Alert archive / Illinois / Mesoscale Discussions in 2004

Mesoscale Discussion 940

May 27, 200431 counties in Illinois; 15 counties in Iowa; 26 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 27, 2004, 11:10 AM CDT for 31 counties in Illinois; 15 counties in Iowa; 26 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 27, 2004, 11:10 AM CDT (16:10 UTC)
Expired
May 27, 2004, 1:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 72 counties

Appanoose County, IA, Clarke County, IA, Davis County, IA, Decatur County, IA, Des Moines County, IA, Henry County, IA, Jefferson County, IA, Lee County, IA, Lucas County, IA, Monroe County, IA, Ringgold County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Wayne County, IA, Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, DeWitt County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Henderson County, IL, Jersey County, IL, Knox County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Warren County, IL, Adair County, MO, Audrain County, MO, Chariton County, MO, Clark County, MO, Daviess County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Mercer County, MO, Monroe County, MO, Pike County, MO, Putnam County, MO, Ralls County, MO, Randolph County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO, Worth County, MO

The radar

The Quad Cities radar (KDVN), 181 km from the middle of the area, began a volume at 16:11 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 4.2 hours before the alert went out and 269 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 12:00Z on 2004-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 577 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 12:00Z on 2004-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 119 square meters per square second.1939587897Sfc1 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
577 J/kg
Mixed-layer CIN
-123 J/kg
Mixed-layer LCL
465 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
119 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

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 26, 7:57 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 13 more63 min
May 26, 8:55 PM CDTTornado WatchSPCEdwards, Franklin, Gallatin, Hamilton, Hardin, Jackson and 16 more5 hr
May 26, 9:36 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 25 more54 min
May 26, 11:14 PM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more2 hr
May 27, 1:53 AM CDTMesoscale DiscussionSPCChristian, Clark, Clay, Coles, Crawford, Cumberland and 9 more3 hr
May 27, 11:55 AM CDTSevere Thunderstorm WatchSPCAdams, Brown, Hancock, Henderson, McDonough, Pike and 3 more6 hr
May 27, 1:07 PM CDTMesoscale DiscussionSPCChampaign, Clark, Coles, DeWitt, Douglas, Edgar and 12 more113 min
May 27, 1:30 PM CDTSevere Thunderstorm WatchSPCCass, Champaign, Christian, Coles, DeWitt, Douglas and 22 more7 hr
May 27, 1:52 PM CDTMesoscale DiscussionSPCAdams, Calhoun, Greene, Jersey, Macoupin, Pike and 1 more113 min
May 27, 2:25 PM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Clinton, Fayette, Franklin, Greene and 12 more7 hr
May 27, 3:12 PM CDTMesoscale DiscussionSPCChampaign, Christian, Clark, Coles, Cumberland, DeWitt and 13 more2 hr
May 27, 3:37 PM CDTMesoscale DiscussionSPCBond, Calhoun, Clay, Clinton, Edwards, Effingham and 22 more113 min
May 27, 4:00 PM CDTSevere Thunderstorm WatchSPCClark, Clay, Crawford, Cumberland, Edwards, Effingham and 7 more4 hr
May 27, 5:01 PM CDTMesoscale DiscussionSPCBond, Calhoun, Clinton, Fayette, Greene, Jackson and 11 more89 min
May 27, 6:00 PM CDTMesoscale DiscussionSPCChampaign, DeWitt, Douglas, Edgar, Macon, Morgan and 4 more90 min
May 26, 8:29 PM CDTMesoscale DiscussionSPCMcDonald91 min
May 26, 8:30 PM CDTTornado WatchSPCBarton, Bates, Benton, Camden, Cedar, Dade and 15 more6 hr
May 26, 11:40 PM CDTSevere Thunderstorm WatchSPCCass, Clay, Cooper, Henry, Howard, Jackson and 6 more5 hr
May 27, 1:16 AM CDTMesoscale DiscussionSPCCarroll, Cass, Clay, Cooper, Howard, Jackson and 6 more119 min
May 27, 1:50 AM CDTTornado WatchSPCBarton, Camden, Cedar, Christian, Dade, Dallas and 15 more4 hr
May 27, 3:27 AM CDTMesoscale DiscussionSPCCedar, Christian, Dade, Dallas, Douglas, Greene and 12 more2 hr
May 27, 3:55 AM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Carroll, Cass and 14 more95 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; radar from the NEXRAD Level II archive.