Between late evening of February 8th and late morning of the 9th, an Arctic cold front moved from near the I-90 corridor in western and southwest Montana to a position extending southeastward from northwestern Idaho to east-central Idaho. Behind this front, a strong Arctic high pressure ridge settled southward across north-central and southwest Montana.
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.
Between late evening of February 8th and late morning of the 9th, an Arctic cold front moved from near the I-90 corridor in western and southwest Montana to a position extending southeastward from northwestern Idaho to east-central Idaho. Behind this front, a strong Arctic high pressure ridge settled southward across north-central and southwest Montana. This ridge was accompanied by a tight surface pressure gradient, especially over southwest Montana and along the Rocky Mountain Front. The tight pressure gradient resulted in breezy surface winds. In turn, the combination of these winds and frigid temperatures yielded warning-criteria wind chills for parts of the area.
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 9, 4:50 AM MST, 1 hour 27 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 450 AM MST Sat Feb 9 2019 ...UPDATED AVIATION SECTION... .SYNOPSIS... Temperatures will remain below zero today for all but a few locations across Montana. Areas of light snow continue today as Pacific moisture lifts over the bitter cold air. Breezy winds gusting to around 35 mph are producing areas of blowing snow and dangerously cold wind chill temperatures. Snow becomes more widespread tonight through Sunday across Southwest Montana. Expect the very cold temperatures to continue through next week, along with additional periods of snow. && .DISCUSSION... Light snow continues today across much of our region as Pacific moisture ascends over the Arctic airmass where surface temperatures have fallen well below zero. Snowfall may start and stop today as the atmosphere becomes more stable and the low level northerly flow weakens. Overall snow amounts have been a bit lower than originally forecast due to lower than expected snow ratios associated with the lack of dendrite production. The cold front marking the leading edge of this airmass has advanced all the way down to the MT/ID border. Pressure rises over central Montana are producing wind gusts of 25 to 35 mph. The combination of bitter cold temperatures with these locally windy conditions are creating dangerous wind chill values as low as 30 to 45 degrees below zero. The Wind Chill Advisory remains in effect. The Winter Storm Warning that had been in effect for the Rocky Mountain Front has been downgraded to a Winter Weather Advisory. New snowfall amounts in this area are expected to remain less than around one inch, and impacts from blowing snow have not been overly significant. The next minor shortwave trough crosses the region late tonight. This will resume or expand areas of light snow from Southwest up through central Montana. Snow will dissipate over North-central Mt by early Sunday, but with temperatures dropping below minus 20 for many locations. Higher snow totals will occur over far Southwest Montana. The additional snow combined with the potential for blowing snow in gusty winds warrants and new Winter Weather Advisory later today through Sunday. Temperatures remain cold going into Monday as areas of snow return with a passing upper level trough. Longer range model guidance suggests that temperatures will remain well below average with periods of snow through mid- to late in the week. Temperatures may begin to moderate slightly by the end of the week. && .AVIATION... Updated 450 AM MST Sat Feb 9 2019 MVFR/IFR conditions with mountain obscuration in clouds and snow will gradually improve to low VFR/high MVFR between 15Z and 21Z with areas of light snow. A disturbance will then bring another round of MVFR/IFR conditions in snow will then move to southwest Montana between 23Z and 05Z and to central/north central Montana between 02Z and 12Z. Coulston && .CLIMATE... Temperatures at the Cut Bank Municipal Airport (ASOS ID KCTB) have not been above zero since Saturday February 2nd. This puts the period of consecutive below-zero days at six as of midnight Friday night, which ties the 15th longest streak all-time with eight other such streaks from the 1920s through 1980. The current forecast has temperatures staying below zero there for at least the next two days, and possibly the next three. Eight days would tie for the 8th longest streak (the most recent occurrence started on November 25th, 1985), while nine days would make it tied for 5th (the most recent occurrence started on December 21st, 1996). (Records kept there since 1903.) The Havre City-County Airport (ASOS ID KHVR) has been below zero since Monday February 4th, putting their run at five days as of midnight Friday night. This only ranks as tied for the 39th longest streak of below-zero days, but similar to Cut Bank, two or three more days of similar conditions are being forecast. A seven-day stretch would be tied for 18th longest all-time, while an eight-day stretch would tie for 16th. (Records kept there since 1880.) && .PRELIMINARY POINT TEMPS/POPS... GTF -8 -21 -4 -14 / 90 80 30 30 CTB -11 -26 -7 -19 / 90 60 30 10 HLN -3 -18 8 -7 / 80 60 20 30 BZN 7 -12 14 -3 / 60 70 20 40 WEY 22 5 24 -2 / 70 90 90 70 DLN 13 -4 23 0 / 70 80 40 20 HVR -5 -17 -3 -14 / 100 100 50 30 LWT -6 -19 3 -11 / 80 70 30 30 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 11 PM MST this evening Blaine... Cascade...Central and Southern Lewis and Clark...Chouteau... Eastern Glacier...Eastern Pondera...Eastern Teton...Fergus... Hill...Judith Basin...Liberty...Northern Rocky Mountain Front... Southern Rocky Mountain Front...Toole. Wind Chill Advisory until 2 PM MST Sunday Beaverhead...Blaine... Broadwater...Cascade...Central and Southern Lewis and Clark... Chouteau...Eastern Glacier...Eastern Pondera...Eastern Teton... Fergus...Gallatin...Hill...Jefferson...Judith Basin...Liberty... Madison...Meagher...Northern Rocky Mountain Front...Southern Rocky Mountain Front...Toole. Winter Weather Advisory from 2 PM this afternoon to 5 PM MST Sunday Beaverhead...Gallatin...Madison. && http://www.weather.gov/greatfalls
9 extreme cold/wind chill. Local standard time, as filed.
Pendroy MT DOT station recorded -43F wind chill with 22 mph sustained wind. Location: 2-miles SW of Pendroy.
Sweet Grass MT DOT station recorded -41F wind chill with sustained wind of 16 mph. Location: 6-miles NNW of Sunburst.
Two Medicine Bridge MT DOT station recorded -42F wind chill with 14 mph sustained wind. Location: 1-mile ENE of East Glacier.
Hays MT DOT station recorded -41F wind chill with sustained wind of 24 mph. Location: 3-miles WSW of Hays.
MacDonald Pass MT DOT station recorded -53F wind chill with 24 mph sustained wind. Location: 12-miles S of Marysville.
Boulder Hill MT DOT station recorded wind chill of -41F with sustained wind of 16 mph. Location: 2-miles SE of Wickes.
Cut Bank Airport ASOS recorded -42F wind chill with sustained wind of 21 mph. Location: 3-miles SW of Cut Bank.
Browning MT DOT station recorded -42F wind chill with sustained wind of 16 mph. Location: 2-miles SE of Browning.
Citizen Weather Observer Program (CWOP) station recorded wind chill of -41F accompanied by sustained wind of 25 mph. Location: 2-miles NNW of Joplin.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2019Every state in 2019This day in weather historyWarnings in Montana, February 2019
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: 802248, 802244, 802247, 802243, 802249, 802242, 802246, 802245, 802241.