ACUS11 KWNS 280339
SWOMCD
SPC MCD 280338=20
SDZ000-NEZ000-280545-

Mesoscale Discussion 1362
NWS Storm Prediction Center Norman OK
1038 PM CDT Sat Jun 27 2026

Areas affected...parts of north central Nebraska through south
central and southeastern South Dakota

Concerning...Tornado Watch 406...

Valid 280338Z - 280545Z

The severe weather threat for Tornado Watch 406 continues.

SUMMARY...Intensifying thunderstorms, perhaps including evolving
supercell structures ahead of an increasingly organized cluster, are
likely to pose an increasing risk for strong to severe wind gusts,
large hail and perhaps a couple of tornadoes through midnight to 2
am CDT, near and north of the Nebraska/South Dakota state border
area. A new severe weather watch will likely be needed within the
next hour or so.

DISCUSSION...Warmer elevated mixed-layer air (as generally depicted
by 16-18 C temperatures around 700 mb) continues to nose northeast
of the southern Rockies, downstream of the broad mid-level low
centered over the Northwest. As this continues through late
evening, latest Rapid Refresh suggests that a 700 mb thermal
gradient demarcating the stronger mid-level inhibition will focus
near the Nebraska/South Dakota state border by 05-07Z. Beneath this
regime, it appears that a surface cyclone is undergoing further
deepening as it migrates across and northeast of the Cheyenne Ridge
vicinity of the high plains. As this continues, a southerly 850 mb
jet across the Panhandle vicinity through north central Nebraska is
forecast to undergo notable further strengthening to 50-60+ kt.

It appears that strengthening low-level convergence and warm
advection near the nose of this jet, where inflow of seasonably high
moisture content with sizable potential instability will be
maintained, will support potential for substantive further
intensification, upscale growth and organization of ongoing
convection. The evolution of preceding supercell structures might
also not be out of the question, posing a risk for large hail and
perhaps a couple of tornadoes, while the potential for strong to
severe wind gusts increases with the evolving larger-scale
convective system.

..Kerr.. 06/28/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!6PRRHta3a6WRt9QRb0wg2jLPKnHdsrCOmB0-e_JU288PIMLqOdOHKd2jw-aQgakNdj0X_a65R= jP3MYZgwUih8dausuQ$ for graphic product...

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

LAT...LON 43340151 43740029 44059839 43209780 42369995 42490154
43340151=20

MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK WIND GUST...75-90 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


=3D =3D =3D
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* Origin: Capitol City Weather Station (1:2320/127)