800 ACUS11 KWNS 191731 SWOMCD SPC MCD 191731 INZ000-KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-191930- Mesoscale Discussion 0786 NWS Storm Prediction Center Norman OK 1231 PM CDT Tue May 19 2026 Areas affected...Lower Ohio River Valley Concerning...Severe potential...Watch possible Valid 191731Z - 191930Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorm coverage is expected to increase this afternoon across much of the Ohio River Valley as daytime heating brings the boundary layer to convective temperatures. These storms will primarily be capable of damaging straight-line winds and hail. DISCUSSION...Thunderstorms have begun to develop within moist and uncapped boundary layers where MLCAPE exceeds 2500 J/kg. Convective coverage is expected to increase throughout the afternoon, though will remain disorganized initially due to a lack of deep-layer shear. Still, large environmental DCAPE, steep low-level lapse rates, and relatively high PWATs will support strong downdrafts capable of damaging wind gusts. Localized corridors of increased threat could occur with any local organization along leading-edge outflow boundaries or with outflow boundary interactions. ..Halbert/Hart.. 05/19/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILN...LMK...IND...PAH...ILX...MEG...LSX... LAT...LON 37589038 38458917 39578772 39918713 40028678 40098648 40098622 40028577 39748540 39228521 38588528 38138563 37308700 36448861 36388874 36108926 36118947 36148962 36228993 36469026 36739039 37109047 37589038 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  319 ACUS11 KWNS 191744 SWOMCD SPC MCD 191744 OHZ000-MIZ000-INZ000-191915- Mesoscale Discussion 0787 NWS Storm Prediction Center Norman OK 1244 PM CDT Tue May 19 2026 Areas affected...Northern Indiana/Ohio into Southeastern Michigan Concerning...Severe potential...Watch likely Valid 191744Z - 191915Z Probability of Watch Issuance...80 percent SUMMARY...Thunderstorms capable of damaging wind gusts are anticipated this afternoon across portions of northern Indiana/Ohio into southeastern Michigan. A severe thunderstorm watch is likely. DISCUSSION...Current expectations are that thunderstorm coverage will continue to increase this afternoon in an environment characterized by steep low-level lapse rates, strong buoyancy, and modest deep-layer shear. This should support storm organization into linear segments capable of damaging wind gusts and hail, with the highest threat for damaging winds anticipated where any bowing line segments may develop. ..Halbert/Hart.. 05/19/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...DTX...IWX...GRR... LAT...LON 42378214 41688256 41408292 41228343 41038396 40668481 40808525 41058539 41408547 41708537 41828525 42358455 42818403 43218355 43448327 43578301 43698280 43758257 43618234 43268212 42908207 42378214 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN