Alert archive / Illinois / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 21, NWS Chicago, IL

May 2, 2008Cook County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at May 2, 2008, 7:22 PM CDT for Cook County, Illinois. It was in force for 25 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
May 2, 2008, 7:22 PM CDT (00:22 UTC)
Expired
May 2, 2008, 7:47 PM CDT
In force
25 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon

County Cook County, IL

The radar

The Chicago radar (KLOT), 26 km from the middle of the area, began a volume at 00:24 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 nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.4 hours before the alert went out and 187 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 2008-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2008-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 square meters per square second.1939587897117Sfc1 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
21 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
2068 m above ground
0-6 km bulk shear
82 kt
0-1 km storm-relative helicity
84 m²/s²
0-3 km storm-relative helicity
126 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.

000 
WUUS53 KLOT 030022
SVRLOT
ILC031-030100-
/O.NEW.KLOT.SV.W.0021.080503T0022Z-080503T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
722 PM CDT FRI MAY 2 2008

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL COOK COUNTY IN NORTHEAST ILLINOIS...

* UNTIL 800 PM CDT...

* AT 720 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
  THUNDERSTORM LOCATED NEAR PALOS HILLS...AND MOVING NORTHEAST AT 59
  MPH. THIS STORM IS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF
  60 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BRIDGEPORT...ENGLEWOOD...CICERO...AND 6 MILES NORTHWEST OF CHATHAM
  BY 730 PM...
  DOUGLAS PARK...HUMBOLDT PARK...AND 6 MILES SOUTHEAST OF LOGAN
  SQUARE BY 735 PM...

LAT...LON 4171 8789 4197 8770 4174 8756 4158 8779
      4166 8790 4168 8797
TIME...MOT...LOC 0022Z 218DEG 51KT 4172 8778

$$

WILSON
2 follow-up statements
000 
WWUS53 KLOT 030037
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
736 PM CDT FRI MAY 2 2008

ILC031-030100-
/O.CON.KLOT.SV.W.0021.000000T0000Z-080503T0100Z/
COOK IL-
736 PM CDT FRI MAY 2 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM CDT
FOR CENTRAL COOK COUNTY...

AT 734 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR DOUGLAS PARK...OR
ABOUT NEAR MEIGS FIELD...MOVING NORTHEAST AT 59 MPH.

THE RADAR STILL SHOWS WINDS UP TO 58 MPH OVER CHICAGO. THE 
THUNDERSTORMS COULD PRODUCE DAMAGE. AN AMATUER RADIO SPOTTER 
REPORTED WIND ESTIMATED 40 TO 60 MPH ON FOSTER AND CENTRAL IN 
CHICAGO. 

LAT...LON 4171 8789 4197 8770 4174 8756 4158 8779
      4166 8790 4168 8797
TIME...MOT...LOC 0036Z 218DEG 51KT 4187 8761

$$
000 
WWUS53 KLOT 030047
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
746 PM CDT FRI MAY 2 2008

ILC031-030056-
/O.CAN.KLOT.SV.W.0021.000000T0000Z-080503T0100Z/
COOK IL-
746 PM CDT FRI MAY 2 2008

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL COOK COUNTY IS
CANCELLED...

THE THUNDERSTORMS HAVE MOVED OUT OF THE WARNED AREA IN COOK COUNTY
ILLINOIS. 

LAT...LON 4171 8789 4197 8770 4174 8756 4158 8779
      4166 8790 4168 8797
TIME...MOT...LOC 0046Z 218DEG 51KT 4198 8749

$$

WILSON

The office that day

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

IssuedProductOfficeCountiesLasted
May 2, 7:27 PM CDTSpecial Marine WarningLOT67 min
May 2, 7:38 PM CDTSevere Thunderstorm WarningLOTIroquois52 min
May 2, 7:51 PM CDTSpecial Marine WarningLOT54 min
May 2, 8:18 PM CDTAreal Flood AdvisoryLOTCook, DeKalb, DuPage, Kane, Kankakee, Lake and 1 more37 days

Nearby

Severe Thunderstorm Warnings in Illinois, 2008Every severe thunderstorm warning in 2008

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.