SPC MD 491

MD 0491 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN KENTUCKY INTO EASTERN OHIO AND WESTERN PENNSYLVANIA Mesoscale Discussion 0491 NWS Storm Prediction Center Norman OK 1138 AM CDT Sat Apr 18 2026 Areas affected...northern Kentucky into eastern Ohio and western Pennsylvania Concerning...Severe potential...Watch possible Valid 181638Z - 181915Z Probability of Watch Issuance...40 percent SUMMARY...Storms may strengthen through the afternoon with potential for strong to severe winds and some instances of hail. DISCUSSION...Remnant shower activity is ongoing across portions of the Ohio Valley from northern Kentucky into central Ohio. Ahead of this activity, temperatures are warming into the upper 70s to 80s amid broken mid-level cloud cover with increasing cumulus observed in visible satellite. Dew points are largely in the mid to upper 50s, with a better plume of 60s dew points across northern Kentucky. The cold front remains further west, extending from northern Arkansas into central Indiana/northwestern Ohio. Guidance suggests that some strengthening of activity along the leading edge of the shower activity may be possible into the afternoon. Though MLCAPE remains marginal, with around 250 J/kg ahead of the ongoing activity in northern Kentucky, steep low to mid-level lapse rates (7-8 degrees C/km), and strong deep layer shear (around 40-50 kts) may support a few more organized storms to develop. Should that occur, strong to severe winds and marginally severe hail may be possible. Confidence in the exact evolution of thunderstorm activity remains low but trends will be monitored. ..Thornton/Hart.. 04/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK... LAT...LON 37488411 37818446 39408365 40748245 41248198 41458150 41528118 41498085 41468062 41368029 41288008 41187991 41007974 40927968 40597957 39428014 39078052 38778086 38328134 38118159 37728235 37328333 37488411 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more