Alert archive / Tennessee / Mesoscale Discussions in 2020

Mesoscale Discussion 671

May 22, 20204 states

The Storm Prediction Center issued this mesoscale discussion at May 22, 2020, 4:29 PM CDT for 4 states. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: May 22, 2020, 4:29 PM CDT (21:29 UTC)
Expired: May 22, 2020, 6:00 PM CDT
In force: 91 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

All 22 counties

Lauderdale County, AL, Crittenden County, AR, Alcorn County, MS, DeSoto County, MS, Chester County, TN, Crockett County, TN, Decatur County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, McNairy County, TN, Perry County, TN, Shelby County, TN, Tipton County, TN, Wayne County, TN

The radar

The Memphis radar (KNQA), 97 km from the middle of the area, began a volume at 21:33 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, 9.5 hours before the alert went out and 125 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: 132 J/kg
Mixed-layer CIN: -197 J/kg
Mixed-layer LCL: 616 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 307 m²/s²
0-3 km storm-relative helicity: 383 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

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 22, 9:15 AM CDT	Mesoscale Discussion	SPC	Crawford, Franklin, Madison, Scott, Sebastian, Washington	90 min
May 22, 12:02 PM CDT	Mesoscale Discussion	SPC	Arkansas, Cleburne, Conway, Craighead, Cross, Faulkner and 22 more	88 min

Nearby

Mesoscale Discussions in Tennessee, 2020 Mesoscale Discussions in Mississippi, 2020 Mesoscale Discussions in Alabama, 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.