ACUS11 KWNS 302021
SWOMCD
SPC MCD 302021=20
NDZ000-SDZ000-MTZ000-WYZ000-302245-

Mesoscale Discussion 0906
NWS Storm Prediction Center Norman OK
0321 PM CDT Sat May 30 2026

Areas affected...Parts of eastern MT...northeast WY...southwest
ND...northwest SD

Concerning...Severe potential...Watch unlikely=20

Valid 302021Z - 302245Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong to severe storms are possible through late
afternoon.

DISCUSSION...Occasionally strong storms are ongoing this afternoon
across eastern MT, to the northeast of a negative-tilt mid/upper
shortwave trough approaching the central/northern High Plains. This
convection is ongoing within a weak to moderately unstable
environment, with generally limited deep-layer shear. Storms in this
area may tend to remain disorganized through the afternoon, though
marginally severe hail and localized strong gusts cannot be ruled
out in the near term.=20

In the wake of this convection, diurnal heating is underway from
northeast WY/southeast MT into northwest SD/southwest ND, where
somewhat stronger instability will evolve by late afternoon. Renewed
storm initiation will be possible with time, with the highest
confidence in redevelopment near the Big Horns and northern parts of
the Black Hills. Deep-layer shear will generally remain modest, but
a few stronger multicells could develop, accompanied by an isolated
hail threat. Increasingly prominent outflow may also lead to
localized strong to severe gusts, especially if any stronger
clusters or line segments evolve with time.

..Dean/Hart.. 05/30/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!4ZdB6fdo799jzfTsICCOElAi_OKfF_ORsi-haSp5GcMx4Biq0RysuTNZlSEbsJ0-O5kEN80gz= sDSywKvSpHiD3UgPT0$ for graphic product...

ATTN...WFO...BIS...UNR...BYZ...GGW...RIW...

LAT...LON 45160752 45600863 46930848 47620777 47890609 47730487
47400442 46400349 45630335 44930323 44720353 44560427
44360502 44150550 44320584 45160752=20

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


=3D =3D =3D
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