Tree damage with 58 to 60 mph winds estimated in parts of Cassia and Oneida counties.
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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.
Tree damage with 58 to 60 mph winds estimated in parts of Cassia and Oneida counties.
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 May 16, 12:26 PM MST, 3 hours 34 minutes earlier.
Area Forecast Discussion National Weather Service Pocatello ID 126 PM MDT Sun May 16 2021 .SHORT TERM...Today through Tuesday. An upper level low over southern CA and southern NV is continuing to bring moisture into our area. We were clear over our area most of the morning bringing instability. Expect scattered showers and thunderstorms mainly over our southern areas this afternoon. Along the Montana Divide, northern Eastern Highlands, and the southern Central mountains, expect isolated showers and thunderstorms the afternoon into early evening. Look for small hail and gusty winds of around 40 mph, with locally higher amounts. The northeast winds over the American Falls reservoir will drop below 10 mph around 3 pm. So will let the lake wind advisory expire at 3 pm. Winds will shift to the southwest by mid to late afternoon. Regardless, southerly outflow winds are expected over the American Falls reservoir by late afternoon and early evening creating rough conditions on the reservoir. Monday the upper level low moves east over southern UT. Models are still showing moisture and instability mainly over our extreme southeast areas by the Bear Lake region. However, some light showers and possible thunderstorms are again possible over the southern Central mountains, the Montana Divide and the northern Eastern Highlands. Tuesday looks mostly dry in breezy southwest flow ahead of the next system. Look for temperatures 4 to 8 degrees above normal today and Monday and 8 to 12 degrees above normal on Tuesday. Wyatt .LONG TERM...Wednesday through next Sunday. A major cold storm is expected to traverse through the region Wed night through Sat. This storm will carry a lot of moisture and enough cold air to bring snow back, even possibly to higher elevations in the Snake River plain, such as the Arco-Mud Lake desert, Craters of the Moon, etc, although it will likely be just a dusting at that elevation. Winter Storm Warnings could be needed in the central Idaho mountains and the Island Park region. Windy to very windy conditions mean that Wind Advisories are also part of the mix. Any significant snow must come with the cold air, which will be more at the end of the period, Fri night/Sat night, but snow above 6000ft elevation will be occurring at night even on Wed night. There should be full melting at inhabited elevations below 7000ft, and some partial melting above that. The high temperatures rebound strongly in the spring sun on Sun, with an increase in temperatures from Sat middle to upper 50s in the Snake River plain to middle to upper 60s for Sun afternoon. Messick && .AVIATION...Expecting isold TSRA mainly during the early evening, with severe conditions possible in the mountains to the south of the three valley airdromes. The main body of SHRA enters the Snake River plain/eastern Magic Valley between 16/23Z and 17/01Z, and this should make the wind highly variable, so have added TEMPO groups to reflect the highly variable and breezy to windy conditions expected with the SHRA. If a severe TSRA develops in the right location, outflow going down any drainage could spill onto an airdrome, but chances are fairly remote. The highest risk is KBYI and KPIH, with KIDA and KDIJ farther away from the strong convection. KSUN is nearly out of the TSRA risk, but outflow even from SHRA could wreak havoc even there. No impactful CIGs of VSBYs expected, only the TSRA hazards of LTG, GR, and LLWS along with highly variable wind both for speed and direction. Messick && .PIH WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory until 3 PM MDT this afternoon for IDZ054. &&
Special Weather Statement National Weather Service Pocatello ID 307 PM MDT Sun May 16 2021 IDZ062>064-162145- Big Hole Mountains ID-Caribou Range ID-Blackfoot Mountains ID- 307 PM MDT Sun May 16 2021 ...SPECIAL WEATHER STATEMENT... At 306 PM MDT, Doppler radar was tracking a strong thunderstorm near Wayan, moving east at 15 mph. Half inch hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Swan Valley, Palisades Reservoir, Wayan, Irwin, Alpine Campground, Smokey Canyon Mine, Freedom, Grays Lake and Alpine Airport. PRECAUTIONARY/PREPAREDNESS ACTIONS... If on or near Palisades Reservoir, Move to safe shelter now! Do not be caught on or near the water. Gusty winds and choppy waves are likely. && LAT...LON 4297 11147 4350 11146 4330 11104 4265 11105 TIME...MOT...LOC 2106Z 248DEG 11KT 4292 11133 DMH
Special Weather Statement National Weather Service Pocatello ID 337 PM MDT Sun May 16 2021 IDZ060-061-162215- Bear Lake Valley ID-Bear River Range ID- 337 PM MDT Sun May 16 2021 ...SPECIAL WEATHER STATEMENT... At 337 PM MDT, Doppler radar was tracking a thunderstorm over southern Bear Lake Idaho Portion, moving northwest at 25 mph. Winds in excess of 30 mph will be possible with this storm. Boaters can expect a sudden increase in waves and very choppy waters which will result in hazardous boating conditions. Boaters are urged to seek safe harbor if possible. PRECAUTIONARY/PREPAREDNESS ACTIONS... This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. If on or near Bear Lake, Move to safe shelter now! Do not be caught on or near the water. Gusty winds and choppy waves are likely. && LAT...LON 4213 11168 4230 11124 4200 11115 4200 11145 TIME...MOT...LOC 2137Z 127DEG 22KT 4202 11134 DMH
Special Weather Statement National Weather Service Pocatello ID 458 PM MDT Sun May 16 2021 IDZ055-057>060-170030- Eastern Magic Valley ID-Franklin/Eastern Oneida Region ID- Bear River Range ID-Marsh and Arbon Highlands ID- Raft River Region ID- 458 PM MDT Sun May 16 2021 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN CARIBOU...ONEIDA... SOUTHEASTERN BANNOCK...SOUTHERN POWER...FRANKLIN AND EASTERN CASSIA COUNTIES UNTIL 630 PM MDT... At 457 PM MDT, Doppler radar was tracking strong thunderstorms along a line extending from near Franklin to 9 miles north of Howell. Movement was northwest at 30 mph. Half inch hail and winds in excess of 40 mph will be possible with these storms. Locations impacted include... Preston, Malad, McCammon, Lava Hot Springs, Swanlake, Franklin, Downey, Arimo, Rockland, Holbrook Summit, Pleasantview, Fort Hall Bannock Peak, Cherry Creek Rest Area, Virginia, Dayton, Weston, Clifton, Oxford, Mapleton and Hawkins Reservoir. LAT...LON 4200 11258 4258 11315 4272 11204 4200 11158 TIME...MOT...LOC 2257Z 144DEG 24KT 4202 11170 4190 11238 DMH
The Salt Lake City radar (KMTX), 102 km away, was scanning. The volume nearest the first event began at 22:57 UTC.
3 thunderstorm wind. Local standard time, as filed.
A large tree branch was snapped in two along with some roof damage in Holbrook with strong thunderstorm outflow winds.
Sixty mph winds estimated near Holbrook with blowing dust reducing visibility to 1/4 mile or less.
A 58 mph wind gust was measured at the Raft River RAWS site.
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, May 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: 962589, 962590, 962592.