A tightened pressure gradient along the Rocky Mountain Front caused strong winds to develop and become gusty. The strongest winds occurred along the Northern Rocky Mountain Front.
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.
A tightened pressure gradient along the Rocky Mountain Front caused strong winds to develop and become gusty. The strongest winds occurred along the Northern Rocky Mountain Front.
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 Jan 21, 10:38 PM MST, 2 hours 22 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 1038 PM MST Wed Jan 21 2015 Updated Aviation .UPDATE... Tonight...An upper level high pressure ridge will keep the airmass dry tonight. A shortwave moving into the ridge across the Pacific Northwest will keep a tight surface gradient across the lee of the Rockies. Brisk winds will continue through the night and keep mild across the plains. Clear skies and light winds will bring another night over very cold temps in the valleys of Southwest Montana. Zelzer && .AVIATION... UPDATED 0600Z. Moist northwest flow aloft will shift westerly with increasing high clouds overnight and mid-level clouds by tomorrow afternoon. Westerly winds will also increase and become gusty along the Rocky Mountain Front tonight and spread into the plains Thursday. Wind gusts of 35 to 45 kts are possible at KCTB and KGTF tomorrow afternoon with higher gusts over the Rocky Mountain Front. As an upper-level shortwave approaches Thursday evening, mountains will become obscured and showers will be possible in higher terrain along the Continental Divide. Have added VCSH to KHLN after 00z Friday. Increased mountain wave activity is also possible on Thursday, however VFR conditions will prevail at all sites over the next 24 hours. MLV && .PREV DISCUSSION... /ISSUED 430 PM MST Wed Jan 21 2015/ Tonight through Saturday...An upper level ridge of high pressure centered just inland of the West Coast will gradually expand further inland over the next several days. Temperatures will progressively warm over the next several days under a generally dry and stable N-NW flow aloft. At the surface, high pressure will remain anchored over areas west of the continental divide through the remainder of this week. Low pressure developing east of the Canadian Rockies tonight will bring increasing surface winds to north central MT tonight, which will continue breezy to windy at times through Friday. Strongest winds look to occur Thursday morning along the east slopes of the Rockies where the pressure gradient may be strong enough to produce some isolated gusts in excess of 50 mph through favored passes and and along the immediate front range. A very weak weather disturbance embedded within the NW flow aloft will pass SE across the region Thursday night, mainly bringing a period of cloudiness, with just some light snow showers possible across the Rockies and a few flurries/sprinkles further east across the plains Thursday night. Hoenisch Friday Night through Wednesday...Moisture increases from the west northwest Friday and a trough moves across Central Montana and the Continental Divide during the day Saturday. Precipitation chances climb across Central Montana but the system moves through fairly quickly suggesting most places will not see much in quantity. Precipitation looks to be rain at lower elevations and snow in the mountains. Summer-like high pressure over the west coast builds north late Sunday helping push most moisture out of the region for Monday and Tuesday. The pattern holds into Wednesday as moisture from a low pressure system in Mexico moves north through the Western U.S. and into Southwest Montana Wednesday afternoon. West-southwest winds across much of the region look to remain brisk in the 15 to 20 MPH range throughout the period. High temperatures remain well above seasonal averages with many locations near 50 this coming weekend. && .PRELIMINARY POINT TEMPS/POPS... GTF 26 44 30 45 / 0 0 10 0 CTB 23 42 25 43 / 0 0 10 0 HLN 15 35 21 39 / 0 0 10 10 BZN 8 33 18 38 / 0 0 10 10 WEY -7 26 5 31 / 0 0 10 10 DLN 14 38 21 43 / 0 0 10 0 HVR 21 41 25 43 / 0 0 10 0 LWT 17 45 25 43 / 0 0 10 0 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && weather.gov/greatfalls www.twitter.com/NWSGreatFalls www.facebook.com/NWSGreatFalls
6 high wind. Local standard time, as filed.
High wind gusts, measured at 60KT (69MPH), were reported 1 mi E of East Glacier Park, MT at the Two Medicine Bridge DOT sensor.
High wind gusts, measured at 62KT (71MPH), were reported 13 mi W of Bynum, MT at the Dellwo sensor.
High sustained winds, measured at 38KT (44MPH), were reported 3 mi SW of Cut Bank, MT at the Cut Bank airport ASOS.
High sustained winds, measured at 35KT (40MPH), were reported 8 mi WNW of Whitlash, MT.
High wind gusts, measured at 51KT (59MPH), were reported 29 mi SE of Lewistown, MT.
High wind gusts, measured at 50KT (58MPH), were reported 2 mi SSE of Geyser, MT at the Geyser DOT sensor.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2015Every state in 2015This day in weather historyWarnings in Montana, January 2015
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: 552780, 552781, 552782, 552783, 552786, 552784.