Alert archive / Illinois / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 189, NWS St. Louis, MO

June 17, 2026Macoupin County, Montgomery County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 17, 2026, 7:53 PM CDT for Macoupin County, Montgomery County, Illinois. It was in force for 42 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jun 17, 2026, 7:53 PM CDT (00:53 UTC)
Expired: Jun 17, 2026, 8:35 PM CDT
In force: 42 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Tornado: Possible
Hail: 1.25 in
Wind: 60.0 mph

Counties Macoupin County, IL, Montgomery County, IL

The radar

The St Louis radar (KLSX), 104 km from the middle of the area, began a volume at 00:53 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 17, 2:14 PM CDT	Tornado Watch	SPC	11 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.9 hours before the alert went out and 138 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: 611 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 895 m above ground
0-6 km bulk shear: 70 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.5

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 17, 7:02 PM CDT, 51 minutes earlier.

Area forecast discussion, Jun 17, 7:02 PM CDT, 51 minutes before

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In the hours before

Local storm report, Jun 17, 5:18 PM CDT, 2 hours 35 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
518 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0308 PM     Non-Tstm Wnd Dmg Sandoval                38.62N 89.12W
06/17/2026                   Marion             IL   Emergency Mngr

            Non-convective high winds snapped a power
            pole in Sandoval. The wires landed on a
            church and burned the structure to the
            ground. Ignition time not certain.

&&

LSJ

Local storm report, Jun 17, 5:19 PM CDT, 2 hours 34 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
519 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0308 PM     Non-Tstm Wnd Dmg Centralia               38.53N 89.13W
06/17/2026                   Marion             IL   Emergency Mngr

            Non-convective wind gusts blew over multiple
            power lines in Centralia.

&&

LSJ

Local storm report, Jun 17, 5:34 PM CDT, 2 hours 19 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
534 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0531 PM     Non-Tstm Wnd Dmg Iuka                    38.62N 88.79W
06/17/2026                   Marion             IL   Emergency Mngr

            Power lines downed on a house. The house is
            smoking.

&&

LSJ

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 17, 7:49 PM CDT	Severe Thunderstorm Warning	LSX	Fayette	15 min
Jun 17, 8:09 PM CDT	Tornado Warning	LSX	Fayette, Montgomery	41 min
Jun 17, 8:39 PM CDT	Tornado Warning	LSX	Fayette	26 min
Jun 17, 10:13 PM CDT	Severe Thunderstorm Warning	LSX	Fayette	17 min
Jun 18, 11:43 AM CDT	River Flood Warning	LSX	Brown	18 days
Jun 18, 11:43 AM CDT	River Flood Warning	LSX	Morgan, Pike	21 days

Nearby

Severe Thunderstorm Warnings in Illinois, 2026 Every severe thunderstorm warning 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.