Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 196, NWS St. Louis, MO

December 10, 2021Clinton County, Saint Clair County, Washington County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Dec 10, 2021, 10:51 PM CST for Clinton County, Saint Clair County, Washington County, Illinois. It was in force for 39 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: Dec 10, 2021, 10:51 PM CST (04:51 UTC)
Expired: Dec 10, 2021, 11:30 PM CST
In force: 39 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Clinton County, IL, Saint Clair County, IL, Washington County, IL

The radar

The St Louis radar (KLSX), 112 km from the middle of the area, began a volume at 04:53 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
Dec 10, 3:07 PM CST	Tornado Watch	SPC	11 hr
Dec 10, 5:17 PM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 4.9 hours before the alert went out and 205 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: 119 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 662 m above ground
0-6 km bulk shear: 73 kt
0-1 km storm-relative helicity: 341 m²/s²
0-3 km storm-relative helicity: 357 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

257 
WUUS53 KLSX 110451
SVRLSX
ILC027-163-189-110530-
/O.NEW.KLSX.SV.W.0196.211211T0451Z-211211T0530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
1051 PM CST Fri Dec 10 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Central Clinton County in south central Illinois...
  Washington County in south central Illinois...
  Southeastern St. Clair County in southwestern Illinois...

* Until 1130 PM CST.

* At 1050 PM CST, a severe thunderstorm was located near New Memphis,
  moving northeast at 75 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Okawville and Germantown around 1100 PM CST.
  Beckemeyer around 1105 PM CST.

Other locations in the path of this severe thunderstorm include Wamac
and Shattuc.

This includes Interstate 64 in Illinois between exits 34 and 61.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM CST for south central
and southwestern Illinois. A Tornado Watch also remains in effect
until 1100 PM CST for south central Illinois.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

A Tornado Watch remains in effect until 1100 PM CST for south central
and southwestern Illinois. A Tornado Watch also remains in effect
until 1100 PM CST for south central Illinois.

&&

LAT...LON 3836 8915 3823 8989 3845 8989 3872 8914
TIME...MOT...LOC 0450Z 245DEG 67KT 3839 8970 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Britt

2 follow-up statements

759 
WWUS53 KLSX 110506
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1106 PM CST Fri Dec 10 2021

ILC163-110515-
/O.CAN.KLSX.SV.W.0196.000000T0000Z-211211T0530Z/
St. Clair IL-
1106 PM CST Fri Dec 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ST. CLAIR COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area.  Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 200 AM CST for south central
Illinois. A Tornado Watch also remains in effect until 500 AM CST for
south central Illinois.

LAT...LON 3836 8915 3826 8970 3855 8962 3872 8914
TIME...MOT...LOC 0505Z 249DEG 55KT 3848 8949 

$$

ILC027-189-110530-
/O.CON.KLSX.SV.W.0196.000000T0000Z-211211T0530Z/
Clinton IL-Washington IL-
1106 PM CST Fri Dec 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 PM CST
FOR CENTRAL CLINTON AND WASHINGTON COUNTIES...

At 1105 PM CST, a severe thunderstorm was located near Okawville,
moving east at 65 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

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

This severe storm will be near...
  Beckemeyer around 1110 PM CST.

Other locations in the path of this severe thunderstorm include Wamac
and Shattuc.

This includes Interstate 64 in Illinois between exits 34 and 61.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 200 AM CST for south central
Illinois. A Tornado Watch also remains in effect until 500 AM CST for
south central Illinois.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 3836 8915 3826 8970 3855 8962 3872 8914
TIME...MOT...LOC 0505Z 249DEG 55KT 3848 8949 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Britt

723 
WWUS53 KLSX 110523
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
1123 PM CST Fri Dec 10 2021

ILC027-189-110533-
/O.EXP.KLSX.SV.W.0196.000000T0000Z-211211T0530Z/
Clinton IL-Washington IL-
1123 PM CST Fri Dec 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL CLINTON AND WASHINGTON
COUNTIES WILL EXPIRE AT 1130 PM CST...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 200 AM CST for south central
Illinois. A Tornado Watch also remains in effect until 500 AM CST for
south central Illinois.

LAT...LON 3836 8915 3826 8970 3855 8962 3872 8914
TIME...MOT...LOC 0523Z 245DEG 67KT 3861 8912 

$$

Britt

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 10, 6:42 PM CST	Tornado Warning	LSX	Pike	48 min
Dec 10, 7:11 PM CST	Tornado Warning	LSX	Pike	49 min
Dec 10, 7:16 PM CST	Tornado Warning	LSX	Pike	14 min
Dec 10, 7:30 PM CST	Tornado Warning	LSX	Calhoun, Greene, Jersey	45 min
Dec 10, 7:35 PM CST	Tornado Warning Tornado observed	LSX	Calhoun, Jersey	40 min
Dec 10, 7:36 PM CST	Tornado Warning	LSX	Pike	21 min
Dec 10, 8:06 PM CST	Tornado Warning Tornado observed	LSX	Jersey, Macoupin, Madison	39 min
Dec 10, 8:33 PM CST	Tornado Warning Tornado observedConsiderable damage threat	LSX	Bond, Madison	42 min
Dec 10, 8:37 PM CST	Tornado Warning	LSX	Macoupin, Madison	17 min
Dec 10, 8:44 PM CST	Tornado Warning Tornado observed	LSX	Fayette, Macoupin, Madison, Montgomery	46 min
Dec 10, 8:56 PM CST	Tornado Warning	LSX	Bond, Fayette, Montgomery	34 min
Dec 10, 9:07 PM CST	Severe Thunderstorm Warning	LSX	Calhoun	38 min
Dec 10, 9:39 PM CST	Tornado Warning	LSX	Macoupin, Madison	51 min
Dec 10, 10:05 PM CST	Severe Thunderstorm Warning	LSX	Madison, Saint Clair	25 min
Dec 10, 10:18 PM CST	Severe Thunderstorm Warning	LSX	Bond, Fayette, Macoupin, Madison, Montgomery	57 min
Dec 10, 10:19 PM CST	Severe Thunderstorm Warning	LSX	Monroe, Randolph, Saint Clair	41 min
Dec 10, 10:26 PM CST	Tornado Warning	LSX	Bond, Fayette, Montgomery	49 min
Dec 10, 11:02 PM CST	Tornado Warning	LSX	Fayette	29 min
Dec 10, 11:10 PM CST	Tornado Warning	LSX	Clinton, Marion, Washington	50 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2021 Every 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.