Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 878

May 9, 20034 states

The Storm Prediction Center issued this mesoscale discussion at May 9, 2003, 2:48 PM CDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: May 9, 2003, 2:48 PM CDT (19:48 UTC)
Expired: May 9, 2003, 4:45 PM CDT
In force: 117 min
Issued by: the Storm Prediction Center

All 44 counties

Clinton County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Monroe County, IL, Perry County, IL, Pope County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Posey County, IN, Union County, KY, Bollinger County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Crawford County, MO, Dent County, MO, Franklin County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Madison County, MO, Maries County, MO, Perry County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Shannon County, MO, Texas County, MO, Washington County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 91 km from the middle of the area, began a volume at 19:42 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, 7.8 hours before the alert went out and 304 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2615 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 727 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 348 m²/s²
0-3 km storm-relative helicity: 389 m²/s²
Significant tornado parameter: 5.6
Supercell composite: 21.6

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.

Issued	Product	Office	Counties	Lasted
May 8, 7:06 PM CDT	Mesoscale Discussion	SPC	Hamilton, White	54 min
May 8, 7:55 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Hancock, Henderson, Pike, Scott	5 hr
May 8, 9:10 PM CDT	Severe Thunderstorm Watch	SPC	Bureau, Carroll, Cass, Champaign, DeKalb, DeWitt and 32 more	6 hr
May 8, 9:27 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Bureau, Carroll, Cass, Champaign and 40 more	93 min
May 8, 11:50 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Hancock, Henderson, Pike, Scott	55 min
May 9, 12:05 AM CDT	Severe Thunderstorm Watch	SPC	Bond, Brown, Calhoun, Cass, Champaign, Christian and 28 more	6 hr
May 9, 2:02 PM CDT	Mesoscale Discussion	SPC	Edwards, Lawrence, Wabash, Wayne, White	2 hr
May 9, 4:17 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 21 more	28 min
May 9, 4:45 PM CDT	Tornado Watch	SPC	Calhoun, Greene, Morgan, Pike, Scott	6 hr
May 9, 5:44 PM CDT	Mesoscale Discussion	SPC	Champaign, Christian, Clark, Coles, Cumberland, DeWitt and 15 more	31 min
May 9, 6:05 PM CDT	Tornado Watch	SPC	Bond, Champaign, Christian, Clark, Clinton, Coles and 13 more	5 hr
May 9, 1:21 AM CDT	Mesoscale Discussion	SPC	Adams, Allen, Bartholomew, Blackford, Boone, Brown and 51 more	84 min
May 9, 1:45 AM CDT	Severe Thunderstorm Watch	SPC	Adams, Allen, Blackford, Boone, Carroll, Cass and 34 more	5 hr
May 9, 5:04 AM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Boone, Carroll, Cass and 34 more	86 min
May 9, 2:40 PM CDT	Severe Thunderstorm Watch	SPC	Bartholomew, Brown, Clark, Crawford, Daviess, Dearborn and 22 more	5 hr
May 9, 5:00 PM CDT	Severe Thunderstorm Watch	SPC	Boyd, Johnson, Lawrence, Martin	5 hr
May 9, 5:26 PM CDT	Mesoscale Discussion	SPC	Anderson, Bath, Bourbon, Boyle, Breathitt, Bullitt and 41 more	64 min
May 9, 6:35 PM CDT	Severe Thunderstorm Watch	SPC	Bell, Boyle, Breathitt, Casey, Clay, Clinton and 24 more	5 hr
May 8, 7:13 PM CDT	Mesoscale Discussion	SPC	Andrew, Barton, Bates, Buchanan, Caldwell, Carroll and 23 more	2 hr
May 8, 9:00 PM CDT	Tornado Watch	SPC	Audrain, Benton, Boone, Callaway, Camden, Cole and 26 more	5 hr

Nearby

Mesoscale Discussions in Illinois, 2003 Mesoscale Discussions in Missouri, 2003 Mesoscale Discussions in Indiana, 2003 Every mesoscale discussion in 2003

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.