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

Name: High Wind and Strong Wind in Idaho, March 28 to 29, 2021
Start: 2021-03-28T19:00
End: 2021-03-29T06:00
Location: Idaho

March 28 to 29, 2021 · NWS MSO · 5 events in 5 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; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. 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: $2,000
Crop damage: None recorded
Events: 5

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, 11:58 AM PST, 7 hours 2 minutes earlier.

Area forecast discussion, Mar 28, 11:58 AM PST, 7 hours 2 minutes before

Area Forecast Discussion
National Weather Service Missoula MT
158 PM MDT Sun Mar 28 2021

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

.DISCUSSION...An exceptionally strong North Pacific cold front is
still on track to impact the Northern Rockies today through Monday
morning. This storm system will bring a number of impacts to the
region with damaging winds, low visibility due to blowing snow,
and 1 to 2 inch per hour snow rates along the cold front as it
moves through. As such, High Wind Warnings remain in place
throughout the Northern Rockies, along with Winter Weather
Advisories for the West Glacier, Seeley/Swan, Butte/Blackfoot
regions, and the Clearwater/Bittrroot/Sapphire Mountains. If you
haven't prepared by securing loose outdoor items, now is the time
to finish those preparations.

Wind Impacts: Confidence still remains high for very strong
damaging winds, particularly across northwest and southwest
Montana, as well as the Clearwater Mountains in north-central
Idaho. Latest forecast guidance this morning suggest 70 mph wind
gusts are not out of the question. The strongest winds are
expected to be just ahead, along, and behind the cold front as it
moves through. Power outages, tree damage, and very difficult
driving are just a few potential impacts from the wind. Although
the locations mentioned above are most likely to see the strongest
winds, the rest of western Montana and north-central Idaho will
still have the potential for damaging winds with gusts of 50 to
55 mph.

Timing: As mentioned, the strongest winds will be along the cold
front later this evening and going through the overnight hours.
For northwest Montana, the hours between 5 PM and 9 PM will be the
time period for the highest impacts. West-central Montana and
north-central Idaho can expect the front between the hours of 9 PM
and Midnight, and southwest Montana and Lemhi county, between 11
PM and 2 AM. The timing mentioned above will be for when the cold
front approaches with the strongest gusts. Having said that,
damaging winds of lesser magnitude will still be possible on
either end of these periods.

Winter Impacts: Temperatures this afternoon are quite warm (mid
60s). As the front approaches from the west, the onset of
precipitation is likely to be rain, then quickly changing to snow
as the front moves over. Temperatures will rapidly drop anywhere
from 20 to 30 degrees behind the front. Wet slushy roads,
particularly area mountain passes, will quickly freeze. Also, the
snow rates are expected to be quite high, with 1 to 2 inch per
hour rates. Due to the combination of the wind and snowfall, near
whiteout conditions can be expected, especially for those areas
mentioned above where Winter Weather Advisories have been issued.
All other locations (valleys) across the Northern Rockies can
expect to see snow as the front moves overhead as well, just not
expecting the same degree of impacts as the mountains.

A cold and blustery day can be expected during the day Monday, as
scattered snow showers and breezy conditions persist.  Luckily,
the weather is expected to improve by mid-week, as the wind
diminishes and temperatures rise to slightly above normal for this
time of the year.

&&

.AVIATION...A powerful pacific cold front remains on track to
impact the Northern Rockies late this afternoon into Monday
morning. Pre-frontal southwesterly winds will begin to increase by
28/2000 this afternoon for all terminals (KBTM has already seen a
slight increase at this time). Damaging winds will reach
northwest Montana by 28/2300-29/0300z 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
expected. 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.

&&

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

     Red Flag Warning until 7 PM MDT this evening East Beaverhead.

     Winter Weather Advisory from midnight tonight to 11 AM MDT
     Monday Butte/Blackfoot Region.

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

     Winter Weather Advisory from 9 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 until 6 AM MDT Monday Lower Clark Fork Region.

     High Wind Warning until 6 AM MDT Monday Flathead/Mission Valleys.

     High Wind Warning until 6 AM MDT Monday West Glacier Region.

     Winter Weather Advisory from 9 PM this evening to 9 AM MDT
     Monday Potomac/Seeley Lake Region...West Glacier Region.

     High Wind Warning until 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.

     Winter Weather Advisory from 8 PM this evening to 8 AM PDT
     Monday Southern Clearwater Mountains.

     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.

&&

In the hours before

Local storm report, Mar 28, 3:09 PM PST, 3 hours 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
509 PM MDT SUN MAR 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0200 PM     NON-TSTM WND GST 6 E LONEPINE            47.70N 114.51W
03/28/2021  M54 MPH          LAKE               MT   MESONET

            MESONET STATION MTM57 5.7 E LONEPINE
            (MT-MESO).

&&

Local storm report, Mar 28, 3:42 PM PST, 3 hours 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
542 PM MDT SUN MAR 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0531 PM     NON-TSTM WND GST 3 NE KILA               48.15N 114.42W
03/28/2021  M49 MPH          FLATHEAD           MT   MESONET

            MESONET STATION DW0711 KILA.

&&

Local storm report, Mar 28, 4:01 PM PST, 2 hours 59 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
601 PM MDT SUN MAR 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0257 PM     NON-TSTM WND DMG 1 N LAKESIDE            48.03N 114.23W
03/28/2021                   FLATHEAD           MT   UTILITY COMPANY

            TREE DOWN WITH A POWER OUTAGE. 60 WITHOUT
            POWER.

&&

Local storm report, Mar 28, 4:02 PM PST, 2 hours 58 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
602 PM MDT SUN MAR 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0530 PM     NON-TSTM WND DMG 1 E CORAM               48.42N 114.03W
03/28/2021                   FLATHEAD           MT   UTILITY COMPANY

            TREE DOWN. 71 WITHOUT POWER.

&&

Local storm report, Mar 28, 4:04 PM PST, 2 hours 56 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
604 PM MDT SUN MAR 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0453 PM     NON-TSTM WND DMG 6 NNE MARION            48.18N 114.59W
03/28/2021                   FLATHEAD           MT   UTILITY COMPANY

            TREE DOWN, 277 WITHOUT POWER. ASHLEY LAKE
            ROAD.

&&

Local storm report, Mar 28, 4:05 PM PST, 2 hours 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
605 PM MDT SUN MAR 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0307 PM     NON-TSTM WND DMG 3 NW MARION             48.13N 114.71W
03/28/2021                   FLATHEAD           MT   UTILITY COMPANY

            TREE DOWN. 143 WITHOUT POWER.

&&

The radar

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

Open the radar archive at this moment

Event by event

3 high wind, 2 strong wind. Local standard time, as filed.

Strong Wind, Northern Clearwater Mountains

When: March 28, 7:00 PM PST to March 29, 2:46 AM PST
Where: Northern Clearwater Mountains forecast zone
Measured: 37 kt (43 mph) measured gust
Property damage: $1,000
Reported by: Mesonet
Coordinates: 46.674, -115.657 (the zone’s center; the record gives no point)

The highest observed wind gust of 43 mph was measured at the Dent RAWS along the northern shore of the Dworshak Reservoir. A power outage north of Weippe resulted in approximately 27 customers losing power.

High Wind, Orofino / Grangeville Region

When: March 28, 7:00 PM PST to March 29, 1:46 AM PST
Where: Orofino / Grangeville Region forecast zone
Measured: 56 kt (64 mph) measured gust
Reported by: Utility Company
Coordinates: 46.259, -115.562 (the zone’s center; the record gives no point)

Widespread wind gusts between 50 and 60 mph were observed during this storm with the peak wind gust of 66 mph occurring just northwest of Grangeville. Close to 4000 customers lost power during this event. Additionally, the Idaho Department of Transportation reported a few trees down on ID-12 east of Lowell, ID.

Strong Wind, Southern Clearwater Mountains

When: March 28, 8:00 PM PST to March 29, 3:00 AM PST
Where: Southern Clearwater Mountains forecast zone
Measured: 49 kt (56 mph) estimated gust
Property damage: $1,000
Reported by: RAWS
Coordinates: 45.844, -115.467 (the zone’s center; the record gives no point)

More than 600 customers were affected by power outages in an area from Grangeville to Elk City to Dixie, ID. In the mountains, there were multiple measured gusts in the 40s mph, while Hells Half RAWS (elevation of 8100 feet) measured the highest gust of 57 mph.

High Wind, Eastern Lemhi County

When: March 28, 11:00 PM MST to March 29, 6:00 AM MST
Where: Eastern Lemhi County forecast zone
Measured: 75 kt (86 mph) measured gust
Reported by: RAWS
Coordinates: 44.943, -113.933 (the zone’s center; the record gives no point)

With widespread measured wind gusts from 50s to 60s mph and the highest measured of 86 mph at Kriley creek RAWs, close to 1000 customers lost power during the event.

High Wind, Western Lemhi County

When: March 28, 11:00 PM MST to March 29, 6:00 AM MST
Where: Western Lemhi County forecast zone
Measured: 56 kt (64 mph) measured gust
Reported by: RAWS
Coordinates: 44.943, -113.933 (the zone’s center; the record gives no point)

Impacts were difficult to find. However, 12 customers lost power, and a max gust of 64 mph was measured at the Skull Gulch RAWS.

What these are

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

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

The same day elsewhere

Every storm in Idaho in 2021 Every state in 2021 This day in weather history Warnings in Idaho, 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: 944784, 944851, 944837, 944862, 949143.