Alert archive / Iowa / Mesoscale Discussions in 2004

Mesoscale Discussion 2135

August 27, 200420 counties in Illinois; 27 counties in Iowa; 6 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2004, 4:10 PM CDT for 20 counties in Illinois; 27 counties in Iowa; 6 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 27, 2004, 4:10 PM CDT (21:10 UTC)
Expired
Aug 27, 2004, 6:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 53 counties

Appanoose County, IA, Cedar County, IA, Clarke County, IA, Clinton County, IA, Davis County, IA, Decatur County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Adams County, IL, Brown County, IL, Bureau County, IL, Fulton County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Knox County, IL, Marshall County, IL, McDonough County, IL, Mercer County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Schuyler County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Woodford County, IL, Clark County, MO, Knox County, MO, Lewis County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 129 km from the middle of the area, began a volume at 21:12 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, 9.2 hours before the alert went out and 135 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 2004-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 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 2004-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 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
27 J/kg
Mixed-layer CIN
-358 J/kg
Mixed-layer LCL
1278 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
114 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.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 26, 9:13 PM CDTMesoscale DiscussionSPCCarroll, Jo Daviess, Rock Island, Stephenson62 min
Aug 26, 9:45 PM CDTSevere Thunderstorm WatchSPCBoone, Carroll, Henderson, Henry, Jo Daviess, Mercer and 5 more6 hr
Aug 26, 11:53 PM CDTMesoscale DiscussionSPCBureau, Cook, DeKalb, DuPage, Grundy, Kane and 8 more97 min
Aug 27, 1:25 AM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Cook, DeKalb, DeWitt, DuPage and 25 more6 hr
Aug 27, 1:49 AM CDTMesoscale DiscussionSPCHenderson, Henry, Mercer, Ogle, Rock Island, Whiteside and 1 more56 min
Aug 27, 4:36 AM CDTMesoscale DiscussionSPCCook, DeWitt, Ford, Fulton, Grundy, Hancock and 11 more84 min
Aug 27, 6:33 AM CDTMesoscale DiscussionSPCChampaign, DeWitt, Ford, Iroquois, McLean, Mason and 4 more27 min
Aug 27, 9:24 AM CDTMesoscale DiscussionSPCCalhoun, Greene, Jersey, Macoupin, Madison, Morgan and 2 more96 min
Aug 27, 9:40 AM CDTSevere Thunderstorm WatchSPCBrown, Calhoun, Cass, Greene, Jersey, Macoupin and 7 more5 hr
Aug 27, 1:07 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Greene, Jersey and 6 more113 min
Aug 27, 2:45 PM CDTSevere Thunderstorm WatchSPCCalhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more6 hr
Aug 27, 3:49 PM CDTMesoscale DiscussionSPCCalhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more86 min
Aug 26, 7:45 PM CDTMesoscale DiscussionSPCAdair, Adams, Allamakee, Audubon, Benton, Black Hawk and 56 more90 min
Aug 27, 2:45 PM CDTSevere Thunderstorm WatchSPCAdair, Buchanan, Caldwell, Carroll, Chariton, Clay and 17 more6 hr

Nearby

Mesoscale Discussions in Iowa, 2004Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Missouri, 2004Every mesoscale discussion in 2004

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.