Alert archive / Illinois / Mesoscale Discussions in 2026

Mesoscale Discussion 933

June 1, 20264 states

The Storm Prediction Center issued this mesoscale discussion at Jun 1, 2026, 6:01 AM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 1, 2026, 6:01 AM CDT (11:01 UTC)
Expired
Jun 1, 2026, 8:30 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 50 counties

Alexander County, IL, Clinton County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Monroe County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Washington County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Muhlenberg County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Cape Girardeau County, MO, Iron County, MO, Madison County, MO, Mississippi County, MO, Perry County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Washington County, MO, Weakley County, TN

The radar

The Paducah radar (KPAH), 92 km from the middle of the area, began a volume at 11:05 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 11.0 hours before the alert went out and 281 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2026-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2026-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2185 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
342 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 1, 3:34 AM CDTSevere Thunderstorm WatchSPCCalhoun, Clinton, Jersey, Madison, Monroe, Randolph and 2 more4 hr
Jun 1, 4:02 AM CDTMesoscale DiscussionSPCMonroe, Saint Clair118 min
May 31, 7:12 PM CDTMesoscale DiscussionSPCBates, Buchanan, Cass, Clay, Jackson, Platte3 hr
May 31, 8:53 PM CDTSevere Thunderstorm WatchSPCBates, Benton, Camden, Carroll, Cass, Cedar and 18 more8 hr
May 31, 10:53 PM CDTMesoscale DiscussionSPCBates, Benton, Camden, Carroll, Cass, Cedar and 20 more2 hr
Jun 1, 1:54 AM CDTMesoscale DiscussionSPCAudrain, Bates, Benton, Boone, Callaway, Camden and 26 more2 hr
Jun 1, 1:40 PM CDTMesoscale DiscussionSPCChristian, Douglas, Greene, Howell, Ozark, Stone and 2 more50 min
Jun 1, 2:13 PM CDTSevere Thunderstorm WatchSPCBarry, Christian, Douglas, Howell, McDonald, Oregon and 3 more9 hr
Jun 1, 9:30 AM CDTMesoscale DiscussionSPCChester, Decatur, Fayette, Giles, Hardeman, Hardin and 10 more2 hr
Jun 1, 11:26 AM CDTSevere Thunderstorm WatchSPCFayette, Hardeman, Hardin, McNairy, Shelby, Tipton12 hr
Jun 1, 5:16 PM CDTMesoscale DiscussionSPCShelby119 min

Nearby

Mesoscale Discussions in Illinois, 2026Mesoscale Discussions in Kentucky, 2026Mesoscale Discussions in Missouri, 2026Every mesoscale discussion in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.