High Wind in Montana, December 21, 2018

Name: High Wind in Montana, December 21, 2018
Start: 2018-12-21T09:40
End: 2018-12-21T10:58
Location: Montana

December 21, 2018 · NWS BYZ · 2 events in 2 counties and zones

Tight surface pressure gradients across the area resulted in a few high wind gusts.

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 BYZ wrote it up.

Tight surface pressure gradients across the area resulted in a few high wind gusts.

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 21, 3:32 AM MST, 6 hours 8 minutes earlier.

Area forecast discussion, Dec 21, 3:32 AM MST, 6 hours 8 minutes before

Area Forecast Discussion
National Weather Service Billings MT
332 AM MST Fri Dec 21 2018

.SHORT TERM...valid for Tdy and Sat...

Cold front was around Butte area at 230 am this morning. Pre
frontal pressure pattern still producing strong winds at
Livingston and Nye at this time with gusts around 65 mph common.
We expect the front to move through our CWA early today, reaching
Livingston about 530 am and Billings by 8 am. Once the front moves
through the pressure gradient will relax along the Beartooth
Foothills, which will reduce the peak gusts. However, strong
westerly winds behind the front will develop from Livingston and
Big Timber up to Harlowton by midday. Soundinsg suggest 40 to 55
mph gusts will remain a possibility in these areas until late
afternoon.

In the meantime, the front will also bring across a shot of
Pacific moisture and lift to produce a few inches of snow in the
high country today, and perhaps some scattered areas of rain/snow
showers on the plains. The best chance of measurable precipitation
at the lower elevations is east of Billings where the downslope
affect becomes weaker. Pressure rises and cold air advection
behind the front this afternoon will create blustery to strong
winds that spread eastward into the plains. Gusts 25 to 40 mph are
likely, including the Billings vicinity.

Wind will quiet down tonight for most locations. There is a
secondary weak wave moving across northern Wyoming late today and
tonight, so expect some lingering light snow over the high
country. Dry northwest flow over the area is still on tap for
Saturday with breezy and somewhat cooler conditions. Winds will
pick up again in the foothills Saturday night as the pressure
gradient again tightens ahead of next short wave expected on
Sunday. BT

.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...

Another wind event is expected for Sunday and then tapering off
through the day Monday. With the fast moving flow aloft being
zonal to weakly ridging, and some lee-side surface troughing
expected, the pressure gradient along the foothills is expected to
increase again. Local guidance is showing that wind gusts will be
at least into the 40s and up to 55 mph. Otherwise, the mountains
will see a chance for some snow Sunday night.

The models for Christmas into the middle part of next week are
still more towards the splitting system dropping into the Four
Corners region. It still looks like the area may be on the fringe
of the system. However, while the deterministic models are still
in some agreement, there is still some substantial spread in the
ensemble guidance. Given the uncertainty have not made any
significant changes to the remainder of the extended. Reimer
&&

.AVIATION...

VFR conditions are expected to prevail through most of the
forecast period. A cold front will continue to move across the
area this morning. As it does expect brief reductions in flight
conditions and mountain obscurations through generally 18z. Winds
around KLVM will also decrease as the front moves through. Reimer

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sat     Sun     Mon     Tue     Wed     Thu
-------------------------------------------------------
BIL 046 024/040 021/042 028/044 025/033 019/031 018/029
    2/W 00/B    01/B    11/E    12/J    33/J    22/J
LVM 040 022/033 022/039 026/040 024/031 016/028 014/027
    6/W 00/N    01/N    22/W    23/J    22/J    22/J
HDN 048 020/042 015/044 023/045 020/034 018/031 016/029
    2/W 00/B    00/B    11/E    12/J    33/J    32/J
MLS 044 023/036 015/037 023/039 020/030 016/029 014/025
    3/W 00/N    00/U    11/B    11/E    34/J    33/J
4BQ 044 021/036 015/039 023/040 021/032 017/030 014/026
    3/W 00/N    00/U    01/E    11/E    34/J    33/J
BHK 044 022/036 015/037 021/040 019/027 014/028 012/025
    5/W 00/N    00/U    01/B    11/E    23/J    33/J
SHR 047 019/037 015/042 020/044 018/033 017/031 014/027
    2/W 00/B    01/B    11/E    12/J    33/J    22/J

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Wind Advisory in effect until 8 AM MST this morning FOR ZONES
      65-66.
WY...None.

&&

weather.gov/billings

In the hours before

Local storm report, Dec 21, 8:45 AM MST, 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
845 AM MST FRI DEC 21 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1212 AM     NON-TSTM WND GST 17 NE WILSALL           46.16N 110.38W
12/21/2018  M51.00 MPH       PARK               MT   MESONET

0318 AM     NON-TSTM WND GST 17 S FORT SMITH         45.07N 107.89W
12/21/2018  M53.00 MPH       BIG HORN           MT   MESONET

&&

TRC

Local storm report, Dec 21, 8:46 AM MST, 54 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
846 AM MST FRI DEC 21 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0515 AM     NON-TSTM WND GST 3 ENE LIVINGSTON        45.69N 110.50W
12/21/2018  M59.00 MPH       PARK               MT   DEPT OF HIGHWAYS

&&

TRC

Local storm report, Dec 21, 8:50 AM MST, 50 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
850 AM MST FRI DEC 21 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0115 AM     NON-TSTM WND GST 6 WSW RED LODGE         45.16N 109.36W
12/21/2018  M54.00 MPH       CARBON             MT   MESONET

0122 AM     NON-TSTM WND GST 3 W FISHTAIL            45.46N 109.57W
12/21/2018  M51.00 MPH       STILLWATER         MT   MESONET

0200 AM     NON-TSTM WND GST 1 S ROSCOE              45.34N 109.49W
12/21/2018  M54.00 MPH       CARBON             MT   DEPT OF HIGHWAYS

0400 AM     NON-TSTM WND GST 12 W LIVINGSTON         45.67N 110.80W
12/21/2018  M55.00 MPH       PARK               MT   DEPT OF HIGHWAYS

0404 AM     NON-TSTM WND GST 1 NW BURGESS JUNCTION   44.79N 107.54W
12/21/2018  M52.00 MPH       SHERIDAN           WY   MESONET

&&

TRC

Local storm report, Dec 21, 9:31 AM MST, 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
931 AM MST FRI DEC 21 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0845 AM     NON-TSTM WND GST 8 SSE WYOLA             45.03N 107.32W
12/21/2018  M54.00 MPH       BIG HORN           MT   DEPT OF HIGHWAYS

0910 AM     NON-TSTM WND GST 2 SSW SHERIDAN          44.77N 106.97W
12/21/2018  M51.00 MPH       SHERIDAN           WY   ASOS

&&

TRC

Event by event

2 high wind. Local standard time, as filed.

High Wind, Northern Sweet Grass

When: December 21, 9:40 AM MST to 10:40 AM MST
Where: Northern Sweet Grass forecast zone
Measured: 51 kt (59 mph) measured gust
Reported by: AWOS

A wind gust of 59 mph was recorded in the Big Timber area.

High Wind, Yellowstone

When: December 21, 10:58 AM MST
Where: Yellowstone forecast zone
Measured: 50 kt (58 mph) measured gust
Reported by: ASOS

A wind gust of 58 mph was recorded at the Billings Airport.

What these are

High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.

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

The same day elsewhere

Every storm in Montana in 2018 Every state in 2018 This day in weather history Warnings in Montana, December 2018

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: 799691, 799692.