MD 1372 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF NORTHEASTERN IA…NORTHERN IL…AND SOUTHERN WI
Mesoscale Discussion 1372
NWS Storm Prediction Center Norman OK
1256 PM CDT Sat Jun 22 2024
Areas affected…Portions of northeastern IA…northern IL…and
southern WI
Concerning…Severe potential…Watch likely
Valid 221756Z – 222000Z
Probability of Watch Issuance…95 percent
SUMMARY…Severe storms capable of producing damaging winds, a
couple tornadoes, and isolated large hail are expected this
afternoon into the evening. A watch is likely in the next hour or
two.
DISCUSSION…Latest visible satellite imagery indicates filtered
diurnal heating/destabilization of a very moist boundary layer
(middle 70s dewpoints) along/south of an east/west-oriented
stationary boundary extending across portions of northern IA into
southern WI. Over the next couple hours, a weak frontal wave
currently near far northwest IA will track eastward along the
boundary, promoting scattered thunderstorm development — aided by
the aforementioned destabilization and modest midlevel height falls
ahead of a midlevel trough.
Around 50 kt of midlevel westerly flow atop a 30-40-kt southwesterly
low-level jet (per regional VWP) will promote organized
surface-based storms (including a few supercells) near the boundary.
Easterly storm motions and deep-layer shear parallel to the boundary
may favor congealing cold pools and localized upscale growth, though
the favorable shear profile (large clockwise-curved low-level
hodographs) should encourage a few sustained semi-discrete
supercells. Damaging winds up to 70 mph, a couple tornadoes, and
isolated large hail are all possible with this activity. Current
thinking is that severe storms will develop/mature in the 19-20Z
time frame and persist into the evening hours. A watch is likely for
parts of the area in the next hour or two.
..Weinman/Hart.. 06/22/2024
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…LOT…MKX…DVN…ARX…DMX…
LAT…LON 41729328 41889371 42309395 42769393 43079356 43249277
43389085 43338912 43088858 42328852 41908884 41708959
41649094 41679239 41729328
