MD 1323 CONCERNING SEVERE THUNDERSTORM WATCH 408… FOR PORTIONS OF EASTERN WY…WESTERN NE/SD AND FAR NORTHEAST CO
Mesoscale Discussion 1323
NWS Storm Prediction Center Norman OK
0859 PM CDT Wed Jun 28 2023
Areas affected...portions of eastern WY...western NE/SD and far
northeast CO
Concerning...Severe Thunderstorm Watch 408...
Valid 290159Z - 290330Z
The severe weather threat for Severe Thunderstorm Watch 408
continues.
SUMMARY...Ongoing storms will continue to pose a risk for large to
very large hail, damaging gusts and a tornado or two this evening.
Additional redevelopment across the western portions of the watch
area is also possible.
DISCUSSION...As of 0155 UTC, a cluster of severe storms, including a
recently tornadic supercell, were ongoing mainly across southern
portions of WW408. Located along a remnant surface boundary,
convection has maintained intensity and should continue to do so for
the next few hours. Weak upslope flow and moderate buoyancy/shear
will support strong supercellular updrafts capable of large to very
large hail, isolated damaging gusts, and a tornado or two. Recent
hi-res guidance also suggests some upscale growth of this convection
is possible tonight potentially supporting a greater risk of
damaging winds. Storms have thus far remained within WW408, but
local extensions or an additional watch may be needed later this
evening if convection begins to move out of the watch and or
persists beyond 0300z.
Farther west across WY/SD, redevelopment has been noted near the
north Laramie Range and Pine Ridge Escarpment. Hi-res guidance is
supportive of additional storm development/maintenance this evening
within a broadly favorable upslope environment of 1000 J/kg of
MLCAPE and 45-50 kt of effective shear. Should storms become
sustained, a supercellular mode would favor isolated large hail and
damaging gusts for a few more hours this evening across portions of
eastern WY and western SD.
..Lyons.. 06/29/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...UNR...GLD...BOU...CYS...
LAT...LON 41040161 40450189 40320217 40320273 40390318 40660402
41160482 42450552 43050604 44410564 44550549 44700510
44780443 44720371 44580316 44320277 44080251 43810229
43510203 42720162 42270161 41920161 41040161
