More snow and wind gusts closed many roads in the Upper Snake River Highlands again on the 19th and 20th of February.
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.
More snow and wind gusts closed many roads in the Upper Snake River Highlands again on the 19th and 20th of February.
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 Feb 19, 1:17 PM MST, 4 hours 43 minutes earlier.
Area Forecast Discussion National Weather Service Pocatello ID 117 PM MST Fri Feb 19 2021 .SHORT TERM...Tonight through Sunday night. We're sitting in the warm sector this afternoon with a few isolated snow showers still drifting through the region. A cold front will arrive Saturday morning. In advance of that front, expect to see showers increase tonight. The eastern highlands still looks like they receive the best snowfall amounts tonight into tomorrow morning. But, the model qpf has picked up on the showery nature of tonight's event and as a result the forecast snowfall amounts have gone down in the valleys but remain reasonably high near pass level. As mentioned in yesterday's discussion, expect snowfall tonight to be feast or famine. Where the heavier bands/showers set up will see the more impressive amounts but some areas will see very little. With that said plan on expanding the advisory in the eastern highlands to include the Ashton Hill to Island Park stretch. Expect winds to increase late tonight into tomorrow morning which may produce some blowing and drifting issues across the eastern highland areas. Snow amounts look less in the Snake Plain south of Rexburg where too much warm air will work in resulting in an inch or less of snow. The central mountains from Bellevue up to Stanley should see 1 to 3 inches with an inch or less expected for the remainder of the central mountains. Light snow showers may persist across the high country through the weekend as we remain in the moist northwest flow. But amounts look fairly light. Temperatures in the forecast may be too warm for Sunday as the models may not be fully accounting for current snowpack. 13 .LONG TERM...Monday through next Friday night. Deterministic and ensemble guidance remain in solid agreement through Friday before some differences emerge. Overall, the forecast has changed little through this time. Moist northwest flow is expected to remain in place through Monday evening, maintaining high-elevation snow showers, with local enhancement on northwest-facing slopes. Winds will increase through the day, with a modest warm-up favored for the downslope corridor across the southern Snake Plain from Burley to Blackfoot, where highs in the 40s may be achieved. A strong cold front will then swing through the area Tuesday morning, bringing a chance for snow showers to the Snake Plain and eastern Magic Valley. Combined with gusty winds and falling temperatures, this remains a period where travel could get a bit dicey. Moist northwest flow will once again become re-established by late Tuesday/early Wednesday across the region in the face of low-level cold advection. Snow showers will once again be favored for mainly high-terrain areas with some local northwest-facing slope enhancement. Breezy conditions will likely remain, especially across the southern Snake Plain. High elevation snow showers should gradually taper off through the day Wednesday as shortwave ridging gradually builds in. Pattern recognition and WPC clusters indicate there is some potential for temperatures to be a bit colder than currently forecast in the Tuesday night-Wednesday night period -- especially for typical cold spots where cold air drains/pools. By Thursday, another low pressure system is seen approaching from the west, and current indications suggest precipitation will develop from west to east across the region by late Thursday. This system bears some resemblance to our Tuesday system, with cold, moist northwest flow expected to re-develop in its wake by Friday-Saturday. There remain some differences in the strength and timing of trailing troughing that is expected to develop across the Great Basin in this system's wake, so future adjustments to precipitation timing, coverage and temperatures are possible during this period. AD && .AVIATION...The aviation forecast through the period will be challenging. To start things off this afternoon, freezing drizzle and associated IFR CIGs has developed where mid-level moisture has stripped away across the northern Snake Plain. This has impacted the KIDA terminal this afternoon. High-resolution guidance suggests this may continue through the 22-00Z timeframe. MVFR stratus remains in place at KPIH and KDIJ -- and this may linger through a similar timeframe, and possibly beyond. A shortwave trough will zip east across the region tonight, bringing a round of showers to area terminals tonight. Due to the spotty nature of this activity, have timed the start and end of this activity using a high-resolution ensemble blend, which places the most likely timeframe for showers generally between 02-09Z across the area. It is possible for showers to begin earlier than this (especially KBYI) and end later than this (especially KDIJ). Went with a blanket MVFR predominant group, but given the expected spotty/convective nature of the activity, there will be times with VFR conditions overnight interspersed with periods of IFR conditions, with briefly worse conditions possible under the heavier showers. Will need to address this with TEMPOs and amendments as necessary tonight. IFR or MVFR stratus is then expected to build across the Snake Plain after the passage of the shortwave disturbance, mainly after 09Z. A weak Snake Plain convergence band is then expected to spread a renewed round of SNSH activity across KIDA, KDIJ and possibly as far south as KPIH during the mid-morning hours. Gusty W/SW winds will develop after the passage of the shortwave trough as well, with winds expected to increase into the 15-25kt range with occasionally higher gusts through the day. AD && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 6 PM this evening to noon MST Saturday for IDZ060-063>066. &&
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
524 PM MST FRI FEB 19 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0130 PM AVALANCHE 7 W KETCHUM 43.69N 114.52W
02/19/2021 BLAINE ID BROADCAST MEDIA
*** 1 FATAL *** A SNOWMOBILER WAS KILLED IN AN AVALANCHE
IN THE SMILEY CREEK DRAINAGE, ABOUT 8 MILES SOUTHWEST OF
GALENA SUMMIT. TIME OF THE AVALANCHE IS ESTIMATED.
&&
MCKAUGHANThe national radar mosaic for the moment the first event began.
3 winter storm, 1 avalanche. Local standard time, as filed.
Idaho Highway 47 was closed from Ashton to north of the Warm River Area. Wind gusts of 30 to 40 mph caused blowing and drifting snow. The Island Park COOP site recorded 9.4 inches of snow.
Four to 8 inches of snowfall combined with 30 to 40 mph wind gusts to cause extensive blowing and drifting snow. Idaho Highway 47 closed from Ashton to north of Warm River. Idaho Highway 32 closed from Ashton to Tetonia. 7 inches of snow fell 3 miles north northeast of Driggs.
Six to 7 inches of snow were recorded at the Saint Anthony and Sugar City COOP sites and Idaho State Highway 33 was closed from Newdale to Tetonia on the 20th. Winds gusted to 30 to 40 mph combining with the snow fall caused extensive drifting.
A 48 year old male snow mobile operator was killed in an avalanche near Sherman Peak in between Grace and Montpelier after causing an avalanche.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Avalanche, Bear River Range | 2021-02-20 | 48 | Male | Outside/Open Areas | Indirect |
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, February 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: 945313, 945323, 945305, 945462.