Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 153, NWS St. Louis, MO

August 26, 2021Montgomery County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 26, 2021, 2:04 PM CDT for Montgomery County, Illinois. It was in force for 41 min. 1 report 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
Aug 26, 2021, 2:04 PM CDT (19:04 UTC)
Expired
Aug 26, 2021, 2:45 PM CDT
In force
41 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Montgomery County, IL

The radar

The Lincoln radar (KILX), 102 km from the middle of the area, began a volume at 19:03 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
Aug 26, 2:30 PM CDTTSTM WND DMG1 Nne Hillsboro, ILTREE BLOWN OVER. VIA TWITTER WITH PICTURE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.1 hours before the alert went out and 127 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 2021-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1067 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 2021-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 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
1067 J/kg
Mixed-layer CIN
-78 J/kg
Mixed-layer LCL
954 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.6

Open this sounding in Storm Lab

The text

As transmitted.

238 
WUUS53 KLSX 261904
SVRLSX
ILC135-261945-
/O.NEW.KLSX.SV.W.0153.210826T1904Z-210826T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service St Louis MO
204 PM CDT Thu Aug 26 2021

The National Weather Service in St Louis has issued a

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

* Until 245 PM CDT.

* At 204 PM CDT, a severe thunderstorm was located near Hillsboro,
  moving northeast at 15 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Witt and Nokomis.

This includes Interstate 55 in Illinois near exit 60.
 
This also includes Lake Lou Yaeger.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3913 8962 3927 8969 3935 8952 3935 8929
      3923 8929
TIME...MOT...LOC 1904Z 235DEG 15KT 3924 8954 

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

$$

Glass
2 follow-up statements
720 
WWUS53 KLSX 261916
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
216 PM CDT Thu Aug 26 2021

ILC135-261945-
/O.CON.KLSX.SV.W.0153.000000T0000Z-210826T1945Z/
Montgomery IL-
216 PM CDT Thu Aug 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM CDT
FOR CENTRAL MONTGOMERY COUNTY...

At 216 PM CDT, a severe thunderstorm was located near Raymond, moving
northeast at 5 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Litchfield, Hillsboro, Nokomis, Raymond, Witt, Irving, Coalton,
Butler, Wenonah and Honey Bend.

This also includes Lake Lou Yaeger.
 
This includes Interstate 55 in Illinois near exit 60.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3913 8962 3927 8969 3935 8952 3935 8929
      3923 8929
TIME...MOT...LOC 1916Z 230DEG 6KT 3923 8956 

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

$$

Glass
029 
WWUS53 KLSX 261943
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
243 PM CDT Thu Aug 26 2021

ILC135-261953-
/O.EXP.KLSX.SV.W.0153.000000T0000Z-210826T1945Z/
Montgomery IL-
243 PM CDT Thu Aug 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY COUNTY WILL
EXPIRE AT 245 PM CDT...
                
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 will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

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

LAT...LON 3913 8962 3927 8969 3935 8952 3935 8929
      3923 8929
TIME...MOT...LOC 1943Z 235DEG 15KT 3929 8945 

$$

Glass

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 2:45 PM CDTFlash Flood WarningLSXMontgomery4 hr
Aug 26, 4:38 PM CDTSevere Thunderstorm WarningLSXGreene52 min
Aug 26, 5:28 PM CDTSevere Thunderstorm WarningLSXAdams25 min
Aug 26, 5:57 PM CDTSevere Thunderstorm WarningLSXBond, Fayette48 min
Aug 26, 6:54 PM CDTAreal Flood AdvisoryLSXBond3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.