Alert archive / Missouri / Mesoscale Discussions in 2020

Mesoscale Discussion 533

May 4, 20204 counties in Arkansas; 9 counties in Missouri; 8 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 4, 2020, 3:44 PM CDT for 4 counties in Arkansas; 9 counties in Missouri; 8 counties in Tennessee. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: May 4, 2020, 3:44 PM CDT (20:44 UTC)
Expired: May 4, 2020, 4:45 PM CDT
In force: 61 min
Issued by: the Storm Prediction Center

All 21 counties

Clay County, AR, Greene County, AR, Mississippi County, AR, Randolph County, AR, Butler County, MO, Carter County, MO, Dunklin County, MO, Howell County, MO, New Madrid County, MO, Oregon County, MO, Pemiscot County, MO, Ripley County, MO, Shannon County, MO, Crockett County, TN, Dyer County, TN, Fayette County, TN, Haywood County, TN, Lake County, TN, Lauderdale County, TN, Shelby County, TN, Tipton County, TN

The radar

The Memphis radar (KNQA), 128 km from the middle of the area, began a volume at 20:46 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

Little Rock, AR (KLZK), launched 12:00Z, 8.7 hours before the alert went out and 176 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: 404 J/kg
Mixed-layer CIN: -252 J/kg
Mixed-layer LCL: 689 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 145 m²/s²
0-3 km storm-relative helicity: 167 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 4, 9:00 AM CDT	Mesoscale Discussion	SPC	Benton, Boone, Carroll, Crawford, Franklin, Johnson and 4 more	90 min
May 4, 10:38 AM CDT	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Cleburne, Fulton and 12 more	97 min
May 4, 12:35 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Cleburne, Fulton, Independence, Izard and 9 more	5 hr
May 4, 1:04 PM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Cleburne, Fulton, Independence, Izard and 8 more	86 min
May 4, 1:21 PM CDT	Mesoscale Discussion	SPC	Benton	114 min
May 4, 2:02 PM CDT	Mesoscale Discussion	SPC	Clay, Craighead, Greene, Mississippi, Poinsett	118 min
May 4, 2:32 PM CDT	Tornado Watch	SPC	Benton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more	9 hr
May 4, 2:58 PM CDT	Severe Thunderstorm Watch	SPC	Clay, Craighead, Crittenden, Greene, Mississippi, Poinsett	6 hr
May 4, 6:21 PM CDT	Mesoscale Discussion	SPC	Mississippi	54 min
May 4, 6:42 PM CDT	Mesoscale Discussion	SPC	Benton, Boone, Carroll, Crawford, Franklin, Johnson and 6 more	2 hr
May 4, 5:50 AM CDT	Mesoscale Discussion	SPC	Barton, Bates, Cedar, Jasper, Newton, Vernon	55 min
May 4, 6:33 AM CDT	Severe Thunderstorm Watch	SPC	Barry, Barton, Bates, Benton, Buchanan, Camden and 40 more	12 hr
May 4, 6:42 PM CDT	Severe Thunderstorm Watch	SPC	Bedford, Bledsoe, Bradley, Cannon, Cheatham, Coffee and 31 more	6 hr

Nearby

Mesoscale Discussions in Missouri, 2020 Mesoscale Discussions in Tennessee, 2020 Mesoscale Discussions in Arkansas, 2020 Every mesoscale discussion in 2020

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.