Alert archive / Illinois / Flash Flood Warnings in 2026

Flash Flood Warning 39, NWS St. Louis, MO

June 21, 2026Marion County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 21, 2026, 4:27 PM CDT for Marion County, Illinois. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 21, 2026, 4:27 PM CDT (21:27 UTC)
Expired
Jun 21, 2026, 10:00 PM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

County Marion County, IL

The radar

The Evansville,IN radar (KVWX), 116 km from the middle of the area, began a volume at 21:30 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, 9.5 hours before the alert went out and 155 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 12:00Z on 2026-06-21Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2026-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.19395878Sfc1 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
1482 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

550 
WGUS53 KLSX 212127
FFWLSX
ILC121-220130-
/O.NEW.KLSX.FF.W.0039.260621T2127Z-260622T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
427 PM CDT Sun Jun 21 2026

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Northern Marion County in south central Illinois...

* Until 830 PM CDT.

* At 427 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 2 and 4 inches of rain
  have fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flash flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Kinmundy, Patoka, Farina, Omega, Stephen Forbes Station, Fairman,
  Alma, Vernon and Brubaker.

This includes the following State Parks...
Stephen A. Forbes State Recreation Area.

This includes Interstate 57 in Illinois near exit 127.

This includes the following streams and drainages...
  Flat Creek, Lee Creek, and East Fork Kaskaskia River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3883 8870 3868 8870 3867 8914 3882 8914
      3882 8893

FLASH FLOOD...RADAR INDICATED

$$

Carney
2 follow-up statements
713 
WGUS73 KLSX 212259
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
559 PM CDT Sun Jun 21 2026

ILC121-220130-
/O.CON.KLSX.FF.W.0039.000000T0000Z-260622T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marion IL-
559 PM CDT Sun Jun 21 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM CDT THIS
EVENING FOR NORTHERN MARION COUNTY IN SOUTH CENTRAL ILLINOIS...

At 559 PM CDT, Doppler radar indicated thunderstorms have produced
between 4 and 6 inches of rainfall. Runoff from this heavy rain is
producing life threatening flash flooding.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar indicated.

IMPACT...Life threatening flash flooding of creeks and streams, urban
         areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Kinmundy, Patoka, Farina, Omega, Stephen Forbes Station, Fairman,
  Alma, Vernon and Brubaker.

This includes the following State Parks...
Stephen A. Forbes State Recreation Area.

This includes Interstate 57 in Illinois near exit 127.

This includes the following streams and drainages...
  Flat Creek, Lee Creek, and East Fork Kaskaskia River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3883 8870 3868 8870 3867 8914 3882 8914
      3882 8893

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Carney
293 
WGUS53 KLSX 220127
FFWLSX
ILC121-220300-
/O.EXT.KLSX.FF.W.0039.000000T0000Z-260622T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
827 PM CDT Sun Jun 21 2026

The National Weather Service in St Louis has extended the

* Flash Flood Warning for...
  Northern Marion County in south central Illinois...

* Until 1000 PM CDT.

* At 827 PM CDT, Doppler radar indicated thunderstorms produced heavy
  rain across the warned area. Between 4 and 5 inches of rain have
  fallen. Life threatening flash flooding is ongoing.

  HAZARD...Life threatening flash flooding. Thunderstorms produced
           flash flooding.

  SOURCE...Radar indicated.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Kinmundy, Patoka, Farina, Omega, Stephen Forbes Station, Fairman,
  Alma, Vernon and Brubaker.

This includes the following State Parks...
Stephen A. Forbes State Recreation Area.

This includes Interstate 57 in Illinois near exit 127.

This includes the following streams and drainages...
  Louse Run, Crooked Creek, Davidson Creek, Skillet Fork, Crabapple
  Branch, Bee Branch, Wills Creek, Brubaker Creek, Barden Creek,
  Warren Branch, Flat Creek, Kaskaskia River, Lost Fork, Bear Creek,
  Town Creek, Schneider Springs Branch, Jims Creek, Dums Creek and
  East Fork Kaskaskia River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3883 8870 3868 8870 3867 8914 3882 8914
      3882 8893

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Jaja

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 2:47 PM CDTSevere Thunderstorm WarningLSXFayette43 min
Jun 21, 2:54 PM CDTTornado WarningLSXBond, Madison36 min
Jun 21, 3:03 PM CDTTornado WarningLSXFayette15 min
Jun 21, 3:23 PM CDTTornado WarningLSXBond, Fayette52 min
Jun 21, 3:26 PM CDTFlash Flood WarningLSXBond, Fayette, Montgomery4 hr
Jun 21, 3:44 PM CDTFlash Flood WarningLSXFayette6 hr
Jun 21, 3:45 PM CDTTornado WarningLSXFayette, Marion60 min
Jun 21, 5:02 PM CDTTornado WarningLSXClinton, Madison, Saint Clair43 min
Jun 21, 5:07 PM CDTTornado WarningLSXBond, Fayette, Marion38 min
Jun 21, 5:19 PM CDTTornado WarningLSXFayette, Marion41 min
Jun 21, 5:35 PM CDTSevere Thunderstorm WarningLSXClinton, Marion70 min
Jun 21, 5:40 PM CDTTornado WarningLSXMarion39 min
Jun 21, 5:43 PM CDTSevere Thunderstorm WarningLSXClinton39 min
Jun 21, 5:50 PM CDTTornado WarningLSXClinton32 min
Jun 21, 6:08 PM CDTTornado WarningLSXMarion10 min
Jun 21, 6:15 PM CDTTornado WarningLSXMarion37 min

Nearby

Flash Flood Warnings in Illinois, 2026Every flash flood 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.