A vigorous Pacific storm system moved into western Montana, with an associated strong upper jet. Large scale lift and a surface cold front caused widespread strong surface winds and significant precipitation totals.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
The episode as NWS MSO wrote it up.
A vigorous Pacific storm system moved into western Montana, with an associated strong upper jet. Large scale lift and a surface cold front caused widespread strong surface winds and significant precipitation totals.
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 Oct 16, 2:16 AM PST, 1 hour 14 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
416 AM MDT Tue Oct 16 2012
...POSSIBLE DAMAGING WINDS ACROSS NORTHERN ROCKIES TODAY...
.DISCUSSION...
A powerful Pacific jet stream will move across the Northern
Rockies today, producing potentially damaging winds and widespread
precipitation. For much of the region, the strongest winds gusting
40 to 50 mph will be present in the vicinity of a surface cold
front anticipated between this morning and early afternoon. Winds
surrounding the frontal passage will be erratic and may damage
trees and structures, as well as create hazardous crosswinds along
highways. As the cold front approaches the Continental Divide,
west winds gusting to 60 mph are expected this afternoon and
evening, including Butte and Interstate 90 Drummond to Homestake
Pass and beyond. Cross winds of this magnitude may cause high
profile vehicles to lose control and be blown off highways.
Precipitation will also be present across the Northern Rockies
today, with rain accumulations exceeding one inch over the
Clearwater Range of north central Idaho. Snow levels will slowly
drop to near mountain pass elevations overnight tonight, with
minor accumulations mainly over area mountain peaks.
High pressure is expected to return to the Northern Rockies
Wednesday afternoon through Thursday, with drier conditions
present. Thursday morning temperatures will drop to sub freezing
throughout the region, with partial clearing and calm wind
anticipated. Daytime temperatures will rebound somewhat before the
next round of storm systems this coming weekend.
A series of fairly moist and very cold storm systems are expected
to impact the Northern Rockies Friday through early next week. In
fact the first widespread low elevation snowfall this season may
be possible as soon as Sunday night. Strong winds also be possible
once again during this time as well.
&&
.AVIATION...Soggy start to the day this morning across all
terminals. Ceilings ranging between 4000 to 5000ft have been
observed across the area associated with this light precipitation. Light
rain will become showery throughout the morning before lifting and
yielding to strong and gusty winds today. Strongest winds appear
to begin at or around 15Z at KGPI and KMSO, working south and east
to KSMN and finally KBTM near 18Z. Sustained winds 30-40kts, along
with gusts up to 50kts will materialize as the front passes.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WARNING from 9 AM this morning to Midnight MDT tonight
Butte/Blackfoot Region.
HIGH WIND WARNING from 9 AM this morning to 9 PM MDT this
evening Bitterroot/Sapphire Mountains...Missoula/Bitterroot
Valleys...Potomac/Seeley Lake Region.
WIND ADVISORY until 6 PM MDT this evening Kootenai/Cabinet
Region...Lower Clark Fork Region.
HIGH WIND WARNING from 9 AM this morning to 9 PM MDT this
evening Flathead/Mission Valleys...West Glacier Region.
ID...HIGH WIND WARNING from 9 AM this morning to 9 PM MDT this
evening Eastern Lemhi County.
WIND ADVISORY until 5 PM PDT this afternoon Northern Clearwater
Mountains...Southern Clearwater Mountains.
WIND ADVISORY until 8 AM PDT this morning Lower Hells
Canyon/Salmon River Region...Orofino/Grangeville Region.
&&
Zumpfe
Aviation...Neigher
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https://www.twitter.com/NWSMissoulaThe national radar mosaic for the moment the first event began.
4 high wind, 2 heavy rain. Local standard time, as filed.
A 60 mph wind gust was measured 5 miles south southeast of Finn.
The Lowell ASOS measured 0.42 inch of rain in an hour.
Heavy rain was measured 4 miles southeast of Lowell when 0.57 inch fell in an hour.
A 62 mph wind gust was measured 10 miles west southwest of Shoup.
A wind gust was measured at 69 mph 4 miles south of Grangeville.
A wind gust of 62 mph was measured 1 mile north of Grangeville.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2012Every state in 2012This day in weather historyWarnings in Idaho, October 2012
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: 415555, 415554, 415553, 415552, 415548, 415549.