Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 29, NWS Chicago, IL

August 9, 2021DeKalb County, Kane County, Illinois

NWS Chicago, IL issued this tornado warning at Aug 9, 2021, 5:15 PM CDT for DeKalb County, Kane County, Illinois. It was in force for 60 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
Aug 9, 2021, 5:15 PM CDT (22:15 UTC)
Expired
Aug 9, 2021, 6:15 PM CDT
In force
60 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), 68 km from the middle of the area, began a volume at 22:17 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

TimeReportWhereRemark
Aug 9, 5:26 PM CDTTSTM WND DMG2 Wsw Burlington, ILKANE COUNTY SHERIFFS OFFICE REPORTS DAMAGE TO A STRUCTURE ALONG PLANK ROAD NEAR EAGLE ROAD. POSSIBLE TORNADO. TIME ESTIMATED BY RADAR.
Aug 9, 5:26 PM CDTTORNADO2 Wsw Burlington, ILCORRECTS AND UPDATES PREVIOUS TSTM WND DMG REPORT FROM 2 WSW BURLINGTON. KANE COUNTY SHERIFFS OFFICE REPORTS DAMAGE TO A STRUCTURE ALONG PLANK ROAD NEAR EAGLE ROAD. CONFIRMED TORNADO WITH THIS DAMAGE GIVEN TORNADO DEBRIS SIGNATURE ON KLOT FROM ABOUT 5:24 PM UN

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.

IssuedProductOfficeLasted
Aug 9, 2:43 PM CDTTornado WatchSPC9 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.3 hours before the alert went out and 161 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, Davenport, at 12:00Z on 2021-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1676 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, Davenport, at 12:00Z on 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 171 square meters per square second.193958Sfc1 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
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.

044 
WFUS53 KLOT 092215
TORLOT
ILC037-089-092315-
/O.NEW.KLOT.TO.W.0029.210809T2215Z-210809T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville
515 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...
  Northwestern Kane County in northeastern Illinois...

* Until 615 PM CDT.
    
* At 515 PM CDT, a severe thunderstorm capable of producing a 
  tornado was located over Kingston, or near Genoa, moving east at 
  20 mph. Another storm capable of producing a tornado was 3 miles 
  south of Genoa. These storms have a history of producing tornadoes.

  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...
  Sycamore and Genoa around 530 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Hampshire, Lily Lake and Pingree Grove.

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 4204 8878 4213 8877 4212 8844 4193 8846
TIME...MOT...LOC 2215Z 273DEG 16KT 4207 8878 

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

$$

Carlaw
2 follow-up statements
397 
WWUS53 KLOT 092228
SVSLOT

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

ILC037-089-092315-
/O.CON.KLOT.TO.W.0029.000000T0000Z-210809T2315Z/
De Kalb IL-Kane IL-
528 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
NORTHEASTERN DE KALB AND NORTHWESTERN KANE COUNTIES...
        
At 528 PM CDT, a confirmed tornado was located near Hampshire, or 7 
miles southeast of Genoa or due west of Burlington, moving east at 
20 mph. An additional storm capable of producing a tornado was 
located 3 miles south of Genoa.

HAZARD...Damaging tornado.

SOURCE...Radar 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 and Pingree Grove.

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 4204 8878 4213 8877 4212 8844 4193 8846
TIME...MOT...LOC 2228Z 276DEG 17KT 4205 8857 

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

$$

Carlaw
293 
WWUS53 KLOT 092251
SVSLOT

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

ILC037-089-092315-
/O.CON.KLOT.TO.W.0029.000000T0000Z-210809T2315Z/
De Kalb IL-Kane IL-
551 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
NORTHEASTERN DE KALB AND NORTHWESTERN KANE COUNTIES...
    
At 550 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Lily Lake, or 7 miles northwest of Campton Hills, 
moving southeast at 15 mph. An additional storm capable of producing 
a tornado is located near Genoa.

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...
Sycamore, Genoa, Pingree Grove, Hampshire, Kingston, Lily Lake,
Burlington and Virgil.

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 4204 8878 4213 8877 4212 8844 4193 8846
TIME...MOT...LOC 2250Z 294DEG 15KT 4201 8855 

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

$$

Carlaw

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 6:52 AM CDTSpecial Weather StatementLOTWinnebago23 min
Aug 9, 11:49 AM CDTAreal Flood AdvisoryLOTBoone, DeKalb, Kane, McHenry, Ogle, Winnebago3 hr
Aug 9, 2:46 PM CDTHeat AdvisoryLOTBoone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more28 hr
Aug 9, 3:14 PM CDTSevere Thunderstorm WarningLOTBoone, DeKalb, Ogle, Winnebago61 min
Aug 9, 3:25 PM CDTAreal Flood AdvisoryLOTBoone, Winnebago3 hr
Aug 9, 3:46 PM CDTTornado WarningLOTBoone, Winnebago26 min
Aug 9, 4:12 PM CDTAreal Flood AdvisoryLOTBoone, McHenry3 hr
Aug 9, 4:34 PM CDTTornado Warning Tornado observedLOTDeKalb41 min
Aug 9, 4:39 PM CDTTornado WarningLOTDeKalb, Ogle51 min
Aug 9, 5:11 PM CDTTornado WarningLOTLee49 min
Aug 9, 5:32 PM CDTTornado Warning Tornado observedLOTDeKalb, Ogle43 min
Aug 9, 5:42 PM CDTTornado WarningLOTKane48 min
Aug 9, 6:00 PM CDTTornado WarningLOTDeKalb, Lee26 min
Aug 9, 6:09 PM CDTTornado WarningLOTDeKalb, Kane51 min
Aug 9, 6:24 PM CDTTornado WarningLOTDuPage, Kane66 min
Aug 9, 6:45 PM CDTSpecial Marine WarningLOT90 min
Aug 9, 6:50 PM CDTTornado WarningLOTKane40 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.