Alert archive / Illinois / Mesoscale Discussions in 2006

Mesoscale Discussion 1883

August 25, 200620 counties in Illinois; Scott County, Iowa; 7 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 25, 2006, 1:42 PM CDT for 20 counties in Illinois; Scott County, Iowa; 7 counties in Wisconsin. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 25, 2006, 1:42 PM CDT (18:42 UTC)
Expired
Aug 25, 2006, 3:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 28 counties

Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Putnam County, IL, Stephenson County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Jefferson County, WI, Kenosha County, WI, Milwaukee County, WI, Racine County, WI, Rock County, WI, Walworth County, WI, Waukesha County, WI

The radar

The Chicago radar (KLOT), 65 km from the middle of the area, began a volume at 18:46 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

Davenport, (KDVN), launched 12:00Z, 6.7 hours before the alert went out and 170 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 2006-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 685 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 2006-08-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 square meters per square second.19395878Sfc1 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
685 J/kg
Mixed-layer CIN
-230 J/kg
Mixed-layer LCL
1278 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 24, 11:24 PM CDTMesoscale DiscussionSPCJo Daviess, Stephenson, Winnebago96 min
Aug 25, 5:05 AM CDTMesoscale DiscussionSPCBoone, Carroll, Jo Daviess, Ogle, Stephenson, Winnebago55 min
Aug 25, 11:35 AM CDTMesoscale DiscussionSPCBoone, Cook, DuPage, Kane, Lake, McHenry and 1 more115 min
Aug 25, 6:38 PM CDTMesoscale DiscussionSPCBoone, Carroll, Cook, DeKalb, DuPage, Jo Daviess and 9 more2 hr
Aug 24, 9:08 PM CDTMesoscale DiscussionSPCAllamakee, Buena Vista, Cerro Gordo, Cherokee, Chickasaw, Clay and 20 more97 min
Aug 24, 11:52 PM CDTSevere Thunderstorm WatchSPCAllamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more6 hr
Aug 25, 2:27 AM CDTMesoscale DiscussionSPCAllamakee, Chickasaw, Clayton, Dubuque, Fayette, Floyd and 3 more2 hr
Aug 24, 9:32 PM CDTMesoscale DiscussionSPCAdams, Calumet, Clark, Columbia, Crawford, Dane and 24 more88 min

Nearby

Mesoscale Discussions in Illinois, 2006Mesoscale Discussions in Wisconsin, 2006Mesoscale Discussions in Iowa, 2006Every mesoscale discussion in 2006

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.