Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 33, NWS Chicago, IL

August 9, 2021DeKalb County, Kane County, Illinois

NWS Chicago, IL issued this tornado warning at Aug 9, 2021, 6:09 PM CDT for DeKalb County, Kane County, Illinois. It was in force for 51 min. 7 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: Aug 9, 2021, 6:09 PM CDT (23:09 UTC)
Expired: Aug 9, 2021, 7:00 PM CDT
In force: 51 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties DeKalb County, IL, Kane County, IL

The radar

The Chicago radar (KLOT), 60 km from the middle of the area, began a volume at 23:10 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
Aug 9, 6:13 PM CDT	TORNADO	2 Sse Sycamore, IL	TV CREW REPORTS DAMAGE TO TREES AND POWER LINES NEAR BETHANY ROAD AND FENSTERMAKER ROAD NEAR SYCAMORE. TIME ESTIMATED BY RADAR.
Aug 9, 6:17 PM CDT	TORNADO	2 Se Sycamore, IL	TORNADO ON THE GROUND EAST OF SPOTTER AT BETHANY ROAD AND IL-23.
Aug 9, 6:18 PM CDT	TORNADO	4 Ese Sycamore, IL	TORNADO ON THE GROUND EAST OF SYCAMORE. POSSIBLE DAMAGE TO STRUCTURES.
Aug 9, 6:29 PM CDT	FUNNEL CLOUD	3 Ne Maple Park, IL	TORNADO ON THE GROUND NORTHEAST OF MAPLE PARK.
Aug 9, 6:31 PM CDT	TORNADO	1 S Virgil, IL	RAIN-WRAPPED TORNADO REPORTED NEAR BEITH ROAD AND MEREDITH ROAD.
Aug 9, 6:44 PM CDT	TORNADO	1 Ese Lily Lake, IL	MULTIPLE REPORTS OF A WEAK TORNADO NEAR LILY LAKE.
Aug 9, 6:58 PM CDT	TORNADO	1 Wsw Campton Hills, IL	MULTIPLE REPORTS OF A BRIEF TORNADO NEAR CAMPTON HILLS.

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
Aug 9, 2:43 PM CDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.2 hours before the alert went out and 160 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: 1676 J/kg
Mixed-layer CIN: -63 J/kg
Mixed-layer LCL: 705 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 171 m²/s²
0-3 km storm-relative helicity: 208 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

As transmitted.

609 
WFUS53 KLOT 092309
TORLOT
ILC037-089-100000-
/O.NEW.KLOT.TO.W.0033.210809T2309Z-210810T0000Z/

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

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Northeastern De Kalb County in north central Illinois...
  West central Kane County in northeastern Illinois...

* Until 700 PM CDT.
    
* At 608 PM CDT, a severe thunderstorm capable of producing a 
  tornado was located over Sycamore, moving east at 25 mph. Trained 
  weather spotters report a rotating wall cloud with this storm. 

  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...
  Maple Park around 625 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Lily Lake, Campton Hills and Elburn.

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 4195 8878 4204 8874 4201 8839 4183 8844
TIME...MOT...LOC 2308Z 284DEG 22KT 4198 8871 

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

$$

Carlaw

4 follow-up statements

244 
WWUS53 KLOT 092318
SVSLOT

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

ILC037-089-100000-
/O.CON.KLOT.TO.W.0033.000000T0000Z-210810T0000Z/
De Kalb IL-Kane IL-
618 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM CDT FOR EAST
CENTRAL DE KALB AND WEST CENTRAL KANE COUNTIES...
    
At 617 PM CDT, a confirmed tornado was located near Sycamore, moving
east at 25 mph.

HAZARD...Damaging tornado.

SOURCE...Weather spotters confirmed tornado.

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...
  Lily Lake, Campton Hills and Elburn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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 4195 8878 4203 8867 4201 8839 4183 8844
TIME...MOT...LOC 2317Z 282DEG 22KT 4197 8863 

TORNADO...OBSERVED
MAX HAIL SIZE...<.75 IN

$$

Carlaw

366 
WWUS53 KLOT 092332
SVSLOT

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

ILC037-092341-
/O.CAN.KLOT.TO.W.0033.000000T0000Z-210810T0000Z/
De Kalb IL-
632 PM CDT Mon Aug 9 2021

...THE TORNADO WARNING FOR EAST CENTRAL DE KALB COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

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

LAT...LON 4191 8860 4201 8860 4201 8839 4186 8843
TIME...MOT...LOC 2331Z 285DEG 20KT 4195 8855 

$$

ILC089-100000-
/O.CON.KLOT.TO.W.0033.000000T0000Z-210810T0000Z/
Kane IL-
632 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM CDT FOR WEST
CENTRAL KANE COUNTY...
    
At 631 PM CDT, a confirmed large and extremely dangerous tornado was 
located 3 miles northeast of Maple Park, or 7 miles west of Campton 
Hills, moving east at 25 mph.

This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

HAZARD...Damaging tornado.

SOURCE...Weather spotters confirmed tornado.

IMPACT...You are in a life-threatening situation. Flying debris may 
         be deadly to those caught without shelter. Mobile homes 
         will be destroyed. Considerable damage to homes, 
         businesses, and vehicles is likely and complete destruction 
         is possible.

Locations impacted include...
Campton Hills, Elburn, Maple Park, Lily Lake and Virgil. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous and potentially deadly
tornado is on the ground. To protect your life, 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 4191 8860 4201 8860 4201 8839 4186 8843
TIME...MOT...LOC 2331Z 285DEG 20KT 4195 8855 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
MAX HAIL SIZE...<.75 IN

$$

Carlaw

026 
WWUS53 KLOT 092335
SVSLOT

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

ILC089-100000-
/O.CON.KLOT.TO.W.0033.000000T0000Z-210810T0000Z/
Kane IL-
635 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM CDT FOR WEST
CENTRAL KANE COUNTY...
    
At 634 PM CDT, a confirmed large and extremely dangerous tornado was 
located 3 miles northeast of Maple Park, or 7 miles west of Campton 
Hills, moving east at 25 mph. Weather spotters report the tornado 
has become rain wrapped and will be difficult if not impossible to 
see!

This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

HAZARD...Damaging tornado.

SOURCE...Weather spotters confirmed tornado.

IMPACT...You are in a life-threatening situation. Flying debris may 
         be deadly to those caught without shelter. Mobile homes 
         will be destroyed. Considerable damage to homes, 
         businesses, and vehicles is likely and complete destruction 
         is possible.

Locations impacted include...
Campton Hills, Elburn, Maple Park, Lily Lake and Virgil. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous and potentially deadly
tornado is on the ground. To protect your life, 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 4191 8860 4201 8860 4201 8839 4186 8843
TIME...MOT...LOC 2334Z 281DEG 21KT 4195 8853 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
MAX HAIL SIZE...<.75 IN

$$

Carlaw

308 
WWUS53 KLOT 092359
SVSLOT

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

ILC089-100008-
/O.EXP.KLOT.TO.W.0033.000000T0000Z-210810T0000Z/
Kane IL-
659 PM CDT Mon Aug 9 2021

...THE TORNADO WARNING FOR WEST CENTRAL KANE COUNTY WILL EXPIRE AT
700 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire. An additional 
thunderstorm north or Virgil has recently shown signs of rotation. 

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

LAT...LON 4191 8860 4201 8860 4201 8839 4186 8843
TIME...MOT...LOC 2358Z 273DEG 11KT 4197 8851 

$$

Carlaw

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 6:52 AM CDT	Special Weather Statement	LOT	Winnebago	23 min
Aug 9, 11:49 AM CDT	Areal Flood Advisory	LOT	Boone, DeKalb, Kane, McHenry, Ogle, Winnebago	3 hr
Aug 9, 2:46 PM CDT	Heat Advisory	LOT	Boone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more	28 hr
Aug 9, 3:14 PM CDT	Severe Thunderstorm Warning	LOT	Boone, DeKalb, Ogle, Winnebago	61 min
Aug 9, 3:25 PM CDT	Areal Flood Advisory	LOT	Boone, Winnebago	3 hr
Aug 9, 3:46 PM CDT	Tornado Warning	LOT	Boone, Winnebago	26 min
Aug 9, 4:12 PM CDT	Areal Flood Advisory	LOT	Boone, McHenry	3 hr
Aug 9, 4:34 PM CDT	Tornado Warning Tornado observed	LOT	DeKalb	41 min
Aug 9, 4:39 PM CDT	Tornado Warning	LOT	DeKalb, Ogle	51 min
Aug 9, 5:11 PM CDT	Tornado Warning	LOT	Lee	49 min
Aug 9, 5:15 PM CDT	Tornado Warning	LOT	DeKalb, Kane	60 min
Aug 9, 5:32 PM CDT	Tornado Warning Tornado observed	LOT	DeKalb, Ogle	43 min
Aug 9, 5:42 PM CDT	Tornado Warning	LOT	Kane	48 min
Aug 9, 6:00 PM CDT	Tornado Warning	LOT	DeKalb, Lee	26 min
Aug 9, 6:24 PM CDT	Tornado Warning	LOT	DuPage, Kane	66 min
Aug 9, 6:45 PM CDT	Special Marine Warning	LOT		90 min
Aug 9, 6:50 PM CDT	Tornado Warning	LOT	Kane	40 min

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.