ACUS11 KWNS 232131
SWOMCD
SPC MCD 232131 
MTZ000-WYZ000-232230-

Mesoscale Discussion 2104
NWS Storm Prediction Center Norman OK
0431 PM CDT Sun Aug 23 2026

Areas affected...portions of central and eastern Montana

Concerning...Severe potential...Watch likely 

Valid 232131Z - 232230Z

Probability of Watch Issuance...80 percent

SUMMARY...Widely scattered thunderstorms (including some supercells)
will continue eastward with a risk for severe gusts and isolated
hail. A downstream Watch is likely needed.

DISCUSSION...As of 2130 UTC, widely scattered thunderstorms were
ongoing across central MT. New convection was also developing near
the WY border. Ascent from an approaching upper trough should
continue to support these storms and any new development this
evening. Moisture is modest (40s and 50s F dewpoints), but strong
diurnal heating has steepened low and mid-level lapse rates enough
for moderate destabilization. This will support stronger updrafts as
they move eastward over the next couple of hours. 40-50 kt of
westerly flow aloft with supercells and some upscale growth into
linear clusters. The dry sub-cloud layer and flow aloft will favor
severe gusts, especially with clustering. Hail is also possible,
especially with any persistent supercells. Given the increasing
severe risk, a downstream Severe Thunderstorm Watch is likely needed
soon.

..Lyons/Thompson.. 08/23/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BYZ...GGW...RIW...TFX...

LAT...LON   49050884 49250603 49060504 48710487 48380473 47470496
            46050568 45270625 44940708 44760872 44920911 45330913
            46040889 48020883 49050884 

MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN