Montana, 2015

Winter Storm in Montana, November 3, 2015

November 3, 2015 · NWS MSO · 2 events in 1 county or zone

A closed low tracked east through southern Idaho on November 3rd, bringing snow and the first widespread travel impacts to Butte and southwest Montana for the 2015 - 2016 winter. Bert Mooney Airport in Butte, MT had to cancel multiple flights, and multiple accidents were reported from the slushy snow accumulations.

Where it happened

Every event with a place to put it; 2 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

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
2

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 closed low tracked east through southern Idaho on November 3rd, bringing snow and the first widespread travel impacts to Butte and southwest Montana for the 2015 - 2016 winter. Bert Mooney Airport in Butte, MT had to cancel multiple flights, and multiple accidents were reported from the slushy snow accumulations.

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 Nov 3, 3:58 AM MST, 3 hours 43 minutes earlier.

Area forecast discussion, Nov 3, 3:58 AM MST, 3 hours 43 minutes before
Area Forecast Discussion
National Weather Service Missoula MT
358 AM MST TUE NOV 3 2015

...Widespread snowfall across SW Montana and Lemhi County today...

.DISCUSSION...Periods of light snow have persisted overnight
across Lemhi County, ID and across SW Montana. However, all
indications suggest this is still just a foretaste of what's to
come today as a consolidated upper level low pressure system lifts
northeast out of Nevada, tracking across Idaho and Montana through
tonight. Overall, little change has been observed in the
models/forecast overnight, which basically match previous forecast
reasoning and still fully support the current suite of winter
weather highlights. If anything, the latest models suggest a
slight bump in precipitation/snowfall, with positioning of the
storm's wrap-around moisture a bit more to the west. When it's
all said and done, the valleys of SW Montana will see widespread
2-4 inches of accumulation, and locally up to 6 inches (including
Butte). The higher terrain will see widespread 4-6 inch amounts,
with some of the peaks measuring up to 10 inches!

Snow showers will taper off overnight and come to an end by midday
Wednesday. Dry air in between weather systems will lead to a
mostly clear sky and some very cold morning low temperatures on
Thursday, especially in the areas with fresh snowfall still
remaining on the ground.

Moisture moving southward out of British Columbia on Friday will
bring the return of precipitation, and could bring about the first
light coating of snow to many valley floors across western
Montana and central Idaho. Northwest flow will be conducive to
keeping lingering snow showers going through Saturday. The one
caveat to this forecast is the disagreement on how much moisture
will be available. One thing is for sure: prepare for an
unsettled, showery, colder beginning to the weekend for the
Northern Rockies.

Models agree on another brief ridge of high pressure persisting
through Sunday, although that's where most of their agreement
ends. The next system, which could impact the Intermountain West
as early as Sunday night/Monday morning, could produce measurable
precipitation area-wide. However, an influx of warmer air and
resultant rising snow levels may nix any chance of valleys seeing
snowfall. This will continue to be monitored closely.

&&

.AVIATION...Visibility reduction due to snow and fog are likely to
impact operations at KSMN and KBTM through the better part of
today. Periods of heavier precipitation are possible, especially
over the surrounding higher terrain which will also be completely
obscured through tonight. Although the precipitation will
gradually taper off overnight, areas of fog and/or stratus are
likely to develop by early Wednesday morning. Meanwhile KMSO will
be on the edge of precipitation and should bear little, if any
impact to aviating interests. This applies even more so to KGPI
which will be far north of anything but a few stray showers.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Warning until 11 PM MST this evening
     Butte/Blackfoot Region.

     Winter Weather Advisory from 6 AM this morning to 5 PM MST this
     afternoon Bitterroot/Sapphire Mountains.

ID...Winter Weather Advisory until 5 PM MST this afternoon Eastern
     Lemhi County...Western Lemhi County.

&&

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 storm. Local standard time, as filed.

Winter Storm, Butte / Blackfoot Region

When
November 3, 7:41 AM MST to 10:00 PM 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)

Roads were reported to have slushy accumulations of 3 to 6 inches in Butte, with at least 5 slide-offs accidents influenced by weather. Widespread storm accumulations of 3 to 6 inches were reported, with a highest estimated snow report of 7.0 inches 7 miles southeast of Butte, and the highest measured report of 6.5 inches 7 miles south of Butte. Additionally, the public reported 7 - 9 inches of snow over Homestake Pass.

Winter Storm, Butte / Blackfoot Region

When
November 3, 9:00 AM MST to 1:00 PM MST
Where
Butte / Blackfoot Region forecast zone
Reported by
ASOS
Coordinates
46.306, -113.025 (the zone’s center; the record gives no point)

The Bert Mooney Airport in Butte, MT had to divert a flight at 9am and cancel a flight at 12pm due to observations of 1/2 mile visibility along with overcast skies at 1000 feet.

What these are

Winter Storm
A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.

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

The same day elsewhere

More

Every storm in Montana in 2015Every state in 2015This day in weather historyWarnings in Montana, November 2015

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: 604791, 604805.