Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 178, NWS St. Louis, MO

October 24, 2021Jefferson County, Saint Louis County, Missouri; Monroe County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Oct 24, 2021, 9:08 PM CDT for Jefferson County, Saint Louis County, Missouri; Monroe County, Saint Clair County, Illinois. It was in force for 54 min. 8 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, 9:08 PM CDT (02:08 UTC)
Expired
Oct 24, 2021, 10:02 PM CDT
In force
54 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Monroe County, IL, Saint Clair County, IL, Jefferson County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 58 km from the middle of the area, began a volume at 02:12 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, 9:12 PM CDTTSTM WND DMG1 Sw Arnold, MOLARGE TREE DOWN IN THE TOWN OF ARNOLD - VIA FACEBOOK.
Oct 24, 9:12 PM CDTTSTM WND DMGArnold, MOA LARGE TREE DOWN IN THE TOWN OF ARNOLD - REPORT VIA FACEBOOK.
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, 9:47 PM CDTTSTM WND DMGMascoutah, ILPOLE BARN LIFTED, FLIPPED, AND LAID ON A BUSINESS 30 FT TO THE EAST.
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, 2:06 PM CDTTornado WatchSPC9 hr
Oct 24, 5:44 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 2.1 hours before the alert went out and 233 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.

321 
WUUS53 KLSX 250208
SVRLSX
ILC133-163-MOC099-189-250315-
/O.NEW.KLSX.SV.W.0178.211025T0208Z-211025T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
908 PM CDT Sun Oct 24 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Northwestern Monroe County in southwestern Illinois...
  St. Clair County in southwestern Illinois...
  Northeastern Jefferson County in east central Missouri...
  South central St. Louis County in east central Missouri...

* Until 1015 PM CDT.

* At 908 PM CDT, severe thunderstorms were located along a line
  extending from near Murphy to near Antonia to near Barnhart to near
  Horine, moving northeast at 55 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Arnold around 915 PM CDT.
  Oakville, Mehlville, Lemay, Valmeyer, Fountain and Concord around 
  920 PM CDT.
  Columbia, Dupo and East Carondelet around 925 PM CDT.

Other locations in the path of these severe thunderstorms include
Cahokia, Waterloo, Millstadt, Cahokia Parks Airport, Alorton, East
St. Louis, Centreville, Belleville, Fairview Heights, Swansea,
Shiloh, Caseyville, Smithton, O'Fallon, Freeburg, Mascoutah, Lebanon
and Scott AFB.

This includes the following highways...
 Interstate 64 in Illinois between exits 12 and 27.
 Interstate 55 in Missouri between exits 180 and 191.

This also includes Mastodon Historic Site, Sandy Creek Covered Bridge
Historic Site, and Gov. Dunklin's Grave Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM CDT for east central
Missouri. A Tornado Watch also remains in effect until 100 AM CDT for
southwestern Illinois.

For your protection move to an interior room on the lowest floor of a
building.

A Tornado Watch remains in effect until 1000 PM CDT for east central
Missouri. A Tornado Watch also remains in effect until 100 AM CDT for
southwestern Illinois.

&&

LAT...LON 3833 9004 3824 9053 3830 9055 3843 9053
      3866 8990 3865 8971 3841 8971
TIME...MOT...LOC 0208Z 246DEG 46KT 3843 9046 3839 9043 3834 9044 3828
9049

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CVKING
4 follow-up statements
760 
WWUS53 KLSX 250223
SVSLSX

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

MOC099-189-250232-
/O.CAN.KLSX.SV.W.0178.000000T0000Z-211025T0315Z/
Jefferson MO-St. Louis MO-
923 PM CDT Sun Oct 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN JEFFERSON AND
SOUTH CENTRAL ST. LOUIS COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 1000 PM CDT for east central
Missouri. A Tornado Watch also remains in effect until 100 AM CDT for
southwestern Illinois.

LAT...LON 3833 9004 3827 9037 3834 9037 3838 9035
      3844 9029 3853 9026 3866 8991 3865 8971
      3841 8971
TIME...MOT...LOC 0222Z 246DEG 46KT 3850 9027 3846 9024 3841 9025 3835
9030

$$

ILC133-163-250315-
/O.CON.KLSX.SV.W.0178.000000T0000Z-211025T0315Z/
Monroe IL-St. Clair IL-
923 PM CDT Sun Oct 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT
FOR NORTHWESTERN MONROE AND ST. CLAIR COUNTIES...

At 922 PM CDT, severe thunderstorms were located along a line
extending from near Lemay to Columbia to near Oakville to Fountain,
moving northeast at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Cahokia, Cahokia Parks Airport, Centreville, Millstadt, Alorton, 
  Belleville, East St. Louis, Fairview Heights, Swansea, Smithton, 
  Shiloh, Freeburg, Caseyville, O'Fallon, Lebanon, Scott AFB, 
  Mascoutah and New Baden.

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

A Tornado Watch remains in effect until 1000 PM CDT for east central
Missouri. A Tornado Watch also remains in effect until 100 AM CDT for
southwestern Illinois.

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3833 9004 3827 9037 3834 9037 3838 9035
      3844 9029 3853 9026 3866 8991 3865 8971
      3841 8971
TIME...MOT...LOC 0222Z 246DEG 46KT 3850 9027 3846 9024 3841 9025 3835
9030

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CVKING
498 
WWUS53 KLSX 250235
SVSLSX

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

ILC133-250245-
/O.CAN.KLSX.SV.W.0178.000000T0000Z-211025T0315Z/
Monroe IL-
935 PM CDT Sun Oct 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MONROE COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area.Therefore, the warning has been cancelled.

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

LAT...LON 3833 9004 3844 9014 3855 9018 3866 8991
      3865 8971 3841 8971
TIME...MOT...LOC 0235Z 246DEG 46KT 3856 9009 3852 9006 3847 9007 3841
9012

$$

ILC163-250315-
/O.CON.KLSX.SV.W.0178.000000T0000Z-211025T0315Z/
St. Clair IL-
935 PM CDT Sun Oct 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT
FOR ST. CLAIR COUNTY...

At 935 PM CDT, severe thunderstorms were located along a line
extending from Centreville to near Belleville to Millstadt to 6 miles
north of Waterloo, moving northeast at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Belleville, O'Fallon, East St. Louis, Fairview Heights, Cahokia,
Swansea, Shiloh, Mascoutah, Centreville, Lebanon, Freeburg,
Caseyville, Millstadt, New Baden, Scott AFB, Cahokia Parks Airport,
Smithton, Alorton, Summerfield and Barr.

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

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

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3833 9004 3844 9014 3855 9018 3866 8991
      3865 8971 3841 8971
TIME...MOT...LOC 0235Z 246DEG 46KT 3856 9009 3852 9006 3847 9007 3841
9012

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CVKING
249 
WWUS53 KLSX 250250 RRA
SVSLSX

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

ILC163-250315-
/O.CON.KLSX.SV.W.0178.000000T0000Z-211025T0315Z/
St. Clair IL-
950 PM CDT Sun Oct 24 2021

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

At 950 PM CDT, severe thunderstorms were located along a line
extending from near O'Fallon to near Lebanon to Scott AFB to near
Freeburg, moving northeast at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Trained weather spotters reported 60 mph wind near 
         Belleville.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
O'Fallon, Mascoutah, Lebanon, New Baden, Scott AFB and Summerfield. 

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

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

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3853 8971 3851 8983 3866 8991 3865 8971
TIME...MOT...LOC 0250Z 246DEG 46KT 3863 8988 3859 8985 3854 8986 3848
8992

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CVKING
856 
WWUS53 KLSX 250302
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1002 PM CDT Sun Oct 24 2021

ILC163-250312-
/O.CAN.KLSX.SV.W.0178.000000T0000Z-211025T0315Z/
St. Clair IL-
1002 PM CDT Sun Oct 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ST. CLAIR COUNTY
IS CANCELLED...
    
The storms which prompted the warning have 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 3853 8971 3851 8983 3866 8991 3865 8971
TIME...MOT...LOC 0301Z 246DEG 46KT 3869 8970 3865 8967 3860 8968 3854
8974

$$

CVKING

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 24, 7:00 PM CDTSevere Thunderstorm WarningLSXPike34 min
Oct 24, 7:03 PM CDTSevere Thunderstorm WarningLSXLincoln, Montgomery, Warren42 min
Oct 24, 7:06 PM CDTTornado WarningLSXReynolds39 min
Oct 24, 7:07 PM CDTSevere Thunderstorm WarningLSXCallaway, Franklin, Gasconade, Montgomery, Osage, Warren38 min
Oct 24, 7:09 PM CDTTornado WarningLSXCrawford, Iron, Washington31 min
Oct 24, 7:37 PM CDTSevere Thunderstorm WarningLSXReynolds38 min
Oct 24, 7:39 PM CDTSevere Thunderstorm WarningLSXJefferson, Sainte Genevieve, Saint Francois, Washington51 min
Oct 24, 7:48 PM CDTTornado WarningLSXIron, Madison, Reynolds, Saint Francois27 min
Oct 24, 8:03 PM CDTTornado WarningLSXSainte Genevieve, Saint Francois42 min
Oct 24, 8:09 PM CDTTornado WarningLSXSainte Genevieve, Saint Francois40 min
Oct 24, 8:10 PM CDTTornado WarningLSXIron, Madison, Reynolds50 min
Oct 24, 8:23 PM CDTTornado WarningLSXIron, Madison, Reynolds52 min
Oct 24, 8:34 PM CDTTornado Warning Tornado observedConsiderable damage threatLSXSainte Genevieve41 min
Oct 24, 8:48 PM CDTTornado Warning Tornado observedConsiderable damage threatLSXMadison, Saint Francois27 min
Oct 24, 9:11 PM CDTTornado WarningLSXIron, Madison49 min
Oct 24, 9:12 PM CDTFlash Flood WarningLSXIron, Madison4 hr
Oct 24, 9:37 PM CDTSevere Thunderstorm WarningLSXIron, Reynolds36 min
Oct 24, 10:07 PM CDTSevere Thunderstorm WarningLSXIron, Reynolds38 min
Oct 24, 10:12 PM CDTFlash Flood WarningLSXMadison4 hr
Oct 24, 7:59 PM CDTRiver Flood WarningLSXBrown33 hr
Oct 24, 8:27 PM CDTSevere Thunderstorm WarningLSXMonroe, Randolph, Saint Clair48 min
Oct 24, 9:00 PM CDTTornado WarningLSXClinton, Randolph, Saint Clair, Washington45 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, 9:33 PM CDTTornado WarningLSXSaint Clair30 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

Severe Thunderstorm Warnings in Missouri, 2021Severe Thunderstorm Warnings in Illinois, 2021Every severe thunderstorm warning 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.