A vigorous upper level low moved northeast out of California and spread strong to severe thunderstorms across Southeast Oregon and Southwest Idaho with large hail and damaging winds.
Every event with a place to put it. 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.
A vigorous upper level low moved northeast out of California and spread strong to severe thunderstorms across Southeast Oregon and Southwest Idaho with large hail and damaging winds.
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 25, 12:51 PM MST, 5 hours 14 minutes earlier.
Area Forecast Discussion National Weather Service Boise ID 151 PM MDT Fri May 25 2018 .SHORT TERM...Tonight through Sunday...An upper level low will move slowly from nrn CA into NV today into tomorrow, before slowly drifting toward the NV/UT line Sunday. Convection initiating on the northern side of this system is likely to grow into a significant convective event across much of the area this afternoon and evening. Thunderstorms are forming in southeast Oregon at this time, and they are expected to move/develop northward and expand into southwest Idaho generally west of Mountain Home. High resolution models indicate that a large and strong outflow boundary will form ahead of these storms as the afternoon wears on. Wind gusts could go over 60 mph along and behind this boundary. Also, multiple boundaries are possible. The main boundary is forecast to move through northern Harney and Malheur counties and into Baker County late this afternoon and early this evening. It will also likely extend east into southwest Idaho, entering around 6 pm and moving through the Boise and Mountain Home areas by 8 pm. It is unclear at this point how strong the boundary might be once it gets east of Mountain Home. In addition to the wind threat, flash flooding is possible in eastern Oregon as multiple rounds of storms occur. Recent burn scars are most prone to problems, but flash flooding may occur elsewhere as well. Rainfall totals may reach 2 inches in a short amount of time this afternoon/evening. A flash flood watch has been posted for our eastern Oregon zones. After this event ends late tonight, additional showers and storms are forecast Saturday and Sunday, but they are not expected to be nearly as strong. The location with the best chance of precipitation will shift east Saturday and especially Sunday, and by then there is very little chance of precip in the Oregon zones. Temps will cool down 10-15 degrees tomorrow compared to today, then warm up slightly Sunday. .LONG TERM...Sunday night through Wednesday...Lingering showers in the central Idaho mountains to start the period as our upper level low still sits just east of us. By Monday night a short wave ridge builds over the Pacific Northwest which helps increase temperatures to above normal again. This is a short lived break as yet another long wave trough begins to drop down along the coast bringing moist southwesterly flow aloft to our area. Showers begin to hit SE Oregon again by early Wednesday increasing in coverage by late afternoon. Wednesday night through Friday...Models show the trough along the coast moving inland during this period, but the latest runs differ on timing and amplitude. They do agree on at least a slight chance of showers Wednesday night through Friday, and there will be enough instability for isolated afternoon and evening thunderstorms. Temperatures will be close to normal. && .AVIATION...VFR. Scattered showers and thunderstorms this afternoon with much of the coverage staying in SE Oregon. KBNO and KBKE will see heavy rain and thunderstorms through late afternoon. Thunderstorms have the potential of producing gusty winds up to 50kts. Outflow winds are of concern this afternoon after 22z and could travel up into the Treasure Valley. Surface winds outside of thunderstorms, variable 15-20kts. Winds aloft to 10k feet MSL, southerly 25-35kts. Weekend Outlook...Shower and thunderstorms continue through the weekend with coverage migrating more to SW Idaho for Saturday and Sunday with the Oregon side starting to dry out. Gusty winds with thunderstorms of 25-35kts. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...Flash Flood Watch through late tonight ORZ061>063. && www.weather.gov/Boise www.facebook.com/NWSBoise www.twitter.com/NWSBoise SHORT TERM...SP LONG TERM....JC/JT AVIATION.....JC
Special Weather Statement National Weather Service Boise ID 210 PM MDT FRI MAY 25 2018 ORZ063-252115- Malheur County OR- 210 PM MDT FRI MAY 25 2018 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MALHEUR COUNTY UNTIL 315 PM MDT/215 PM PDT/... At 210 PM MDT/110 PM PDT/, Doppler radar was tracking a strong thunderstorm over Basque Station, or 29 miles north of McDermitt, moving north at 20 mph. Half inch hail and wind gusts up to 50 mph will be possible with this storm. This strong thunderstorm will be near... Three Man Butte around 220 PM MDT. Rome Airport around 250 PM MDT. Burns Junction and Flat Top Mountain around 310 PM MDT. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. When safe to do so, please relay storm reports to the National Weather Service in Boise via local law enforcement, or National Weather Service Boise Facebook and Twitter accounts. && LAT...LON 4235 11771 4229 11794 4271 11819 4280 11784 TIME...MOT...LOC 2010Z 161DEG 17KT 4240 11786 SP
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
417 PM MDT FRI MAY 25 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0200 PM HAIL 6 S PUEBLO MOUNTAIN 42.01N 118.63W
05/25/2018 E1.00 INCH HARNEY OR PUBLIC
SOCIAL MEDIA REPORT. HAIL OCCURED AROUND 2 PM MDT JUST
NORTH OF DENIO, NV ON THE IDAHO SIDE.
&&
EPPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE BOISE ID
425 PM MDT FRI MAY 25 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0300 PM HAIL 6 S PUEBLO MOUNTAIN 42.01N 118.63W
05/25/2018 E1.00 INCH HARNEY OR PUBLIC
SOCIAL MEDIA REPORT. HAIL OCCURED AROUND 3 PM PDT JUST
NORTH OF DENIO, NV ON THE IDAHO SIDE.
&&
EPADIANPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
623 PM MDT FRI MAY 25 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0510 PM TSTM WND DMG BURNS 43.59N 119.06W
05/25/2018 HARNEY OR LAW ENFORCEMENT
TREES AND POWERLINES DOWN. PARTS OF TOWN WITHOUT POWER.
&&Special Weather Statement National Weather Service Boise ID 700 PM MDT FRI MAY 25 2018 IDZ011-260145- West Central Mountains ID- 700 PM MDT FRI MAY 25 2018 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN VALLEY AND NORTHEASTERN ADAMS COUNTIES UNTIL 745 PM MDT... At 658 PM MDT, Doppler radar was tracking a strong thunderstorm near Little Payette Lake, or near McCall, moving north at 20 mph. Half inch hail and wind gusts up to 50 mph will be possible with this storm. Reports of hail covering the ground south of McCall have been received with this storm. This strong thunderstorm will be near... Little Payette Lake and Lake Fork Guard Station around 710 PM MDT. McCall around 720 PM MDT. Payette Lake and Meadows around 730 PM MDT. New Meadows, Brundage Ski Area and Upper Payette Lake around 740 PM MDT. PRECAUTIONARY/PREPAREDNESS ACTIONS... When safe to do so, please relay storm reports to the National Weather Service in Boise via local law enforcement, or National Weather Service Boise Facebook and Twitter accounts. && LAT...LON 4515 11597 4477 11590 4473 11614 4508 11634 TIME...MOT...LOC 0058Z 165DEG 17KT 4483 11605 DG
The Boise radar (KCBX), 42 km away, was scanning. The volume nearest the first event began at 01:03 UTC.
3 hail. Local standard time, as filed.
Golf ball sized hail was reported via social media near Givens Hot Springs. Quarter sized hail was reported at Marsing.
Trained spotters south of Caldwell reported lime and half dollar sized hail.
A trained spotter reported golf ball sized hail just north of New Meadows along U.S. Highway 95.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2018Every state in 2018This day in weather historyWarnings in Idaho, May 2018
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: 749297, 749298, 749299.