Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 3, NWS Chicago, IL

June 20, 2021Cook County, DuPage County, Illinois

NWS Chicago, IL issued this tornado warning at Jun 20, 2021, 10:46 PM CDT for Cook County, DuPage County, Illinois. It was in force for 20 min. 2 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, 10:46 PM CDT (03:46 UTC)
Expired: Jun 20, 2021, 11:06 PM CDT
In force: 20 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Cook County, IL, DuPage County, IL

The radar

The Chicago radar (KLOT), 55 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, 10:51 PM CDT	TSTM WND GST 60	1 N Roselle, IL	RELAYED VIA SPOTTERNETWORK.
Jun 20, 11:00 PM CDT	TSTM WND DMG	Albany Park - Chicago, IL	PUBLIC REPORTS POSSIBLE TREE DAMAGE IN ALBANAY PARK NEIGHBORHOOD OF CHICAGO. 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

Lincoln, IL (KILX), launched 00:00Z, 3.8 hours before the alert went out and 221 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: 1632 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 1351 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 159 m²/s²
0-3 km storm-relative helicity: 421 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 13.7

Open this sounding in Storm Lab

The text

As transmitted.

840 
WFUS53 KLOT 210346
TORLOT
ILC031-043-210430-
/O.NEW.KLOT.TO.W.0003.210621T0346Z-210621T0430Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville
1046 PM CDT Sun Jun 20 2021

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Northeastern DuPage County in northeastern Illinois...
  Northeastern Cook County in northeastern Illinois...

* Until 1130 PM CDT.

* At 1046 PM CDT, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located over
  Itasca, or near Addison, moving east at 30 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.

* These dangerous storms will be near...
  Elk Grove Village and Wood Dale around 1055 PM CDT.
  Arlington Heights, Ohare Airport, Franklin Park and Bensenville 
  around 1100 PM CDT.
  Des Plaines, Mount Prospect, Schiller Park and Rosemont around 
  1105 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Park Ridge, Niles, Norridge, Harwood Heights, Glenview, Dunning,
Morton Grove, Skokie, Portage Park, Lincolnwood, Northfield, West
Ridge, Irving Park, Wilmette, Albany Park, Winnetka, Kenilworth,
Chicago, Evanston, Lake View, Rogers Park, Edgewater and Uptown.

This includes...  Loyola University, Oakton Community College,
Northeastern Illinois University, and Northwestern University.
 
Including the following interstates...
 I-90 between mile markers 72 and 84.
 I-94 between mile markers 32 and 45.
 I-290 between mile markers 3 and 9.
 I-294 between mile markers 32 and 45.

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 4210 8771 4208 8768 4206 8767 4203 8767
      4201 8766 4198 8765 4196 8763 4196 8764
      4195 8764 4194 8807 4200 8808 4213 8774
TIME...MOT...LOC 0346Z 259DEG 25KT 4197 8805 

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

OEMC zones...TORNADO WARNING.  
1...2...3...and 4.
 
$$

Borchardt

2 follow-up statements

484 
WWUS53 KLOT 210356
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
1056 PM CDT Sun Jun 20 2021

ILC031-043-210430-
/O.CON.KLOT.TO.W.0003.000000T0000Z-210621T0430Z/
DuPage IL-Cook IL-
1056 PM CDT Sun Jun 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1130 PM CDT FOR
NORTHEASTERN DUPAGE AND NORTHEASTERN COOK COUNTIES...

At 1056 PM CDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located over
Wood Dale, or over Elk Grove Village, moving east at 30 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.

These dangerous storms will be near...
  Ohare Airport and Franklin Park around 1100 PM CDT.
  Des Plaines, Schiller Park and Rosemont around 1105 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Glenview, Park Ridge, Niles, Norridge, Harwood Heights, Portage Park,
Dunning, Morton Grove, Skokie, Lincolnwood, Northfield, Evanston,
West Ridge, Irving Park, Wilmette, Albany Park, Winnetka, Kenilworth,
Chicago, Lake View, Rogers Park, Edgewater and Uptown.

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 4210 8771 4208 8768 4206 8767 4203 8767
      4201 8766 4198 8765 4196 8763 4196 8764
      4195 8764 4194 8800 4203 8801 4213 8774
TIME...MOT...LOC 0356Z 259DEG 25KT 4198 8796 

TORNADO...RADAR INDICATED
HAIL...0.00IN

OEMC zones...TORNADO WARNING.  
1...2...3...and 4.
 
$$

Borchardt

885 
WWUS53 KLOT 210406
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
1106 PM CDT Sun Jun 20 2021

ILC031-043-210416-
/O.CAN.KLOT.TO.W.0003.000000T0000Z-210621T0430Z/
DuPage IL-Cook IL-
1106 PM CDT Sun Jun 20 2021

...THE TORNADO WARNING FOR NORTHEASTERN DUPAGE AND NORTHEASTERN COOK
COUNTIES 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 gusty winds and
heavy rain are still possible with this thunderstorm.

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

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

LAT...LON 4210 8771 4208 8768 4206 8767 4203 8767
      4201 8766 4198 8765 4196 8763 4196 8764
      4195 8764 4194 8800 4203 8801 4213 8774
TIME...MOT...LOC 0404Z 259DEG 25KT 4199 8786 

$$

Borchardt

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, 10:43 PM CDT	Tornado Warning	LOT	DuPage, Kane	32 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.