Alert archive / Missouri / Mesoscale Discussions in 2003

Mesoscale Discussion 513

April 20, 2003Clay County, Arkansas; 5 counties in Illinois; 14 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2003, 4:00 AM CDT for Clay County, Arkansas; 5 counties in Illinois; 14 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 20, 2003, 4:00 AM CDT (09:00 UTC)
Expired: Apr 20, 2003, 6:00 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Clay County, AR, Jackson County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Washington County, IL, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, New Madrid County, MO, Perry County, MO, Ripley 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), 136 km from the middle of the area, began a volume at 09:01 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 nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 9.0 hours before the alert went out and 313 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: 11 J/kg
Mixed-layer CIN: -140 J/kg
Mixed-layer LCL: 902 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 286 m²/s²
0-3 km storm-relative helicity: 217 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

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 19, 7:54 PM CDT	Mesoscale Discussion	SPC	Polk, Sebastian	96 min
Apr 19, 8:55 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Crawford, Sebastian, Washington	5 hr
Apr 19, 9:40 PM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Carroll, Franklin, Johnson, Madison and 3 more	65 min
Apr 19, 10:35 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Carroll, Franklin, Johnson, Madison and 5 more	5 hr
Apr 19, 10:42 PM CDT	Mesoscale Discussion	SPC	Benton, Crawford, Sebastian, Washington	93 min
Apr 20, 1:25 AM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Clay, Cleburne, Craighead, Fulton and 13 more	2 hr
Apr 20, 11:52 AM CDT	Mesoscale Discussion	SPC	Arkansas, Bradley, Cleveland, Craighead, Crittenden, Cross and 8 more	2 hr
Apr 20, 1:00 PM CDT	Mesoscale Discussion	SPC	Crittenden, Lee, Mississippi	3 hr
Apr 20, 3:02 PM CDT	Mesoscale Discussion	SPC	Ashley, Chicot, Desha, Drew	3 hr
Apr 20, 1:50 AM CDT	Severe Thunderstorm Watch	SPC	Jackson, Monroe, Perry, Randolph, Washington	5 hr
Apr 20, 12:20 PM CDT	Severe Thunderstorm Watch	SPC	Clark, Crawford, Edgar, Edwards, Hamilton, Jasper and 6 more	6 hr
Apr 20, 1:45 PM CDT	Severe Thunderstorm Watch	SPC	Gallatin, Hardin, Johnson, Massac, Pope, Saline	5 hr
Apr 19, 8:29 PM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Camden, Cass, Cedar and 15 more	2 hr

Nearby

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