ZCZC SPCSWOMCD ALL
ACUS11 KWNS 201513 
SPC MCD 201513 
INZ000-ILZ000-WIZ000-201645-

Mesoscale Discussion 0850
NWS Storm Prediction Center Norman OK
1013 AM CDT Mon May 20 2024

Areas affected...Northern IL into southeast WI

Concerning...Severe potential...Watch possible 

Valid 201513Z - 201645Z

Probability of Watch Issuance...60 percent

SUMMARY...Strong to locally severe storms are possible later today.

DISCUSSION...An MCV and related surface reflection are moving
east-northeastward across eastern IA this morning. This feature is
expected to track along a warm frontal zone that is moving northward
from northern IL into southern WI. Along/south of the warm front,
diurnal heating of a relatively moist environment will result in
moderate destabilization, with MLCAPE expected to increase above
1500 J/kg by late morning/early afternoon. As this occurs, a zone of
stronger low/midlevel flow associated with the MCV will move across
the effective warm sector, resulting in a conditionally favorable
environment for organized convection. 

While most convection has been focused north of the warm front
through the morning, storm development appears imminent closer to
the warm front from far southern WI into northern IL. Stronger
storms, including the potential for organized clusters and a couple
supercells, are expected to develop from late morning into early
afternoon. Low-level shear/SRH will be sufficient to support a
couple tornadoes if supercells can be sustained within this regime.
Otherwise, damaging gusts and hail may accompany the stronger
storms. Watch issuance is possible if trends continue to support
storm development across the warm sector late this morning.

..Dean/Hart.. 05/20/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LOT...ILX...MKX...DVN...

LAT...LON   41288765 41008921 41198988 41468985 41668979 42618947
            43078938 43448892 43508820 43418778 43138735 42428713
            41768719 41288765 

NNNN