Alert archive / Illinois / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 129, NWS Chicago, IL

July 7, 2008Lake County, McHenry County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 7, 2008, 9:44 PM CDT for Lake County, McHenry County, Illinois. It was in force for 61 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 7, 2008, 9:44 PM CDT (02:44 UTC)
Expired
Jul 7, 2008, 10:45 PM CDT
In force
61 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon

Counties Lake County, IL, McHenry County, IL

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.7 hours before the alert went out and 209 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 00:00Z on 2008-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3226 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, Davenport, at 00:00Z on 2008-07-08The 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
3226 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
1042 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
274 m²/s²
Significant tornado parameter
2.7
Supercell composite
16.8

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 9:50 PM CDTSpecial Marine WarningLOT80 min
Jul 7, 10:27 PM CDTSevere Thunderstorm WarningLOTBoone, DeKalb, Kane, Lee, McHenry, Ogle and 1 more63 min
Jul 7, 10:58 PM CDTSevere Thunderstorm WarningLOTDeKalb, Kane, Kendall, Lee, Ogle62 min
Jul 7, 11:24 PM CDTAreal Flood AdvisoryLOTBoone, Winnebago4 hr
Jul 7, 11:40 PM CDTSpecial Marine WarningLOT2 hr
Jul 7, 11:44 PM CDTSevere Thunderstorm WarningLOTLake36 min
Jul 8, 1:41 AM CDTSpecial Marine WarningLOT49 min
Jul 8, 10:02 AM CDTRiver Flood WarningLOTWinnebago19 hr

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.