Scattered mostly dry thunderstorms developed on the afternoon on the 28th with subsequent lightning leading to a fire that damaged a local hay crop.
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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 MSO wrote it up.
Scattered mostly dry thunderstorms developed on the afternoon on the 28th with subsequent lightning leading to a fire that damaged a local hay crop.
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 Missoula, MT wrote its last area forecast discussion before the first event at Jul 30, 12:44 PM MST, 2 hours 16 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
144 PM MDT Sun Jul 30 2023
.DISCUSSION...A ridge of high pressure with its axis over eastern
Montana, in conjunction with a closed low spinning along the
coast of British Columbia, is keeping the Northern Rockies under
southwest flow aloft. The jet stream is also positioned over the
northern U.S. The lower atmosphere will experience some drying
through Wednesday. The low-level drying will limit thunderstorm
development compared to the last few days, though isolated thunder
will still not be out of the question for this afternoon and
evening over northwest and southwest Montana. Combined with
modest instability, the dry lower atmosphere and high winds aloft
will mean increased winds will be able to descend to the surface.
Drier conditions and increased winds will be conducive to
increased fire danger, especially across the Bitterroot, southwest
Montana, and the Mission Valley for today and Monday. Red Flag
Warnings are in effect this afternoon for CSKT Tribal Lands and
the Bitterroot National Forest.
Ensemble model solutions begin to show a change after Wednesday.
Most members show an increase in precipitable water and continued
southwest flow. This pattern will suggest chances for more
convective storms by Thursday afternoon.
&&
.AVIATION... Mostly clear skies and VFR conditions will persist
over the Northern Rockies airspace today and Monday. Expect an
increase in westerly winds to about 20-25 knots this afternoon
and Monday at most locations. KGPI and KBTM will have a slight
chance for a shower or thunderstorm this afternoon.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Red Flag Warning until 9 PM MDT this evening for Flathead
Reservation.
Red Flag Warning until 9 PM MDT this evening for Bitterroot.
ID...&&The Missoula radar (KMSX), 112 km away, was scanning. The volume nearest the first event began at 21:58 UTC.
1 lightning. Local standard time, as filed.
A lightning caused fire consumed hay stored for winter cattle feeding at the Double K Ranch. More than 400 bales each weighting 1000 pounds were lost, which is a year's worth of feed for this ranch. Fencing was also lost in the fire.
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, July 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: 1106175.