ACUS11 KWNS 171659
SWOMCD
SPC MCD 171658=20
SDZ000-NEZ000-171830-

Mesoscale Discussion 0748
NWS Storm Prediction Center Norman OK
1158 AM CDT Sun May 17 2026

Areas affected...south-central SD into north-central NE

Concerning...Severe potential...Watch possible=20

Valid 171658Z - 171830Z

Probability of Watch Issuance...60 percent

SUMMARY...Severe thunderstorm potential will increase through early
afternoon downstream from ongoing elevated convection across
north-central Nebraska into south-central South Dakota. Area is
being monitored for possible watch issuance.

DISCUSSION...Elevated convection is ongoing at midday near the
surface cold front. Inflow ahead of this storm complex is aiding in northwestward moisture transport across NE and near a modifying
outflow boundary draped across north-central NE. With addition heating/moistening into early afternoon, convection developing along
the southern flank of this storm complex may eventually become
surface-based near the residual outflow boundary. Stronger
destabilization is expected into the afternoon and this currently
elevated activity may gradually become surface-based. Uncertainty
remains regarding how this area of convection will ultimately evolve
and how much severe potential will accompany this activity in the
short term, before a more substantial risk develops further east
later this afternoon. At least some large hail and damaging wind
risk may accompany initial convection. Trends will be monitored and
an initial watch issuance may be needed.

..Leitman/Mosier.. 05/17/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!9Hw4hIm0k0oITKCBONa6Nw-R7Tu4lYse0UZ6xFFSIvNtnyRak7V1gcTXv0N71xy-SMTRbdAJc= SC4jc_8sOqVQtUyFV4$ for graphic product...

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

LAT...LON 42870114 43679978 43739910 43339845 42499842 41859885
41659992 41670077 41850129 42260140 42870114=20

MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN


=3D =3D =3D
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