Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 36, NWS Chicago, IL

August 9, 2021Kankakee County, Will County, Illinois

NWS Chicago, IL issued this tornado warning at Aug 9, 2021, 9:30 PM CDT for Kankakee County, Will County, Illinois. It was in force for 45 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 9, 2021, 9:30 PM CDT (02:30 UTC)
Expired
Aug 9, 2021, 10:15 PM CDT
In force
45 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Kankakee County, IL, Will County, IL

The radar

The Chicago radar (KLOT), 35 km from the middle of the area, began a volume at 02:30 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 9, 2:43 PM CDTTornado WatchSPC9 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 2.5 hours before the alert went out and 134 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 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4598 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 00:00Z on 2021-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 179 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
4598 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
775 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
284 m²/s²
Significant tornado parameter
3.9
Supercell composite
24.2

Open this sounding in Storm Lab

The text

As transmitted.

138 
WFUS53 KLOT 100230
TORLOT
ILC091-197-100315-
/O.NEW.KLOT.TO.W.0036.210810T0230Z-210810T0315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville
930 PM CDT Mon Aug 9 2021

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Southwestern Will County in northeastern Illinois...
  North central Kankakee County in northeastern Illinois...

* Until 1015 PM CDT.
    
* At 930 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Wilmington, 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
  southwestern Will and north central Kankakee Counties, including
  the following locations... Symerton and Wilton Center.

Including the following interstate...
 I-55 between mile markers 237 and 240.
 
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 4123 8822 4134 8823 4142 8789 4122 8790
TIME...MOT...LOC 0230Z 261DEG 17KT 4128 8817 

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

$$

Carlaw
3 follow-up statements
911 
WWUS53 KLOT 100248
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
948 PM CDT Mon Aug 9 2021

ILC091-100257-
/O.CAN.KLOT.TO.W.0036.000000T0000Z-210810T0315Z/
Kankakee IL-
948 PM CDT Mon Aug 9 2021

...THE TORNADO WARNING FOR NORTH CENTRAL KANKAKEE COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning is tracking 
north of the area. Therefore, the warning has been cancelled.

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

LAT...LON 4130 8790 4129 8810 4137 8809 4142 8789
TIME...MOT...LOC 0247Z 250DEG 21KT 4133 8805 

$$

ILC197-100315-
/O.CON.KLOT.TO.W.0036.000000T0000Z-210810T0315Z/
Will IL-
948 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR
SOUTHWESTERN WILL COUNTY...
    
At 947 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Lakewood Shores, or near Wilmington, moving east at
25 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.

Locations impacted include...
Manhattan, Wilton Center and Symerton. 

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 4130 8790 4129 8810 4137 8809 4142 8789
TIME...MOT...LOC 0247Z 250DEG 21KT 4133 8805 

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

$$

Carlaw
954 
WWUS53 KLOT 100300
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
1000 PM CDT Mon Aug 9 2021

ILC197-100315-
/O.CON.KLOT.TO.W.0036.000000T0000Z-210810T0315Z/
Will IL-
1000 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR SOUTH
CENTRAL WILL COUNTY...
    
At 959 PM CDT, a severe thunderstorm capable of producing a tornado 
was located near Wilton Center, or 7 miles west of Peotone, 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.

Locations impacted include...
Manhattan and Wilton Center. 

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.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4132 8790 4131 8800 4138 8802 4142 8789
TIME...MOT...LOC 0259Z 257DEG 19KT 4136 8795 

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

$$

Carlaw
449 
WWUS53 KLOT 100314
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
1014 PM CDT Mon Aug 9 2021

ILC197-100324-
/O.EXP.KLOT.TO.W.0036.000000T0000Z-210810T0315Z/
Will IL-
1014 PM CDT Mon Aug 9 2021

...THE TORNADO WARNING FOR SOUTH CENTRAL WILL COUNTY WILL EXPIRE AT
1015 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until midnight CDT for northeastern
Illinois.

LAT...LON 4132 8790 4131 8800 4138 8802 4142 8789
TIME...MOT...LOC 0314Z 261DEG 17KT 4137 8786 

$$

Carlaw

The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 9, 7:18 PM CDTSevere Thunderstorm WarningLOTCook, DuPage42 min
Aug 9, 8:21 PM CDTSpecial Marine WarningLOT114 min
Aug 9, 9:19 PM CDTSpecial Weather StatementLOTGrundy26 min
Aug 9, 10:06 PM CDTTornado WarningLOTWill54 min
Aug 9, 10:12 PM CDTSpecial Marine WarningLOT2 hr
Aug 10, 3:07 PM CDTHeat AdvisoryLOTBoone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more28 hr
Aug 10, 5:21 PM CDTSpecial Weather StatementLOTLee, Ogle, Winnebago54 min
Aug 10, 5:39 PM CDTSevere Thunderstorm WarningLOTLee, Ogle, Winnebago81 min
Aug 10, 6:10 PM CDTSevere Thunderstorm WarningLOTDeKalb, LaSalle, Lee65 min
Aug 10, 6:16 PM CDTSevere Thunderstorm WarningLOTBoone, DeKalb, McHenry74 min
Aug 10, 6:34 PM CDTSevere Thunderstorm Warning Considerable damage threatLOTCook, DuPage, Kane, Lake, McHenry86 min
Aug 10, 6:38 PM CDTSevere Thunderstorm WarningLOTGrundy, Kane, Kendall82 min
Aug 10, 6:55 PM CDTSevere Thunderstorm Warning Considerable damage threatLOTCook, DuPage, Will95 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.