Mesoscale Discussion 1848
NWS Storm Prediction Center Norman OK
0523 AM CDT Fri Aug 07 2026
Areas affected...parts of eastern South Dakota into southwestern
Minnesota
Concerning...Severe potential...Watch unlikely
Valid 071023Z - 071300Z
Probability of Watch Issuance...5 percent
SUMMARY...Thunderstorms may continue to increase in coverage, with
stronger storms accompanied by small to marginally severe hail
before consolidating into a more prominent cluster by 7-9 AM CDT.
With the risk for severe weather expected to remain limited, a
severe weather watch is not anticipated, but trends will be
monitored.
DISCUSSION...To the south of digging mid-level troughing across the
international border area, an associated cold front continues to
advance slowly southeastward across the northern Great Plains toward
the Upper Midwest. Based on forecast soundings, thermodynamic
profiles ahead of the front are characterized by a relatively cool,
stable boundary layer surmounted by dry elevated mixed-layer air
based around 850 mb.
However, within a pre-frontal corridor of lower/mid-tropospheric
warm advection across eastern South Dakota into southwestern
Minnesota, moisture return is contributing to sufficient
destabilization to support increasing thunderstorm development.
Deeper boundary-layer based moisture return appears confined to a
narrow corridor along a southwesterly pre-frontal low-level jet,
which is forecast to nose across the South Dakota/Minnesota state
border area through 13-15Z, before being overtaken by the cold
front.
Aided by destabilization in the presence of increasing large-scale
ascent, thunderstorm development may continue to increase into a
consolidating/upscale growing cluster. As this occurs, the
potential for small to marginally severe hail in stronger storms may
remain limited and/or tend to diminish, and a lingering near-surface
inversion layer probably will minimize the risk for severe surface
gusts.
..Kerr/Smith.. 08/07/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...FSD...ABR...
LAT...LON 45389640 45519545 45319454 44259435 43549569 43429654
43709737 45389640
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Source link