ZCZC SPCSWOMCD ALL
ACUS11 KWNS 252002 
SPC MCD 252002 
IAZ000-MNZ000-SDZ000-NEZ000-252130-

Mesoscale Discussion 1601
NWS Storm Prediction Center Norman OK
0302 PM CDT Wed Aug 25 2021

Areas affected...northeast Nebraska...southeast South Dakota and
northwest Iowa

Concerning...Severe potential...Watch unlikely 

Valid 252002Z - 252130Z

Probability of Watch Issuance...20 percent

SUMMARY...A small storm cluster along the southeast South Dakota /
northeast Nebraska border may produce a few locally strong wind
gusts and some hail next couple hours. Threat does not appear
sufficient to warrant a WW.

DISCUSSION...This afternoon a small storm cluster is situated along
the NE/SD border moving east at around 40 kt. Sub-severe wind gusts
up to 45 mph have been reported. Activity is developing above a
stable near-surface layer within a weak warm advection regime and
updrafts based around 700 mb. Near-surface temperatures are modestly
warmer with larger temperature / dewpoint spreads downstream of the
storms, suggesting a somewhat greater threat for wind gusts might be
realized. Also steep mid-level lapse rates, moderate instability and
up to 45 kt effective bulk shear may support some threat for hail.
There is some chance the updrafts could become rooted in the surface
layer farther downstream. However, degree of surface-based
convective inhibition associated with a warm layer aloft lowers
confidence in this scenario and how long storms will persist.
Nevertheless, at least for the next couple hours, activity may
remain capable of producing a few strong gusts and hail as it
continues east.

..Dial/Kerr.. 08/25/2021

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

ATTN...WFO...FSD...OAX...LBF...

LAT...LON   43139898 43509786 43569590 42739579 42559869 43139898 

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