MD 0454 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PORTIONS OF NORTHERN IL
Mesoscale Discussion 0454
NWS Storm Prediction Center Norman OK
1016 AM CDT Tue Apr 04 2023
Areas affected...portions of northern IL
Concerning...Severe potential...Watch possible
Valid 041516Z - 041645Z
Probability of Watch Issuance...40 percent
SUMMARY...An isolated supercell may continue to pose a risk for
large hail and sporadic damaging gusts across parts of northern IL
the next 1-2 hours.
DISCUSSION...An elevated supercell moving across east-central IA
into northwest IL has a history of producing large hail up to 2.5
inches in diameter and localized damaging wind gusts. This storm is
in an area of modest MUCAPE (500-1000 J/kg) and intense vertical
shear. Radar structure and evolution of this supercell has shown
potential intense rear-flank downdraft surges or possibility of
trying to develop a rear-inflow jet to transition from supercell to
bowing segment. As such, sporadic damaging gusts may continue
despite the elevated nature of the storm and a relatively cool/dry
boundary-layer. Additionally, strong shear and steep midlevel lapse
rates will continue to support large hail potential.
This cell may persist another couple of hours as it moves across
parts of northern IL along the instability gradient. Confidence in
longevity of this cell is low and the need for a watch unclear.
Given the isolated nature of convection a watch does not appear
imminent through trends will continue to be monitored.
..Leitman/Hart.. 04/04/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...ILX...DVN...
LAT...LON 41238984 41299029 41469044 41579049 41699045 41799037
41869021 41978920 41958882 41898856 41768841 41558840
41378851 41278876 41198921 41238984
