Parts of the Midwest, including much of Illinois, could face the threat of severe tornadoes of EF3 or higher on Monday as a multi-day severe weather outbreak enters its most dangerous stage yet.
Widespread damaging winds, large hail and tornadoes also threatened Monday for about 40 million people across a wide swath from the Mississippi Valley to the lower Ohio Valley.
The threat comes after days of severe weather have already carved a path of destruction across the Plains and parts of the South, with more than 50 reports of tornadoes since Thursday. These include a severe EF-4 tornado in Enid, Oklahoma, a preliminary assessment of a tornado, a deadly tornado in North Texas, and multiple “particularly dangerous conditions” tornado warnings Sunday evening.
A Level 3/5 severe thunderstorm threat was in effect Monday from parts of the central Mississippi Valley to the lower Ohio Valley, including most of Illinois and portions of Missouri, western Indiana, western Kentucky, and northwestern Tennessee.
Some of these same areas have already experienced severe storms in recent days. The first round of supercells could take place on Monday, followed by a second round with the possibility of a squall line forming later in the day.
Monday’s supercell could produce several potentially violent EF-3 or higher tornadoes and hail the size of baseballs or larger. As the storm progresses into the evening, this line could produce widespread damaging winds, while the embedded circulation could continue to pose a tornado risk.
The corridor from south-central Missouri to central Illinois may hold the most favorable conditions for the strongest storms, but the exact location of the largest potential tornadoes may depend, in part, on how morning thunderstorms shape the atmosphere ahead of their afternoon round.
On Tuesday, this severe system will move eastward from the southern Plains through the south central region and into the lower Ohio Valley with a moderately low risk of severe thunderstorms, equivalent to a Level 2/5.
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A violent tornado struck Enid, Oklahoma on Thursday night, creating a rare tornado emergency that caused EF-4 damage to parts of the city and flattened some areas.
The Enid tornado had wind speeds estimated at 170 to 175 mph, making it the strongest in the United States since June 2025. At least 10 people were injured and about 40 homes were damaged, but authorities said no deaths were reported.
Deadly tornadoes struck North Texas on Saturday, including an EF-2 tornado near Runaway Bay, about 130 miles northwest of Dallas. At least two people were killed, homes and infrastructure damaged, and dozens of residents evacuated, adding to the damage caused by a multi-day outbreak of severe weather.
