Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 9, NWS St. Louis, MO

May 27, 20214 counties in Illinois

NWS St. Louis, MO issued this tornado warning at May 27, 2021, 12:56 PM CDT for 4 counties in Illinois. It was in force for 28 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 27, 2021, 12:56 PM CDT (17:56 UTC)
Expired
May 27, 2021, 1:24 PM CDT
In force
28 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Bond County, IL, Macoupin County, IL, Madison County, IL, Montgomery County, IL

The radar

The St Louis radar (KLSX), 92 km from the middle of the area, began a volume at 17:57 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
May 27, 11:26 AM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 5.9 hours before the alert went out and 157 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 2021-05-27Temperature 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 2021-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.19395878Sfc1 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
1679 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

294 
WFUS53 KLSX 271756
TORLSX
ILC005-117-119-135-271845-
/O.NEW.KLSX.TO.W.0009.210527T1756Z-210527T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service St Louis MO
1256 PM CDT Thu May 27 2021

The National Weather Service in St Louis has issued a

* Tornado Warning for...
  Northwestern Bond County in south central Illinois...
  Northeastern Madison County in southwestern Illinois...
  Southeastern Macoupin County in southwestern Illinois...
  Southwestern Montgomery County in south central Illinois...

* Until 145 PM CDT.
    
* At 1256 PM CDT, a severe thunderstorm capable of producing a
  tornado was located near Staunton, moving east at 35 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 dangerous storm will be near...
  Staunton and Mount Clare around 100 PM CDT.
  Benld, Livingston, Sawyerville and Eagarville around 105 PM CDT.
  Mount Olive around 110 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Sorento, Reno, Hillsboro, Taylor Springs, Schram City and Coffeen.

This includes Interstate 55 in Illinois between exits 37 and 44.
 
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 3894 8992 3905 8995 3925 8936 3895 8937
TIME...MOT...LOC 1756Z 258DEG 30KT 3901 8986 

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

$$

MRM
1 follow-up statement
357 
WWUS53 KLSX 271824
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
124 PM CDT Thu May 27 2021

ILC005-117-119-135-271834-
/O.CAN.KLSX.TO.W.0009.000000T0000Z-210527T1845Z/
Bond IL-Madison IL-Macoupin IL-Montgomery IL-
124 PM CDT Thu May 27 2021

...THE TORNADO WARNING FOR NORTHWESTERN BOND COUNTY IN SOUTH CENTRAL
ILLINOIS...NORTHEASTERN MADISON...SOUTHEASTERN MACOUPIN COUNTIES IN
SOUTHWESTERN ILLINOIS AND SOUTHWESTERN MONTGOMERY COUNTIES IN SOUTH
CENTRAL ILLINOIS 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.

A Severe Thunderstorm Watch remains in effect until 700 PM CDT for
south central and southwestern Illinois.

LAT...LON 3894 8992 3905 8995 3925 8936 3895 8937
TIME...MOT...LOC 1821Z 258DEG 30KT 3906 8957 

$$

MRM

The office that day

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

IssuedProductOfficeCountiesLasted
May 27, 11:13 AM CDTSevere Thunderstorm WarningLSXCalhoun, Greene, Jersey47 min
May 27, 11:32 AM CDTSevere Thunderstorm WarningLSXGreene, Macoupin43 min
May 27, 11:50 AM CDTSevere Thunderstorm WarningLSXCalhoun, Greene, Jersey, Macoupin, Madison, Saint Clair55 min
May 27, 12:07 PM CDTSevere Thunderstorm WarningLSXGreene, Macoupin, Montgomery38 min
May 27, 12:26 PM CDTTornado WarningLSXMacoupin, Madison34 min
May 27, 12:39 PM CDTAreal Flood AdvisoryLSXCalhoun, Madison3 hr
May 27, 2:16 PM CDTAreal Flood AdvisoryLSXBond, Fayette3 hr
May 27, 2:31 PM CDTSevere Thunderstorm WarningLSXClinton, Fayette, Marion44 min
May 27, 2:46 PM CDTSevere Thunderstorm WarningLSXMonroe, Randolph29 min

Nearby

Tornado Warnings in Illinois, 2021Every tornado warning in 2021Tornadoes 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.