ACUS11 KWNS 301951
SWOMCD
SPC MCD 301951=20
WIZ000-MNZ000-302215-

Mesoscale Discussion 1400
NWS Storm Prediction Center Norman OK
0251 PM CDT Tue Jun 30 2026

Areas affected...Southeast Minnesota into Central and Northern
Wisconsin

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

Valid 301951Z - 302215Z

Probability of Watch Issuance...60 percent

SUMMARY...A conditional risk for severe thunderstorms capable of
mainly large hail and damaging winds appears to be materializing
across the discussion area this afternoon. Convective trends are
being monitored for a possible Severe Thunderstorm Watch.

DISCUSSION...Recent trends in visible satellite indicate a deepening
cumulus field along the nose of richer low-level moisture return
from the Rochester, MN, area into central WI, near Marshfield. The
shallow near-surface moisture profile observed by the 18z GRB
sounding is likely not representative of the boundary-layer
structure in the vicinity of the growing cumulus, where latest
objective analysis indicates MLCAPE of 3500-4500 J/kg with little to
no remaining convective inhibition.

In the absence of appreciable forcing for ascent and discernible
low-level boundaries, it remains unclear whether any storms that
initiate will become sustained and rooted within the strongly
unstable boundary layer. On the condition that storm initiation and
sustenance occur, the 18z GRB sounding sampled sufficient vertical
shear for supercells with the initial hazard being large hail.
Damaging wind potential would likely increase by late afternoon into
evening as storms coalesce along a common cold pool.

..Mead/Guyer.. 06/30/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!4eI6zNOzI3LQFa7Vl-1hGlA5H4Poq8wjmSR3Ell8TTUE_k9nZG7UlrrwYCS2etlD3cO6P1h9C= a6ihggSRz4nFKWnhYM$ for graphic product...

ATTN...WFO...GRB...DLH...ARX...MPX...

LAT...LON 45908981 45648899 44748888 44468950 44339009 44209072
44039244 44709263 45369211 45908981=20

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


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