Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 35, NWS St. Louis, MO

October 24, 2021Saint Clair County, Illinois

NWS St. Louis, MO issued this tornado warning at Oct 24, 2021, 9:33 PM CDT for Saint Clair County, Illinois. It was in force for 30 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Oct 24, 2021, 9:33 PM CDT (02:33 UTC)
Expired
Oct 24, 2021, 10:03 PM CDT
In force
30 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

County Saint Clair County, IL

The radar

The St Louis radar (KLSX), 65 km from the middle of the area, began a volume at 02:36 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.

What was reported inside it

TimeReportWhereRemark
Oct 24, 9:37 PM CDTTSTM WND DMG1 Sse Swansea, ILLARGE TREE LIMB DOWN ON A FENCE IN SWANSEA, IL.
Oct 24, 9:41 PM CDTTSTM WND DMG1 Sse O'Fallon, ILTREE BLOCKING DARTMOUTH DR AT WHITEHALL DR.
Oct 24, 9:44 PM CDTTSTM WND DMG1 S Scott Afb, ILFACEBOOK REPORT AND PHOTOGRAPHS SHOW ROOF OF STORAGE BUILDING AT AIR FORCE BASE STORAGE WAS BLOWN EAST ONTO ADJACENT HOUSE ALONG STATE ROUTE 161 E NEAR THE INTERSECTION OF HANNAH CHASE CT.
Oct 24, 9:44 PM CDTTSTM WND GST 621 Se Scott Afb, ILAWOS STATION KBLV SCOTT AIR FORCE BASE.
Oct 24, 9:50 PM CDTTSTM WND DMG1 Wnw Swansea, ILREPORTS OF 60 MPH WIND GUSTS, MEDIUM TREE BRANCHES DOWN, AND POWER OUTAGES NEAR JOYCE DRIVE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

IssuedProductOfficeLasted
Oct 24, 5:44 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 2.6 hours before the alert went out and 213 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 2021-10-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2021-10-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 371 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
3 J/kg
Mixed-layer CIN
-286 J/kg
Mixed-layer LCL
585 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
371 m²/s²
0-3 km storm-relative helicity
467 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.1

Open this sounding in Storm Lab

The text

As transmitted.

941 
WFUS53 KLSX 250233
TORLSX
ILC163-250315-
/O.NEW.KLSX.TO.W.0035.211025T0233Z-211025T0315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service St Louis MO
933 PM CDT Sun Oct 24 2021

The National Weather Service in St Louis has issued a

* Tornado Warning for...
  Northern St. Clair County in southwestern Illinois...

* Until 1015 PM CDT.

* At 933 PM CDT, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located near
  Belleville, moving east at 50 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* These dangerous storms will be near...
  Shiloh around 940 PM CDT.
  O'Fallon and Mascoutah around 945 PM CDT.
  Lebanon and Scott AFB around 950 PM CDT.

Other locations in the path of this tornadic thunderstorm include New
Baden.

This includes Interstate 64 in Illinois between exits 12 and 27.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 3845 9014 3855 9018 3866 8991 3865 8971
      3853 8971
TIME...MOT...LOC 0233Z 253DEG 45KT 3853 9006 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

CVKING
3 follow-up statements
551 
WWUS53 KLSX 250241
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
941 PM CDT Sun Oct 24 2021

ILC163-250315-
/O.CON.KLSX.TO.W.0035.000000T0000Z-211025T0315Z/
St. Clair IL-
941 PM CDT Sun Oct 24 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR
NORTHEASTERN ST. CLAIR COUNTY...

At 941 PM CDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located over
Shiloh, moving east at 50 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

These dangerous storms will be near...
  Mascoutah and Scott AFB around 945 PM CDT.
  Lebanon around 950 PM CDT.

Other locations in the path of this tornadic thunderstorm include New
Baden.

This includes Interstate 64 in Illinois between exits 12 and 27.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 3848 8998 3861 9004 3866 8991 3865 8971
      3853 8971
TIME...MOT...LOC 0241Z 253DEG 45KT 3856 8993 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

CVKING
782 
WWUS53 KLSX 250249
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
949 PM CDT Sun Oct 24 2021

ILC163-250315-
/O.CON.KLSX.TO.W.0035.000000T0000Z-211025T0315Z/
St. Clair IL-
949 PM CDT Sun Oct 24 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR
NORTHEASTERN ST. CLAIR COUNTY...

At 949 PM CDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located over
Lebanon, moving east at 50 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
northeastern St. Clair County, including the following locations...
Summerfield.

This includes Interstate 64 in Illinois between exits 23 and 27.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 3851 8983 3866 8992 3866 8991 3865 8971
      3853 8971
TIME...MOT...LOC 0249Z 253DEG 45KT 3859 8981 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

CVKING
315 
WWUS53 KLSX 250303
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1003 PM CDT Sun Oct 24 2021

ILC163-250312-
/O.CAN.KLSX.TO.W.0035.000000T0000Z-211025T0315Z/
St. Clair IL-
1003 PM CDT Sun Oct 24 2021

...THE TORNADO WARNING FOR NORTHEASTERN ST. CLAIR COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 100 AM CDT for southwestern
Illinois.

LAT...LON 3851 8983 3866 8992 3866 8991 3865 8971
      3853 8971
TIME...MOT...LOC 0301Z 253DEG 45KT 3864 8960 

$$

CVKING

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 24, 7:39 PM CDTSevere Thunderstorm WarningLSXMonroe51 min
Oct 24, 7:59 PM CDTRiver Flood WarningLSXBrown33 hr
Oct 24, 8:03 PM CDTTornado WarningLSXMonroe, Randolph42 min
Oct 24, 8:27 PM CDTSevere Thunderstorm WarningLSXMonroe, Randolph, Saint Clair48 min
Oct 24, 8:34 PM CDTTornado Warning Tornado observedConsiderable damage threatLSXRandolph41 min
Oct 24, 9:00 PM CDTTornado WarningLSXClinton, Randolph, Saint Clair, Washington45 min
Oct 24, 9:08 PM CDTSevere Thunderstorm WarningLSXMonroe, Saint Clair54 min
Oct 24, 9:08 PM CDTTornado Warning Tornado observedConsiderable damage threatLSXRandolph40 min
Oct 24, 9:15 PM CDTTornado Warning EmergencyTornado observedCatastrophic damage threatLSXRandolph19 min
Oct 24, 9:48 PM CDTTornado WarningLSXBond, Clinton, Madison42 min
Oct 24, 9:58 PM CDTTornado WarningLSXMarion, Washington16 min
Oct 24, 10:13 PM CDTSevere Thunderstorm WarningLSXClinton, Fayette, Marion62 min
Oct 24, 10:40 PM CDTSevere Thunderstorm WarningLSXFayette, Marion26 min

Nearby

Tornado Warnings in Illinois, 2021Every tornado warning in 2021Tornadoes in 2021

Sources

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