ACUS11 KWNS 131745
SWOMCD
SPC MCD 131745=20
MTZ000-131945-

Mesoscale Discussion 1271
NWS Storm Prediction Center Norman OK
1245 PM CDT Fri Jun 13 2025

Areas affected...Central into Eastern/Southeastern MT

Concerning...Severe potential...Watch likely=20

Valid 131745Z - 131945Z

Probability of Watch Issuance...80 percent

SUMMARY...Increasing thunderstorm coverage is expected across
central and eastern/southeastern MT this afternoon. Large to very
large hail and strong gusts are possible with these storms.

DISCUSSION...Despite relatively modest temperatures, still in the
mid/upper 60s, and low-level moisture, with dewpoints in the low to
mid 50s, the airmass is quickly destabilizing across central and
eastern MT. This destabilization is supported predominantly by
cooling mid-level temperatures, which are already -11 to -15 deg C
at 500 mb across the region. Southwesterly mid-level flow is
expected to gradually strengthen throughout the day as a shortwave
trough progresses across the Pacific Northwest into the region. The strengthening flow will contribute to orographic ascent across the
higher terrain, with large-scale lift also increasing ahead of the
approaching shortwave. Resulting combination of lift and
destabilization is expected to foster widespread thunderstorms
across the region.=20

Overall buoyancy is expected to remain relatively modest across
central MT, while increasing slightly with southeasterly extent
where better low-level moisture exists. Even so, there is enough
buoyancy for strong updrafts, particularly when combined with the
moderate to strong deep-layer vertical shear in place. Storms will
likely persist off the terrain into more of the High Plains. The
strong deep-layer shear will favor large to very large hail, with
some hail greater than 2 inches in diameter possible. Strong and
damaging outflow gusts that could reach or exceed 75 mph are also
possible. Overall, the tornado risk is low, but greater low-level
moisture and stronger southeasterly flow across eastern/southeastern
MT suggests there is a relatively higher risk there than areas
farther west.

..Mosier/Thompson.. 06/13/2025

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!9FriOs_kmoJ-bnWYhtdRxiQk_5Sc0UkoWyPHa6kY12vjxC2ePuaVfZJpKv-IkWqE_WZxSsJa7= o9tZfmMLjrCeyPeUNE$ for graphic product...

ATTN...WFO...BYZ...GGW...TFX...MSO...

LAT...LON 46561316 47741128 48340707 47790545 46220535 45250752
45321281 46561316=20

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


=3D =3D =3D
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