Alert archive / Missouri / Mesoscale Discussions in 2026

Mesoscale Discussion 932

June 1, 2026Monroe County, Saint Clair County, Illinois; 12 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jun 1, 2026, 4:02 AM CDT for Monroe County, Saint Clair County, Illinois; 12 counties in Missouri. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: Jun 1, 2026, 4:02 AM CDT (09:02 UTC)
Expired: Jun 1, 2026, 6:00 AM CDT
In force: 118 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 260

Counties Monroe County, IL, Saint Clair County, IL, City of Saint Louis, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Montgomery County, MO, Osage County, MO, Saint Charles County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 43 km from the middle of the area, began a volume at 09:02 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, 9.0 hours before the alert went out and 283 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

Issued	Product	Office	Counties	Lasted
Jun 1, 3:34 AM CDT	Severe Thunderstorm Watch	SPC	Calhoun, Clinton, Jersey, Madison, Monroe, Randolph and 2 more	4 hr
Jun 1, 6:01 AM CDT	Mesoscale Discussion	SPC	Alexander, Clinton, Franklin, Gallatin, Hamilton, Hardin and 15 more	2 hr
May 31, 7:12 PM CDT	Mesoscale Discussion	SPC	Bates, Buchanan, Cass, Clay, Jackson, Platte	3 hr
May 31, 8:53 PM CDT	Severe Thunderstorm Watch	SPC	Bates, Benton, Camden, Carroll, Cass, Cedar and 18 more	8 hr
May 31, 10:53 PM CDT	Mesoscale Discussion	SPC	Bates, Benton, Camden, Carroll, Cass, Cedar and 20 more	2 hr
Jun 1, 1:54 AM CDT	Mesoscale Discussion	SPC	Audrain, Bates, Benton, Boone, Callaway, Camden and 26 more	2 hr
Jun 1, 1:40 PM CDT	Mesoscale Discussion	SPC	Christian, Douglas, Greene, Howell, Ozark, Stone and 2 more	50 min
Jun 1, 2:13 PM CDT	Severe Thunderstorm Watch	SPC	Barry, Christian, Douglas, Howell, McDonald, Oregon and 3 more	9 hr

Nearby

Mesoscale Discussions in Missouri, 2026 Mesoscale Discussions in Illinois, 2026 Every 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.