Alert archive / Illinois / Tornado Warnings in 2011

Tornado Warning 10, NWS Chicago, IL

May 22, 2011Boone County, DeKalb County, McHenry County, Illinois

NWS Chicago, IL issued this tornado warning at May 22, 2011, 6:54 PM CDT for Boone County, DeKalb County, McHenry County, Illinois. It was in force for 51 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
May 22, 2011, 6:54 PM CDT (23:54 UTC)
Expired
May 22, 2011, 7:45 PM CDT
In force
51 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon

Counties Boone County, IL, DeKalb County, IL, McHenry County, IL

The radar

The Milwaukee radar (KMKX), 75 km from the middle of the area, began a volume at 23:56 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
May 22, 7:25 PM CDTTSTM WND DMGHebron, ILAT LEAST 8 LARGE TREES UPROOTED BLOWN DOWN IN HEBRON AREA IN A NORTHWEST TO SOUTHEAST DIRECTION...INDICATIVE OF STRAIGHT LINE WIND DAMAGE. ESTIMATED 10 INCH DIAMETER TREES.7 POWERPOLES BLOWN DOWN ALONG ROUTE 47 3 MILES SOUTH OF HEBRON.
May 22, 7:29 PM CDTTSTM WND DMGRichmond, ILTREES UPROOTED. ROUTE 12 BLOCKED BY TREE EAST OF ROUTE 31.

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
May 22, 2:04 PM CDTTornado WatchSPC9 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.9 hours before the alert went out and 178 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 2011-05-22Temperature 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, Davenport, at 12:00Z on 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 233 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1775 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
233 m²/s²
0-3 km storm-relative helicity
287 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

543 
WFUS53 KLOT 222354
TORLOT
ILC007-037-111-230045-
/O.NEW.KLOT.TO.W.0010.110522T2354Z-110523T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
654 PM CDT SUN MAY 22 2011

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN BOONE COUNTY...
  NORTHEASTERN DE KALB COUNTY...
  MCHENRY COUNTY...

* UNTIL 745 PM CDT

* AT 650 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE SQUALL LINE CAPABLE OF PRODUCING RAIN-WRAPPED
  TORNADOES IN ADDITION TO WIDESPREAD STRAIGHT LINE WIND DAMAGE.
  THESE DANGEROUS STORMS WERE LOCATED ALONG A LINE EXTENDING FROM 7
  MILES NORTHWEST OF ROCKTON TO 6 MILES SOUTHWEST OF ROCKTON TO
  ROCKFORD TO ROCKFORD AIRPORT TO STILLMAN VALLEY...AND MOVING EAST
  AT 60 MPH.

* THESE STORMS WILL BE NEAR...
  CAPRON AROUND 710 PM.
  MARENGO AND HARVARD AROUND 715 PM.
  WOODSTOCK AROUND 720 PM.
  WONDER LAKE...HEBRON AND BULL VALLEY AROUND 725 PM.
  RICHMOND...MCHENRY...MCCULLOM LAKE AND LAKEWOOD AROUND 730 PM.

OTHER LOCATIONS IMPACTED BY THESE TORNADIC THUNDERSTORMS INCLUDE
UNION AND CRYSTAL LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4248 8824 4219 8831 4215 8851 4215 8859
      4214 8859 4209 8885 4222 8879 4238 8876
      4249 8886 4250 8825
TIME...MOT...LOC 2354Z 255DEG 54KT 4252 8911 4242 8910
          4230 8900 4220 8897 4207 8905

$$

IZZI
5 follow-up statements
958 
WWUS53 KLOT 230003
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
703 PM CDT SUN MAY 22 2011

ILC007-037-111-230045-
/O.CON.KLOT.TO.W.0010.000000T0000Z-110523T0045Z/
MCHENRY IL-BOONE IL-DE KALB IL-
703 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN DE KALB...
EASTERN BOONE AND MCHENRY COUNTIES UNTIL 745 PM CDT...

AT 700 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE SQUALL LINE CAPABLE OF PRODUCING DAMAGING STRAIGHT LINE WINDS
AND RAIN-WRAPPED TORNADOES.  THESE DANGEROUS STORMS WERE LOCATED 
ALONG A LINE EXTENDING FROM SOUTH BELOIT TO BELVIDERE TO 6
MILES WEST OF KIRKLAND...MOVING EAST AT 60 MPH.

THESE DANGEROUS STORMS WILL BE NEAR...
  CAPRON AROUND 710 PM CDT.
  MARENGO AND HARVARD AROUND 715 PM CDT.
  WOODSTOCK AROUND 720 PM CDT.
  WONDER LAKE...HEBRON AND BULL VALLEY AROUND 725 PM CDT.
  RICHMOND...MCHENRY...MCCULLOM LAKE AND LAKEWOOD AROUND 730 PM CDT.

OTHER LOCATIONS IMPACTED BY THIS LINE OF TORNADO PRODUCING STORMS
INCLUDE UNION AND CRYSTAL LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

&&

LAT...LON 4248 8824 4219 8831 4215 8851 4215 8859
      4214 8859 4209 8885 4222 8879 4238 8876
      4249 8886 4250 8825
TIME...MOT...LOC 0002Z 255DEG 54KT 4251 8896 4222 8881
          4207 8892

$$

IZZI
047 
WWUS53 KLOT 230012
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
712 PM CDT SUN MAY 22 2011

ILC007-037-111-230045-
/O.CON.KLOT.TO.W.0010.000000T0000Z-110523T0045Z/
MCHENRY IL-BOONE IL-DE KALB IL-
712 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN DE KALB...
EASTERN BOONE AND MCHENRY COUNTIES UNTIL 745 PM CDT...

AT 708 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE SQUALL LINE CAPABLE OF PRODUCING DAMAGING STRAIGHT LINE WINDS
AND RAIN-WRAPPED TORNADOES.  THESE DANGEROUS STORMS WERE LOCATED 
ALONG A LINE EXTENDING FROM CLINTON TO MARENGO TO KINGSTON...
MOVING EAST AT 60 MPH.

THESE DANGEROUS STORMS WILL BE NEAR...
  WOODSTOCK AROUND 720 PM CDT.
  WONDER LAKE...HEBRON AND BULL VALLEY AROUND 725 PM CDT.
  RICHMOND...MCHENRY...MCCULLOM LAKE AND LAKEWOOD AROUND 730 PM CDT.

OTHER LOCATIONS IMPACTED BY THIS LINE OF TORNADO PRODUCING STORMS
INCLUDE CRYSTAL LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

&&

LAT...LON 4248 8824 4219 8831 4215 8851 4215 8859
      4214 8859 4209 8885 4222 8879 4238 8876
      4249 8886 4250 8825
TIME...MOT...LOC 0012Z 255DEG 54KT 4254 8876 4225 8861
          4210 8872

$$

IZZI
953 
WWUS53 KLOT 230024
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
724 PM CDT SUN MAY 22 2011

ILC007-037-111-230045-
/O.CON.KLOT.TO.W.0010.000000T0000Z-110523T0045Z/
MCHENRY IL-BOONE IL-DE KALB IL-
724 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN DE KALB...
EASTERN BOONE AND MCHENRY COUNTIES UNTIL 745 PM CDT...

AT 720 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE SQUALL LINE CAPABLE OF PRODUCING DAMAGING STRAIGHT LINE WINDS
AND RAIN-WRAPPED TORNADOES.  THESE DANGEROUS STORMS WERE LOCATED 
ALONG A LINE EXTENDING FROM FONTANA-ON-GENEVA LAKE TO WOODSTOCK TO 
HAMPSHIRE...MOVING EAST AT 60 MPH.

THESE DANGEROUS STORMS WILL BE NEAR...
  RICHMOND...MCHENRY...MCCULLOM LAKE AND LAKE IN THE HILLS AROUND 730
  PM CDT.

OTHER LOCATIONS IMPACTED BY THIS LINE OF TORNADO PRODUCING STORMS
INCLUDE CRYSTAL LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

&&

LAT...LON 4250 8825 4248 8824 4219 8831 4215 8850
      4215 8859 4214 8859 4212 8880 4222 8875
      4239 8873 4249 8871
TIME...MOT...LOC 0024Z 255DEG 54KT 4258 8852 4229 8837
          4214 8848

$$

IZZI
162 
WWUS53 KLOT 230031
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
731 PM CDT SUN MAY 22 2011

ILC007-037-230042-
/O.CAN.KLOT.TO.W.0010.000000T0000Z-110523T0045Z/
BOONE IL-DE KALB IL-
731 PM CDT SUN MAY 22 2011

...THE TORNADO WARNING FOR NORTHEASTERN DE KALB AND EASTERN BOONE
COUNTIES IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE 
WARNED AREA.

LAT...LON 4219 8831 4215 8850 4216 8862 4229 8855
      4249 8855 4250 8825 4248 8824
TIME...MOT...LOC 0032Z 256DEG 55KT 4251 8830 4237 8827
          4219 8837

$$

ILC111-230045-
/O.CON.KLOT.TO.W.0010.000000T0000Z-110523T0045Z/
MCHENRY IL-
731 PM CDT SUN MAY 22 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR CENTRAL MCHENRY COUNTY
UNTIL 745 PM CDT...

AT 729 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE SQUALL LINE CAPABLE OF PRODUCING DAMAGING STRAIGHT LINE WINDS
AND RAIN-WRAPPED TORNADOES.  THESE DANGEROUS STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM GENOA CITY TO MCCULLOM LAKE TO
HUNTLEY...MOVING EAST AT 65 MPH.

THIS LINE OF TORNADO PRODUCING STORMS WILL AFFECT MAINLY RURAL AREAS
OF CENTRAL MCHENRY COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

&&

LAT...LON 4219 8831 4215 8850 4216 8862 4229 8855
      4249 8855 4250 8825 4248 8824
TIME...MOT...LOC 0032Z 256DEG 55KT 4251 8830 4237 8827
          4219 8837

$$

IZZI
445 
WWUS53 KLOT 230041
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
741 PM CDT SUN MAY 22 2011

ILC111-230051-
/O.EXP.KLOT.TO.W.0010.000000T0000Z-110523T0045Z/
MCHENRY IL-
741 PM CDT SUN MAY 22 2011

...THE TORNADO WARNING FOR CENTRAL MCHENRY COUNTY WILL EXPIRE AT 745
PM CDT...

REMEMBER...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR 
EASTERN MCHENRY COUNTY UNTIL 815 PM.

LAT...LON 4219 8831 4215 8850 4216 8862 4229 8855
      4249 8855 4250 8825 4248 8824
TIME...MOT...LOC 0041Z 256DEG 55KT 4254 8812 4240 8809
          4222 8819

$$

IZZI

The office that day

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

IssuedProductOfficeCountiesLasted
May 22, 2:01 AM CDTMarine Dense Fog AdvisoryLOT3 hr
May 22, 2:26 PM CDTSevere Thunderstorm WarningLOTGrundy, Livingston34 min
May 22, 3:00 PM CDTSevere Thunderstorm WarningLOTFord, Grundy, Iroquois, Kankakee, Livingston60 min
May 22, 3:08 PM CDTSevere Thunderstorm WarningLOTKankakee, Will67 min
May 22, 3:12 PM CDTSpecial Marine WarningLOT63 min
May 22, 3:16 PM CDTSevere Thunderstorm WarningLOTCook, Lake19 min
May 22, 3:21 PM CDTSpecial Marine WarningLOT114 min
May 22, 3:21 PM CDTSevere Thunderstorm WarningLOTCook, Will54 min
May 22, 3:23 PM CDTSevere Thunderstorm WarningLOTCook, DuPage38 min
May 22, 3:27 PM CDTSpecial Marine WarningLOT2 hr
May 22, 3:28 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Kankakee, Livingston77 min
May 22, 4:12 PM CDTSevere Thunderstorm WarningLOTIroquois78 min
May 22, 4:22 PM CDTAreal Flood AdvisoryLOTKankakee, Will3 hr
May 22, 4:31 PM CDTFlash Flood WarningLOTLivingston3 hr
May 22, 4:38 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois67 min
May 22, 4:47 PM CDTFlash Flood WarningLOTFord, Iroquois5 hr
May 22, 4:47 PM CDTSpecial Weather StatementLOTWinnebago28 min
May 22, 4:51 PM CDTSevere Thunderstorm WarningLOTLee, Ogle39 min
May 22, 5:08 PM CDTFlash Flood WarningLOTIroquois, Kankakee4 hr
May 22, 5:13 PM CDTSevere Thunderstorm WarningLOTBoone, Ogle, Winnebago47 min
May 22, 5:51 PM CDTSevere Thunderstorm WarningLOTOgle, Winnebago25 min
May 22, 6:18 PM CDTSevere Thunderstorm WarningLOTBoone, DeKalb, Lee, Ogle, Winnebago50 min
May 22, 6:37 PM CDTTornado WarningLOTBoone, DeKalb, Ogle, Winnebago38 min
May 22, 6:56 PM CDTSpecial Marine WarningLOT2 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.