Mesoscale Discussion 0390
NWS Storm Prediction Center Norman OK
0303 PM CDT Sun Apr 12 2026
Areas affected...portions of northeastern Minnesota into far
northwestern Wisconsin
Concerning...Severe potential...Watch unlikely
Valid 122003Z - 122200Z
Probability of Watch Issuance...20 percent
SUMMARY...A conditional hail/tornado threat will accompany any storm
that develops and becomes sustained, though confidence in this
scenario is currently low.
DISCUSSION...A mid-level shortwave trough is currently overspreading
the Upper MS Valley region, prompting the eastward progression of a
surface low over northwestern Minnesota. Low-level moisture
convergence (evident via 60+ F surface dewpoints) is occurring along
the warm front ahead of the surface low (along a Cass to Carlton
County, MN line), with a separate differential heating boundary
noted from Cass to Pine Counties in MN. A cold front also extends
from roughly Cass to Big Stone Counties. Ahead of the cold front,
and in between the warm front and differential heating boundary,
some increase in CU has been noted. Mesoanalysis shows 1000-1500
J/kg MLCAPE in place over this region, with CINH continuing to
erode. Furthermore, mesoanalysis and RAP forecast soundings depict
elongated mid-level hodographs with modest low-level curvature and
over 40 kts of effective bulk shear.
The ambient environment along the warm front supports supercell
potential, accompanied by a hail and perhaps tornado threat should a
storm develop. The main question is if convective initiation will
occur given weak to modest deep-layer forcing for ascent. At the
moment, thunderstorm development is uncertain.
..Squitieri/Mosier.. 04/12/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...MPX...
LAT...LON 46019146 45889144 45759146 45659151 45519168 45409192
45349215 45449269 45679332 46019394 46289431 46679432
46899431 47079419 47139414 47189400 47169355 47009276
46809212 46349158 46019146
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
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