Alert archive / Illinois / Tornado Warnings in 2023

Tornado Warning 21, NWS Chicago, IL

July 12, 20234 counties in Illinois

NWS Chicago, IL issued this tornado warning at Jul 12, 2023, 5:37 PM CDT for 4 counties in Illinois. It was in force for 23 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 12, 2023, 5:37 PM CDT (22:37 UTC)
Expired
Jul 12, 2023, 6:00 PM CDT
In force
23 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.0 in

Counties DuPage County, IL, Kane County, IL, Kendall County, IL, Will County, IL

The radar

The Chicago radar (KLOT), 20 km from the middle of the area, began a volume at 22:40 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 12, 3:53 PM CDTTornado WatchSPC5 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.6 hours before the alert went out and 173 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, Lincoln, IL at 12:00Z on 2023-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Lincoln, IL at 12:00Z on 2023-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2084 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
80 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

855 
WFUS53 KLOT 122237
TORLOT
ILC043-089-093-197-122300-
/O.NEW.KLOT.TO.W.0021.230712T2237Z-230712T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville
537 PM CDT Wed Jul 12 2023

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Northeastern Kendall County in northeastern Illinois...
  Northwestern Will County in northeastern Illinois...
  Southeastern Kane County in northeastern Illinois...
  Southwestern DuPage County in northeastern Illinois...

* Until 600 PM CDT.
    
* At 537 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Oswego, 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 dangerous storm will be near...
  Aurora around 540 PM CDT.
  Naperville around 550 PM CDT.
  Plainfield around 555 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Bolingbrook and Romeoville.

Including the following interstate...
 I-55 near mile marker 262.
 
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 4164 8839 4173 8839 4179 8817 4164 8813
TIME...MOT...LOC 2237Z 258DEG 24KT 4169 8833 

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

$$

Izzi
2 follow-up statements
141 
WWUS53 KLOT 122248
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
548 PM CDT Wed Jul 12 2023

ILC089-093-197-122257-
/O.CAN.KLOT.TO.W.0021.000000T0000Z-230712T2300Z/
Kendall IL-Will IL-Kane IL-
548 PM CDT Wed Jul 12 2023

...THE TORNADO WARNING FOR NORTHEASTERN KENDALL...NORTHWESTERN WILL
AND SOUTHEASTERN KANE COUNTIES 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 4179 8817 4173 8815 4173 8816 4172 8817
      4172 8826 4176 8826
TIME...MOT...LOC 2247Z 248DEG 25KT 4173 8822 

$$

ILC043-122300-
/O.CON.KLOT.TO.W.0021.000000T0000Z-230712T2300Z/
DuPage IL-
548 PM CDT Wed Jul 12 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 600 PM CDT FOR
SOUTHWESTERN DUPAGE COUNTY...
    
At 547 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Naperville, moving east-northeast 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.

Locations impacted include...
Aurora and Naperville. 

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 4179 8817 4173 8815 4173 8816 4172 8817
      4172 8826 4176 8826
TIME...MOT...LOC 2247Z 248DEG 25KT 4173 8822 

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

$$

Ogorek
015 
WWUS53 KLOT 122254
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
554 PM CDT Wed Jul 12 2023

ILC043-122303-
/O.EXP.KLOT.TO.W.0021.000000T0000Z-230712T2300Z/
DuPage IL-
554 PM CDT Wed Jul 12 2023

...THE TORNADO WARNING FOR SOUTHWESTERN DUPAGE COUNTY WILL EXPIRE AT
600 PM CDT...
        
The storm which prompted the warning has weakened below severe 
limits and has exited the warned area. Therefore, the warning will 
be allowed to expire.

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

LAT...LON 4179 8817 4173 8815 4173 8816 4172 8817
      4172 8826 4176 8826
TIME...MOT...LOC 2253Z 258DEG 24KT 4174 8817 

$$

Ogorek

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 3:49 AM CDTFlood WatchLOTCook, DuPage, Will15 hr
Jul 12, 4:24 AM CDTAreal Flood AdvisoryLOTCook, DeKalb, Kendall, Will3 hr
Jul 12, 10:42 AM CDTRiver Flood WarningLOTCook20 hr
Jul 12, 11:42 AM CDTSpecial Weather StatementLOTPutnam63 min
Jul 12, 12:05 PM CDTSpecial Weather StatementLOTLaSalle40 min
Jul 12, 1:20 PM CDTFlash Flood WarningLOTCook, DuPage, Will3 hr
Jul 12, 6:10 PM CDTTornado WarningLOTCook20 min
Jul 12, 6:13 PM CDTTornado WarningLOTMcHenry32 min
Jul 12, 6:18 PM CDTTornado WarningLOTKane27 min
Jul 12, 6:20 PM CDTTornado Warning Tornado observedConsiderable damage threatLOTCook23 min
Jul 12, 6:22 PM CDTSpecial Marine WarningLOT113 min
Jul 12, 6:31 PM CDTTornado WarningLOTCook, DuPage29 min
Jul 12, 6:35 PM CDTTornado WarningLOTLake25 min
Jul 12, 6:51 PM CDTTornado WarningLOTCook, DuPage24 min

Nearby

Tornado Warnings in Illinois, 2023Every tornado warning in 2023Tornadoes in 2023

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.