Alert archive / Illinois / Mesoscale Discussions in 2015

Mesoscale Discussion 216

April 7, 20154 states

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2015, 1:14 PM CDT for 4 states. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Apr 7, 2015, 1:14 PM CDT (18:14 UTC)
Expired: Apr 7, 2015, 2:15 PM CDT
In force: 61 min
Issued by: the Storm Prediction Center

All 34 counties

Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Pope County, IL, Saline County, IL, Union County, IL, Wabash County, IL, White County, IL, Williamson County, IL, Crawford County, IN, Dubois County, IN, Gibson County, IN, Harrison County, IN, Orange County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Crittenden County, KY, Daviess County, KY, Hancock County, KY, Henderson County, KY, McLean County, KY, Union County, KY, Webster County, KY, Cape Girardeau County, MO, Perry County, MO

The radar

The Evansville,IN radar (KVWX), 30 km from the middle of the area, began a volume at 18:16 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.

Severe Thunderstorm Watch 28Apr 7, 1:40 PM CDT

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 6.2 hours before the alert went out and 229 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: 593 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 594 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 179 m²/s²
0-3 km storm-relative helicity: 160 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 3.2

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
Apr 7, 8:17 AM CDT	Mesoscale Discussion	SPC	Bond, Clinton, Franklin, Hamilton, Jackson, Jefferson and 11 more	88 min
Apr 7, 8:34 AM CDT	Severe Thunderstorm Watch	SPC	Clinton, Franklin, Jackson, Jefferson, Johnson, Madison and 7 more	7 hr
Apr 7, 10:51 AM CDT	Mesoscale Discussion	SPC	Franklin, Gallatin, Hamilton, Hardin, Jackson, Jefferson and 11 more	54 min
Apr 7, 1:37 PM CDT	Severe Thunderstorm Watch	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 10 more	5 hr
Apr 7, 2:53 PM CDT	Mesoscale Discussion	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 14 more	97 min
Apr 7, 3:34 PM CDT	Mesoscale Discussion	SPC	Anderson, Boyle, Bullitt, Edmonson, Franklin, Grayson and 13 more	86 min
Apr 7, 5:34 PM CDT	Mesoscale Discussion	SPC	Bath, Bourbon, Boyle, Breathitt, Carter, Casey and 35 more	56 min
Apr 7, 5:58 PM CDT	Severe Thunderstorm Watch	SPC	Bath, Breathitt, Clay, Elliott, Estill, Floyd and 17 more	2 hr
Apr 7, 3:51 AM CDT	Mesoscale Discussion	SPC	Audrain, Boone, Caldwell, Carroll, Chariton, Daviess and 9 more	54 min
Apr 7, 5:03 PM CDT	Mesoscale Discussion	SPC	Barton, Bates, Cass, Cedar, Dade, Greene and 9 more	2 hr

Nearby

Mesoscale Discussions in Illinois, 2015 Mesoscale Discussions in Indiana, 2015 Mesoscale Discussions in Kentucky, 2015 Every mesoscale discussion in 2015

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.