Breaking down Monday's threat for severe weather

 Monday will continue the streak of active weather this April with yet another threat for severe storms. This potential has a very high ceiling with potent severe weather possible, but is very conditional. A round of storms will develop Sunday night across the Southern plains and work toward the Ohio River valley Monday morning. The placement and evolution of these storms is very important to see how the afternoon storm environment will look.

There is a chance the morning storms work to lay down an outflow boundary and wipe out the environment for the afternoon. If the early day round of storms fizzles out or moves through quicker, the afternoon window could be more potent for storms. The highest confidence on a severe weather risk will remain primarily South of I-80 in Central Illinois with a better chance to see the environment recover following any morning storms. Conversely, there is less confidence that far Northern Illinois will have enough time to recover following any morning activity. There is still a potentially high end severe risk locally, but it hinges greatly on how quickly morning storms are able to clear out.

We will have two rounds of storm activity locally in the Stateline. One round early in the day and another late afternoon-evening round. 8AM through 3PM will bring scattered, but largely non-severe storms. Heavy rain and small hail may still be possible, but the severe threat will be low with this wave. Late afternoon into evening will bring a higher risk for strong to severe storms, but as mentioned above, hinges on how quickly the morning round clears out. Severe storms will be most likely between 3-8PM locally, with some scattered storms remaining through 10PM-12AM but quickly decreasing severe threat during that time.

IF all comes together with the morning round clearing and atmosphere recovering for the afternoon window, all hazards of severe weather may be possible -- including some tornadoes. Storms will initially develop in discrete supercell structures with a higher threat for tornadoes and large hail. But quickly those storms will merge into a line or cluster, enhancing the wind threat. Embedded tornadoes will remain possible during this time as well.

This is one of those potentially higher-end scenarios that also has high uncertainty. It will depend very heavily on how the storms to the West evolve overnight and where outflows are laid by early morning. If all falls into place, a widespread severe weather outbreak is possible. But if morning storms wash out the environment, we would be limited to a weaker evening round. Monday morning should bring some much-needed confidence to the forecast. That said, remain weather aware Monday afternoon and make those severe weather plans now in case any warnings are issued. We will be sure to keep you updated!