Alert archive / Illinois / Mesoscale Discussions in 2013

Mesoscale Discussion 910

May 31, 201310 counties in Illinois; 7 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 31, 2013, 5:21 PM CDT for 10 counties in Illinois; 7 counties in Missouri. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: May 31, 2013, 5:21 PM CDT (22:21 UTC)
Expired: May 31, 2013, 6:15 PM CDT
In force: 54 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

Counties Calhoun County, IL, Christian County, IL, Greene County, IL, Jersey County, IL, Logan County, IL, Macoupin County, IL, Montgomery County, IL, Morgan County, IL, Sangamon County, IL, Scott County, IL, Franklin County, MO, Lincoln County, MO, Montgomery County, MO, Pike County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 71 km from the middle of the area, began a volume at 22:21 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, 10.4 hours before the alert went out and 187 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: 8 J/kg
Mixed-layer CIN: -299 J/kg
Mixed-layer LCL: 1021 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 215 m²/s²
0-3 km storm-relative helicity: 222 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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.

Issued	Product	Office	Counties	Lasted
May 30, 7:04 PM CDT	Mesoscale Discussion	SPC	Bond, Boone, Calhoun, Champaign, Christian, Clark and 56 more	56 min
May 30, 7:38 PM CDT	Severe Thunderstorm Watch	SPC	Champaign, Christian, Clark, Clay, Coles, Crawford and 12 more	5 hr
May 30, 10:03 PM CDT	Mesoscale Discussion	SPC	Champaign, Clark, Clay, Coles, Cook, Crawford and 11 more	87 min
May 31, 8:45 AM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Clinton, Greene, Jersey, Macoupin and 5 more	90 min
May 31, 5:45 PM CDT	Tornado Watch	SPC	Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more	4 hr
May 30, 7:41 PM CDT	Mesoscale Discussion	SPC	Atchison	2 hr
May 30, 8:46 PM CDT	Tornado Watch	SPC	Dunklin, Pemiscot	7 hr
May 31, 1:57 AM CDT	Mesoscale Discussion	SPC	Butler, Carter, Oregon, Ripley	93 min
May 31, 2:05 AM CDT	Mesoscale Discussion	SPC	Buchanan, Clay, Clinton, Jackson, Platte, Ray	85 min
May 31, 2:44 AM CDT	Severe Thunderstorm Watch	SPC	Buchanan, Caldwell, Carroll, Cass, Chariton, Clay and 14 more	5 hr
May 31, 4:51 AM CDT	Mesoscale Discussion	SPC	Caldwell, Carroll, Cass, Chariton, Clay, Clinton and 11 more	114 min
May 31, 7:03 AM CDT	Mesoscale Discussion	SPC	Cass, Cooper, Howard, Johnson, Pettis	57 min
May 31, 1:49 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Bates, Benton, Camden, Cass and 29 more	116 min
May 31, 2:15 PM CDT	Tornado Watch	SPC	Barry, Barton, Bates, Benton, Boone, Callaway and 30 more	8 hr

Nearby

Mesoscale Discussions in Illinois, 2013 Mesoscale Discussions in Missouri, 2013 Every mesoscale discussion in 2013

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.