ZCZC SPCSWOMCD ALL
ACUS11 KWNS 252028 
SPC MCD 252028 
SDZ000-NEZ000-252230-

Mesoscale Discussion 1345
NWS Storm Prediction Center Norman OK
0328 PM CDT Sun Jul 25 2021

Areas affected...Portions of South Dakota

Concerning...Severe potential...Watch unlikely 

Valid 252028Z - 252230Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated to widely-scattered storms are possible in South
Dakota this afternoon/early-evening. Storm coverage is not certain,
but a few supercell storms could pose a threat for damaging winds
and large hail. No watch is anticipated, but trends will be
monitored.

DISCUSSION...Cumulus development along a weak warm front from
southwestern into northeastern South Dakota is increasing this
afternoon. With continued heating, as well as an expected weak
increase in 850 mb winds into the boundary this evening, may promote
isolated to widely-scattered storm development. Regional 12Z
observed soundings sampled steep mid-level lapse rates with
low-level lapse rates also quite steep given strong heating. Modest
northwesterly flow aloft has contributed to around 35-50 kts of
effective shear roughly perpendicular to the boundary. Storms would
likely be supercellular in character. Damaging winds and large hail
would be possible. Large hail would have a higher probability in
northeast South Dakota where shear is stronger. There is a fair
amount of uncertainty as to the coverage of storms as overall
large-scale support is weak. Some guidance does develop a small
cluster this afternoon and evening, however. Should that occur, a
greater wind gust threat would also develop. While a watch is not
currently anticipated, trends will continue to be monitored.

..Wendt/Hart.. 07/25/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FSD...ABR...LBF...UNR...CYS...

LAT...LON   43600296 44500168 45539946 45699841 45609797 45399765
            44929781 43410002 42890180 42730256 43050317 43600296 

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