Mesoscale Discussion 0510 NWS Storm Prediction Center Norman OK 1144 PM CDT Sun Apr 20 2025 Areas affected...east Arkansas...northwest Tennessee...far west Kentucky...southeast Illinois...and southwest Indiana Concerning...Tornado Watch 156...158... Valid 210444Z - 210615Z The severe weather threat for Tornado Watch 156, 158 continues. SUMMARY...Thunderstorms will continue to slowly move east overnight. The tornado threat in Arkansas has sufficiently diminished to allow Tornado Watch #156 to expire at 12 AM CDT. Strong low-level flow may support a brief tornado or severe wind gust across Tornado Watch #158. DISCUSSION...A long-lived, mixed-mode convective line continues to move east across Arkansas, Missouri, and Illinois late this evening. Despite a favorable kinematic environment (0-1 km shear of 40-50 knots and 0-1 km SRH between 300-500 m2/s2), increasing convective inhibition and decreasing CAPE have resulted in a general decreasing trend in convective intensity. With the upper-/mid-level forcing moving farther away, this general decrease in intensity is expected to continue. Given the overall decrease in intensity, especially across Arkansas, Tornado Watch #156 will be allowed to expire at 12 AM CDT. Farther east/north in Tornado Watch #158, the strength of the kinematic environment may support a brief tornado or wind gust, despite the increasingly hostile thermodynamic environment. ..Marsh.. 04/21/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OHX...IND...PAH...ILX...MEG...JAN...LSX...LZK... LAT...LON 33869233 36578960 37468906 39148903 38748705 36458803 34459015 33279176 33869233 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
Category: Watches, Warnings, Advisories, & Hazards