Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 2, NWS Chicago, IL

June 20, 2021DuPage County, Kane County, Illinois

NWS Chicago, IL issued this tornado warning at Jun 20, 2021, 10:43 PM CDT for DuPage County, Kane County, Illinois. It was in force for 32 min. 3 reports 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: Jun 20, 2021, 10:43 PM CDT (03:43 UTC)
Expired: Jun 20, 2021, 11:15 PM CDT
In force: 32 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties DuPage County, IL, Kane County, IL

The radar

The Chicago radar (KLOT), 34 km from the middle of the area, began a volume at 03:45 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

Time	Report	Where	Remark
Jun 20, 10:46 PM CDT	TSTM WND DMG	3 E Kaneville, IL	SEVERAL TREES DOWNED BETWEEN KANEVILLE AND NORTH AURORA. TIME ESTIMATED BY RADAR.
Jun 20, 10:46 PM CDT	TSTM WND GST 60	2 W Sugar Grove, IL	AURORA AIRPORT OBSERVED 60 MPH GUST.
Jun 20, 10:50 PM CDT	TSTM WND DMG	3 Nw Montgomery, IL	TREE DAMAGE NEAR CANTERBURY ROAD AND GALENA BOULEVARD. RELAYED BY AURORA PD. TIME ESTIMATED BY RADAR.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 20, 9:40 PM CDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.7 hours before the alert went out and 184 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1058 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 1009 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 174 m²/s²
0-3 km storm-relative helicity: 230 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 7.8

Open this sounding in Storm Lab

The text

As transmitted.

358 
WFUS53 KLOT 210343
TORLOT
ILC043-089-210415-
/O.NEW.KLOT.TO.W.0002.210621T0343Z-210621T0415Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville
1043 PM CDT Sun Jun 20 2021

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Southern Kane County in northeastern Illinois...
  Northwestern DuPage County in northeastern Illinois...

* Until 1115 PM CDT.
    
* At 1042 PM CDT, a severe thunderstorm capable of producing a
  tornado was located near North Aurora, or near Batavia, moving 
  east at 40 mph. There's also developing rotation southeast of 
  Maple Park.

  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...
  Northern Aurora around 1045 PM CDT.
  Geneva and North Aurora around 1050 PM CDT.
  St. Charles, Batavia, Wayne and Dupage Airport around 1055 PM CDT.
  West Chicago and Warrenville around 1100 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Carol Stream, Winfield and Wheaton.

This includes...  Fermilab, IL Math and Science Academy, Kane County
Cougars Ballpark, and Waubonsee Community College.
 
Including the following interstate...
 I-88 between mile markers 103 and 126.
 
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 4176 8815 4175 8857 4194 8856 4199 8826
      4199 8814
TIME...MOT...LOC 0342Z 255DEG 33KT 4184 8840 

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

$$

FRIEDLEIN

2 follow-up statements

282 
WWUS53 KLOT 210353
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
1053 PM CDT Sun Jun 20 2021

ILC043-089-210415-
/O.CON.KLOT.TO.W.0002.000000T0000Z-210621T0415Z/
Kane IL-DuPage IL-
1053 PM CDT Sun Jun 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT FOR SOUTHERN
KANE AND NORTHWESTERN DUPAGE COUNTIES...
    
At 1052 PM CDT, a severe thunderstorm capable of producing a tornado
was located near North Aurora, or near Batavia, moving east at 30
mph. Aurora Airport in Sugar Grove gusted to 60 mph near this area.

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...
  Aurora around 1055 PM CDT.
  North Aurora around 1100 PM CDT.

Other locations in the path of this tornadic thunderstorm include St.
Charles, Batavia, Geneva, Valley View, Bartlett, West Chicago,
Warrenville, Wayne, Dupage Airport, Carol Stream, Winfield and
Wheaton.

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 4175 8854 4193 8852 4199 8826 4199 8814
      4176 8815
TIME...MOT...LOC 0352Z 254DEG 27KT 4184 8839 

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

$$

FRIEDLEIN

838 
WWUS53 KLOT 210409
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
1109 PM CDT Sun Jun 20 2021

ILC043-089-210418-
/O.EXP.KLOT.TO.W.0002.000000T0000Z-210621T0415Z/
Kane IL-DuPage IL-
1109 PM CDT Sun Jun 20 2021

...THE TORNADO WARNING FOR SOUTHERN KANE AND NORTHWESTERN DUPAGE
COUNTIES WILL EXPIRE AT 1115 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire. However, gusty 
winds greater than 40 mph are still expected at times through 1130 
PM.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
northeastern Illinois.

LAT...LON 4175 8854 4193 8852 4199 8826 4199 8814
      4176 8815
TIME...MOT...LOC 0408Z 255DEG 33KT 4187 8822 

$$

FRIEDLEIN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 8:39 PM CDT	Severe Thunderstorm Warning	LOT	Winnebago	21 min
Jun 20, 9:02 PM CDT	Severe Thunderstorm Warning	LOT	Ogle	58 min
Jun 20, 10:12 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb	33 min
Jun 20, 10:22 PM CDT	Severe Thunderstorm Warning	LOT	Kane	53 min
Jun 20, 10:40 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	50 min
Jun 20, 10:46 PM CDT	Tornado Warning	LOT	Cook, DuPage	20 min
Jun 20, 10:48 PM CDT	Special Marine Warning	LOT		117 min
Jun 20, 10:50 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Grundy, Kane, Kendall, LaSalle	55 min
Jun 20, 10:56 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Will	79 min
Jun 20, 11:05 PM CDT	Tornado Warning	LOT	Cook, DuPage, Will	40 min
Jun 20, 11:08 PM CDT	Areal Flood Advisory	LOT	Cook, DuPage, Kane, Kendall, Lake, McHenry and 1 more	4 hr
Jun 20, 11:15 PM CDT	Tornado Warning	LOT	Cook, DuPage	30 min
Jun 20, 11:30 PM CDT	Severe Thunderstorm Warning	LOT	Cook	30 min
Jun 20, 11:41 PM CDT	Severe Thunderstorm Warning	LOT	Kankakee, Will	79 min
Jun 21, 12:00 AM CDT	Tornado Warning	LOT	Will	34 min
Jun 21, 3:22 PM CDT	Small Craft Advisory	LOT		7 hr

Nearby

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