The passage of a cold front brought extremely strong winds with gusts over 60 mph with most of the impacts and damage occurring in the Snake River Plain.
Every event with a place to put it; 4 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 PIH wrote it up.
The passage of a cold front brought extremely strong winds with gusts over 60 mph with most of the impacts and damage occurring in the Snake River Plain.
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 13, 3:29 PM MST, 9 hours 31 minutes earlier.
Area Forecast Discussion National Weather Service Pocatello ID 329 PM MST Mon Dec 13 2021 ...LONG DURATION WINTER STORM CONTINUES, POTENTIAL FOR TRAVEL IMPACTS TO FINALLY ARRIVE IN THE SNAKE PLAIN AND SOUTHERN AND EASTERN HIGHLANDS TUESDAY... .SHORT TERM...TODAY THROUGH TUESDAY NIGHT... The final 36 hours of this 4-day winter storm has arrived! The core trough of low pressure is moving onshore along the Pacific coast, and will cross our region with a cold front Tue. For the main impact corridor from the Sawtooths and Wood River Valley, NE across Arco and the srn Central Mntns, NE into Clark and Fremont Counties, periods of snow will continue into Tue afternoon/eve for most, but into Wed AM for the Island Park region and Big Holes, with additional accums ranging anywhere from 3 inches to another 1-2 feet (see our latest WINTER STORM WARNING and WINTER WEATHER ADVISORY products for details, which have been extended again). We saw no overwhelming reason to downgrade any of the warning zones to advisories at this time. Nearly all snow is expected for this corridor, along with strong winds resulting in areas of blowing snow. Further south, confidence is slowly/cautiously increasing in storm impacts finally arriving across the ern Magic Valley, Snake Plain, and srn/ern highlands Tue. Winds will be noticeable first, increasing early Tue AM with gusts of 40 to 55 MPH through the day, strongest from Cassia County south of Burley, NE across the lower Snake Plain and adjacent highlands, and also at many peaks/ridges across the region. Deterministic NBM guidance and even the GFS/EC ensembles continue to run on the low side for winds, but 700mb flow now exceeds 50kts across GFS/ECMWF/Canadian/HRRR guidance as a strong low-mid level jet continues to wrap around and up the leading side of the trough, and newly calibrated NBM/HREF winds also advertise gusts over 50 MPH in this zone. Thus, even if the low levels aren't terribly unstable, we have a hard time envisioning some of this wind will not mix down to the sfc. Light rain/snow showers are possible during the AM, but snow-related impacts will likely hold off for most until after 1 PM in the mntns, and after 2- 3 PM in the Snake Plain/valleys where high temps may reach the low 40s, thus precip ahead of the cold front will begin as rain. The 2 PM to 6 PM window is our greatest concern, as a strong cold front blasts across the region. We believe temps are likely to rapidly drop 10+ degrees in 1-2 hours, potentially resulting in a flash freeze on roadways and precip changing to all snow. One of our greatest sources of forecast uncertainty over the past couple days has been the timing of the front, and exactly how much precip precedes the front (mostly rain) vs. follows the front (mostly snow). Our confidence in frontal timing is slowly increasing...arriving in Burley between 2 PM and 5 PM, and Pocatello/Idaho Falls between 3 PM and 6 PM. Model simulated precip/reflectivity looks to somewhat "bisect" the front, with at least some mixed rain/snow ahead of it and at least some snow behind it (southerly downsloping may continue to really mitigate that pre- front precip potential for the Lower Snake Plain). The high-res HREF members advertise a solid, impressive round of snow behind the front for at least a couple hours, resulting in a coating to 2 inches for Burley, 1-3 inches for Pocatello (with locally higher amounts on the benches) and many srn/ern highland valleys, 1-2 inches for Idaho Falls, and 4-9 inches across most of the srn/ern highlands above about 5,500 feet (higher totals in the Bear River Range) by early Wed AM. Finally, in addition to the flash freeze and snow accum potential, weak instability coupled with strong frontogenical forcing, strong flow becoming increasingly perpendicular to the front, and snow squall parameter values greater than 1 do suggest there may be at least some modest snow squall potential along the front, which could result in rapid/sudden drops in visibility and dangerous/icy road conditions. Instead of complicating our messaging with multiple different headlines for wind and snow, we decided to cover ALL hazards under a WINTER WEATHER ADVISORY (WINTER STORM WARNING in the Bear River Range). These alerts start early Tue AM to capture the strong winds (driving may be difficult for high profile vehicles), although again snowfall impacts don't arrive until after 1-3 PM. If the forecast pans out as outlined above, we certainly may be seeing some significant travel impacts during the Tue eve commute, including in the lower Snake Plain. Stay tuned. - KSmith .LONG TERM...WEDNESDAY THROUGH NEXT MONDAY... The cold front that moved through the short term period will leave in place much colder temperatures to start off Wednesday, with widespread lows in the single digits to low 20s. High temperatures through at least Monday of next week stay slightly below normal for this time of year with highs below or around freezing each day. Lingering snow showers will continue throughout the day Wednesday in the Eastern Highlands and along the Idaho/Wyoming border ahead of our next system, with accumulations around 1-2 inches. Looking at the remainder of the week, there are two separate systems in the extended forecast with one right on the backside of the early week system. A break in the action is expected for much of the forecast area Wednesday, with our first system inbound in the form of a positively tilted upper level trough. This system brings snowfall across nearly the entire forecast area through Friday morning, with possible winter needed headlines for the Southeast Highlands. The one major exception to this is around the Big Lost River Valley and Mud Lake Region, where accumulations stay below 2 inches. Lower elevations below 7,000ft elsewhere are looking at about 2-5 inches with highest amounts in the southern portion of the forecast area. For the mountains, about 6-12" is likely above 7,000ft for the Southern Hills, Southeast Highlands, and Eastern Highlands with about 4-8" in the western portions of the Central Mountains. The orientation of this system looks to keep the bulk of the snowfall further west of the Sawtooth NF and just outside our forecast area. A look towards the second system has it arriving around that late Saturday early Sunday into Monday timeframe as again a widespread snow event, with the GFS trending towards a wetter solution over the ECMWF. Beyond Monday, the forecast looks to stay active with a favorable jet stream environment bringing more systems on the way. - MacKay && .AVIATION... Mixed bag of aviation impacts are expected over the next 24-36 hours across East Idaho. Moderate snowfall continues over the central mountains through Tuesday at KSUN with IFR and occasional LIFR. KDIJ also expected to see periods of mainly light VFR/MVFR snow with occasional IFR ceilings. The three Snake Plain terminals are expected to remain VFR/MVFR overnight tonight, though that may occasionally mix with IFR at KIDA as weak waves of very light precipitation move through. Expect mostly -RA at KBYI, mix of -RA/- SN and occasional -IP at KPIH, and -SN at KIDA. Later today, expect winds above the surface to increase significantly, leading to wind shear concerns at all terminals except KSUN, with winds at the top of the shear layer reaching or exceeding 50kts at KPIH overnight into the day Tuesday. Cold front passage late in the day Tuesday expected to bring snow levels down to the valley floor for all locations, and shifting focus to the Snake Plain terminals and KDIJ and an increase in conditions with winds shifting to the west for KSUN after 18Z. Expect worsening ceilings for KBYI/KPIH/KIDA/KDIJ as snowfall begins, with an expected decrease in wind shear conditions associated with passage of the front. - DMH && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 5 AM Tuesday to 5 AM MST Wednesday for IDZ053>059-061>063-065. Winter Storm Warning until 9 PM MST Tuesday for IDZ067-069- 072>075. Winter Weather Advisory until 9 PM MST Tuesday for IDZ051-052- 068-071. Winter Weather Advisory until 5 AM MST Wednesday for IDZ064. Winter Storm Warning until 5 AM MST Wednesday for IDZ066. Winter Storm Warning from 5 AM Tuesday to 5 AM MST Wednesday for IDZ060. &&
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
808 PM MST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0759 PM HEAVY SNOW 2 W KETCHUM 43.69N 114.42W
12/13/2021 M9.0 INCH BLAINE ID MESONET
BALDY SNOW SNAKE FROM SUN VALLEY SKI RESORT, 24 HR TOTAL
ENDING AT 4 PM TODAY
0759 PM HEAVY SNOW 2 W KETCHUM 43.69N 114.42W
12/13/2021 M9.0 INCH BLAINE ID MESONET
24 HR SNOW ENDING AT 4 PM. TAKEN FROM SUN VALLEY RESORT
SNOW STAKE.
&&
TWYATTSpecial Weather Statement
National Weather Service Pocatello ID
925 PM MST Mon Dec 13 2021
IDZ054>058-141015-
Eastern Magic Valley-Marsh and Arbon Highlands-Raft River
Region-Southern Hills/Albion Mountains-Lower Snake River Plain-
925 PM MST Mon Dec 13 2021
...GUSTY Downslope Winds Along the I-86 Corridor...
The stronger gusty southerly downslope winds have started a little
earlier. Southerly wind gusts of 35 to 45 mph are currently
occurring along the I-86 corridor from Pocatello to Burley including
Yale on I-84. Expect 35 to 45 mph gusts with periods of wind gusts
up to 50 to 55 mph through the evening into tomorrow afternoon
before a cold front moves through the area.
Locations impacted include...
Pocatello, Burley, Rupert, American Falls, Heyburn, Neeley, Lake
Walcott, American Falls Reservoir, Chubbuck, Paul, Declo, Cold Water
Rest Area, Fort Hall Buffalo Lodge, Fort Hall Townsite, Fort Hall
Bannock Creek Lodge, Pocatello Airport, Acequia, Yale Rest Area,
Massacre Rocks and Interstate 84 And 86 Junction.
LAT...LON 4250 11361 4247 11394 4253 11395 4254 11393
4265 11393 4271 11336 4310 11246 4289 11234
4242 11334
TWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
1028 PM MST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1028 PM HEAVY SNOW 10 NE GANNETT 43.45N 114.04W
12/13/2021 M14.0 INCH BLAINE ID PUBLIC
NEAR LITTLE WOOD RESERVOIR. REPORTED VIA
SOCIAL MEDIA.
&&
JKEYESThe national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
Several 50 to 55 mph wind gusts were measured along interstate 84 between Burley and the Utah border.
A 59 mph wind gust was measured at the Burley airport. Widespread gusts of over 50 mph occurred through the morning of the 14th.
A 68 mph wind gusts occurred at the Pocatello Regional airport. In the Pocatello region extensive damage occurred with several downed trees...one on top of a car with a passenger in it causing injury. One tree went through a roof. Multiple signs of businesses were blown over, several power lines downs with multiple power outages. Roofs and shingles were blown off buildings.
Eight-hundred customers were without power in McCammon. A power pole was downed in Lava Hot Springs with 1,200 customers without power.
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: 999594, 999597, 999583, 999588.