Alert archive / Tennessee / Mesoscale Discussions in 2025

Mesoscale Discussion 908

May 20, 20256 states

The Storm Prediction Center issued this mesoscale discussion at May 20, 2025, 3:33 PM CDT for 6 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
May 20, 2025, 3:33 PM CDT (20:33 UTC)
Expired
May 20, 2025, 5:30 PM CDT
In force
117 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 303...305
All 85 counties

Colbert County, AL, Lauderdale County, AL, Arkansas County, AR, Ashley County, AR, Chicot County, AR, Crittenden County, AR, Desha County, AR, Drew County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, St. Francis County, AR, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Trigg County, KY, Mississippi County, MO, Pemiscot County, MO, Alcorn County, MS, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Marshall County, MS, Montgomery County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Washington County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Lewis County, TN, Madison County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 59 km from the middle of the area, began a volume at 20:34 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, 8.6 hours before the alert went out and 57 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, Little Rock, AR at 12:00Z on 2025-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Little Rock, AR at 12:00Z on 2025-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1276 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 20, 10:19 AM CDTMesoscale DiscussionSPCColbert, Lauderdale, Limestone, Madison2 hr
May 20, 1:48 PM CDTMesoscale DiscussionSPCBlount, Colbert, Cullman, DeKalb, Etowah, Fayette and 14 more117 min
May 20, 2:36 PM CDTTornado WatchSPCColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more8 hr
May 20, 5:08 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Chilton, Clay and 20 more2 hr
May 20, 5:47 PM CDTMesoscale DiscussionSPCColbert, Lauderdale, Lawrence, Limestone, Madison118 min
May 20, 6:46 PM CDTTornado WatchSPCBibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 16 more7 hr
May 19, 8:04 PM CDTMesoscale DiscussionSPCBoone, Carroll, Crawford, Franklin, Johnson, Logan and 6 more86 min
May 19, 10:42 PM CDTMesoscale DiscussionSPCBaxter, Clay, Cleburne, Conway, Craighead, Cross and 26 more2 hr
May 20, 12:00 AM CDTSevere Thunderstorm WatchSPCSebastian3 hr
May 20, 1:21 AM CDTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Dallas, Garland, Grant and 19 more54 min
May 20, 1:57 AM CDTSevere Thunderstorm WatchSPCArkansas, Clark, Cleburne, Cleveland, Columbia, Conway and 33 more5 hr
May 20, 4:21 AM CDTMesoscale DiscussionSPCArkansas, Clark, Cleburne, Cleveland, Columbia, Conway and 26 more54 min
May 20, 12:34 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clay and 29 more116 min
May 20, 1:09 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clay and 30 more8 hr
May 20, 3:13 PM CDTSevere Thunderstorm WatchSPCUnion6 hr
May 19, 7:02 PM CDTMesoscale DiscussionSPCLogan, Simpson, Todd88 min
May 20, 1:07 AM CDTMesoscale DiscussionSPCBallard, Caldwell, Carlisle, Christian, Crittenden, Daviess and 16 more83 min
May 20, 2:15 AM CDTTornado WatchSPCBallard, Caldwell, Carlisle, Crittenden, Daviess, Hancock and 11 more4 hr
May 20, 12:10 PM CDTTornado WatchSPCBath, Bell, Bourbon, Boyd, Breathitt, Carter and 39 more5 hr
May 20, 2:42 PM CDTMesoscale DiscussionSPCFloyd, Harlan, Johnson, Knott, Lawrence, Letcher and 3 more2 hr
May 20, 5:13 PM CDTMesoscale DiscussionSPCBell, Boyle, Breathitt, Clark, Clay, Estill and 25 more62 min
May 20, 6:27 PM CDTTornado WatchSPCBell, Breathitt, Clay, Estill, Harlan, Jackson and 15 more6 hr
May 20, 5:38 PM CDTMesoscale DiscussionSPCCalhoun, Carroll, Grenada, Holmes, Humphreys, Lafayette and 7 more97 min
May 20, 5:50 PM CDTTornado WatchSPCAdams, Attala, Carroll, Choctaw, Claiborne, Clay and 27 more5 hr
May 19, 7:36 PM CDTMesoscale DiscussionSPCAudrain, Bollinger, Boone, Butler, Callaway, Camden and 39 more2 hr
May 19, 8:26 PM CDTTornado WatchSPCAudrain, Barry, Bollinger, Boone, Butler, Callaway and 52 more7 hr
May 19, 8:58 PM CDTMesoscale DiscussionSPCAdair, Andrew, Buchanan, Caldwell, Carroll, Chariton and 22 more2 hr

Nearby

Mesoscale Discussions in Tennessee, 2025Mesoscale Discussions in Mississippi, 2025Mesoscale Discussions in Kentucky, 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.