Idaho, 2021High Wind in Idaho, January 12 to 13, 2021
January 12 to 13, 2021 · NWS MSO · 1 event in 1 county or zone
A strong southerly pressure gradient developed ahead of a robust Pacific cold front to bring two distinct periods of high winds to the Camas Prairie. On the morning of the 12th, wind gusts near 60 mph ahead of the front brought severe cross-wind to US-95 south of Grangeville.
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- Deaths
- 0
- Injuries
- 0
- Property damage
- $20,000
- 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.
A strong southerly pressure gradient developed ahead of a robust Pacific cold front to bring two distinct periods of high winds to the Camas Prairie. On the morning of the 12th, wind gusts near 60 mph ahead of the front brought severe cross-wind to US-95 south of Grangeville. The second period of wind, associated with the passing cold front, occurred in the early morning hours of the 13th, and brought more widespread impacts to the area.
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 Jan 12, 1:36 PM PST, 8 hours 54 minutes earlier.
Area forecast discussion, Jan 12, 1:36 PM PST, 8 hours 54 minutes before
Area Forecast Discussion
National Weather Service Missoula MT
236 PM MST Tue Jan 12 2021
...Wet & Windy Weather This Evening Through Wednesday: Potential
For Damaging Wind Exists...
.DISCUSSION...Another surge of a copious amount of moisture will
arrive to the Northern Rockies this afternoon, and continue to
stream overhead through the day Wednesday. At the same time, warm
air aloft will drive snow levels up to around 7000 feet across
the entire region. This will lead to some impressive rainfall
amounts for this time of the year. Areas with the highest amounts
will be in the mountains along the Idaho & Montana border, and
along the Continental Divide where 1 to 3 inches of liquid
precipitation is expected. Some isolated higher amounts will be
possible, especially in the Cabinet Mountains in and around the
Bull River and Bull Lake area. Due to the amount of rainfall, rock
and mudslides will become a concern for the mid slopes and lower
elevations in north-central Idaho and the lower Clark Fork regions
of western Montana.
Another expected high impact from this weather system will be the
strong gusty winds that will accompany it. The potential for
damaging winds still exists for various locations across western
Montana and north-central Idaho, starting tonight and continuing
through the day Wednesday. First, a strong southerly pressure
gradient will setup near the Grangeville area, where winds are
already gusting in the low 40 mph range. As the front approaches
around midnight tonight, winds are expected to gust in excess of
50 mph, with isolated gusts over 60 mph. The High Wind Watch has
been replaced with a High Wind Warning starting this evening at 10
PM.
Strong southwesterly winds will arrive in western Montana just
before daybreak, and will continue through the day Wednesday.
Locations with the greatest threat for damaging winds, will be
along the Continental Divide and the Missoula/Bitterroot Valley.
High resolution forecast models are indicating the potential for
mountain waves developing, producing dangerous crosswinds along
Highway 93 south of Missoula, and Interstate 90 from Deer Lodge to
Anaconda. Isolated wind gusts in these regions could reach if not
exceed 60 mph in the morning and early afternoon hours. Isolated
downed trees and power outages will also be a concern in these
locations. Due to these expected wind impacts, the High Wind Watch
has been upgraded to a High Wind Warning for areas along the
divide and the Missoula/Bitterroot Valleys. All other locations in
western Montana previously under the watch, have been placed under
Wind Advisories. For further details in your local area, please
visit www.weather.gov/missoula.
After the front moves through the Northern Rockies in the late
afternoon and early evening, snow levels will crash to most valley
floors. The atmosphere will remain quite unstable allowing for the
development of intense snow showers. Snow bands are no longer an
elevated threat, however the quick hitting snow showers will be
capable of producing intense snowfall rates for a short period of
time through the evening.
High confidences exists for a ridge of high pressure to amplify
across the western US Thursday. Seasonal day-time highs are
anticipated with valley lows dropping into the teens and low-20s
Thursday and Friday.
A few weak upper level disturbances embedded within northwesterly
flow will impact the Northern Rockies Friday and Sunday. The
primary impacts will be felt across area mountain passes, where
periodic winter driving conditions are possible.
In the extended (January 20th onward), ensemble model guidance
continues to suggest a prolonged period of cold northwesterly flow
across the Northern Rockies. This pattern will favor the return
of wintry weather throughout Idaho and Montana. Stay tuned!
&&
.AVIATION...Another surge of a copious amount of moisture will
arrive to the Northern Rockies this afternoon, and continue to
stream overhead through the day Wednesday. Moderate to heavy
rainfall is expected for elevations below 7000 feet overnight
tonight and tomorrow. As the front approaches in the early morning
hours around day break, mountain wave activity is expected to
develop. Isolated wind gusts approaching 60 mph will be possible
along the north/south oriented valleys in western Montana. All
other locations can expect widespread 40 to 45 mph wind gusts
throughout the day. Mountain top winds could reach 70 mph in the
later afternoon and evening as a strong jet stream moves overhead.
Strong LLWS is expected for aviation sites KGPI, KMSO, and KBTM
during the day Wednesday.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Wind Advisory from 4 AM to 9 PM MST Wednesday Lower Clark Fork
Region.
Wind Advisory from 4 AM to 9 PM MST Wednesday Flathead/Mission
Valleys...Kootenai/Cabinet Region.
High Wind Warning from 5 AM to 9 PM MST Wednesday West Glacier
Region.
Wind Advisory from 5 AM to 9 PM MST Wednesday
Bitterroot/Sapphire Mountains.
High Wind Warning from 5 AM to 9 PM MST Wednesday
Butte/Blackfoot Region...Potomac/Seeley Lake Region.
High Wind Warning from 5 AM to 9 PM MST Wednesday
Missoula/Bitterroot Valleys.
ID...High Wind Warning from 10 PM this evening to 7 AM PST Wednesday
Orofino/Grangeville Region.
Wind Advisory from 5 AM to 9 PM MST Wednesday Eastern Lemhi
County...Western Lemhi County.
&&High Wind, Orofino / Grangeville Region
- When
- January 12, 10:30 PM PST to January 13, 6:31 AM PST
- Where
- Orofino / Grangeville Region forecast zone
- Measured
- 56 kt (64 mph) measured gust
- Property damage
- $20,000
- Reported by
- Mesonet
- Coordinates
- 46.259, -115.562 (the zone’s center; the record gives no point)
Besides frequent gusts above 60 mph in the Grangeville area, wind gusts up to 55 mph were observed at Greer in western Clearwater County. Power outages were observed during this event due to multiple trees down in the vicinity of Orofino and Grangemont. Trees and power poles were reported down on the Old Dent Bridge Rd. and on Grangemont Rd. between mile-markers 10 and 16. A smaller window of high impact occurred between 8am and noon PST on the 12th when southerly winds between 50 and 60 mph caused severe cross-wind on US-95 south of Grangeville and caused a tractor trailer to tip over on Whitebird Grade.
- 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.
- Flooding in Washington, January 12 to 16, 2021$2.9 million · 7 events
- High Wind in Washington, January 12 to 13, 2021$800,000 · 63 kt wind · 7 events
- High Wind in Montana, January 12 to 13, 202182 kt wind · 42 events
- High Wind in Montana, January 12 to 14, 202177 kt wind · 26 events
- High Wind in Wyoming, January 12 to 14, 2021$3,000 · 88 kt wind · 14 events
- Frost and Freeze in Texas, January 12 to 13, 20218 events
- Flooding and Coastal Flood in Washington, January 12 to 14, 2021$2,000 · 70 kt wind · 6 events
- Drought in Texas, January 12 to 31, 20214 events
- Winter Weather in Texas, January 12, 20214 events
- High Wind in Oregon, January 12 to 13, 202168 kt wind · 3 events
- High Wind in Alaska, January 12, 202165 kt wind · 3 events
- High Wind in Oregon, January 12 to 13, 202159 kt wind · 3 events
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: 937000.