A cold front draped across the Oregon Idaho border combined with hot afternoon temperatures for the development of strong to severe thunderstorms over parts of Southwest Idaho.
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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 BOI wrote it up.
A cold front draped across the Oregon Idaho border combined with hot afternoon temperatures for the development of strong to severe thunderstorms over parts of Southwest Idaho.
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 Aug 24, 1:53 PM MST, 4 hours 47 minutes earlier.
Area Forecast Discussion National Weather Service Boise ID 253 PM MDT Thu Aug 24 2017 .SHORT TERM...Tonight through Saturday...Satellite across the area demonstrates increasing cloud development this afternoon as a cold front remains draped across the OR/ID border. Showers and thunderstorms are expected with the frontal passage this afternoon and evening, with the strongest storms expected across the West Central Mountains of Idaho and west into Baker County, OR. Strong wind gusts may accompany any stronger storm development this afternoon. Radar trends show an increase across southern Oregon and Idaho, with the updated forecast package seeing bumped up forecasts for these areas. Passage of the front will bring a return to quieter conditions, though some remnant moisture may generate a few showers and thunderstorms on Friday. Temperatures on Friday will be similar to today, though some locations will see slight cooling. Models in good agreement with the rebuilding of a ridge across the Intermountain West over the weekend. This will bring dry and warming conditions on Saturday. .LONG TERM...Saturday night through Thursday...A strong upper level ridge will build across the western United States bringing above normal temperatures starting on Saturday. Temperatures in the valleys will approach 100F on Monday and Tuesday, slightly below records at this time. Monsoon moisture will wrap around the ridge starting on Monday as the ridge aloft weakens. Afternoon showers and thunderstorms are possible over the higher terrain on Tuesday into Thursday. Temperatures will begin a downward trend on Tuesday toward normal as the ridge weakens. && .AVIATION...VFR. SCT-BKN mid and high level clouds. Smoke layers and haze. Showers and thunderstorms developing in the afternoon mainly north of a KBNO-KONO-KSNT line. Surface winds SW 5-15kt during the afternoon in SE Oregon and Magic Valley with variable winds elsewhere, becoming light after sunset. Gusty outflow winds to 45kt possible in the vicinity of thunderstorms. Winds aloft at 10kft MSL: SW 10-20kt. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Red Flag Warning until midnight MDT tonight IDZ400>403. OR...Red Flag Warning until 11 PM PDT this evening ORZ646. && www.weather.gov/Boise www.facebook.com/NWSBoise www.twitter.com/NWSBoise SHORT TERM...KB LONG TERM....KA/WH AVIATION.....KA
Special Weather Statement National Weather Service Boise ID 355 PM MDT THU AUG 24 2017 IDZ011-ORZ062-242245- West Central Mountains ID-Baker County OR- 355 PM MDT THU AUG 24 2017 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN WASHINGTON AND EAST CENTRAL BAKER COUNTIES UNTIL 445 PM MDT/345 PM PDT/... At 355 PM MDT/255 PM PDT/, Doppler radar was tracking a strong thunderstorm near Durkee, or 21 miles southeast of Baker City, moving east at 20 mph. Dime size hail and wind gusts up to 50 mph will be possible with this storm. This strong thunderstorm will be near... Little Lookout Mountain around 310 PM PDT. Sheep Mountain and Big Lookout Mountain around 320 PM PDT. Sweedes Landing around 330 PM PDT. Richland, Halfway and Brownlee Reservoir around 340 PM PDT. 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 4453 11750 4472 11758 4489 11706 4459 11695 TIME...MOT...LOC 2155Z 255DEG 18KT 4464 11743 BW
Special Weather Statement National Weather Service Boise ID 651 PM MDT THU AUG 24 2017 IDZ012-014-250130- Upper Treasure Valley ID-Lower Treasure Valley ID- 651 PM MDT THU AUG 24 2017 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN ADA...SOUTHEASTERN CANYON AND NORTHWESTERN OWYHEE COUNTIES UNTIL 730 PM MDT... At 650 PM MDT, Doppler radar was tracking a strong thunderstorm over Walters Ferry, or 16 miles south of Nampa, moving northeast 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... Melba around 700 PM MDT. Swan Falls and Lake Lowell around 710 PM MDT. Initial Point around 720 PM MDT. Nampa and Kuna around 730 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 4317 11651 4341 11686 4361 11663 4335 11618 TIME...MOT...LOC 0050Z 232DEG 17KT 4334 11662 BW
Special Weather Statement National Weather Service Boise ID 721 PM MDT THU AUG 24 2017 IDZ012>014-250200- Upper Treasure Valley ID-Lower Treasure Valley ID-Boise Mountains ID- 721 PM MDT THU AUG 24 2017 ...SIGNIFICANT WEATHER ADVISORY FOR ADA...SOUTHWESTERN BOISE...WEST CENTRAL ELMORE...SOUTHEASTERN CANYON...NORTHWESTERN OWYHEE AND SOUTH CENTRAL GEM COUNTIES UNTIL 800 PM MDT... At 720 PM MDT, Doppler radar was tracking a strong thunderstorm near Kuna, or 7 miles southwest of Boise, moving northeast at 50 mph. Half inch hail and wind gusts up to 50 mph will be possible with this storm. This strong thunderstorm will be near... Boise, Garden City, Lucky Peak Dam and Boise Stage Stop around 730 PM MDT. Aldape Summit, Hidden Springs, Lucky Peak Reservoir and Lucky Peak Spring Shores Marina around 740 PM MDT. Horseshoe Bend, Gardena, Bogus Basin Ski Area and Arrowrock Reservoir around 750 PM MDT. Harris Creek Summit and Twin Springs around 800 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 4316 11639 4348 11684 4402 11617 4360 11559 TIME...MOT...LOC 0120Z 224DEG 42KT 4354 11636 BW
The Boise radar (KCBX), 9 km away, was scanning. The volume nearest the first event began at 01:40 UTC.
1 thunderstorm wind. Local standard time, as filed.
The Boise airport measured a wind gust of 58 MPH at 6:41 MST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2017Every state in 2017This day in weather historyWarnings in Idaho, August 2017
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: 709949.