Montana, 2017

Heavy Rain in Montana, February 9, 2017

February 9, 2017 · NWS MSO · 3 events in 3 counties and zones

A warm and moist southwest flow pattern set up over the Northern Rockies during the second week of February. Significant rain and warming temperatures combined with the abundant low elevation snow to cause widespread ponding and flooding in fields and on roadways.

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
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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
3

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.

A warm and moist southwest flow pattern set up over the Northern Rockies during the second week of February. Significant rain and warming temperatures combined with the abundant low elevation snow to cause widespread ponding and flooding in fields and on roadways. The Bitterroot Valley near Corvallis, MT saw the most widespread areal flooding. Interstate 90 was also impacted for several hours as water ponded to a depth of 3 feet in a low spot on the roadway near Saltese, MT.

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 Feb 9, 3:29 AM MST, 1 hour 31 minutes earlier.

Area forecast discussion, Feb 9, 3:29 AM MST, 1 hour 31 minutes before
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The radar

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

Open the radar archive at this moment

Event by event

3 heavy rain. Local standard time, as filed.

Heavy Rain, Mineral

When
February 9, 5:00 AM MST to 4:00 PM MST
Where
Mineral County, St Regis to Lookout
Reported by
Department of Highways
Coordinates
47.300, -115.100

Ponding water up to 3 feet deep near Saltese, MT on I-90 lead the Montana Dept. of Transportation to close the roadway for much of the day. Antecedent heavy low-elevation snow allowed for this event, as water was unable to drain off the sides of the road. After plows cut breaks in the snow berms, ponding decreased. Roads were reopened during the evening.

Heavy Rain, Missoula

When
February 9, 6:00 AM MST to 4:00 PM MST
Where
Missoula County, 5.7 mi NE of Lolo Hot Spgs to 0.68 mi N of Lolo Hot Spgs
Reported by
NWS Employee
Coordinates
46.777, -114.431

An NWS employee reported water ponding on Hwy 12 leading up to Lolo Pass. Snow berms along the road from previous snow events caused a 3-inch deep flow of rainwater on the road surface.

Heavy Rain, Ravalli

When
February 9, 12:00 PM MST to 4:00 PM MST
Where
Ravalli County, 1.54 mi WNW of Florence to 3.01 mi ESE of Corvallis
Reported by
NWS Employee
Coordinates
46.636, -114.111

An NWS Employee reported extensive ponding in fields and near property in Corvallis, MT. The exceptionally high amount of valley snow-pack allowed for periods of moderate rain combined with relatively warm temperatures to cause unusually extensive areal flooding on Feb. 9 & 10.

What these are

Heavy Rain
Rainfall totals unusual for the place and season that did not produce a flood.

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

The same day elsewhere

More

Every storm in Montana in 2017Every state in 2017This day in weather historyWarnings in Montana, February 2017

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: 682529, 682536, 682531.