Flood in Montana, May 1 to 31, 2018

Name: Flood in Montana, May 1 to 31, 2018
Start: 2018-05-01T00:00
End: 2018-05-31T22:59
Location: Montana

May 1 to 31, 2018 · NWS MSO · 1 event in 1 county or zone

Rivers across western Montana exceeded flood stage during much of May 2018. Flooding caused damage of various levels to homes in the Missoula and Seeley Lake regions.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

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.

What happened

The episode as NWS MSO wrote it up.

Rivers across western Montana exceeded flood stage during much of May 2018. Flooding caused damage of various levels to homes in the Missoula and Seeley Lake regions.

What forecasters said that day

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 Apr 30, 1:51 PM MST, 10 hours 9 minutes earlier.

Area forecast discussion, Apr 30, 1:51 PM MST, 10 hours 9 minutes before

Area Forecast Discussion
National Weather Service Missoula MT
251 PM MDT Mon Apr 30 2018

.DISCUSSION...Doppler radar is showing scattered showers across
western Montana this afternoon. Expect showers to persist through
the early evening hours.

Another weather system will move through the Northern Rockies
early Tuesday morning through early Tuesday evening resulting in
widespread showers. Showers will impact the region from north to
south through the day.

Drier and warmer conditions will return for Wednesday through
Friday. Showers may increase Saturday but they would be light and
of little impact. Warmer conditions late in the week will
contribute to continued snow melt runoff.

&&

.AVIATION...
Instability rain showers will continue near KMSO, KGPI, KBTM, and
KSMN through 0200 UTC, with skies remaining overcast tonight. The
TAF sites will see VFR CIGS overnight. The next weather
disturbance arrives Tuesday morning across the area. KGPI could
see light rain develop as early as 1200 UTC. Rain will likely hold
off at KMSO and KBTM until the early afternoon with KSMN seeing
rainfall later tomorrow afternoon. MVFR CIGS can be expected
within rain showers Tuesday.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flood. Local standard time, as filed.

Flood, Missoula

When: May 1, 12:00 AM MST to May 31, 10:59 PM MST
Where: Missoula County, 1.92 mi N of Missoula Southwest to 1.86 mi SSE of Orchard Homes
Cause: Heavy Rain / Snow Melt
Reported by: Emergency Manager
Coordinates: 46.877, -114.044

The Clark Fork River north of Missoula reached 13.82 feet and 32,500 CFS on May 11 between 830 pm and 845 pm MDT which goes down as the highest river level since June 1, 1908 when the river reached 17.4 feet. Three mobile homes were washed away and most likely broke up off of Schmidt Road on May 11. Multiple residences and structures in the Orchard Homes area, including those along Tower Street and Kehrwald Drive experienced flood damage. Flooding caused the evacuation of 50 to 60 homes conducted by the Missoula County Sheriff and Northwest Energy had to cut electricity and gas to these homes. Despite the fact that this continuous flooding ended on June 8, the event altered the river channel to the extent flooding occurred well below the established flood stage on June 11 and again with a basin rain event on June 19-25.

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Montana in 2018 Every state in 2018 This day in weather history Warnings in Montana, May 2018

Sources

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: 749902.