Extremely heavy snow fell in high elevations mainly over an extended period with the brunt of it on the 13th and 14th. Some localized amounts of over 30 inches were recorded.
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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 PIH wrote it up.
Extremely heavy snow fell in high elevations mainly over an extended period with the brunt of it on the 13th and 14th. Some localized amounts of over 30 inches were recorded.
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 Pocatello, ID wrote its last area forecast discussion before the first event at Dec 11, 4:47 AM MST, 2 hours 13 minutes earlier.
Area Forecast Discussion National Weather Service Pocatello ID 447 AM MST Sat Dec 11 2021 .SHORT TERM...Today through Monday night. Strong atmospheric river event moves into the region today. Already seeing light radar returns across the central mountains and also over by the Tetons this morning. Snowfall should pick up in intensity and remain limited today to the Sawtooth and Wood River regions along with the upper Snake highlands. An enhanced surge of moisture will arrive tonight. This will help increase snow rates in those areas and spread snow into other areas of eastern and central Idaho including the Magic Valley and Snake Plain. Warnings and advisories are in effect for the heavy snow areas and we'll get to those totals shortly. Outside of the warning and advisory areas, generally looking at an inch or less of snow. This surge of moisture exits the region Sunday leaving light to moderate snow rates across the central mountains into the upper Snake highlands through much of the day. Another surge of moisture arrives late Sunday night and Monday producing moderate to heavy snow once again over the warning and advisory areas. Light snow will remain possible elsewhere. Snow totals in the warning area above 7000 feet continue to look very impressive with 2 to 3 feet likely, and perhaps approaching 4 feet in some areas. In the valleys, generally looking at 8 to 20 inches. Even in the advisory areas, several inches are possible with the potential for up to 12 inches of snow in some locations. Gusty winds are also likely through the event, so blowing and drifting snow is a distinct possibility. 13 .LONG TERM...Tuesday through next Saturday. We currently have a Winter Storm Warning and Winter Weather Advisory issued through Tuesday for the Sawtooths, Wood River, and Upper Snake Highlands areas. Tuesday brings more widespread concern for the region, extending additional accumulations into the lower elevations. Both the GFS and ECMWF have the PNW trough reaching the west coast on Tuesday, bringing an associated cold front to the region during the afternoon/evening. By this time, significant accumulations will also be a possibility across the Snake Plain and Magic Valley, considering the cooler temperatures and upslope flow behind the front. The majority of our QPF for the Snake Plain/Magic Valley during this timeframe is currently forecasted following the cold front passage, making several inches Tuesday and Wednesday a real possibility for these areas. However, there is still a lot of uncertainty considering the timing of the precipitation and cold front passage, and keeping in mind the warm air in place ahead of the front. Cold temperatures and winds will likely be major concerns across the Snake Plain. If we see precipitation fall ahead of the front, falling temperatures could result in a flash freeze and icy road conditions. Strong winds will likely result in widespread blowing snow. Wednesday forward looks to be drier across the region, but we could still see lingering precipitation that may be impactful considering temperatures will generally continue to fall through the end of the week. Cropp && .AVIATION...Expect vfr conditions today at PIH, IDA and BYI with breezy conditions developing by afternoon. deteriorating conditions likely at SUN with snow and IFR ceilings/visibilities likely by 06z. VCSH likely throughout the day at DIJ with low vfr ceilings mostly. Brief period of IFR through 13z possible as light snow departs area. 13 && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 8 PM this evening to 5 AM MST Tuesday for IDZ051-052-064-067-068. Winter Storm Warning from 8 PM this evening to 5 AM MST Tuesday for IDZ066. Winter Weather Advisory from 11 AM this morning to 5 AM MST Tuesday for IDZ069-071. Winter Storm Warning from 11 AM this morning to 5 AM MST Tuesday for IDZ072>075. &&
Special Weather Statement National Weather Service Pocatello ID 431 AM MST Sat Dec 11 2021 IDZ053>063-065-070-112100- Upper Snake River Plain-Lower Snake River Plain- Eastern Magic Valley-Southern Hills/Albion Mountains- Raft River Region-Marsh and Arbon Highlands- Franklin/Eastern Oneida Region-Bear River Range-Bear Lake Valley- Blackfoot Mountains-Caribou Range-Teton Valley- Challis/Pahsimeroi Valleys- Including the cities of Idaho Falls, Rexburg, St. Anthony, Pocatello, Blackfoot, American Falls, Shelley, Fort Hall, Burley, Rupert, Heyburn, Oakley, Albion, Almo, Malta, Rockland, Holbrook, Inkom, McCammon, Downey, Lava Hot Springs, Malad, Preston, Thatcher, Emigration Summit, St. Charles, Montpelier, Georgetown, Grace, Soda Springs, Henry, Bone, Wayan, Swan Valley, Ashton, Tetonia, Driggs, and Challis 431 AM MST Sat Dec 11 2021 ...Strong cold front arrives Tuesday... A cold front to move through the area Tuesday into Wednesday. There is still uncertainty on the exact timing. This cold front will bring mostly moderate snowfall amounts to the area, including some valley areas. Warmer temperatures ahead of the front may produce rain for the Snake Plain and the valleys of southeast Idaho. Icy conditions could result as temperatures quickly fall behind the front. Also, low visibilities and blowing snow is possible.
The national radar mosaic for the moment the first event began.
7 heavy snow. Local standard time, as filed.
AS much as 26 to 32 inches of snow was reported in Sun Valley and Ketchum.
Ten to 12 inches of snow was recorded by multiple observers in Bellevue with 17 inches recorded by multiple sources in Hailey.
Heavy snow fell in the Sawtooth region with the Stanley COOP observer reporting 13 inches and the public reporting 32.5 inches 14 miles west northwest of Stanley.
Very heavy snow reported by the public and spotters with the following amounts: 4 miles north northwest of Darlington 20 inches, Moore 18 inches, Mackey 16 inches, Darlington 15 inches and Mackay 14 inches.
The Island Park COOP observer recorded 30 inches of snow with 14 inches 14 miles north northwest of Macks Inn.
The COOP observer at Dubois measured 11 inches of snow and the one 6 miles north of Small measured 18 inches.
Heavy snow fell with 8.5 inches at the Preston COOP site, 8.5 inches at the Malad City COOP site, with 9 to 10 inches reported at Preston via the public and cocorahs.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2021Every state in 2021This day in weather historyWarnings in Idaho, December 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: 999617, 999601, 999671, 999672, 999674, 999678, 999684.