Arctic air pushed across the Continental Divide into western Montana and central Idaho. Temperatures well below zero were experienced, along with dangerously cold wind chills.
Every event with a place to put it; 1 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 MSO wrote it up.
Arctic air pushed across the Continental Divide into western Montana and central Idaho. Temperatures well below zero were experienced, along with dangerously cold wind chills.
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 Missoula, MT wrote its last area forecast discussion before the first event at Feb 22, 2:56 AM MST, 4 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
256 AM MST Wed Feb 22 2023
.DISCUSSION...With a strong pressure gradient in place and not
expected to budge over the next 24 to 48 hours (at least), gusty
east to northeasterly winds will continue across western Montana
and north central Idaho. In addition, with such cold ambient
temperatures in place thanks to our resident Arctic airmass, wind
chill values today and Thursday will be dangerous for locations
along the Continental Divide and for all higher
terrain/backcountry areas. Wind chill values of -40 to -50
degrees have been occurring in some parts of northwest Montana
terrain already this morning, with the likelihood that this will
continue into Thursday as well.
In fact, many forecast models suggest that the blustery winds and
resultant cold wind chills could persist through the bulk of the
day Friday. As such, additional Wind Chill Warnings and/or
Advisories may need to be issued in the future, so please stay
tuned to all forecast updates. This is a critical time period for
humans and animals alike, so take precautions now and do your part
to protect those most vulnerable to the winds and cold.
By Saturday, temperatures will begin to moderate to warmer
values. As we head into Sunday and the beginning of next week,
high temperatures across the Northern Rockies will be very close
to normal (upper 30s).
The next round of precipitation to impact our region looks to be
late Sunday into Monday, with west to northwesterly flow and
continued unsettled weather likely through the first half of the
week.
&&
.AVIATION...Gusty east to northeasterly winds will plague most
aviation terminals throughout the day today and into tonight.
Persistent gusts to 30 knots will be common. Lingering light
snowfall may continue at KBTM through the day as well, with
periodic reductions in visibility from snowfall and blowing snow.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT... Wind Chill Advisory until 5 PM MST this afternoon for
Kootenai/Cabinet Region.
Wind Chill Warning until 5 PM MST this afternoon for West
Glacier Region.
Wind Chill Warning until 5 PM MST this afternoon for
Flathead/Mission Valleys.
Wind Chill Advisory until 5 PM MST this afternoon for Lower
Clark Fork Region.
Wind Chill Advisory until 5 PM MST this afternoon for
Bitterroot/Sapphire Mountains...Missoula/Bitterroot
Valleys.
Wind Chill Warning until 5 PM MST this afternoon for
Butte/Blackfoot Region...Potomac/Seeley Lake Region.
ID...Winter Weather Advisory until 8 AM PST this morning for Northern
Clearwater Mountains...Southern Clearwater Mountains.
Winter Weather Advisory until 8 AM PST this morning for Lower
Hells Canyon/Salmon River Region...Orofino/Grangeville
Region.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
950 PM MST TUE FEB 21 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0949 PM HEAVY SNOW 2 N CHARLOS HEIGHTS 46.16N 114.18W
02/21/2023 E6.0 INCH RAVALLI MT PUBLIC
OVER 3 HOURS. STILL SNOWING.
&&The national radar mosaic for the moment the first event began.
1 cold/wind chill. Local standard time, as filed.
The lowest wind chill values observed ranged between -20F and -30F.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2023Every state in 2023This day in weather historyWarnings in Idaho, 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: 1081290.