Wyoming, 2015

Winter Storm in Wyoming, December 14 to 15, 2015

December 14 to 15, 2015 · NWS BYZ · 1 event in 1 county or zone

An arctic front backed in from the northeast and moved westward across the Billings Forecast Area. A deep upslope flow was ushered in behind the front.

The toll

Deaths
0
Injuries
0
Property damage
None recorded
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.

What happened

The episode as NWS BYZ wrote it up.

An arctic front backed in from the northeast and moved westward across the Billings Forecast Area. A deep upslope flow was ushered in behind the front. This upslope flow combined with a strong, unstable disturbance aloft, resulted in heavy snow across the central and western portions of the area, as well as the mountain foothills locations.

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 Billings, MT wrote its last area forecast discussion before the first event at Dec 14, 9:26 AM MST, 4 hours 4 minutes earlier.

Area forecast discussion, Dec 14, 9:26 AM MST, 4 hours 4 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
926 AM MST MON DEC 14 2015

.SHORT TERM...VALID FOR TDY AND TUE...

GOING FORECAST IS IN GREAT SHAPE WITH RESPECT TO HIGHLIGHTS AND SNOWFALL
AMOUNTS. WEB CAMS HAVE SHOWN ACCUMULATIONS IN BIG TIMBER...AROUND
4 INCHES...COLUMBUS...2 INCHES...AND WILSALL...4.5 INCHES. RADAR
REFLECTIVITY DEPICTING THE DRY AIR NICELY IN AND AROUND BILLINGS
AT THE CURRENT TIME. HOWEVER...NICE BANDING IS JUST SOUTH OF
BILLINGS...SO EXPECTING SNOW TO START FLYING AND ACCUMULATING IN
THE NEXT FEW HOURS. ITS INTERESTING TO SEE HOW THE 850 MB FLOW IS
REALLY IMPACTING THE LOCATION OF THE DRY SLOT...AND THAT IT LIKELY
IS SNOWING PRETTY GOOD NEAR LAUREL AND PARK CITY.  THE EVENING
COMMUTE WILL BE TRICKY FOR THOSE IN THE BILLINGS AREA...AS THE
MOST SIGNIFICANT ACCUMULATIONS WILL LIKELY COME BETWEEN NOON AND 8
PM. SINGER

.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...

NORTHWEST FLOW ALOFT WEDNESDAY AND THURSDAY FOLLOWED BY A
FLATTENING RIDGE THAT MOVES INTO THE AREA ON FRIDAY AND
TRANSITIONS TO A FAST SOUTHWEST FLOW ALOFT ON SATURDAY WITH THIS
FLOW BECOMING MORE UNSETTLED BY SUNDAY.

CLIPPER SYSTEM IN THE NORTHWEST FLOW ON WEDNESDAY BRING ANOTHER
SHOT OF SNOW FOR THE REGION BUT ITS A BRIEF ROUND SO ADDITIONAL
ACCUMULATIONS WILL BE MINIMAL. COLDER AIR GETS PULLED INTO THE
AREA BEHIND THIS SYSTEM WHICH WILL WORK WITH THE SNOW COVER TO
YIELD THE COLDEST TEMPERATURES OF THE WEEK ON THURSDAY WITH
READINGS 10 TO 15 DEGREES BELOW NORMAL.

AS THE FLOW BECOMES WESTERLY ON FRIDAY TEMPERATURES MODERATE AND
WINDS WILL INCREASE ESPECIALLY FOR THE GAP FLOW AREAS. COULD BE
SOME AREAS OF BLOWING SNOW BUT IT SEEMS LIKE A SHORT WINDOW GIVEN
HOW QUICKLY TEMPERATURES WANT TO CLIMB ABOVE FREEZING. SATURDAY
WILL BE EVEN WARMER WITH NEAR FREEZING LOWS CONTRIBUTING STRONGLY
TO SNOW MELT. A SLOW COOLING TREND EXPECTED FOR SUNDAY AND MONDAY.
WITH INCREASING MOUNTAIN SNOW SHOWERS. BORSUM

&&

.AVIATION...

SNOW OVER WESTERN PORTIONS OF SOUTH CENTRAL MONTANA THIS MORNING
WILL MOVE EAST BRINGING IFR TO LIFR CONDITIONS THROUGH THE
REMAINDER OF THE DAY. MOUNTAIN OBSCURATIONS WILL ALSO BE A
PROBLEM. KBIL HAS BEEN SLOW TO SEE THE MVFR AND IFR CIGS AND VIS
START THIS MORNING BUT EVENTUALLY THEY WILL DROP DOWN AROUND 18Z
WHEN SNOW MOVES IN. EXPECT SIMILAR TIMING AND IMPACTS FOR KSHR.
SNOW WILL COVER ALL OF THE REGION THIS EVENING WITH WIDESPREAD
LIFR CONDITIONS. BORSUM/DOBBS

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY TUE     WED     THU     FRI     SAT     SUN
-------------------------------------------------------
BIL 033 021/027 013/024 007/020 004/033 029/044 029/036
    +/S +6/S    23/J    21/B    11/E    11/B    11/E
LVM 031 014/025 012/021 003/020 013/039 035/044 030/037
    +/S +4/S    33/J    31/B    12/J    11/N    32/J
HDN 036 021/030 009/027 003/022 902/030 021/045 026/039
    9/S +7/S    34/J    21/E    11/B    11/B    12/W
MLS 036 022/030 010/023 001/014 909/022 015/041 023/037
    7/S 97/S    42/J    21/E    11/B    11/B    11/B
4BQ 038 023/029 013/022 007/017 901/027 021/044 023/040
    5/S 99/S    62/J    21/E    11/B    11/B    11/B
BHK 033 019/028 014/021 006/015 904/023 014/041 021/037
    2/S 77/S    53/J    21/B    11/U    11/B    11/B
SHR 036 018/026 013/024 007/022 003/034 022/047 023/039
    8/S ++/S    62/J    22/J    11/B    11/B    11/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 PM MST TUESDAY FOR
      ZONES 28-29-34-35-39>42-56-63>68.
     WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MST TUESDAY
      NIGHT FOR ZONES 30>32-36-38-57-58.
     WINTER STORM WATCH IN EFFECT FROM 5 PM MST THIS AFTERNOON
      THROUGH LATE TUESDAY NIGHT FOR ZONES 33-37.
WY...WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MST TUESDAY
      NIGHT FOR ZONES 98-99.

&&

WEATHER.GOV/BILLINGS

Event by event

1 winter storm. Local standard time, as filed.

Winter Storm, Sheridan Foothills

When
December 14, 1:30 PM MST to December 15, 3:00 PM MST
Where
Sheridan Foothills forecast zone
Reported by
Trained Spotter

Snowfall of 10 inches was reported about 10 miles south of Sheridan.

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 Wyoming in 2015Every state in 2015This day in weather historyWarnings in Wyoming, December 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: 609684.