday into Monday, bringing more winds and mostly mountain snow. Breezy to windy, but mild, conditions continue through the first half of next week. && .AVIATION... 445 PM MST Fri Feb 3 2023 (04/00Z TAF Period) VFR conditions are expected to generally continue across North Central, Central, and Southwest Montana through at least the next 24 hours, with mainly mid- and high-level cloudiness passing overhead. A moderate westerly flow aloft will allow mountain wave turbulence to persist across the area, with gusty westerly winds over North Central and Central Montana causing low level wind shear. Gusty southerly winds will also blow in the Madison River valley (including KEKS). The passage of a disturbance will also bring periods of virga over the plains, but it will likely obscure mountain tops in snow at times on the Continental Divide. -Coulston Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 445 PM MST Fri Feb 3 2023/ Relatively quiet and mild conditions this afternoon as another Pacific shortwaves approaches from the southwest. The milder air has reached all areas except the far eastern Blaine County, where temperatures remain in the teens as of this writing. I still maintained the forecast highs as is in anticipation of the milder temperatures clearing all of the CWA by late this afternoon. The blowing/drifting snow issues from early seem to have improved, though the mention of blowing snow will be left in the grids for eastern Hill and Blaine counties for the duration of the afternoon. For tonight into Saturday, the focus shifts over to the aforementioned Pacific shortwave. Strong, gusty winds over the plains and the Rocky Mountain Front will be the primary concern with this system. Periods of light accumulating snow can also be expected for areas along the immediate eastern slopes of the Northern Divide. There will be two opportunities for the occurrence of strong winds, one late tonight into Saturday morning with the passage of the strongest H700 flow and another later Saturday afternoon during peak diurnal mixing. Although wind probabilities for gusts exceeding 55 mph have not changed much from previous shifts, I decided to upgrade the eastern counties to a High Wind Warning and expend it to include Chouteau and Cascade counties. A more expansive area of 45 to 50 kts H700 westerly flow and the presence of weak cold air advection to help mix this flow to the ground has helped with this decision despite this being an overall marginal high wind situation. The High Wind Watch for zones 301 and 307 was lifted since the bulk of the higher end wind gusts are anticipated to occur to the east of these areas. As for snowfall, the inherited Winter Weather Advisory for the Marias Pass area still looks good with a 2 to 5 inch snowfall and gusty westerly winds expected. Other areas will be on the drier side, but a few lower elevation rain/snow showers can't be ruled out tonight and on Saturday. After a brief period of upper level ridging Saturday night into Sunday, a broad Pacific trough moves into the Northern Rockies. Precipitation will be more widespread with this system, though on the lighter side with the most of the system's energy moving to our south. The best chances (> 70 percent) for 1 inch or more of snowfall will favor the southwestern mountains/passes, though some minor lower elevation accumulations can be expected Sunday night/early Monday. This system does not pose much of a threat for strong winds until later Monday into Tuesday, when the system exits and the surface pressure gradient begins to tighten. The latest 3 to 7 day cluster analysis indicates that transient upper level ridging will bring drier and milder conditions through mid-week. The tightening surface pressure gradient looks to bring another round of winds to the Rocky Mountain Front and the plains on Tuesday. NBM v4.1 probabilities for gusts over 55 mph are running above 70 percent for the Rocky Mountain Front and the Cut Bank area, but a weaker 35 to 45 kt H700 west to northwesterly flow doesn't seem sufficient enough to maintain prolonged periods of wind gusts of these magnitudes. Regardless, the situation will continue to be monitored in the days. An unsettled northwesterly flow aloft returns for the second half of the week. Passing shortwaves will bring periods of windy conditions and increased chances for precipitation, but ensembles don't have a good grasp on timing yet. In addition to that, some deterministic and ensemble suites bring in colder and potentially more productive systems through the Northern Rockies during this time. -RCG && .PRELIMINARY POINT TEMPS/POPS... GTF 35 44 29 46 / 0 10 0 0 CTB 33 42 24 43 / 10 0 0 0 HLN 26 42 24 39 / 10 0 0 20 BZN 18 37 17 36 / 20 0 0 20 WYS 11 29 12 33 / 30 10 10 80 DLN 18 35 20 35 / 10 0 0 30 HVR 31 39 19 37 / 30 10 0 0 LWT 32 42 26 44 / 10 10 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 5 PM MST Saturday for East Glacier Park Region. High Wind Warning until 3 PM MST Saturday for Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains. High Wind Warning from midnight tonight to 5 PM MST Saturday for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft-Fergus County below 4500ft-Judith Basin County and Judith Gap-Northern Blaine County-Snowy and Judith Mountains-Western and Central Chouteau County. && http://www.weather.gov/greatfalls
The national radar mosaic for the moment the first event began.
12 high wind. Local standard time, as filed.
Mesonet station MTBRN Two Medicine Bridge measured a peak wind gust of 73 mph. Additionally, the same sensor measured sustained winds greater than 40 mph early morning of Feb 4.
Ambient Weather Station LJ Johnson Farms measured a 66 and 73 mph gust associated with a mountain wave.
Mesonet station MTBWG Browning measured a gust of 58 mph.
Mesonet station DELMT Dellwo measured two wind gusts in excess of 58 mph, including a 74 mph gust.
The DOT sensor at Geyser (MTGYS) measured sustained winds of 40 mph over an hour and a wind gust of 58 mph.
An Ambient Weather sensor near Black Butte measured a 58 mph gust.
Mesonet station MTM02 10.2 miles south of Loma measured a gust of 58 mph.
Mesonet station ew1937 Goldstone measured a gust of 58 mph.
An Ambient Weather station measured a gust of 59 mph.
Mesonet station TR276 L-C Portable RAWS NO. 1 measured a gust of 59 mph.
Mesonet station MTM09 2 miles west of Moccasin measured a gust of 60 mph.
An Ambient Weather station 4 miles wsw of Geyser measured a gust of 62 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2023Every state in 2023This day in weather historyWarnings in Montana, February 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: 1071719, 1071720, 1073933, 1071721, 1071739, 1071726, 1071725, 1071731, 1073934, 1073937, 1073935, 1073936.