An anomalously deep upper level low moved into the region, bringing heavy snow accumulations to higher elevations and widespread wet snow at lower elevations. Many tree branches fell in North Boise due to the weight of snow on the foliage.
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 BOI wrote it up.
An anomalously deep upper level low moved into the region, bringing heavy snow accumulations to higher elevations and widespread wet snow at lower elevations. Many tree branches fell in North Boise due to the weight of snow on the foliage. This caused minor damage to houses, yards and led to local road closures.
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 Boise, ID wrote its last area forecast discussion before the first event at May 7, 8:18 PM MST, 3 hours 42 minutes earlier.
Area Forecast Discussion National Weather Service Boise ID 918 PM MDT Sat May 7 2022 .DISCUSSION...Thunderstorm activity has dissipated with the loss of daytime heating. While a rumble of thunder is possible through 06Z it should be fairly quiet the rest of tonight. The chance for showers will continue overnight with the focus of development in the mountains. A cold upper low will move into the Pacific NW tomorrow bringing another round of showers and afternoon thunderstorms. Snow levels will drop to valley floors Sunday morning and again Monday morning. Monday still looks to give the best chance for snow accumulation at lower elevations. Current forecast is on track this evening so no update. && .AVIATION...Mostly VFR. Scattered showers, mainly near the ID-NV border and in the west central Idaho mountains, with areas of MVFR/IFR conditions and mountain obscuration. Showers becoming widespread Sunday afternoon with isolated thunderstorms. Snow levels 4000-5000 feet MSL lowering to 2500-3500 feet MSL by Sunday morning, rising to 3500-4500 feet MSL Sunday afternoon. Surface winds: W-NW 10-20 kts decreasing to 5-15 kts after 06Z. Gusts to 35 kts near thunderstorms. Winds aloft at 10k ft MSL: W-SW 35-50 kts becoming NW 20-30 kts by 07/18Z. && .PREV DISCUSSION... SHORT TERM...Tonight through Monday night...A large-scale deep upper trough will continue across the region through the period. A series of disturbances embedded within the trough, along with instability, will promote periods of showers and isolated afternoon-evening thunderstorms. Gusty winds, small hail/graupel, and brief heavy rainfall will accompany the thunderstorms. Temperatures will be even colder as highs will be only in the 40s and 50s and lows in the 20s and 30s. Snow levels will continue to lower, reaching down to near valley floors by Sunday morning. The snow levels are expected to rise to around 3500-4000 feet Sunday afternoon, then lower back down to valley floors by early Monday morning. Additional light snow accumulations are expected in the higher elevations - mainly above 4500 feet. There is a slight chance for minor snow accumulations in the lower valleys Monday morning, although any accumulations would be limited to grassy areas with temperatures forecast to remain above freezing. LONG TERM...Tuesday through Saturday...An upper level trough will continue to deepen towards the southwest, bringing below normal temperatures and intermittent precipitation through Wednesday night. Tuesday will be mostly dry except for the occasional mountain shower, but precipitation will become widespread in southwest Idaho by Wednesday morning. Temperatures will be 10-15 degrees below normal, with overnight lows nearing freezing on Tuesday and Wednesday morning. Another upper level low on the heels of the previous system will move in Thursday morning, bringing more widespread precipitation to the region and continuing to keep temperatures 10-15 degrees below normal. Snow levels will remain around 4000-5000 feet MSL through Friday morning, rising to 6000-7000 feet MSL as temperatures warm Friday afternoon. A ridge will build into the region later on Friday into Saturday, bringing a return to near normal temperatures and dry conditions for the end of the extended period. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && www.weather.gov/Boise www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...DG AVIATION.....JT PREV SHORT TERM...BW PREV LONG TERM....AL
The national radar mosaic for the moment the first event began.
4 heavy snow. Local standard time, as filed.
Multiple CoCoRaHS observers and an NWS Employee reported snowfall accumulations of 2.0 inches near the Stage Stop.
Multiple reports from CoCoRaHS observers recorded 1.0-2.5 inches of snow in southeast and north Boise.
Multiple reports of 7.0-8.0 inches of snow in the Boise foothills.
A total of 3.5 inches of snow fell in Emmett, Idaho, breaking several tree branches around the city.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2022Every state in 2022This day in weather historyWarnings in Idaho, May 2022
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: 1020074, 1020075, 1020076, 1020077.