Alert archive / Illinois / Mesoscale Discussions in 2004

Mesoscale Discussion 840

May 23, 20044 states

The Storm Prediction Center issued this mesoscale discussion at May 23, 2004, 4:30 AM CDT for 4 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
May 23, 2004, 4:30 AM CDT (09:30 UTC)
Expired
May 23, 2004, 5:30 AM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 90 counties

Clinton County, IA, Des Moines County, IA, Jackson County, IA, Lee County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Adams County, IL, Boone County, IL, Brown County, IL, Bureau County, IL, Carroll County, IL, Cass County, IL, Cook County, IL, DeKalb County, IL, DeWitt County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Iroquois County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McHenry County, IL, McLean County, IL, Menard County, IL, Mercer County, IL, Morgan County, IL, Ogle County, IL, Peoria County, IL, Pike County, IL, Putnam County, IL, Rock Island County, IL, Schuyler County, IL, Scott County, IL, Stark County, IL, Stephenson County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Woodford County, IL, Adair County, MO, Audrain County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Chariton County, MO, Clark County, MO, Clay County, MO, Clinton County, MO, Howard County, MO, Jackson County, MO, Johnson County, MO, Knox County, MO, Lafayette County, MO, Lewis County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Ralls County, MO, Randolph County, MO, Ray County, MO, Saline County, MO, Shelby County, MO, Sullivan County, MO, Green County, WI, Kenosha County, WI, Lafayette County, WI, Milwaukee County, WI, Racine County, WI, Rock County, WI, Walworth County, WI

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 9.5 hours before the alert went out and 256 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 2004-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1518 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 2004-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 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
1518 J/kg
Mixed-layer CIN
-63 J/kg
Mixed-layer LCL
1522 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.3
Supercell composite
4.1

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
May 22, 8:58 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, DuPage, Grundy and 23 more92 min
May 23, 12:24 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 32 more66 min
May 23, 12:40 AM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 27 more5 hr
May 23, 1:21 AM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 6 more24 min
May 23, 1:40 AM CDTSevere Thunderstorm WatchSPCAdams, Brown, Cass, Fulton, Hancock, Logan and 8 more4 hr
May 23, 10:45 AM CDTTornado WatchSPCClark, Clay, Coles, Crawford, Cumberland, Edgar and 19 more5 hr
May 23, 12:25 PM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Calhoun, Carroll, Cass and 31 more95 min
May 23, 12:45 PM CDTMesoscale DiscussionSPCClark, Clay, Coles, Crawford, Cumberland, Edgar and 18 more2 hr
May 23, 1:15 PM CDTTornado WatchSPCAdams, Brown, Calhoun, Cass, Fulton, Greene and 16 more6 hr
May 23, 2:05 PM CDTTornado WatchSPCBoone, Bureau, Carroll, DeKalb, DuPage, Grundy and 18 more8 hr
May 23, 2:53 PM CDTMesoscale DiscussionSPCIroquois, Vermilion67 min
May 23, 3:50 PM CDTTornado WatchSPCCook, DuPage, Iroquois, Kankakee, Vermilion, Will6 hr
May 23, 4:35 PM CDTSevere Thunderstorm WatchSPCMonroe5 hr
May 23, 5:00 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 28 more2 hr
May 23, 5:10 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, DuPage, Grundy and 17 more95 min
May 23, 5:30 PM CDTTornado WatchSPCBond, Calhoun, Christian, Clark, Clay, Clinton and 29 more6 hr
May 23, 6:30 PM CDTMesoscale DiscussionSPCCook, DuPage, Iroquois, Kankakee, Vermilion, Will2 hr
May 22, 7:11 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Clarke, Dallas and 15 more94 min
May 22, 7:23 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Dallas, Fremont and 9 more67 min
May 22, 10:40 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Benton, Cedar, Clarke and 33 more5 hr
May 22, 11:33 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Benton, Cedar, Clarke and 33 more87 min
May 23, 2:21 AM CDTMesoscale DiscussionSPCAppanoose, Buchanan, Cedar, Davis, Delaware, Des Moines and 14 more54 min

Nearby

Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Missouri, 2004Mesoscale Discussions in Iowa, 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.