ZCZC SPCSWOMCD ALL
ACUS11 KWNS 162040 
SPC MCD 162040 
ILZ000-WIZ000-162215-

Mesoscale Discussion 0464
NWS Storm Prediction Center Norman OK
0340 PM CDT Tue Apr 16 2024

Areas affected...portions of northern/central IL

Concerning...Severe potential...Watch possible 

Valid 162040Z - 162215Z

Probability of Watch Issuance...40 percent

SUMMARY...Severe potential may slowly increase over the next few
hours into parts of northern and central Illinois. A watch may be
needed at some point late this afternoon, but timing remains
uncertain.

DISCUSSION...A band of storms continues to lift northeast across
eastern IA into western IL this afternoon. Much of the convection is
somewhat disorganized in a messy storm mode. Downstream into
northern/central IL, some modest increase in boundary-layer moisture
still may occur as a warm front lifts north. While strong heating
has occurred, some weak inhibition remains over parts of the area.
Nevertheless, modest boundary-layer moisture beneath midlevel lapse
rates around 7 C/km are supporting weak instability (MLCAPE 1000
J/kg or less). The initial band of convection moving toward the MCD
area may largely remain unproductive. However, as large-scale ascent
increasing toward evening, a secondary band of convection may move
into the area and post more of a severe risk. Given the somewhat
limited thermodynamic environment (despite favorable vertical
shear), severe potential may only gradually increase toward evening.
The area will be monitored for potential watch issuance, but timing
is uncertain.

..Leitman/Guyer.. 04/16/2024

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

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

LAT...LON   42588989 42398864 41868769 41098752 40288757 39768819
            39688902 40068964 41318962 42588989 

NNNN