Alert archive / Tennessee / Mesoscale Discussions in 2018

Mesoscale Discussion 593

May 31, 20189 counties in Kentucky; 19 counties in Tennessee; 8 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 31, 2018, 4:27 PM EDT for 9 counties in Kentucky; 19 counties in Tennessee; 8 counties in Virginia. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: May 31, 2018, 4:27 PM EDT (20:27 UTC)
Expired: May 31, 2018, 6:00 PM EDT
In force: 93 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 36 counties

Bell County, KY, Clinton County, KY, Harlan County, KY, Knox County, KY, Leslie County, KY, Letcher County, KY, McCreary County, KY, Wayne County, KY, Whitley County, KY, Anderson County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Knox County, TN, Morgan County, TN, Pickett County, TN, Roane County, TN, Scott County, TN, Sullivan County, TN, Union County, TN, Washington County, TN, City of Bristol, VA, City of Norton, VA, Dickenson County, VA, Lee County, VA, Russell County, VA, Scott County, VA, Washington County, VA, Wise County, VA

The radar

The Knoxville radar (KMRX), 48 km from the middle of the area, began a volume at 20:27 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 nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 8.5 hours before the alert went out and 260 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: 1202 J/kg
Mixed-layer CIN: -109 J/kg
Mixed-layer LCL: 822 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 234 m²/s²
0-3 km storm-relative helicity: 224 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.2

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 31, 11:16 AM EDT	Mesoscale Discussion	SPC	Daviess, Hancock, Henderson, Union	119 min
May 31, 11:31 AM EDT	Severe Thunderstorm Watch	SPC	Anderson, Bourbon, Boyle, Breckinridge, Bullitt, Casey and 35 more	6 hr
May 31, 12:26 PM EDT	Mesoscale Discussion	SPC	Anderson, Bath, Bell, Bourbon, Boyle, Breathitt and 39 more	64 min
May 31, 2:05 PM EDT	Mesoscale Discussion	SPC	Anderson, Boone, Bourbon, Bracken, Breckinridge, Bullitt and 25 more	85 min
May 31, 2:30 PM EDT	Severe Thunderstorm Watch	SPC	Boone, Bracken, Campbell, Carroll, Gallatin, Grant and 6 more	3 hr
May 31, 2:57 PM EDT	Tornado Watch	SPC	Ballard, Caldwell, Carlisle, Christian, Crittenden, Fulton and 8 more	6 hr
May 31, 3:29 PM EDT	Mesoscale Discussion	SPC	Adair, Allen, Barren, Clinton, Cumberland, Edmonson and 9 more	91 min
May 31, 3:56 PM EDT	Mesoscale Discussion	SPC	Anderson, Bath, Bourbon, Boyle, Bracken, Breathitt and 37 more	64 min
May 31, 4:44 PM EDT	Mesoscale Discussion	SPC	Bracken, Lewis, Mason	91 min
May 31, 5:31 PM EDT	Mesoscale Discussion	SPC	Bell, Clinton, Cumberland, McCreary, Russell, Wayne and 1 more	59 min
May 31, 5:42 PM EDT	Mesoscale Discussion	SPC	Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 11 more	2 hr
May 31, 6:46 PM EDT	Mesoscale Discussion	SPC	Fulton	2 hr

Nearby

Mesoscale Discussions in Tennessee, 2018 Mesoscale Discussions in Kentucky, 2018 Mesoscale Discussions in Virginia, 2018 Every mesoscale discussion in 2018

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.