366
ACUS01 KWNS 080059
SWODY1
SPC AC 080058

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0758 PM CDT Mon Sep 07 2026

Valid 080100Z - 081200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER CENTRAL NORTH
DAKOTA AND SOUTHEAST SOUTH DAKOTA...

...SUMMARY...
The threat for widely scattered severe storms capable of large hail
and perhaps a tornado or two will continue over central North Dakota
and southeast South Dakota into tonight. More isolated occurrences
of large hail and severe wind gusts remain possible this evening
over the central High Plains.

...Northern Plains...

Two separate severe thunderstorm regimes have evolved late this
afternoon into evening. The first is over northwest into central ND,
where widely scattered storms --including a supercell-- are ongoing
ahead of a cold front pushing through western ND. The 00Z BIS
sounding showed modestly steep low-level lapse rates and a moist
boundary layer with MLCAPE CAPE of around 3000 J/kg. The
corresponding wind profile was quite supportive of updraft rotation
with effective SRH of around 300 m2/s2 and 60 kt of effective bulk
shear, suggesting the supercell north of BIS will remain capable of
large hail and a tornado or two for the next hour or two.
Thereafter, increasing convective inhibition may result in the
gradual weakening of the storms with a decreasing severe weather
threat.

For additional near-term guidance on that regime, see recently
issued MCD #2268.

The second thunderstorm regime is evolving across portions of
northeast NE into southeast SD, near the intersection of a
differential heating zone/outflow boundary and a pre-frontal trough.
 The boundary layer to the north of the baroclinic zone over
southeast SD is slightly cooler with some convective inhibition
noted in latest objective analysis fields. However, the presence of
MLCAPE up to 2000-3000 J/kg, which coincides with 35-40 kt of
deep-layer shear is supportive of supercells with the primary hazard
being large hail, potentially in excess of two inches. The nocturnal
strengthening of the low-level jet is resulting in enlarging
low-level hodographs with effective SRH of 300-400+ m2/s2, per
objective analysis. A tornado recently occurred with the ongoing
storms near the NE-SD border with an additional tornado or two
remaining possible this evening before convective inhibition
increases further.

..Mead.. 09/08/2026

$$