The continued push of Pacific moisture continued into the last 3 days of the month. Periods of snow continued to the last day of December which was the 10th consecutive day with measurable snowfall in southeast Idaho.
Every event with a place to put it; 13 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 continued push of Pacific moisture continued into the last 3 days of the month. Periods of snow continued to the last day of December which was the 10th consecutive day with measurable snowfall in southeast Idaho. Periods of very strong winds also accompanied the snow. Roads were closed on both December 30th and 31st including interstate 84 as well as US Highway 20.
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 29, 1:20 PM MST, 2 hours 40 minutes earlier.
Area Forecast Discussion National Weather Service Pocatello ID 120 PM MST Wed Dec 29 2021 .SHORT TERM...Tonight through Thursday night. WV imagery shows deep, positively-oriented longwave trough over the Western US today. A shortwave trough is seen further north in BC working its way south. Plenty of returns on radar today across the area, and observations showing widespread light snowfall across the region in the base of the longwave trough. The trough axis should push eastward late tonight while the shortwave drops into Washington state. We may get a bit of a break between systems, though some light snow may persist over the Eastern Highlands through the night. With the approach of the shortwave from the north, snow chances increase across the area, but particularly south and east of the I-86/I-15 corridors as upslope flow contributes to the higher PoPs. We're generally seeing a shadowing in the Arco Desert tomorrow on account of the broad nortwesterly flow in the mid and upper levels. Overall snow accumulation the next couple of days will range from trace in the Arco Desert to about 2 to 3 inches around the I-86/I-15 corridors in the Snake Plain. Higher elevations in the Southeastern and South Central Highlands could see around 5 to 9 inches. This has prompted us to expand the winter weather advisory a bit to include the Caribou Range and the Teton Valley and extend through 12Z Friday. Hinsberger .LONG TERM...Friday through next Wednesday. An upper level trough continues to work through southeast Idaho throughout the day on Friday, bringing continued light snow further south and east and breezy winds especially along the Idaho/Utah border. Additional snow showers will continue to linger across the higher elevations in favored upslope conditions into Saturday morning, with accumulations staying light. Snow totals Friday into Saturday will be about a T-4 inches, with highest totals confined above 7,000ft in the southern and eastern higher elevation zones. A cold front associated with that trough passing through Friday afternoon and evening will round out this very active weather period we have been under since Christmas, with partly to mostly sunny skies and colder temperatures for the New Years Weekend. Temperatures Saturday morning are still looking very cold, with lows in the Central Mountains in the negative double digits. Elsewhere, low will generally be between -10 and +10 degrees making for wind chill concerns. Even with a slight breeze, wind chills or apparent temperatures can drop dramatically so we will be keeping a close eye on that for any product issuance. After a cold weekend with highs in the teens and 20s, conditions trend much warmer as broad upper level ridging begins to work back across southeast Idaho bringing mostly zonal/southwest upper level flow back to the area with highs back in the upper 20s to low 40s by Tuesday. That upper level feature keeps things fairly dry through Monday, with continued chances for disturbances to ride along the upper extent of the ridge as shortwaves bringing light snow showers in the Eastern Highlands and northern Central Mountains. An impactful system is still on track for next week, with IVT modeled data showing values indicative of a weak atmospheric river event with scattered values of about 250-400 traversing into Idaho from the Pacific Ocean. The bulk of this moisture looks to be caught up further south but even with a weak atmospheric river event, the Central Mountains and higher terrain are favored fairly well for measuring snow in feet for accumulations. The arrival of this precipitation will be around that Monday/Tuesday timeframe and with warmer high temperatures we may begin to contend with rain mixing in at the lowest elevations. Given this storm is still on days five and six of the forecast, we will continue to track this system and provide updates as it gets closer. MacKay .AVIATION... A series of shortwaves trough continues to bring active weather across the region, with IFR CIGS/VIS currently at IDA and SUN associated with ongoing snow showers. MVFR CIGS/VIS have also begun early this afternoon at DIJ as snow showers continue to track further east. Strong downsloping winds with south gusts up to 35kts at PIH have kept precipitation confined further north of the terminal, but with slight directional change could reintroduce snow showers back to the TAF site. BYI has been contending with strong southerly winds as well, with precipitation still staying confined both north and south of the terminal. This afternoon around 23Z, a more organized band of snow is likely to develop bringing continued impacts where snow is ongoing and MVFR CIGS/VIS to PIH and BYI briefly. Winds will continue to stay elevated across the eastern Magic Valley and Snake River Plain through this evening as we are in between weather systems. There will be a low stratus cloud deck tomorrow as precipitation leaves all terminals this evening, with VCSH and possible freezing fog potential in the saturated lower layers. Ceilings look to rise at SUN this evening, however begin quickly falling with the onset of our next wave of precipitation moving in for tomorrow morning. This snow looks more organized, with all terminals likely to see MVFR/IFR impacts tomorrow afternoon and evening. MacKay && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 5 AM MST Friday for IDZ053-060-064- 066. Winter Weather Advisory from 11 AM Thursday to 5 AM MST Friday for IDZ063-065. &&
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
1012 AM MST WED DEC 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1009 AM SNOW CHESTER 44.00N 111.57W
12/29/2021 E3.5 INCH FREMONT ID TRAINED SPOTTER
OVERNIGHT ACCUMULATION.
&&
JAHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
202 PM MST WED DEC 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0200 PM SNOW 2 S SUGAR CITY 43.85N 111.75W
12/29/2021 E7.0 INCH MADISON ID TRAINED SPOTTER
24-HOUR TOTAL.
&&
JAHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
218 PM MST WED DEC 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM EXTREME COLD 1 NNE PARKER 43.97N 111.75W
12/25/2021 E25 F FREMONT ID PUBLIC
*** 1 FATAL ***
SHERIFF DEPARTMENT REPORTING A DEATH DUE TO
EXPOSURE TO PROLONGED COLD TEMPERATURES.
TEMPERATURES WERE IN THE MID 20S WITH WIND
CHILL READINGS IN THE LOW TEENS.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
239 PM MST WED DEC 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0230 PM SNOW 2 NE IDAHO FALLS 43.51N 112.01W
12/29/2021 M3.0 INCH BONNEVILLE ID CO-OP OBSERVER
ACCUMULATION SINCE 4 PM TUESDAY.
&&
JAHThe national radar mosaic for the moment the first event began.
13 winter storm. Local standard time, as filed.
The COOP observer in Bone recorded 10 inches of snow the last 3 days of the month.
Idaho Highway 47 was closed from Ashton to 2 miles north of Warm River. The COOP observer in Island Park measured 17 inches of snow through the last 3 days of the month. Extensive blowing and drifting of snow was reported.
US Highway 20 was closed from 17 miles east of Butte City to 2 miles west of Idaho Falls on the 30th. Snowfall, strong winds with blowing and drifting snow and reduced visibility was the reason for the closing.
The COOP observer in Bern measured 11 inches of snow on the 30th and 31st.
The Malad City COOP observer reported 7 inches of snow on the 29th and 30th.
The Inkom COOP observer reported 9 inches of snow on the 30th and 31st.
Interstate 84 was closed from 10 miles east of Heyburn to the Utah border due to snow and blowing and drifting snow reducing visibility on the 31st.
The COOP observer at Richfield recorded 6 inches of snow on the 30st and 31st.
Idaho Highway 47 was closed from Ashton to 2 miles north of Warm River. on the 30th 8 to 10 inches of snow was measured 8 miles north northeast of Tetonia with 7 inches in Driggs.
Idaho Highway 33 was closed from Newdale to Tetonia and US Highway 20 was closed from 17 miles east of Butte City to 2 miles west of Idaho Falls on the 30th due to heavy snowfall and strong winds causing blowing and drifting snow with reduced visibility. Snowfall amounts were the following: 7 inches 5 miles south southwest of Osgood, 5 inches Menan, 7 inches Rigby, 10 inches St Anthony, and 8 inches Sugar City.
Interstate 84 was closed on the 31st from 10 miles east of Heyburn to the Utah border due to reduced visibility in blowing and drifting snow and snowfall. Minidoka COOP reported 4 inches of snow on the 30th and 31st.
A spotter measured 10.5 inches of snow 4 miles west of Victor.
Four to 7 inches of snow fell in the Pocatello/Chubbuck area on the 30th and 31st.
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: 1000056, 1000057, 1000054, 1000055, 1000059, 1000062, 1000064, 1000066, 1000068, 1000073, 1000058, 1000161, 1000060.