Alert archive / Illinois / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 729

September 11, 200015 counties in Illinois; Lake County, Porter County, Indiana; 4 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Sep 11, 2000, 1:30 PM CDT for 15 counties in Illinois; Lake County, Porter County, Indiana; 4 counties in Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Sep 11, 2000, 1:30 PM CDT (18:30 UTC)
Expired
Sep 11, 2000, 7:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 21 counties

Boone County, IL, Bureau County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Kane County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Will County, IL, Winnebago County, IL, Lake County, IN, Porter County, IN, Green County, WI, Kenosha County, WI, Rock County, WI, Walworth County, WI

The radar

The Chicago radar (KLOT), 67 km from the middle of the area, began a volume at 18:31 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.

Warnings issued inside it

8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Sep 11, 2:18 PM CDTSevere Thunderstorm WarningLOTOgle27 min
Sep 11, 2:32 PM CDTSevere Thunderstorm WarningLOTCook, DuPage58 min
Sep 11, 2:55 PM CDTSevere Thunderstorm WarningLOTLee, Ogle50 min
Sep 11, 3:58 PM CDTSevere Thunderstorm WarningLOTPorter32 min
Sep 11, 4:01 PM CDTSevere Thunderstorm WarningLOTCook29 min
Sep 11, 6:11 PM CDTSevere Thunderstorm WarningMKXGreen64 min
Sep 11, 6:45 PM CDTSevere Thunderstorm WarningMKXJefferson, Rock75 min
Sep 11, 6:53 PM CDTFlash Flood WarningMKXGreen3 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 6.5 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, Davenport, at 12:00Z on 2000-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1636 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 12:00Z on 2000-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 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
1636 J/kg
Mixed-layer CIN
-239 J/kg
Mixed-layer LCL
1387 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 11, 1:15 PM CDTTornado WatchSPCCarroll, Henry, Jo Daviess, Mercer, Rock Island, Stark and 2 more6 hr
Sep 10, 8:15 PM CDTSevere Thunderstorm WatchSPCAdams, Crawford, Green Lake, Jackson, Juneau, La Crosse and 10 more6 hr
Sep 11, 3:30 PM CDTTornado WatchSPCBarron, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 6 more5 hr
Sep 11, 5:15 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Calumet, Columbia, Crawford, Dodge and 26 more6 hr

Nearby

Severe Thunderstorm Watches in Illinois, 2000Severe Thunderstorm Watches in Wisconsin, 2000Severe Thunderstorm Watches in Indiana, 2000Every severe thunderstorm watch in 2000

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.