Alert archive / Illinois / Tornado Warnings in 2011

Tornado Warning 20, NWS Chicago, IL

June 21, 2011LaSalle County, Livingston County, Illinois

NWS Chicago, IL issued this tornado warning at Jun 21, 2011, 7:27 PM CDT for LaSalle County, Livingston County, Illinois. It was in force for 33 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
Jun 21, 2011, 7:27 PM CDT (00:27 UTC)
Expired
Jun 21, 2011, 8:00 PM CDT
In force
33 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon

Counties LaSalle County, IL, Livingston County, IL

The radar

The Chicago radar (KLOT), 95 km from the middle of the area, began a volume at 00:30 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
Jun 21, 5:42 PM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.5 hours before the alert went out and 95 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 00:00Z on 2011-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3122 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2011-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 147 square meters per square second.1939587897Sfc1 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
3122 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
829 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
147 m²/s²
0-3 km storm-relative helicity
207 m²/s²
Significant tornado parameter
3.5
Supercell composite
15.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

500 
WFUS53 KLOT 220027
TORLOT
ILC099-105-220100-
/O.NEW.KLOT.TO.W.0020.110622T0027Z-110622T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
727 PM CDT TUE JUN 21 2011

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN LA SALLE COUNTY...
  NORTHWESTERN LIVINGSTON COUNTY...

* UNTIL 800 PM CDT

* AT 725 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR MINONK...OR 16 MILES SOUTHWEST OF
  STREATOR...AND MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  STREATOR...DANA...LONG POINT...CORNELL...KANGLEY AND RANSOM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS TORNADO WARNING REPLACES THE SEVERE THUNDERSTORM WARNING THAT
WAS IN EFFECT FOR THE SAME AREA. GO TO A BASEMENT OR SMALL INTERIOR
ROOM ON THE LOWEST FLOOR!

&&

LAT...LON 4080 8891 4081 8894 4092 8894 4092 8905
      4093 8905 4096 8906 4126 8879 4114 8858
      4111 8859 4111 8857
TIME...MOT...LOC 0027Z 217DEG 27KT 4093 8894

$$

IZZI
3 follow-up statements
709 
WWUS53 KLOT 220036
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
736 PM CDT TUE JUN 21 2011

ILC099-105-220100-
/O.CON.KLOT.TO.W.0020.000000T0000Z-110622T0100Z/
LA SALLE IL-LIVINGSTON IL-
736 PM CDT TUE JUN 21 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHWESTERN LIVINGSTON
AND SOUTHEASTERN LA SALLE COUNTIES UNTIL 800 PM CDT...

AT 734 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 8 MILES NORTH OF FLANAGAN...OR 10 MILES SOUTHWEST
OF STREATOR...MOVING NORTHEAST AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...
  STREATOR...CORNELL...KANGLEY AND RANSOM.

LAT...LON 4080 8891 4081 8894 4092 8894 4092 8905
      4093 8905 4096 8906 4126 8879 4114 8858
      4111 8859 4111 8857
TIME...MOT...LOC 0036Z 206DEG 29KT 4101 8890

$$

BIRK
793 
WWUS53 KLOT 220048
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
748 PM CDT TUE JUN 21 2011

ILC099-105-220100-
/O.CON.KLOT.TO.W.0020.000000T0000Z-110622T0100Z/
LA SALLE IL-LIVINGSTON IL-
748 PM CDT TUE JUN 21 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHWESTERN LIVINGSTON
AND SOUTHEASTERN LA SALLE COUNTIES UNTIL 800 PM CDT...

AT 743 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR STREATOR...MOVING NORTHEAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE...
  RANSOM.

LAT...LON 4126 8879 4114 8858 4111 8859 4111 8857
      4088 8882 4098 8904
TIME...MOT...LOC 0048Z 213DEG 41KT 4117 8874

$$

BIRK
574 
WWUS53 KLOT 220100
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
800 PM CDT TUE JUN 21 2011

ILC099-105-220110-
/O.EXP.KLOT.TO.W.0020.000000T0000Z-110622T0100Z/
LA SALLE IL-LIVINGSTON IL-
800 PM CDT TUE JUN 21 2011

...THE TORNADO WARNING FOR NORTHWESTERN LIVINGSTON AND SOUTHEASTERN
LA SALLE COUNTIES HAS EXPIRED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.

LAT...LON 4126 8879 4114 8858 4111 8859 4111 8857
      4088 8882 4098 8904
TIME...MOT...LOC 0100Z 213DEG 41KT 4128 8864

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 7:17 PM CDTSpecial Weather StatementLOTFord, Iroquois, Livingston
Jun 21, 7:19 PM CDTSpecial Marine WarningLOT3 hr
Jun 21, 7:22 PM CDTSevere Thunderstorm WarningLOTMcHenry23 min
Jun 21, 7:23 PM CDTSpecial Weather StatementLOTFord, Iroquois, Kankakee, Will67 min
Jun 21, 7:31 PM CDTSevere Thunderstorm WarningLOTDeKalb, DuPage, Grundy, Kane, Kendall, LaSalle and 2 more37 min
Jun 21, 7:57 PM CDTTornado WarningLOTCook, DeKalb, DuPage, Grundy, Kane, Kendall and 1 more63 min
Jun 21, 8:01 PM CDTAreal Flood AdvisoryLOTLaSalle6 hr
Jun 21, 8:22 PM CDTSevere Thunderstorm WarningLOTCook, DuPage, Kane, Lake, McHenry, Will53 min
Jun 21, 8:38 PM CDTTornado WarningLOTCook, DuPage, Lake52 min
Jun 21, 9:19 PM CDTAreal Flood AdvisoryLOTDeKalb, Grundy, Kane, Kendall, LaSalle6 hr
Jun 22, 9:58 AM CDTSmall Craft AdvisoryLOT12 hr
Jun 22, 11:19 AM CDTRiver Flood AdvisoryLOTLaSalle17 hr

Nearby

Tornado Warnings in Illinois, 2011Every tornado warning in 2011Tornadoes in 2011

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.