High Wind and Strong Wind in Montana, March 28 to 29, 2021

Name: High Wind and Strong Wind in Montana, March 28 to 29, 2021
Start: 2021-03-28T09:00
End: 2021-03-29T12:09
Location: Montana

March 28 to 29, 2021 · NWS MSO · 7 events in 7 counties and zones

A strong Pacific cold front, along with a stronger than normal mid-level wind maximum near 90 knots, brought wind damage to portions of north-central Idaho and western Montana.

Where it happened

Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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Winter weather
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The toll

Deaths: 0
Injuries: 0
Property damage: $4,000
Crop damage: None recorded
Events: 7

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 strong Pacific cold front, along with a stronger than normal mid-level wind maximum near 90 knots, brought wind damage to portions of north-central Idaho and western Montana.

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 Mar 28, 2:32 AM MST, 6 hours 28 minutes earlier.

Area forecast discussion, Mar 28, 2:32 AM MST, 6 hours 28 minutes before

Area Forecast Discussion
National Weather Service Missoula MT
332 AM MDT Sun Mar 28 2021

...Damaging Winds Expected Across North-Central Idaho and Western
Montana Late Sunday Afternoon into Monday Morning...

.DISCUSSION...A strong pacific cold front remains on track to
impact the Northern Rockies later this afternoon through Monday
morning. High Wind Warnings remain in effect area-wide, with the
exception of the Lower Salmon River/Hells Canyon/Riggins area.
NOW is the time to prepare by securing loose items, moving
vehicles which are vulnerable to fallen trees, charging backup
batteries, etc. Southwesterly winds will begin to ramp up late
this morning as the gradient tightens with the approaching
shortwave trough. High temperatures will reach into the 50s and
60s this afternoon under a pre-frontal southwesterly flow.
Damaging winds will arrive across northwest Montana by mid-
afternoon and will slowly shift southward across west central
Montana and north central Idaho Sunday evening, before reaching
Lemhi County, Idaho after midnight.

* Wind Impacts: The latest model trends suggest the threat for
  wind gusts up to 70 mph has increased across northwest Montana
  from 5 to 9 pm MDT. Specific areas to watch for favored to reach
  more widespread damage include: The US Highway 2 corridor from
  Happy’s Inn to Kila, Montana Highway 56 from Bull Lake to
  Montana Highway 200 junction, the Flathead Valley, and northern
  Swan Valley, and areas along US Highway 2 from Columbia Falls to
  West Glacier. Widespread wind gusts between 50 and 60 mph are
  expected with the cold front as it pushes across west central
  Montana and north central Idaho between 6 to 10 pm MDT, before
  reaching Lehmi County and southwest Montana between 9 pm and 1
  am MDT.

* Winter Impacts: High confidence exists for a period of very
  difficult travel conditions across area mountain passes Sunday
  night into Monday morning, particularly for Lolo and Lost Trail
  passes. A brief period (an hour of two) of heavy snow and
  blowing snow will accompany the cold front across higher
  elevation mountain valleys (Butte, Anaconda, Seeley-Swan
  valleys, etc.) and mountain pass areas. Given the convective
  nature of these snow bands along and behind the front, snowfall
  rates between 1 to 2 inches per hour are expected. With
  temperatures falling rapidly behind the front, any wet or slushy
  roadways will likely freeze overnight into Monday morning.

Snow showers will continue Monday afternoon as the Northern
Rockies remains in a cool northwesterly flow. A few showers may
align into bands. The Bitterroot valley and Butte/Blackfoot region
(Philipsburg, Georgetown Lake, Anaconda) will needed to be
closely monitored for any of these bands which linger into the
early evening hours.

Temperatures will remain below average Tuesday and snow and
graupel showers will redevelop during the afternoon. Relatively
warm surface temperatures will limit any accumulations.

A warming and drying trend will occur Wednesday into Thursday as
a broad ridge of high pressure builds across the western US.
Forecast model confidence decreases Friday into the weekend.
Model ensemble clusters analysis suggests a few scenarios are
possible. One scenario suggests a progressive pacific trough
moving across the Pacific Northwest into the Northern Rockies
Saturday into Sunday. The other scenario keeps the Northern
Rockies under a mild southwesterly flow with a broad upper level
ridge centered over the central Rockies into central Montana.
/Lukinbeal

&&

.AVIATION...A powerful pacific cold front remains on track to
impact the Northern Rockies late Sunday afternoon into Monday
morning. Pre-frontal southwesterly winds will begin to increase by
28/1600-28/1800. Damaging winds will reach northwest Montana by
28/2100-29/0000z and will shift across west-central and north-
central Idaho soon thereafter. Damaging winds will reach into
southwest Montana after 29/0300Z and Lemhi County, ID by 29/0600Z.
The strongest peak wind gusts areawide will likely occur across
northwest and southwest Montana, including KGPI and KBTM, where
isolated wind gusts in excess of 50 knots are possible. In
addition to strong winds, a short burst of precipitation will
accompany the cold front, with visibility reductions expected. A
burst of heavy snow is possible at KBTM from 29/0600-29/0900Z.
/Lukinbeal

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...High Wind Warning from 8 PM this evening to 9 AM MDT Monday
     Butte/Blackfoot Region.

     Red Flag Warning from 1 PM this afternoon to 7 PM MDT this
     evening East Beaverhead.

     High Wind Warning from 8 PM this evening to 9 AM MDT Monday
     Bitterroot/Sapphire Mountains.

     High Wind Warning from 9 PM this evening to 6 AM MDT Monday
     Missoula/Bitterroot Valleys.

     High Wind Warning from 3 PM this afternoon to 6 AM MDT Monday
     Lower Clark Fork Region.

     High Wind Warning from 3 PM this afternoon to 6 AM MDT Monday
     Flathead/Mission Valleys.

     High Wind Warning from 3 PM this afternoon to 6 AM MDT Monday
     West Glacier Region.

     High Wind Warning from 3 PM this afternoon to 6 AM MDT Monday
     Kootenai/Cabinet Region.

     High Wind Warning from 9 PM this evening to 6 AM MDT Monday
     Potomac/Seeley Lake Region.

ID...High Wind Warning from midnight tonight to 9 AM MDT Monday
     Eastern Lemhi County.

     High Wind Warning from 8 PM this evening to 5 AM PDT Monday
     Orofino/Grangeville Region.

     High Wind Warning from 8 PM this evening to 5 AM PDT Monday
     Southern Clearwater Mountains.

     High Wind Warning from midnight tonight to 9 AM MDT Monday
     Western Lemhi County.

     High Wind Warning from 8 PM this evening to 5 AM PDT Monday
     Northern Clearwater Mountains.

&&

The radar

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

Open the radar archive at this moment

Event by event

4 high wind, 3 strong wind. Local standard time, as filed.

High Wind, Missoula / Bitterroot Valleys

When: March 28, 9:00 AM MST to March 29, 12:09 PM MST
Where: Missoula / Bitterroot Valleys forecast zone
Measured: 58 kt (67 mph) measured gust
Property damage: $1,000
Reported by: RAWS
Coordinates: 46.560, -114.023 (the zone’s center; the record gives no point)

Widespread wind gusts between 40 and 50 mph with a couple of gusts in the 60s occurred during this event. Overall, impacts were constrained to around 400 customers without power and a single report of a blown-over shed in Stevensville.

High Wind, Butte / Blackfoot Region

When: March 28, 9:53 AM MST to March 29, 6:53 AM MST
Where: Butte / Blackfoot Region forecast zone
Measured: 55 kt (63 mph) measured gust
Reported by: Utility Company
Coordinates: 46.306, -113.025 (the zone’s center; the record gives no point)

High wind gusts were common with gusts to 63 mph west of Butte and 57 mph at Georgetown Lake. Additionally, brief heavy snow, rapidly falling temperatures, and strong gusty winds contributed to slick road conditions, especially between Butte and Anaconda.

Strong Wind, Flathead/Mission Valleys

When: March 28, 12:00 PM MST to 6:45 PM MST
Where: Flathead/Mission Valleys forecast zone
Measured: 47 kt (54 mph) measured gust
Property damage: $1,000
Reported by: ASOS
Coordinates: 47.872, -114.424 (the zone’s center; the record gives no point)

Between 200-500 customers lost power during the event. There was at least 1 report of a tree down north of Lakeside, MT. Winds were relatively uniform with widespread gusts into the 40s mph and a couple of reports in the low 50s mph.

Strong Wind, Kootenai/Cabinet Region

When: March 28, 12:07 PM MST to 11:31 PM MST
Where: Kootenai/Cabinet Region forecast zone
Measured: 45 kt (52 mph) measured gust
Property damage: $1,000
Reported by: RAWS
Coordinates: 48.171, -114.863 (the zone’s center; the record gives no point)

Greater than 400 customers lost power during this wind event. In general, the highest winds were in the mountains with a peak recorded gust of 52 mph at Zonolite. In populated locations, gusts into the 40s were common with a peak gust of 49 mph at Kila, MT.

Strong Wind, Lower Clark Fork Region

When: March 28, 3:30 PM MST to 11:02 PM MST
Where: Lower Clark Fork Region forecast zone
Measured: 40 kt (46 mph) measured gust
Property damage: $1,000
Reported by: Mesonet
Coordinates: 47.286, -114.685 (the zone’s center; the record gives no point)

With wind gusts into the 40s mph, impacts were constrained to 200 or fewer customers without power.

High Wind, West Glacier Region

When: March 28, 5:06 PM MST to March 29, 4:00 AM MST
Where: West Glacier Region forecast zone
Measured: 50 kt (58 mph) measured gust
Reported by: Mesonet
Coordinates: 47.971, -114.069 (the zone’s center; the record gives no point)

High winds caused a downed tree in the Coram area which resulted in a power outage. The highest wind recorded in the valleys was 58 mph in Hungry Horse. The highest gust, measured at 98 mph, reported by the Tunnel Ridge Snow avalanche monitoring station (high elevation). Less than 100 customers were without power during the storm.

High Wind, Bitterroot / Sapphire Mountains

When: March 28, 5:45 PM MST to March 29, 4:00 AM MST
Where: Bitterroot / Sapphire Mountains forecast zone
Measured: 67 kt (77 mph) measured gust
Reported by: RAWS
Coordinates: 46.508, -113.828 (the zone’s center; the record gives no point)

Although wind gusts in the mountains ranged from 60 to 75 mph, the impacts were few in the sparsely populated areas with less than 100 customers without power at one time during the storm.

What these are

High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
Strong Wind: Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.

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

The same day elsewhere

Every storm in Montana in 2021 Every state in 2021 This day in weather history Warnings in Montana, March 2021

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: 944959, 944983, 944946, 944912, 944947, 944944, 944963.