Alert archive / Illinois / Mesoscale Discussions in 2007

Mesoscale Discussion 420

April 3, 200732 counties in Illinois; 5 counties in Indiana; Saint Louis County, City of Saint Louis, Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2007, 9:08 AM CDT for 32 counties in Illinois; 5 counties in Indiana; Saint Louis County, City of Saint Louis, Missouri. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Apr 3, 2007, 9:08 AM CDT (14:08 UTC)
Expired
Apr 3, 2007, 10:15 AM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 39 counties

Bond County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Ford County, IL, Iroquois County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Kankakee County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Randolph County, IL, Saint Clair County, IL, Shelby County, IL, Vermilion County, IL, Washington County, IL, Benton County, IN, Fountain County, IN, Newton County, IN, Vermillion County, IN, Warren County, IN, City of Saint Louis, MO, Saint Louis County, MO

The radar

The Lincoln radar (KILX), 76 km from the middle of the area, began a volume at 14:10 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, 2.1 hours before the alert went out and 50 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 2007-04-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 32 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 2007-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 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
32 J/kg
Mixed-layer CIN
-399 J/kg
Mixed-layer LCL
1864 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
221 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
Apr 2, 9:22 PM CDTSevere Thunderstorm WatchSPCCarroll, Jo Daviess, Rock Island, Stephenson, Whiteside8 hr
Apr 2, 11:33 PM CDTMesoscale DiscussionSPCCarroll, Jo Daviess, Ogle, Stephenson, Winnebago57 min
Apr 3, 1:27 AM CDTMesoscale DiscussionSPCCarroll, Jo Daviess, Rock Island, Stephenson, Whiteside93 min
Apr 3, 4:05 AM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Cass, Fulton, Hancock and 19 more55 min
Apr 3, 4:19 AM CDTSevere Thunderstorm WatchSPCAdams, Brown, Bureau, Fulton, Hancock, Henderson and 16 more6 hr
Apr 3, 7:17 AM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Fulton, Greene and 15 more88 min
Apr 3, 9:46 AM CDTMesoscale DiscussionSPCBond, Calhoun, Christian, Clark, Clay, Clinton and 37 more29 min
Apr 3, 9:48 AM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Cass, Champaign, Christian, Clark and 32 more6 hr
Apr 3, 11:04 AM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 11 more26 min
Apr 3, 11:51 AM CDTTornado WatchSPCAlexander, Bond, Clark, Clay, Clinton, Crawford and 30 more8 hr
Apr 3, 2:25 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clay, Clinton, Crawford, Edwards and 26 more65 min
Apr 3, 1:10 PM CDTMesoscale DiscussionSPCAdams, Allen, Bartholomew, Blackford, Boone, Brown and 43 more65 min
Apr 3, 1:33 PM CDTSevere Thunderstorm WatchSPCAdams, Allen, Bartholomew, Blackford, Boone, Brown and 53 more7 hr
Apr 3, 3:23 PM CDTMesoscale DiscussionSPCBartholomew, Blackford, Brown, Clark, Crawford, Dearborn and 33 more67 min
Apr 2, 8:05 PM CDTMesoscale DiscussionSPCAtchison, Harrison, Mercer, Nodaway, Putnam, Schuyler and 1 more115 min
Apr 2, 11:40 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, DeKalb, Gentry, Harrison and 3 more65 min
Apr 3, 12:03 AM CDTSevere Thunderstorm WatchSPCAdair, Andrew, Atchison, Buchanan, Caldwell, Clinton and 14 more7 hr
Apr 3, 2:22 AM CDTMesoscale DiscussionSPCAdair, Andrew, Atchison, Buchanan, Caldwell, Clinton and 14 more53 min
Apr 3, 4:28 AM CDTMesoscale DiscussionSPCCarroll, Cass, Chariton, Clay, Cole, Cooper and 12 more62 min
Apr 3, 7:37 AM CDTSevere Thunderstorm WatchSPCAudrain, Bates, Benton, Boone, Callaway, Camden and 30 more8 hr
Apr 3, 2:17 PM CDTMesoscale DiscussionSPCDunklin, Pemiscot118 min
Apr 3, 3:12 PM CDTTornado WatchSPCDunklin, Pemiscot7 hr

Nearby

Mesoscale Discussions in Illinois, 2007Mesoscale Discussions in Indiana, 2007Mesoscale Discussions in Missouri, 2007Every mesoscale discussion in 2007

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.