Post-frontal conditions produced high winds across southeast Montana and North-central Wyoming.
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The episode as NWS BYZ wrote it up.
Post-frontal conditions produced high winds across southeast Montana and North-central Wyoming.
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 Apr 13, 1:33 AM MST, 9 hours 55 minutes earlier. Its key messages:
Area Forecast Discussion
National Weather Service Billings MT
233 AM MDT Sun Apr 13 2025
.KEY MESSAGES...
- Scattered showers and thunderstorms into the evening. A few
storms may produce wind gusts as high as 60 mph and small hail.
- Strong winds Sunday with gusts into the 40s (mph) with gusts
45-55 mph possible for SE MT.
- Potentially strong, wet weather system Wednesday night into
early Friday. Mountain snow and rain becoming a rain/snow mix
expected with this system.
&&
.DISCUSSION...
Through Tuesday night...
Winds will be strong today as a low pressure system currently on
the international border moves east into North dakota. The
backside of this low will feature 45-55 kt 850 mb winds and a
strong pressure gradient. These factors along with steep low level
lapse rates will combine to bring widespread wind gusts in the
40s mph across southeast Montana. Ensemble systems are in good
agreement that the strongest winds will be from Rosebud County and
east. These locations will have the best chance (30-50%) at
seeing wind gusts over 50 mph.
The low pressure system will also bring wrap around moisture and a
cold front bringing 40-70% precipitation chances to locations east
of Billings. Precipitation amounts are expected to remain light
with the NBM giving locations east of northern Rosebud County a
50-70% chance of getting greater than 0.1 inches. The
precipitation adds uncertainty to the wind forecast as soundings
indicate it will erase steep low level lapse rates. Any ascent
that may be associated with this precipitation may also hinder
downward momentum transfer.
Monday and Tuesday will see rising heights and warming
temperatures with 70s F returning by Tuesday. Dry conditions and
clear skies are expected both days. Torgerson
Wednesday through Sunday...
After a drastic shift from a weak weak shortwave to very dynamic
upper low swinging south through the NOrthern Rockies, most
ensemble solutions (~75%) continue to show the upper low scenario
panning out late Wednesday through Friday morning.
This scenario will result in deep, moist usplope flow occurring
alongside dynamic lift, resulting in a period of moderate to heavy
precipitation occurring across south-central MT and the Bighorn
Mountains and foothills. All mountains have a 50-75% chance to get
at least 10 inches of snow, and the foothills and surrounding
lower elevations have a 40-60% chance of getting at least 0.5" of
liquid precipitation. Despite highs approaching 70 on Wednesday,
the temperature drop associated with this system looks aggressive,
and while rain will be the dominating precip type at the start, by
the later half of Thursday it looks to switch to snow. Despite
being our wettest time of the year, guidance shows the precip
potential being anomalously high, and while exact details are
hard to determine this far out still, be prepared for ponding in
low- lying areas and small streams and hazardous road conditions
for the foothills.
While there is high confidence in some type of broad, upper ridge
returning next weekend, the uncertainty comes into play are any
shortwaves that keep temperatures from rising too much, and
possibly bringing about periods of off and on light precipitation.
Vertz
&&
.AVIATION...
LLWS still possible at KBIL/KSHR/KMLS/KBHK through this morning as
winds aloft maintain strength (30-45kts). LLWS will end as winds
mix out between 14-15z, but surface winds will be strong for most
of the day, slowly decreasing this evening. Expect occasional
drops to MVFR due to rain occurring at KMLS this afternoon. Vertz
&&
.PRELIMINARY POINT TEMP/POPS...
Tdy Mon Tue Wed Thu Fri Sat
-------------------------------------------------------
BIL 051 031/059 036/075 045/068 038/043 031/050 031/061
2/W 00/U 00/U 14/W 98/W 42/J 00/U
LVM 048 028/059 035/071 041/066 034/039 027/046 028/057
2/J 00/U 00/U 15/W 88/W 41/B 00/U
HDN 051 028/058 033/075 042/070 037/045 030/051 029/063
3/W 00/U 00/U 13/W 98/W 42/J 00/U
MLS 046 030/054 031/073 043/068 040/050 032/051 030/063
7/W 21/B 00/U 01/B 86/W 21/B 00/U
4BQ 048 030/051 032/073 043/069 041/047 032/049 030/060
3/W 01/B 00/U 01/B 77/W 42/J 00/U
BHK 046 028/051 027/069 039/068 038/049 028/049 027/060
7/W 41/N 00/U 01/B 66/W 21/B 00/U
SHR 049 026/054 030/072 040/070 036/044 027/045 025/058
3/W 00/U 00/U 02/W 89/W 64/J 10/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...High Wind Warning in effect from 6 AM this morning to 6 PM
MDT this evening FOR ZONES 33-36-37.
WY...High Wind Warning in effect from 6 AM this morning to 6 PM
MDT this evening FOR ZONE 199.
&&
weather.gov/billingsThe national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Sheridan asos recorded gust at 58 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2025Every state in 2025This day in weather historyWarnings in Wyoming, April 2025
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: 1252806.