Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 36, NWS St. Louis, MO

May 3, 2021Greene County, Macoupin County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 3, 2021, 6:32 PM CDT for Greene County, Macoupin County, Illinois. It was in force for 32 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: May 3, 2021, 6:32 PM CDT (23:32 UTC)
Expired: May 3, 2021, 7:04 PM CDT
In force: 32 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Greene County, IL, Macoupin County, IL

The radar

The St Louis radar (KLSX), 95 km from the middle of the area, began a volume at 23:36 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.

The watch it was issued in

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

Issued	Product	Office	Lasted
May 3, 2:47 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 11.5 hours before the alert went out and 147 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 460 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

122 
WUUS53 KLSX 032332
SVRLSX
ILC061-117-040015-
/O.NEW.KLSX.SV.W.0036.210503T2332Z-210504T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
632 PM CDT Mon May 3 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  East central Greene County in southwestern Illinois...
  Central Macoupin County in southwestern Illinois...

* Until 715 PM CDT.

* At 631 PM CDT, a severe thunderstorm was located over Greenfield,
  moving east at 35 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Carlinville, Greenfield, Wrights, Nilwood, Hettick, Standard City
  and Atwater.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3933 9034 3941 9028 3940 8970 3935 8970
      3935 8971 3924 8970
TIME...MOT...LOC 2331Z 268DEG 31KT 3936 9025 

HAIL...1.00IN
WIND...60MPH
 
$$

Glass

3 follow-up statements

160 
WWUS53 KLSX 032347
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
647 PM CDT Mon May 3 2021

ILC061-032356-
/O.CAN.KLSX.SV.W.0036.000000T0000Z-210504T0015Z/
Greene IL-
647 PM CDT Mon May 3 2021

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

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
south central and southwestern Illinois.

LAT...LON 3932 9015 3941 9015 3940 8970 3935 8970
      3935 8971 3924 8970
TIME...MOT...LOC 2346Z 273DEG 37KT 3938 9007 

$$

ILC117-040015-
/O.CON.KLSX.SV.W.0036.000000T0000Z-210504T0015Z/
Macoupin IL-
647 PM CDT Mon May 3 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM CDT
FOR CENTRAL MACOUPIN COUNTY...

At 646 PM CDT, a severe thunderstorm was located near Palmyra, moving
east at 40 mph.

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

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Carlinville, Nilwood, Hettick, Standard City and Atwater. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3932 9015 3941 9015 3940 8970 3935 8970
      3935 8971 3924 8970
TIME...MOT...LOC 2346Z 273DEG 37KT 3938 9007 

HAIL...1.00IN
WIND...60MPH
 
$$

Glass

602 
WWUS53 KLSX 032357
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
657 PM CDT Mon May 3 2021

ILC117-040015-
/O.CON.KLSX.SV.W.0036.000000T0000Z-210504T0015Z/
Macoupin IL-
657 PM CDT Mon May 3 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM CDT
FOR EAST CENTRAL MACOUPIN COUNTY...

At 657 PM CDT, a severe thunderstorm was located near Palmyra, moving
east at 35 mph.

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

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Carlinville, Nilwood, Standard City and Atwater. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3930 9002 3941 8998 3940 8970 3935 8970
      3935 8971 3924 8970
TIME...MOT...LOC 2357Z 268DEG 31KT 3938 8994 

HAIL...1.00IN
WIND...60MPH
 
$$

Glass

979 
WWUS53 KLSX 040004
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
704 PM CDT Mon May 3 2021

ILC117-040014-
/O.CAN.KLSX.SV.W.0036.000000T0000Z-210504T0015Z/
Macoupin IL-
704 PM CDT Mon May 3 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MACOUPIN COUNTY
IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However heavy rain is
still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
south central and southwestern Illinois.

LAT...LON 3930 9002 3941 8998 3940 8970 3935 8970
      3935 8971 3924 8970
TIME...MOT...LOC 0002Z 268DEG 31KT 3938 8986 

$$

Glass

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 2:54 PM CDT	Severe Thunderstorm Warning	LSX	Adams	51 min
May 3, 3:27 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown	48 min
May 3, 4:13 PM CDT	Severe Thunderstorm Warning	LSX	Brown	28 min
May 3, 6:13 PM CDT	Severe Thunderstorm Warning	LSX	Greene, Macoupin	47 min
May 3, 6:45 PM CDT	Severe Thunderstorm Warning	LSX	Montgomery	23 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.