Alert archive / Alabama / Mesoscale Discussions in 2023

Mesoscale Discussion 982

June 11, 202317 counties in Alabama; 10 counties in Georgia; 8 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2023, 6:22 PM CDT for 17 counties in Alabama; 10 counties in Georgia; 8 counties in Tennessee. It was in force for 23 min.

The area

The outline as issued.

The facts

Issued: Jun 11, 2023, 6:22 PM CDT (23:22 UTC)
Expired: Jun 11, 2023, 6:45 PM CDT
In force: 23 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch needed soon
Chance of a watch: 95%

All 35 counties

Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Floyd County, GA, Gordon County, GA, Murray County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA, Bradley County, TN, Franklin County, TN, Giles County, TN, Hamilton County, TN, Lincoln County, TN, Marion County, TN, Moore County, TN, Polk County, TN

The radar

The Northeast Alabama radar (KHTX), 49 km from the middle of the area, began a volume at 23:24 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.

Severe Thunderstorm Watch 271Jun 11, 6:45 PM CDT

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.4 hours before the alert went out and 183 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: 77 J/kg
Mixed-layer CIN: -164 J/kg
Mixed-layer LCL: 1030 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 183 m²/s²
0-3 km storm-relative helicity: 199 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 11, 6:46 PM CDT	Severe Thunderstorm Watch	SPC	Bibb, Blount, Calhoun, Chambers, Cherokee, Chilton and 31 more	7 hr
Jun 11, 1:56 PM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Cheatham, Chester, Crockett, Davidson and 28 more	3 hr
Jun 11, 2:26 PM CDT	Severe Thunderstorm Watch	SPC	Bedford, Cannon, Cheatham, Clay, Coffee, Cumberland and 32 more	7 hr
Jun 11, 2:47 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Carroll, Chester, Crockett, Decatur, Dyer and 15 more	7 hr
Jun 11, 3:34 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bledsoe, Blount, Campbell, Claiborne, Grainger and 11 more	6 hr
Jun 11, 4:43 PM CDT	Mesoscale Discussion	SPC	Bedford, Cannon, Cheatham, Chester, Davidson, Decatur and 26 more	92 min
Jun 11, 5:48 PM CDT	Mesoscale Discussion	SPC	Anderson, Campbell, Cumberland, Fentress, Morgan, Overton and 3 more	57 min

Nearby

Mesoscale Discussions in Alabama, 2023 Mesoscale Discussions in Georgia, 2023 Mesoscale Discussions in Tennessee, 2023 Every mesoscale discussion in 2023

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.