Northeast Illinois Storms Building Toward Severe Hail, Wind Threat — SevereWX

Thunderstorms are sparking across northeast Illinois late this evening, showing signs of organization that could lead to large hail and damaging winds through the next couple of hours.

The Storm Prediction Center's Mesoscale Discussion 1456 highlights development along a subtle low-level confluence band just ahead of an outflow boundary pushing in from the west. Recent data from an ACARs sounding near Midway Airport reveals a buoyant but modestly sheared environment, with stronger mid-level winds (around 40 knots) approaching from upstream.

Storms may evolve into clusters, and a supercell or two can't be ruled out, especially as the better flow arrives. Coverage and intensity remain key watches—SPC notes a 40% chance of a severe thunderstorm watch if trends support it. However, uncertainty lingers on whether convection will reach severe limits before brushing Lake Michigan's shore, as models struggle with this setup.

Key Threats:

The action centers over the greater Chicago area into extreme southeast Wisconsin. Trends will be closely monitored by SPC forecasters Moore and Guyer.

Stay Prepared: Enable wireless emergency alerts on your phone, keep an eye on radar via local NWS offices (LOT, MKX, DVN), and have a severe weather plan ready. If storms intensify, seek shelter indoors away from windows.