Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 94, NWS St. Louis, MO

June 24, 2021Montgomery County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 24, 2021, 8:42 PM CDT for Montgomery County, Illinois. It was in force for 47 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
Jun 24, 2021, 8:42 PM CDT (01:42 UTC)
Expired
Jun 24, 2021, 9:29 PM CDT
In force
47 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

County Montgomery County, IL

The radar

The Lincoln radar (KILX), 79 km from the middle of the area, began a volume at 01:42 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 nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.7 hours before the alert went out and 116 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 2021-06-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 263 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2021-06-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 245 square meters per square second.193958Sfc1 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
263 J/kg
Mixed-layer CIN
-103 J/kg
Mixed-layer LCL
875 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
245 m²/s²
0-3 km storm-relative helicity
444 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

711 
WUUS53 KLSX 250142
SVRLSX
ILC135-250245-
/O.NEW.KLSX.SV.W.0094.210625T0142Z-210625T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
842 PM CDT Thu Jun 24 2021

The National Weather Service in St Louis has issued a

* Severe Thunderstorm Warning for...
  Northwestern Montgomery County in south central Illinois...

* Until 945 PM CDT.

* At 842 PM CDT, a severe thunderstorm was located over Virden,
  moving east at 10 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.

* This severe thunderstorm will be near...
  Farmersville around 900 PM CDT.

Other locations in the path of this severe thunderstorm include White
Oak.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3944 8970 3952 8970 3953 8966 3952 8953
      3944 8953
TIME...MOT...LOC 0142Z 266DEG 9KT 3954 8973 

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

MRM
2 follow-up statements
189 
WWUS53 KLSX 250206
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
906 PM CDT Thu Jun 24 2021

ILC135-250245-
/O.CON.KLSX.SV.W.0094.000000T0000Z-210625T0245Z/
Montgomery IL-
906 PM CDT Thu Jun 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT
FOR NORTHWESTERN MONTGOMERY COUNTY...

At 905 PM CDT, a severe thunderstorm was located near White Oak,
moving east at 20 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...
  White Oak.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3952 8970 3953 8966 3952 8953 3944 8953
      3946 8969
TIME...MOT...LOC 0205Z 282DEG 18KT 3949 8962 

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

MRM
057 
WWUS53 KLSX 250229
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
929 PM CDT Thu Jun 24 2021

ILC135-250239-
/O.CAN.KLSX.SV.W.0094.000000T0000Z-210625T0245Z/
Montgomery IL-
929 PM CDT Thu Jun 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MONTGOMERY 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.

LAT...LON 3952 8970 3953 8966 3952 8953 3944 8953
      3946 8969
TIME...MOT...LOC 0228Z 266DEG 9KT 3949 8954 

$$

MRM

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 24, 8:11 PM CDTSevere Thunderstorm WarningLSXMacoupin49 min
Jun 24, 11:29 PM CDTSevere Thunderstorm WarningLSXAdams, Pike46 min
Jun 25, 12:03 AM CDTTornado WarningLSXAdams, Pike42 min
Jun 25, 12:17 AM CDTSevere Thunderstorm WarningLSXAdams, Brown, Calhoun, Pike43 min
Jun 25, 12:57 AM CDTSevere Thunderstorm WarningLSXBrown, Calhoun, Greene, Jersey, Pike48 min

Nearby

Severe 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.