Montana, 2014

Avalanche and High Wind in Montana, December 20 to 24, 2014

December 20 to 24, 2014 · NWS TFX · 7 events in 6 counties and zones

A strong upper level jet stream moved across the Rockies bringing very strong winds that spread east across the adjacent plains.

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
7

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 TFX wrote it up.

A strong upper level jet stream moved across the Rockies bringing very strong winds that spread east across the adjacent plains.

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 Great Falls, MT wrote its last area forecast discussion before the first event at Dec 20, 10:35 PM MST, 25 minutes earlier.

Area forecast discussion, Dec 20, 10:35 PM MST, 25 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1035 PM MST Sat Dec 20 2014

Updated Aviation Discussion

.DISCUSSION...
Update forthcoming. Have lowered temperatures a tad in areas where
advancing clouds have yet to arrive. With clouds overspreading the
area from the west overnight, temperatures will not drop too far.
High wind highlights will remain in place, though wind speeds are
currently below warning criteria along the Rocky Mountain Front.
Latest RUC analysis indicates westerly winds aloft will strengthen
considerably after 10z. Winter Weather Advisory highlights will also
continue. Snow has begun over the Rocky Mountain Front and over
portions of southwest Montana. Snow not expected to begin over the
Central mountains until after midnight, closer to daybreak.

&&

.AVIATION...
UPDATED 0535Z.
A strengthening and increasingly moist West/Northwest flow aloft
will move across the Northern Rockies and MT tonight through Sunday.
This will spread increasing cloudiness across the region tonight
with precipitation and terrain obscurations spreading east over the
mountains tonight and continuing through Sunday. Precipitation will
spread into the KBZN terminal vicinity after 08z with occasional
MVFR in lower CIGS/-SN late tonight through Sunday morning before
conditions improve some Sunday afternoon. Precipitation will be less
widespread at lower elevations of Central/N-Central MT and snow
levels will be around 4000-5000 ft MSL. W-NW winds aloft increase to
around 50kts at ridgetops by Sunday morning with Mtn wave turbulence
likely east of the Rockies and gusty surface winds likely at most
terminals by Sunday afternoon. Hoenisch

&&

.PREV DISCUSSION...Issued 303 PM MST Sat Dec 20 2014

Tonight through Monday...A plume of moisture is pushing through
the Pacific Northwest on a strong westerly jetstream. Ridging
further west will turn the upper level flow northwesterly,
positioning western and southwest Montana beneath the jet exit
region. A shortwave trough will move through this flow from
British Columbia to eastern Montana, causing a lee surface trough
to develop. The overall result is heavy mountain snow, areas of
light rain at low elevations, and strong winds across central
Montana. Little, if any precipitation is expected for western
portion of the central plains. Areas of light freezing rain are
possible tonight generally north and east of the Bears Paw
mountains as warmer air spreads over a colder airmass in northeast
Montana.

Wind gusts will strengthen along the Rocky Mountain Front early
Sunday where a high wind warning remains in effect. Strong wind
gusts will extend further east onto the adjacent plains, but the
high wind watch continues with lowered confidence that winds here
will reach warning criteria. Winter weather advisories now cover
the Rocky Mountains above 5000 feet and for the Central and
Southwest mountains above 5500 feet. Travelers through mountain
passes on Sunday should expect snow covered and icy roads. Snow
will be later to start in the Little Belt and other central
Montana ranges...and will likely continue later into Monday. Nutter

Monday night through Saturday...Shortwave ridge develops over the
region Monday night into Tuesday afternoon with dry conditions at
lower levels but scattered to numerous showers over the mountains.
Temperatures are expected to be generally near or above seasonal
averages. For Christmas Eve and Christmas Day...a Pacific storm
system will affect much of the region. At this time, it appears
that anticipated snow amounts west of a line from Cut Bank to
Lewistown should see 3 to 5 inches of snow over the plains with 6
to 15 inches in the mountains. For areas east of this line...snow
accumulations should range from 1 to 4 inches over the plains with
3 to 8 inches in the mountains. It should be noted that the record
snowfall for Great Falls on Christmas day is only 4.4 inches...and
we might have a chance at that record should a heavier snowband
move through Great Falls. Overall this is not a major storm...but
the timing for precipitation during a major holiday period will
affect travel. Temperatures will also trend colder from Wednesday
through Friday. There is the chance that temperatures on Christmas
Day could be a bit colder than currently forecast because of
clouds/snowfall. After this storm exits the region late
Thursday/early Friday...the weather pattern will become a bit less
active. There will be a small chance for a passing snow shower
over the weekend and into the New Years week...but no significant
snowfall is expected at this time. The main concern tonight is the
GFS13/EC are hinting at some very cold air moving into the region
by Tue Dec 30th...again this is a ways out...and things can change
a bit...but at this time current models are trying to bring down
another batch of arctic air before New Years. Brusda/mpj

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  33  49  31  39 /  20  50  30  30
CTB  26  43  28  36 /  20  40  30  20
HLN  30  47  31  38 /  50  80  40  30
BZN  27  45  27  34 /  70  90  50  30
WEY  30  39  21  31 / 100 100  90  50
DLN  34  46  29  35 /  70  90  60  30
HVR  24  44  27  38 /  20  70  20  20
LWT  31  48  30  37 /  30  80  40  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 7 PM this evening to 5 AM MST
Monday FOR ELEVATIONS ABOVE 5000 FEET FOR Central and Southern
Lewis and Clark...Jefferson...Northern Rocky Mountain Front...
Southern Rocky Mountain Front.

HIGH WIND WATCH from late tonight through Sunday afternoon
Eastern Glacier...Eastern Pondera...Eastern Teton...Liberty...
Toole.

HIGH WIND WARNING until 5 PM MST Sunday Northern Rocky Mountain
Front...Southern Rocky Mountain Front.

WINTER WEATHER ADVISORY from 7 PM this evening to 5 AM MST
Monday FOR ELEVATIONS ABOVE 5500 FEET FOR Beaverhead...
Broadwater...Cascade...Gallatin...Judith Basin...Madison...
Meagher.

&&

weather.gov/greatfalls
www.twitter.com/NWSGreatFalls
www.facebook.com/NWSGreatFalls

Event by event

6 high wind, 1 avalanche. Local standard time, as filed.

High Wind, Southern Rocky Mountain Front

When
December 20, 11:00 PM MST to December 21, 4:00 PM MST
Where
Southern Rocky Mountain Front forecast zone
Measured
54 kt (62 mph) measured gust
Reported by
Mesonet

High wind gusts, measuring 54KT (62MPH), were reported 17 mi W of Pendroy, MT.

High Wind, North Rocky Mountain Front

When
December 20, 11:00 PM MST to December 21, 4:00 PM MST
Where
North Rocky Mountain Front forecast zone
Measured
54 kt (62 mph) measured gust
Reported by
Department of Highways

High wind gusts, measuring 54KT (62MPH), were reported 1 mi E of East Glacier Park, MT at the Two Medicine Bridge DOT sensor.

Avalanche, Gallatin

When
December 21, 12:00 AM MST to December 22, 12:00 AM MST
Where
Gallatin forecast zone
Reported by
Park/Forest Service

Two reported avalanches: |1. Silken Slot in Hyalite - 2 climbers almost swept off Silken Slot.|2. Killer Piller in Flanders - Climbers nearly hit at the base of climb.

No injuries were reported.

High Wind, Southern Lewis and Clark

When
December 21, 11:00 AM MST to 2:00 PM MST
Where
Southern Lewis and Clark forecast zone
Measured
60 kt (69 mph) measured gust
Reported by
Department of Highways

High wind gusts, measuring 60KT (69MPH), were reported 8 mi SW of Wolf Creek, MT at the Sieben Flats DOT sensor.

High Wind, Broadwater

When
December 21, 12:00 PM MST to 8:00 PM MST
Where
Broadwater forecast zone
Measured
51 kt (59 mph) measured gust
Reported by
RAWS

High wind gusts, measuring 51KT (59MPH), were reported 3 mi WNW of Townsend, MT.

High Wind, North Rocky Mountain Front

When
December 23, 3:00 PM MST to 11:00 PM MST
Where
North Rocky Mountain Front forecast zone
Measured
52 kt (60 mph) measured gust
Reported by
Department of Highways

High wind gusts, measuring 52KT (60MPH), were reported 1 mi E of East Glacier Park, MT at the Two Medicine Bridge DOT sensor.

High Wind, Madison

When
December 24, 7:00 AM MST to 2:00 PM MST
Where
Madison forecast zone
Measured
37 kt (43 mph) measured sustained
Reported by
Department of Highways

High sustained winds, measuring 37KT (42MPH), were reported 4 mi NE of McAllister, MT at the Norris Hill DOT sensor.

What these are

High Wind
Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
Avalanche
A mass of snow sliding down a mountainside that caused a death, an injury or damage.

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

The same day elsewhere

More

Every storm in Montana in 2014Every state in 2014This day in weather historyWarnings in Montana, December 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: 552716, 552717, 552722, 552718, 552719, 552721, 552720.