Multiple rounds of showers and thunderstorms produced 1-3 inches of rain and subsequent flooding. The addition of snowmelt contributed to the high flows.
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 MSO wrote it up.
Multiple rounds of showers and thunderstorms produced 1-3 inches of rain and subsequent flooding. The addition of snowmelt contributed to the high flows.
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 Missoula, MT wrote its last area forecast discussion before the first event at Jun 11, 12:58 AM PST, 6 hours 47 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
258 AM MDT Sat Jun 11 2022
...HEAVY MOUNTAIN SNOW POSSIBLE STARTING MONDAY NIGHT...
.DISCUSSION...The previously discussed atmospheric river is
currently bringing light to moderate rain to the Northern
Rockies. A substantial band of precipitation is moving through
Western Montana between Kalispell and Missoula and tracking all
the way back southwest off the US west coast. This is the area of
precipitation that is forecast to bring a period of moderate rain
around mid morning to west-central Montana and north-central
Idaho. If you are traveling at that time be prepared for standing
and running water on roadways in those two areas.
For southwest Montana and Lemhi County, ID, these areas will be
along the southern boundary of the atmospheric river and during
the afternoon may experience some thunderstorms. These
thunderstorms will be capable of brief but heavy rain.
The main trough and associated cold front rotates onshore Monday
and is still anticipated to develop a cut-off low pressure system
over southern Alberta, Canada. Steady rain, showers, and
afternoon/ evening thunderstorms will continue through at least
Tuesday.
This low pressure system is a cold system and snow levels are
expected to begin to lower late Monday. For those of you with back
country plans above 5000 feet plan accordingly. If those plans
will take you to Glacier National Park or the Bob Marshall
Wilderness, you should plan for heavy snow above 6000 feet, where
6-18" of snow is forecast and a winter storm watch is in effect
from Monday night through Tuesday evening.
Storm totals for precipitation by Tuesday are as follows:
Valleys of Southwest Montana and Lemhi County, ID... 0.50-0.75"
All other valleys... 1-2" highest in N-C ID
Clearwater Mountains of ID... 2-3" isolated 4+"
Cabinets and Purcell Mountains... 2-3" isolated 5+"
Mission, Seeley, and Bob Marshall Wilderness
Including Glacier National Park... 3-4" isolated 5-6"
Hydrology issues are expected and as such there have been areal
flood watches issued from Saturday evening through Monday evening.
Please read our 'Hydrology' section of this discussion for
specifics on threats and expectations.
&&
.AVIATION...The presence of an atmospheric river of moisture will
keep steady rainfall throughout the region over the weekend and
into next week. This will lead to persistent low ceilings,
widespread terrain obscuration, and occasionally reduced
visibility at all TAF sites and throughout much of the region.
Periods of significant reductions are possible during waves of
heavier precipitation, the first of which appears to arrive
Saturday morning between 11/10z and 11/20z. Conditions at KMSO
between 11/12z and 11/16z could be dramatically affected. Saturday
afternoon thunderstorms may form along the southern boundary of
the precipitation shield affecting both KSMN and KBTM, these
storms will be capable of brief but heavy rain rapidly reducing
visibilities.
&&
.HYDROLOGY...An atmospheric river bringing intense precipitation
to the region will occur today through Tuesday and result in
rising water levels for area streams, creeks, and mainstem rivers.
Forecast rainfall amounts will range between 1.00 to 3.00 inches
and over 3 inches in the Clearwater Mountains and high terrain of
northwest Montana. Saturday through Monday across north central
Idaho and western Montana, particularly locations along the
Montana/Idaho border. As a result, excessive runoff may result in
flooding of rivers, creeks, streams, and other low-lying and
flood-prone locations. Creeks and streams may rise out of their
banks. Rock and mud slides, debris flows, and landslips will also
be possible during this time.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Flood Watch from this evening through Monday afternoon
Bitterroot/Sapphire Mountains...Flathead/Mission Valleys...
Kootenai/Cabinet Region...Lower Clark Fork Region...
Missoula/Bitterroot Valleys...West Glacier Region.
Winter Storm Watch from Monday evening through late Tuesday
night ABOVE 5000 FEET for the West Glacier Region.
ID...Flood Watch from this afternoon through Monday afternoon Lower
Hells Canyon/Salmon River Region...Northern Clearwater
Mountains...Orofino/Grangeville Region...Southern
Clearwater Mountains.
&&The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
The South Fork of the Clearwater River went into minor flood stage leading to flooding of low-lying areas and adjacent roads. Johnston Cutoff Road and Tolo Lake Road west of Grangeville also experienced road closures because of water flowing across the roadway.
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, June 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: 1027696.