Alert archive / Illinois / Mesoscale Discussions in 2026

Mesoscale Discussion 101

February 19, 202611 counties in Illinois; Jefferson County, Sainte Genevieve County, City of Saint Louis, Missouri

The Storm Prediction Center issued this mesoscale discussion at Feb 19, 2026, 3:06 PM CST for 11 counties in Illinois; Jefferson County, Sainte Genevieve County, City of Saint Louis, Missouri. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Feb 19, 2026, 3:06 PM CST (21:06 UTC)
Expired: Feb 19, 2026, 4:30 PM CST
In force: 84 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

Counties Bond County, IL, Clinton County, IL, Fayette County, IL, Jefferson County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, City of Saint Louis, MO, Jefferson County, MO, Sainte Genevieve County, MO

The radar

The St Louis radar (KLSX), 83 km from the middle of the area, began a volume at 21:08 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 12:00Z, 9.1 hours before the alert went out and 218 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: 7 J/kg
Mixed-layer CIN: -290 J/kg
Mixed-layer LCL: 783 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 23 m²/s²
0-3 km storm-relative helicity: 185 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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
Feb 19, 10:44 AM CST	Mesoscale Discussion	SPC	Bond, Calhoun, Clinton, Greene, Jersey, Macoupin and 5 more	91 min
Feb 19, 11:34 AM CST	Mesoscale Discussion	SPC	Bond, Champaign, Christian, Clark, Clay, Clinton and 38 more	116 min
Feb 19, 12:20 PM CST	Tornado Watch	SPC	Clark, Clay, Coles, Crawford, Cumberland, Douglas and 15 more	10 hr
Feb 19, 2:56 PM CST	Mesoscale Discussion	SPC	Clark, Clay, Crawford, Cumberland, Edwards, Effingham and 12 more	2 hr

Nearby

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