Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 141, NWS St. Louis, MO

August 8, 2021Calhoun County, Greene County, Jersey County, Illinois; Lincoln County, Saint Charles County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 8, 2021, 3:54 PM CDT for Calhoun County, Greene County, Jersey County, Illinois; Lincoln County, Saint Charles County, Missouri. It was in force for 66 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 8, 2021, 3:54 PM CDT (20:54 UTC)
Expired
Aug 8, 2021, 5:00 PM CDT
In force
66 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Calhoun County, IL, Greene County, IL, Jersey County, IL, Lincoln County, MO, Saint Charles County, MO

The radar

The St Louis radar (KLSX), 60 km from the middle of the area, began a volume at 20:53 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.

IssuedProductOfficeLasted
Aug 8, 12:44 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.9 hours before the alert went out and 184 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 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 310 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 12:00Z on 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 square meters per square second.1939Sfc1 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
310 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1165 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

870 
WUUS53 KLSX 082054
SVRLSX
ILC013-061-083-MOC113-183-082200-
/O.NEW.KLSX.SV.W.0141.210808T2054Z-210808T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
354 PM CDT Sun Aug 8 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Southeastern Calhoun County in southwestern Illinois...
  Greene County in southwestern Illinois...
  Jersey County in southwestern Illinois...
  North central St. Charles County in east central Missouri...
  Southeastern Lincoln County in east central Missouri...

* Until 500 PM CDT.

* At 353 PM CDT, severe thunderstorms were located along a line
  extending from near Fountain N' Lakes to near O'Fallon, moving
  northeast at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Hardin, Grafton, Elsah, Jerseyville, Carrollton, Old Kane, 
  Greenfield, Kemper and Athensville.

This includes Interstate 70 in Missouri between exits 217 and 220.
 
This also includes Pere Marquette State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in St Louis.

&&

LAT...LON 3949 9015 3904 9015 3900 9023 3900 9027
      3898 9028 3877 9070 3905 9082 3938 9049
      3952 9016
TIME...MOT...LOC 2053Z 226DEG 38KT 3901 9084 3881 9068 

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

$$

Gosselin
3 follow-up statements
063 
WWUS53 KLSX 082124
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
424 PM CDT Sun Aug 8 2021

ILC013-MOC113-183-082134-
/O.CAN.KLSX.SV.W.0141.000000T0000Z-210808T2200Z/
Calhoun IL-St. Charles MO-Lincoln MO-
424 PM CDT Sun Aug 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CALHOUN...NORTH
CENTRAL ST. CHARLES AND SOUTHEASTERN LINCOLN COUNTIES IS CANCELLED...

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

A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
southwestern Illinois...and east central Missouri.

LAT...LON 3949 9015 3904 9015 3900 9023 3900 9027
      3898 9028 3894 9035 3897 9046 3895 9052
      3899 9057 3903 9057 3905 9059 3907 9058
      3914 9062 3917 9061 3920 9059 3926 9061
      3938 9049 3952 9016
TIME...MOT...LOC 2124Z 226DEG 38KT 3921 9057 3901 9041 

$$

ILC061-083-082200-
/O.CON.KLSX.SV.W.0141.000000T0000Z-210808T2200Z/
Greene IL-Jersey IL-
424 PM CDT Sun Aug 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR GREENE AND JERSEY COUNTIES...

At 424 PM CDT, severe thunderstorms were located along a line
extending from near Hardin to near Grafton, moving northeast at 45
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Jerseyville, Carrollton, Brighton, Greenfield, Hardin, Grafton,
Elsah, Athensville, Old Kane, Kemper, Kane, Wrights, Fieldon, Eldred,
Rockbridge, Otterville, Fidelity, Delhi, Belltown and Berdan.

This also includes Pere Marquette State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

&&

LAT...LON 3949 9015 3904 9015 3900 9023 3900 9027
      3898 9028 3894 9035 3897 9046 3895 9052
      3899 9057 3903 9057 3905 9059 3907 9058
      3914 9062 3917 9061 3920 9059 3926 9061
      3938 9049 3952 9016
TIME...MOT...LOC 2124Z 226DEG 38KT 3921 9057 3901 9041 

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

$$

Gosselin
390 
WWUS53 KLSX 082147
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
447 PM CDT Sun Aug 8 2021

ILC061-083-082200-
/O.CON.KLSX.SV.W.0141.000000T0000Z-210808T2200Z/
Greene IL-Jersey IL-
447 PM CDT Sun Aug 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR EASTERN GREENE AND EASTERN JERSEY COUNTIES...

At 447 PM CDT, severe thunderstorms were located along a line
extending from near Carrollton to near Kemper, moving northeast at 45
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Jerseyville, Brighton, Greenfield, Elsah, Athensville, Kemper, Kane,
Wrights, Rockbridge, Fidelity, Delhi, Belltown, Berdan and McClusky.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

&&

LAT...LON 3949 9015 3904 9015 3900 9023 3900 9027
      3898 9028 3894 9035 3901 9034 3925 9037
      3941 9042 3952 9016
TIME...MOT...LOC 2147Z 226DEG 38KT 3936 9037 3916 9021 

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

$$

Gosselin
786 
WWUS53 KLSX 082155
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
455 PM CDT Sun Aug 8 2021

ILC061-083-082205-
/O.EXP.KLSX.SV.W.0141.000000T0000Z-210808T2200Z/
Greene IL-Jersey IL-
455 PM CDT Sun Aug 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN GREENE AND EASTERN
JERSEY COUNTIES WILL EXPIRE AT 500 PM CDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
southwestern Illinois...and east central Missouri.

LAT...LON 3949 9015 3904 9015 3900 9023 3900 9027
      3898 9028 3894 9035 3901 9034 3925 9037
      3941 9042 3952 9016
TIME...MOT...LOC 2155Z 226DEG 38KT 3941 9030 3921 9014 

$$

Gosselin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 2:37 PM CDTHeat AdvisoryLSXAdams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more4 days
Aug 8, 2:54 PM CDTSevere Thunderstorm WarningLSXAdams, Brown, Pike50 min
Aug 8, 4:35 PM CDTAreal Flood AdvisoryLSXAdams, Pike3 hr
Aug 8, 2:43 PM CDTSevere Thunderstorm WarningLSXFranklin, Gasconade47 min
Aug 8, 3:19 PM CDTSevere Thunderstorm WarningLSXFranklin, Lincoln, Saint Charles, Warren41 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2021Severe Thunderstorm Warnings in Missouri, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.