Mesoscale Discussion 0950
NWS Storm Prediction Center Norman OK
0632 PM CDT Sat May 28 2022
Areas affected...extreme northeastern Wyoming...western South Dakota
and far southeastern montana
Concerning...Severe Thunderstorm Watch 281...
Valid 282332Z - 290100Z
The severe weather threat for Severe Thunderstorm Watch 281
SUMMARY...Two clusters of high-based storms will likely continue to
pose a risk for mainly damaging wind gusts and isolated hail over
the next couple of hours across WW281.
DISCUSSION...As of 2230 UTC, regional radar data showed a cluster of
thunderstorms ongoing across far northeastern WY, into southeastern
MT, and northwestern SD. Over the last hour, several reports of
50-60 mph gusts have been observed with this cluster as it tracked
quickly northeast. SPC mesoanalysis shows approx 500 J/kg of MLCAPE
ahead of the cluster suggesting storms will likely continue to pose
a risk for damaging wind gusts over the next hour or two. Farther
north however, cooler and more stable conditions are noted north of
a frontal boundary near the ND/SD border. Storms should gradually
weaken as they approach, and cross the frontal boundary later this
evening. Until then strong downdrafts may support damaging wind gust
potential with theses storms.
Farther south and east, more isolated thunderstorms, including a few
supercells were beginning to organize across portions of
south-central SD. Steep mid-level lapse rates (7.5-8 C/km) and
larger buoyancy (MLCAPE 1000-1500 J/kg) may support a risk for
isolated hail along with the potential for damaging outflow winds.
Latest WOFS/HRRR guidance also suggests some upscale growth may
occur later this evening. This outcome would favor locally greater
potential for damaging gusts, some of which could be 70+ mph. While
it remains unclear how storms will evolve, the potential for
damaging gusts and isolated hail should continue into this evening
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 43170216 44010300 44290339 44750407 44930438 45210477
45580486 45970463 46130407 46040272 45730216 45700203
45360168 44970136 44310122 43830117 43040133 42940156