Alert archive / Illinois / Tornado Warnings in 2021

Tornado Warning 32, NWS Chicago, IL

August 9, 2021DeKalb County, Lee County, Illinois

NWS Chicago, IL issued this tornado warning at Aug 9, 2021, 6:00 PM CDT for DeKalb County, Lee County, Illinois. It was in force for 26 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, 6:00 PM CDT (23:00 UTC)
Expired
Aug 9, 2021, 6:26 PM CDT
In force
26 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.0 in

Counties DeKalb County, IL, Lee County, IL

The radar

The Chicago radar (KLOT), 68 km from the middle of the area, began a volume at 22:59 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, 6:02 PM CDTTORNADO1 Nw Paw Paw, ILMULTIPLE REPORTS OF BRIEF TORNADO TOUCHDOWN.

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, 11.0 hours before the alert went out and 133 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.

805 
WFUS53 KLOT 092300
TORLOT
ILC037-103-092345-
/O.NEW.KLOT.TO.W.0032.210809T2300Z-210809T2345Z/

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

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  East central Lee County in north central Illinois...
  Southwestern De Kalb County in north central Illinois...

* Until 645 PM CDT.
    
* At 558 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Paw Paw, or 8 miles southwest of Shabbona, moving
  east at 25 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.

* This tornadic thunderstorm will remain over mainly rural areas of 
  east central Lee and southwestern De Kalb Counties including the 
  Rollo area.

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 4175 8900 4174 8874 4163 8874 4163 8901
TIME...MOT...LOC 2258Z 275DEG 20KT 4168 8900 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

LENNING
3 follow-up statements
047 
WWUS53 KLOT 092305
SVSLOT

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

ILC037-103-092345-
/O.CON.KLOT.TO.W.0032.000000T0000Z-210809T2345Z/
Lee IL-De Kalb IL-
605 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR EAST
CENTRAL LEE AND SOUTHWESTERN DE KALB COUNTIES...
    
At 604 PM CDT, a confirmed tornado was located over Paw Paw, or 7
miles southwest of Shabbona, moving east at 25 mph.

HAZARD...Damaging tornado.

SOURCE...Weather spotters and an off duty NWS forecaster confirmed a 
         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...
Paw Paw.

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 4175 8900 4174 8874 4163 8874 4163 8901
TIME...MOT...LOC 2304Z 275DEG 20KT 4168 8895 

TORNADO...OBSERVED
MAX HAIL SIZE...0.00 IN

$$

LENNING
683 
WWUS53 KLOT 092320
SVSLOT

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

ILC103-092329-
/O.CAN.KLOT.TO.W.0032.000000T0000Z-210809T2345Z/
Lee IL-
620 PM CDT Mon Aug 9 2021

...THE TORNADO WARNING FOR EAST CENTRAL LEE 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 north central
Illinois.

LAT...LON 4171 8888 4170 8874 4163 8874 4163 8889
TIME...MOT...LOC 2319Z 275DEG 20KT 4167 8884 

$$

ILC037-092345-
/O.CON.KLOT.TO.W.0032.000000T0000Z-210809T2345Z/
De Kalb IL-
620 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR SOUTH
CENTRAL DE KALB COUNTY...
    
At 619 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Leland, or near Shabbona, moving east at 25 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.

This tornadic thunderstorm will remain over mainly rural areas of
south central De Kalb County.

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 4171 8888 4170 8874 4163 8874 4163 8889
TIME...MOT...LOC 2319Z 275DEG 20KT 4167 8884 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

LENNING
259 
WWUS53 KLOT 092326
SVSLOT

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

ILC037-092335-
/O.CAN.KLOT.TO.W.0032.000000T0000Z-210809T2345Z/
De Kalb IL-
626 PM CDT Mon Aug 9 2021

...THE TORNADO WARNING FOR SOUTH CENTRAL DE KALB COUNTY IS
CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has 
been cancelled.  Another warning remains in effect farther north in 
DeKalb County until 630 PM CDT.

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

LAT...LON 4171 8888 4170 8874 4163 8874 4163 8889
TIME...MOT...LOC 2323Z 275DEG 20KT 4167 8879 

$$

LENNING

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, 5:15 PM CDTTornado WarningLOTDeKalb, Kane60 min
Aug 9, 5:32 PM CDTTornado Warning Tornado observedLOTDeKalb, Ogle43 min
Aug 9, 5:42 PM CDTTornado WarningLOTKane48 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.