Alert archive / Kentucky / Mesoscale Discussions in 2025

Mesoscale Discussion 910

May 20, 20254 states

The Storm Prediction Center issued this mesoscale discussion at May 20, 2025, 6:13 PM EDT for 4 states. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
May 20, 2025, 6:13 PM EDT (22:13 UTC)
Expired
May 20, 2025, 7:15 PM EDT
In force
62 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch likely
Chance of a watch
80%
All 54 counties

Bell County, KY, Boyle County, KY, Breathitt County, KY, Clark County, KY, Clay County, KY, Estill County, KY, Fayette County, KY, Garrard County, KY, Harlan County, KY, Jackson County, KY, Jessamine County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Lincoln County, KY, Madison County, KY, Magoffin County, KY, McCreary County, KY, Menifee County, KY, Mercer County, KY, Montgomery County, KY, Owsley County, KY, Perry County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Wayne County, KY, Whitley County, KY, Wolfe County, KY, Cherokee County, NC, Graham County, NC, Swain County, NC, Anderson County, TN, Blount County, TN, Campbell County, TN, Claiborne County, TN, Grainger County, TN, Hamblen County, TN, Hancock County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Roane County, TN, Scott County, TN, Sevier County, TN, Union County, TN, Lee County, VA

The radar

The Knoxville radar (KMRX), 88 km from the middle of the area, began a volume at 22:16 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.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 10.2 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-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2025-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1162 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2025-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 114 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1162 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
904 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
114 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.9
Supercell composite
3.9

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.

IssuedProductOfficeCountiesLasted
May 19, 8:02 PM EDTMesoscale DiscussionSPCLogan, Simpson, Todd88 min
May 20, 2:07 AM EDTMesoscale DiscussionSPCBallard, Caldwell, Carlisle, Christian, Crittenden, Daviess and 16 more83 min
May 20, 3:15 AM EDTTornado WatchSPCBallard, Caldwell, Carlisle, Crittenden, Daviess, Hancock and 11 more4 hr
May 20, 11:19 AM EDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bell and 46 more2 hr
May 20, 1:10 PM EDTTornado WatchSPCBath, Bell, Bourbon, Boyd, Breathitt, Carter and 39 more5 hr
May 20, 2:09 PM EDTTornado WatchSPCBallard, Calloway, Carlisle, Fulton, Graves, Hickman and 3 more8 hr
May 20, 2:48 PM EDTMesoscale DiscussionSPCAllen, Barren, Butler, Christian, Edmonson, Logan and 5 more117 min
May 20, 3:36 PM EDTTornado WatchSPCAdair, Allen, Barren, Breckinridge, Butler, Caldwell and 30 more8 hr
May 20, 3:42 PM EDTMesoscale DiscussionSPCFloyd, Harlan, Johnson, Knott, Lawrence, Letcher and 3 more2 hr
May 20, 4:33 PM EDTMesoscale DiscussionSPCBallard, Caldwell, Calloway, Carlisle, Christian, Fulton and 7 more117 min
May 20, 7:27 PM EDTTornado WatchSPCBell, Breathitt, Clay, Estill, Harlan, Jackson and 15 more6 hr
May 20, 1:34 PM EDTMesoscale DiscussionSPCCrockett, Dyer, Fayette, Haywood, Lake, Lauderdale and 2 more116 min

Nearby

Mesoscale Discussions in Kentucky, 2025Mesoscale Discussions in Tennessee, 2025Mesoscale Discussions in North Carolina, 2025Every mesoscale discussion in 2025

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.