Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 26, NWS Chicago, IL

August 9, 2021DeKalb County, Illinois

NWS Chicago, IL issued this tornado warning at Aug 9, 2021, 4:34 PM CDT for DeKalb County, Illinois. It was in force for 41 min. 1 report 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, 4:34 PM CDT (21:34 UTC)
Expired: Aug 9, 2021, 5:15 PM CDT
In force: 41 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Observed
Hail: 0.75 in

County DeKalb County, IL

The radar

The Chicago radar (KLOT), 74 km from the middle of the area, began a volume at 21:33 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, 4:52 PM CDT	TORNADO	3 Sw Kingston, IL	MULTIPLE REPORTS OF A TORNADO SOUTH OF KENTLAND AND KINGSTON.

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, 9.6 hours before the alert went out and 149 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.

539 
WFUS53 KLOT 092134
TORLOT
ILC037-092215-
/O.NEW.KLOT.TO.W.0026.210809T2134Z-210809T2215Z/

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

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Northwestern De Kalb County in north central Illinois...

* Until 515 PM CDT.

* At 434 PM CDT, a confirmed tornado was located near Kirkland, or 11
  miles northwest of DeKalb, 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...
  DeKalb, Sycamore, Genoa and Cortland.

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 4194 8867 4202 8894 4208 8894 4209 8869
TIME...MOT...LOC 2134Z 278DEG 23KT 4204 8890 

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

$$

Carlaw

1 follow-up statement

636 
WWUS53 KLOT 092153
SVSLOT

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

ILC037-092215-
/O.CON.KLOT.TO.W.0026.000000T0000Z-210809T2215Z/
De Kalb IL-
453 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR NORTH
CENTRAL DE KALB COUNTY...
    
At 453 PM CDT, a confirmed tornado was located approximately 3 
miles south of Kingston, 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...
Sycamore, Genoa and Kirkland. 

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 4197 8868 4201 8885 4208 8885 4209 8869
TIME...MOT...LOC 2153Z 273DEG 21KT 4205 8878 

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

$$

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, 4:39 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, 6:09 PM CDT	Tornado Warning	LOT	DeKalb, Kane	51 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.