Alert archive / Illinois / Mesoscale Discussions in 2014

Mesoscale Discussion 260

April 3, 201416 counties in Illinois; 9 counties in Kentucky; 13 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2014, 12:28 PM CDT for 16 counties in Illinois; 9 counties in Kentucky; 13 counties in Missouri. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Apr 3, 2014, 12:28 PM CDT (17:28 UTC)
Expired: Apr 3, 2014, 1:30 PM CDT
In force: 62 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 38 counties

Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saline County, IL, Union County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Carlisle County, KY, Crittenden County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Marshall County, KY, McCracken County, KY, Union County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Iron County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Perry County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 66 km from the middle of the area, began a volume at 17:27 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.

Tornado Watch 50Apr 3, 12:45 PM CDT

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 5.5 hours before the alert went out and 284 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: 118 J/kg
Mixed-layer CIN: -196 J/kg
Mixed-layer LCL: 711 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 269 m²/s²
0-3 km storm-relative helicity: 253 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.6

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
Apr 3, 1:05 AM CDT	Mesoscale Discussion	SPC	Adams, Hancock, Henderson, McDonough, Mercer, Rock Island and 2 more	55 min
Apr 3, 2:49 AM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Bureau, Calhoun, Cass and 44 more	116 min
Apr 3, 6:24 AM CDT	Mesoscale Discussion	SPC	Bond, Clay, Clinton, Effingham, Fayette, Franklin and 12 more	96 min
Apr 3, 9:22 AM CDT	Mesoscale Discussion	SPC	Hardin, Massac, Pope	83 min
Apr 3, 12:46 PM CDT	Tornado Watch	SPC	Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 10 more	4 hr
Apr 3, 3:17 PM CDT	Mesoscale Discussion	SPC	Adams, Pike	58 min
Apr 3, 4:58 PM CDT	Tornado Watch	SPC	Monroe, Randolph, Saint Clair	7 hr
Apr 3, 5:16 PM CDT	Mesoscale Discussion	SPC	Clay, Harlan, Knott, Knox, Laurel, Leslie and 6 more	89 min
Apr 2, 9:36 PM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Camden, Cass, Cedar and 18 more	54 min
Apr 2, 9:59 PM CDT	Severe Thunderstorm Watch	SPC	Barton, Bates, Benton, Camden, Carroll, Cass and 21 more	7 hr
Apr 3, 12:00 AM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Camden, Carroll, Cass and 22 more	90 min
Apr 3, 9:18 AM CDT	Mesoscale Discussion	SPC	Barry, Camden, Cedar, Christian, Dade, Dallas and 18 more	57 min
Apr 3, 9:33 AM CDT	Tornado Watch	SPC	Barry, Camden, Christian, Dallas, Dent, Douglas and 19 more	7 hr
Apr 3, 12:05 PM CDT	Mesoscale Discussion	SPC	Barry, Camden, Cedar, Christian, Dade, Dallas and 19 more	55 min
Apr 3, 12:33 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Bates, Benton, Cedar, Christian and 15 more	87 min
Apr 3, 1:15 PM CDT	Tornado Watch	SPC	Barry, Barton, Bates, Benton, Camden, Cass and 29 more	8 hr
Apr 3, 3:48 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Benton, Camden, Cedar, Christian and 18 more	57 min
Apr 3, 4:34 PM CDT	Mesoscale Discussion	SPC	Dent, Howell, Oregon, Ozark, Shannon	26 min

Nearby

Mesoscale Discussions in Illinois, 2014 Mesoscale Discussions in Missouri, 2014 Mesoscale Discussions in Kentucky, 2014 Every mesoscale discussion in 2014

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.