A moist, easterly upslope flow near the Crazy Mountains resulted in some heavy snow amounts.
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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.
The episode as NWS BYZ wrote it up.
A moist, easterly upslope flow near the Crazy Mountains resulted in some heavy snow amounts.
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 Mar 5, 2:18 AM MST, 42 minutes earlier.
Area Forecast Discussion
National Weather Service Billings MT
218 AM MST Sun Mar 5 2023
.DISCUSSION...
Today through Monday...
Satellite imagery shows southwest flow aloft with a couple of
embedded shortwaves, ahead of parent low along the Pacific coast.
One wave is lifting from northeast WY into the western Dakotas,
and we are seeing some light snow in Carter county (see Ekalaka
web cams). Another wave is lifting out of southeast ID and will be
today's main player. In fact, just recently we are starting to see
enhancement on BLX radar close to the foothills west of Billings
(indicative of increasing ascent). Further upstream, there is
another distinct wave moving into northern CA. So far we have only
seen intermittent light snow along our western foothills from
Livingston to Harlowton (i.e. upslope areas) but this will change
soon. BLX radar VAD winds show easterly flow to near 10kft msl as
of 2am.
We are poised to see a period of snow today and tonight as ID
energy tracks thru the region...and will make no changes to the
winter highlights in effect. A couple things to point out. As the
wave tracks near the MT/WY border, there will be a downslope
component along our southern foothills, with deep easterly flow a
bit north of the state line, and thus we expect greatest snowfall
amounts north and northeast of the foothills. Models are in
agreement in this regard. Also, by this evening, focus of heaviest
precip may lie along inverted trof axis thru southeast MT. Current
expectation is for this to lie near a line from Hysham to
Colstrip, Broadus and Alzada. Most areas in our cwa should see a
2-4" snowfall over the next 24 hours, but the aforementioned
convergent line could see 4-6". Obviously this will need to be
watched. Latest NBM probs show a good chance (>50%) of at least
1-2" of snow across the region. There is a 20-35% chance of 4+"
from the Bull Mountains to Powder River County. Sheridan will see
only an inch or less with this initial event.
Temps today should be fairly steady in the mid 20s to lower 30s.
This will result in some melting of the snow on area roads, and
elevation-dependent accums during the daytime hours. However, as
we cold advect from the northeast, we expect any wet roads to
freeze up fairly quickly in the late afternoon and early evening.
Metro model forecasts suggest the higher hills on I-90, I-94 and
US-212 may freeze as early as 4-5pm, while lower elevations turn
icy by 5-7pm. A heads up for your evening commute!
Precip will gradually become lighter or taper off late tonight,
but the reprieve will be short-lived as another wave arrives from
the southwest Monday morning. This should bring another 1-2" of
snow Monday to Monday night, with greatest amounts again north and
east of the foothills. NBM probs show a 20-40% chance of 2+" north
and east of Billings. Though our current winter highlights expire
at 15z Monday morning, there is a good chance these will need to
be extended through Monday or Monday night.
We are headed into a period of several days with high temps 15-20
degrees colder than normal. Look for mid 20s to lower 30s today,
mostly teens to around 20F tonight, then 20s to near 30 Monday.
JKL
Monday night through Saturday...
Broad cyclonic flow will be over the northern Rockies through the
period. This will provide cooler and unsettled weather the entire
week, even into early next weekend. There will be several waves
that provide the "best" chance of snowfall during this time, and
will focus the discussion on these days. That being said, there is
a decent chance of getting periods of snow through the week.
Energy will swing out the main trough to the west Monday and
Monday night. Heights will lower over eastern Montana and the
forcing will start to push into the southeast zones, especially as
Monday night enters. Snow will taper off late Monday night and
early Tuesday as lift slides into the Dakotas. Tuesday and
Wednesday looks less unsettled as the strongest dynamics remain
south of the area. An unstable atmosphere, cyclonic flow, and low
to mid level moisture availability, will prompt low snow chances
both days. The GEFS was advertising .2 to .4 inches of QPF for
most of the area, which would translate into 2 to 5 inches of new
snowfall. The EC ensembles were much more focused on the eastern
zones for the heaviest snowfall. So, still a lot to work through
here. Will keep temperatures cold and the pattern unsettled with
scattered to high scattered PoPs and allow the models to
eventually resolve this.
The end of the week into the early weekend is very problematic.
The GFS ensembles slowly lift the northern Rockies troughing into
the central plains. This will keep the cool and unsettled weather
going into Saturday. The EC ensembles aggressively build a broad
ridge over the western and central states, and therefore, it was
much warmer and drier. Obviously a lot to be worked through here
before confidence increases on the forecast going forward for
Friday through next weekend. TWH
&&
.AVIATION...
An approaching disturbance from the southwest combined with cooler
Canadian air will bring snow and deteriorating flying weather this
morning. Expect widespread MVFR-IFR in snow (affecting all
terminals), with local LIFR today and tonight. Mountains will be
obscured. Surface winds will be NE-E with gusts of 15-25 knots.
JKL
&&
.PRELIMINARY POINT TEMP/POPS...
Tdy Mon Tue Wed Thu Fri Sat
-------------------------------------------------------
BIL 030 017/028 013/029 013/028 017/028 015/031 015/033
9/S 86/S 31/E 12/S 44/S 22/S 33/S
LVM 029 015/026 010/030 012/029 012/029 012/034 016/035
9/S 75/S 21/B 11/B 22/S 12/S 33/S
HDN 031 015/029 010/030 009/030 015/029 011/032 011/032
9/S 86/S 42/S 22/S 55/S 42/S 33/S
MLS 031 015/026 014/026 010/026 015/028 015/026 011/027
8/S 64/S 53/S 22/S 45/S 43/S 22/S
4BQ 033 017/027 017/029 011/030 019/029 016/028 014/030
8/S 83/S 53/S 23/S 56/S 43/S 22/S
BHK 030 010/021 006/020 007/026 012/027 014/025 008/022
8/S 63/S 56/S 33/S 46/S 53/S 32/S
SHR 030 015/026 009/028 010/028 013/026 009/028 009/030
6/S 44/S 32/S 23/S 56/S 32/S 22/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until 8 AM MST Monday FOR
ZONES
29>34-36-37-40-42-56>58-63>66-138-141-169-170-173-228-235.
Winter Storm Warning in effect until 8 AM MST Monday FOR ZONE
172.
WY...None.
&&
weather.gov/billingsThe national radar mosaic for the moment the first event began.
2 winter storm. Local standard time, as filed.
Snowfall amounts of 6 to 8 inches were reported.
Snowfall amounts of 6 to 8 inches were reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2023Every state in 2023This day in weather historyWarnings in Montana, March 2023
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: 1079485, 1079486.