MD 1225 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF WESTERN SOUTH DAKOTA INTO CENTRAL NEBRASKA
Mesoscale Discussion 1225
NWS Storm Prediction Center Norman OK
0555 PM CDT Fri Jun 23 2023
Areas affected...portions of western South Dakota into central
Nebraska
Concerning...Severe potential...Watch likely
Valid 232255Z - 240100Z
Probability of Watch Issuance...80 percent
SUMMARY...Storm development will remain possible this afternoon and
early this evening across portions of western SD and central NE.
While uncertain, if storms can form ahead of additional storms
moving out of eastern WY, supercells capable of all hazards may
present enough threat for a new weather watch.
DISCUSSION...Through the afternoon, a broad but capped warm sector
across western SD and central NE has slowly destabilized with
1500-2500 J/kg of MLCAPE now evident on SPC mesoanalysis. While thus
far forcing for ascent has been minimal, inhibition has slowly
waned, and large-scale forcing should increase ahead of a compact
mid-level trough moving out of WY. A couple areas of potential CI
(see graphic) were noted with agitated cumulus evident on recent
visible satellite imagery. Recent hi-res model guidance suggests
storm initiation is possible in the next hour or two as the renaming
inhibition dissipates. Should storms develop, weak forcing, 40-50 kt
of effective shear and moderate buoyancy will support isolated
supercells capable of large hail. Some tornado threat may also exist
along an east-west oriented baroclinic zone near the NE/SD border
where low-level flow is backed and hodographs are larger.
Despite uncertainty a new watch may be needed to cover the potential
for storm initiation within the broad warm sector this evening.
Greater confidence in severe risk exists with additional storms
ongoing currently in eastern WY. Upscale growth should take place
over the next few hours with a line of storms likely to emerge into
western SD and central NE this evening. Damaging winds and a couple
of tornadoes will be possible with this round which is expected
after 02z tonight.
..Lyons/Thompson.. 06/23/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABR...LBF...UNR...BOU...CYS...BYZ...
LAT...LON 45500407 45530208 43870095 43550023 43209988 43059977
41999956 41179998 40640123 40990268 41430282 43080347
45390432 45500407
