Alert archive / Illinois / Tornado Warnings in 2023

Tornado Warning 31, NWS St. Louis, MO

August 6, 2023Brown County, Illinois

NWS St. Louis, MO issued this tornado warning at Aug 6, 2023, 4:33 PM CDT for Brown County, Illinois. It was in force for 13 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 6, 2023, 4:33 PM CDT (21:33 UTC)
Expired
Aug 6, 2023, 4:46 PM CDT
In force
13 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

County Brown County, IL

The radar

The Lincoln radar (KILX), 108 km from the middle of the area, began a volume at 21:36 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.

IssuedProductOfficeLasted
Aug 6, 3:16 PM CDTTornado WatchSPC9 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.6 hours before the alert went out and 170 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 2023-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2023-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -98 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
749 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-98 m²/s²
0-3 km storm-relative helicity
-85 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

304 
WFUS53 KLSX 062133
TORLSX
ILC009-062200-
/O.NEW.KLSX.TO.W.0031.230806T2133Z-230806T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service St Louis MO
433 PM CDT Sun Aug 6 2023

The National Weather Service in St Louis has issued a

* Tornado Warning for...
  Southeastern Brown County in west central Illinois...

* Until 500 PM CDT.
    
* At 433 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles southeast of Mount Sterling, moving east at 20
  mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  southeastern Brown County, including the following locations...
  Versailles, La Grange, and Coopertown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4001 9062 4000 9060 3998 9060 3998 9052
      3999 9053 3998 9051 3997 9051 3995 9053
      3992 9054 3989 9058 3984 9058 3984 9070
      4001 9072 4002 9061
TIME...MOT...LOC 2133Z 261DEG 19KT 3993 9064 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Carney
1 follow-up statement
426 
WWUS53 KLSX 062146
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
446 PM CDT Sun Aug 6 2023

ILC009-062156-
/O.CAN.KLSX.TO.W.0031.000000T0000Z-230806T2200Z/
Brown IL-
446 PM CDT Sun Aug 6 2023

...THE TORNADO WARNING FOR SOUTHEASTERN BROWN COUNTY IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.  However, heavy rain is
still possible with this thunderstorm.

A Tornado Watch remains in effect until 1000 PM CDT for west central
Illinois.

LAT...LON 4001 9062 4000 9060 3998 9060 3998 9052
      3999 9053 3998 9051 3997 9051 3995 9053
      3992 9054 3989 9058 3984 9058 3984 9070
      4001 9072 4002 9061
TIME...MOT...LOC 2144Z 261DEG 19KT 3994 9055 

$$

Carney

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 2:57 PM CDTTornado WarningLSXAdams, Brown63 min
Aug 6, 3:27 PM CDTTornado WarningLSXBrown48 min
Aug 6, 3:39 PM CDTTornado WarningLSXAdams34 min
Aug 6, 4:01 PM CDTAreal Flood AdvisoryLSXAdams, Brown3 hr
Aug 6, 6:12 PM CDTSevere Thunderstorm WarningLSXBond, Fayette48 min
Aug 6, 6:36 PM CDTTornado WarningLSXFayette39 min
Aug 6, 6:48 PM CDTSevere Thunderstorm WarningLSXMontgomery57 min
Aug 6, 6:51 PM CDTSevere Thunderstorm WarningLSXFayette24 min

Nearby

Tornado Warnings in Illinois, 2023Every tornado warning in 2023Tornadoes in 2023

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.