Winter Weather and Strong Wind in Montana, September 9 to 12, 2014

Name: Winter Weather and Strong Wind in Montana, September 9 to 12, 2014
Start: 2014-09-09T00:00
End: 2014-09-12T07:00
Location: Montana

September 9 to 12, 2014 · NWS MSO · 4 events in 4 counties and zones

A very cold air mass from Canada settled over western Montana and brought record cold temperatures, hard frost with crop damage and snowfall along the Continental Divide.

Where it happened

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.

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: $500
Crop damage: $50,000
Events: 4

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 very cold air mass from Canada settled over western Montana and brought record cold temperatures, hard frost with crop damage and snowfall along the Continental Divide.

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 Sep 8, 1:50 PM MST, 10 hours 10 minutes earlier.

Area forecast discussion, Sep 8, 1:50 PM MST, 10 hours 10 minutes before

Area Forecast Discussion
National Weather Service Missoula MT
250 PM MDT MON SEP 8 2014

...Breezy and Cooler conditions starting tonight and lasting
through Thursday night...

...Snow in the higher terrain along the Continental Divide,
especially across Glacier Park...

.DISCUSSION...Two fronts will impact the Northern Rockies tonight
and once again on Wednesday. The first front will push through
northwest Montana tonight around midnight causing gusty
northeasterly winds. The strong winds will be through Bad Rock
canyon and valleys around Essex and West Glacier. As the winds
increase over Flathead Lake, expect choppy conditions by Tuesday
morning. The largest waves are anticipated near the southern
portion of the lake. The front will bring some precipitation to
the Continental Divide, but amounts appear to be light. Snow
levels will fall to around 5000 feet with any accumulating snow
being confined to the highest terrain of Glacier Park.

A second front will swing through the region on Wednesday. The
timing of this secondary system is a little uncertain at this
time, but the best timing appears to be during the day on
Wednesday. This front will bring another round of gusty
northeasterly winds across western Montana. The air mass will
steadily cool with this next system keeping maximum temperatures
20 to 30 degrees below normal for this time of year. The snow
levels are anticipated to lower to around 4000 feet around Glacier
Park on Wednesday. Areas between 4000 to 5000 feet could receive
some light snow with most of impacting accumulations being above
5000 feet. Logan and Marias passes could receive 1 to 3 inches of
snow with the highest peaks of Glacier park getting up to 7
inches.

As the system exits the region Wednesday night into Thursday,
wrap around moisture could cause accumulating snow on MacDonald
and Homestake passes. The amount of snow is uncertain at this
time.

A ridge of high pressure is anticipated to build over the Northern
Rockies this weekend into the first part of next week allowing for
a warming and drying trend.

&&

.AVIATION...High pressure over Idaho and western Montana will
weaken through today as a Canadian cold front approaches the
region. The flattening of the ridge will bring an increase in
winds this afternoon. Cold air will begin to move through the gaps
of the Continental Divide late this evening with gusty northeast
winds expected overnight at KGPI. These winds will also extend
through northwest and west central Montana through Tuesday
morning and the rest of the region by Tuesday afternoon. Terrain
will also become obscured along the divide by clouds and snow
overnight and through Tuesday.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY from 6 AM Wednesday to 6 AM MDT Thursday
     ABOVE 5000 FEET for the West Glacier Region.

ID...None.
&&

The radar

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

Open the radar archive at this moment

Event by event

2 winter weather, 1 strong wind, 1 frost/freeze. Local standard time, as filed.

Winter Weather, West Glacier Region

When: September 9, 12:00 AM MST to September 10, 8:00 PM MST
Where: West Glacier Region forecast zone
Reported by: Park/Forest Service
Coordinates: 47.971, -114.069 (the zone’s center; the record gives no point)

Several inches of snow fell across the region as an arctic air mass pushed in from east of the Divide. The Going-to-the-Sun Road was closed from Big Bend on the west side to Jackson Glacier Overlook on the east side of Glacier National Park due to wind, snow, ice and limited visibility. At Marias Pass on US-2, snow fell with visibility being reduced to 1/2 mile at times. A weather spotter located nine miles north-northeast of Polebridge reported 7 inches of snow at 841 am MDT on the 11th. The COOP station in Polebridge saw a low of 16 degrees on the morning of the 12th.

Strong Wind, Flathead/Mission Valleys

When: September 10, 1:27 PM MST
Where: Flathead/Mission Valleys forecast zone
Measured: 39 kt (45 mph) estimated gust
Property damage: $500
Reported by: Trained Spotter
Coordinates: 47.872, -114.424 (the zone’s center; the record gives no point)

A spotter located in Ronan reported a tree with a three foot diameter base damaged by strong winds. Winds between 35 to 45 mph were reported from the Flathead to Mission Valleys as the cooler and more dense modified arctic air mass pushed southward. Flathead Lake saw choppy waves from the strong north to east winds causing the water to slop over into parking lots in Polson.

Winter Weather, Butte / Blackfoot Region

When: September 10, 8:00 PM MST to September 11, 9:00 AM MST
Where: Butte / Blackfoot Region forecast zone
Reported by: Department of Highways
Coordinates: 46.306, -113.025 (the zone’s center; the record gives no point)

The arctic cold front pushed through during the evening of the 10th and brought several hours of light to moderate snow to MacDonald Pass and subsequently snow-covered roads. This front continued its way south affecting Homestake Pass on I-90 and also the Butte area. A trained spotter located 6 miles south-southwest of Butte at 5900 feet measured 3 inches of snow through 744 am MDT on the 11th.

Frost/Freeze, Missoula / Bitterroot Valleys

When: September 12, 3:00 AM MST to 7:00 AM MST
Where: Missoula / Bitterroot Valleys forecast zone
Crop damage: $50,000
Reported by: Public
Coordinates: 46.560, -114.023 (the zone’s center; the record gives no point)

Several farms and orchards in the Missoula Valley saw damage to corn, tomatoes, squash, pumpkin and basil. A winery saw 25% loss to their grapes despite attempts at mitigation via watering and helicopter operations. The official low temperature at the Missoula International Airport was 25 degrees which broke the old daily record of 28 set back in 1988. It was also the 3rd coldest low in the first 15 days of September since records began in 1893.

What these are

Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.
Strong Wind: Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.
Frost/Freeze: Frost or temperatures at or below freezing during the growing season, usually filed for crop damage.

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

The same day elsewhere

Every storm in Montana in 2014 Every state in 2014 This day in weather history Warnings in Montana, September 2014

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: 544559, 544561, 544560, 544556.