Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 381

April 4, 20034 states

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2003, 7:07 PM CST for 4 states. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Apr 4, 2003, 7:07 PM CST (01:07 UTC)
Expired: Apr 4, 2003, 8:30 PM CST
In force: 83 min
Issued by: the Storm Prediction Center

All 62 counties

Alexander County, IL, Clay 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, Lawrence County, IL, Marion County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Richland County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Gibson County, IN, Knox County, IN, Pike County, IN, Posey County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Mississippi County, MO, New Madrid County, MO, Perry County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 44 km from the middle of the area, began a volume at 01:09 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 90Apr 4, 9:20 PM CST

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 00:00Z, 1.1 hours before the alert went out and 223 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: 289 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 1470 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 135 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

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 4, 6:01 PM CST	Mesoscale Discussion	SPC	Clark	59 min
Apr 4, 6:30 PM CST	Tornado Watch	SPC	Clark, Coles, Crawford, Cumberland, Edgar, Effingham and 2 more	6 hr
Apr 4, 9:00 PM CST	Mesoscale Discussion	SPC	Bartholomew, Clark, Crawford, Dearborn, Decatur, Dubois and 18 more	90 min
Apr 4, 9:20 PM CST	Tornado Watch	SPC	Bartholomew, Clark, Crawford, Dearborn, Decatur, Dubois and 21 more	5 hr
Apr 4, 10:38 PM CST	Mesoscale Discussion	SPC	Switzerland	97 min
Apr 4, 11:05 PM CST	Severe Thunderstorm Watch	SPC	Adair, Anderson, Barren, Bath, Bourbon, Boyd and 57 more	5 hr
Apr 5, 1:34 AM CST	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Bell and 62 more	86 min
Apr 4, 8:00 PM CST	Severe Thunderstorm Watch	SPC	Dunklin, Pemiscot	5 hr

Nearby

Mesoscale Discussions in Illinois, 2003 Mesoscale Discussions in Kentucky, 2003 Mesoscale Discussions in Missouri, 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.