Tight east-west pressure gradients brought high winds to the northern portions of Sweet Grass County.
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The episode as NWS BYZ wrote it up.
Tight east-west pressure gradients brought high winds to the northern portions of Sweet Grass County.
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 2, 8:26 PM MST, 6 hours 4 minutes earlier.
Area Forecast Discussion...Updated
National Weather Service Billings MT
826 PM MST Mon Dec 2 2019
.UPDATE...
Few changes were made to the forecast. Current winds observations
are lower than anticipated and delayed by a couple hours. Winds
will continue to increase over the next 3 hours to advisory and
warning levels. A wind advisory is in effect for the Livingston
and Nye area. A high wind warning is in effect for Big Timber
area. Besides that change, the current forecast is valid.
Carrothers
&&
.DISCUSSION...
Tonight through Wednesday Night...
Overall, a quiet next couple of days can be expected across the
forecast area. A northwest flow aloft today and tonight will give
way to a westerly flow as high pressure ridging builds across the
forecast area Tuesday and Wednesday. This will result in rising
heights and above normal temperatures. Some Pacific moisture will
move across the central Rockies tonight and the northern edge of
this will bring a chance for snow showers to the
Beartooth/Absaroka Mountains.
Elsewhere, tight surface pressure gradients along the upper
Yellowstone Valley will result in windy conditions for Livingston
and the adjacent Beartooth/Absaroka Foothills for the remainder of
the day with strong wind gusts likely late this evening through
the day Tuesday. Model guidance keeps pressure gradients tight
through the day Tuesday with numerical guidance agreeing as well.
A wind advisory is currently in effect for this area through Noon
Tuesday but this advisory will be extended as strong wind gusts
will be likely through late afternoon. Wednesday will see partly
sunny skies with breezy to windy conditions continuing across the
lower elevations but strong winds are not expected. Hooley
Thursday through Monday...
Mean ensembles were in good agreement with the synoptic pattern
until Sunday, when there were differences in the handling of a
Pacific trough which will be the next precipitation producer for
the area. GEFS 850 mb temps showed decent spread through the
extended period which will create temp and precip.-type
uncertainty. Noted the GEFS Plumes showed mixed precip. for
Saturday in KBIL, Sat. night in KMLS and for Sunday in KSHR.
Again, precip. type will be uncertain. QPF was low through the
period.
Upper ridge Thursday through Friday will bring dry weather and
likely normal to above-normal temperatures. Ridge then breaks down
into Saturday, and a cold front will drop S through the area on
Sunday. Chances for rain and snow increase over the SW zones
through Sat., and will spread into the central areas Sat. night.
Chances for rain and snow continue across the area through Sunday
evening. Forecast will be mainly dry after late Sun. night. May
have to add freezing precip. to the system in future forecasts.
Added sub-highlight wind speeds to KLVM, Nye, Big Timber and K3HT
from Fri. afternoon through Sun. morning, based on the pressure
gradient. Had normal to above-normal temps Sat. onward. Arthur
&&
.AVIATION...
West/southwest winds will gust to 45-55 kt at KLVM to K6S0 and
along the Beartooth/Absaroka Foothills overnight into Tuesday.
LLWS is expected tonight into Tuesday morning over south central
and southeast MT and north central WY. VFR will prevail across the
area. Areas of obscuration in the Beartooths/Absarokas/Crazies
will continue into Tuesday. Arthur/RMS
&&
.PRELIMINARY POINT TEMP/POPS...
Tue Wed Thu Fri Sat Sun Mon
-----------------------------------------------------------
BIL 028/043 027/041 025/037 021/041 029/043 026/037 021/036
00/N 00/B 01/E 00/B 01/B 23/O 20/B
LVM 030/044 029/043 025/041 026/045 032/045 029/039 023/038
00/N 00/N 00/B 00/N 12/O 34/O 21/B
HDN 023/043 022/041 022/037 017/042 024/044 023/038 017/036
00/U 00/B 01/B 00/B 01/B 33/O 21/B
MLS 028/043 027/043 024/035 020/040 025/044 024/035 017/033
00/U 00/U 00/E 00/B 01/B 23/S 11/B
4BQ 026/043 024/042 023/036 019/039 025/043 024/036 017/032
00/U 00/U 00/E 00/B 01/B 12/S 11/B
BHK 026/041 025/041 023/032 019/038 025/041 021/031 013/028
00/U 00/U 00/E 00/B 01/B 12/S 11/B
SHR 022/045 022/044 020/040 018/044 024/045 023/039 017/036
00/U 00/U 00/B 00/B 01/B 23/O 31/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Wind Advisory in effect until 6 PM MST Tuesday FOR ZONES
65-66.
High Wind Warning in effect until 6 PM MST Tuesday FOR ZONE
141.
WY...None.
&&
weather.gov/billingsThe national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Winds gusted to 61 mph across the Big Timber area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2019Every state in 2019This day in weather historyWarnings in Montana, December 2019
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: 863647.