Alert archive / Tennessee / Mesoscale Discussions in 2018

Mesoscale Discussion 822

June 22, 20184 states

The Storm Prediction Center issued this mesoscale discussion at Jun 22, 2018, 12:35 PM CDT for 4 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Jun 22, 2018, 12:35 PM CDT (17:35 UTC)
Expired: Jun 22, 2018, 2:00 PM CDT
In force: 85 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 70 counties

Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, St. Clair County, AL, Walker County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Murray County, GA, Walker County, GA, Whitfield County, GA, Chickasaw County, MS, Clay County, MS, Itawamba County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Pontotoc County, MS, Prentiss County, MS, Tishomingo County, MS, Union County, MS, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Bradley County, TN, Cannon County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Loudon County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McMinn County, TN, Meigs County, TN, Moore County, TN, Morgan County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Sequatchie County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN

The radar

The Northeast Alabama radar (KHTX), 54 km from the middle of the area, began a volume at 17:39 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, 5.6 hours before the alert went out and 155 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: 113 J/kg
Mixed-layer CIN: -88 J/kg
Mixed-layer LCL: 1114 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 121 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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
Jun 21, 8:30 PM CDT	Mesoscale Discussion	SPC	Colbert, Franklin, Lauderdale, Lawrence, Limestone	2 hr
Jun 22, 9:09 AM CDT	Mesoscale Discussion	SPC	Fayette, Franklin, Lamar, Marion, Pickens, Tuscaloosa and 2 more	96 min
Jun 22, 8:42 AM CDT	Mesoscale Discussion	SPC	Claiborne, Hinds, Issaquena, Jefferson, Sharkey, Warren and 1 more	93 min
Jun 22, 10:55 AM CDT	Severe Thunderstorm Watch	SPC	Adams, Claiborne, Clarke, Copiah, Covington, Forrest and 19 more	10 hr
Jun 22, 3:03 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Copiah, Covington, Franklin and 15 more	87 min
Jun 22, 6:05 PM CDT	Mesoscale Discussion	SPC	Claiborne, Clarke, Copiah, Covington, Hinds, Issaquena and 14 more	115 min

Nearby

Mesoscale Discussions in Tennessee, 2018 Mesoscale Discussions in Alabama, 2018 Mesoscale Discussions in Mississippi, 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.