Alert archive / Tennessee / Mesoscale Discussions in 2023

Mesoscale Discussion 2313

December 9, 20236 counties in Alabama; 7 counties in Kentucky; 36 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Dec 9, 2023, 6:39 PM CST for 6 counties in Alabama; 7 counties in Kentucky; 36 counties in Tennessee. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Dec 9, 2023, 6:39 PM CST (00:39 UTC)
Expired
Dec 9, 2023, 8:15 PM CST
In force
96 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 715
All 49 counties

Franklin County, AL, Jackson County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Morgan County, AL, Clinton County, KY, Cumberland County, KY, McCreary County, KY, Pulaski County, KY, Rockcastle County, KY, Russell County, KY, Wayne County, KY, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Bradley County, TN, Cannon County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Jackson County, TN, Lincoln County, TN, Loudon County, TN, Marion County, TN, Marshall County, TN, McMinn County, TN, Meigs County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 107 km from the middle of the area, began a volume at 00:39 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.7 hours before the alert went out and 270 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, Peachtre/Fal Fld, GA at 00:00Z on 2023-12-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 441 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, Peachtre/Fal Fld, GA at 00:00Z on 2023-12-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 229 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
441 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
802 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
229 m²/s²
0-3 km storm-relative helicity
302 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.8

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
Dec 9, 7:48 PM CSTTornado WatchSPCBlount, Cherokee, Cullman, DeKalb, Etowah, Jackson and 1 more7 hr
Dec 9, 8:18 PM CSTMesoscale DiscussionSPCLawrence, Limestone, Madison, Morgan87 min
Dec 9, 8:29 PM CSTMesoscale DiscussionSPCAutauga, Bibb, Chilton, Choctaw, Clarke, Clay and 17 more2 hr
Dec 9, 9:31 PM CSTMesoscale DiscussionSPCBlount, Cherokee, DeKalb, Etowah, Marshall119 min
Dec 9, 10:10 PM CSTTornado WatchSPCAutauga, Bibb, Calhoun, Chilton, Choctaw, Clarke and 14 more6 hr
Dec 9, 11:40 PM CSTMesoscale DiscussionSPCCherokee65 min
Dec 9, 11:53 PM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Butler, Calhoun and 33 more2 hr
Dec 10, 12:58 AM CSTTornado WatchSPCBarbour, Bullock, Butler, Chambers, Coffee, Conecuh and 16 more9 hr
Dec 10, 2:02 AM CSTMesoscale DiscussionSPCBaldwin, Barbour, Bullock, Butler, Chambers, Clarke and 22 more88 min
Dec 10, 4:00 AM CSTMesoscale DiscussionSPCBarbour, Bullock, Coffee, Covington, Crenshaw, Dale and 7 more90 min
Dec 10, 6:02 AM CSTMesoscale DiscussionSPCBarbour, Dale, Geneva, Henry, Houston88 min
Dec 9, 8:53 PM CSTMesoscale DiscussionSPCBell, Clay, Harlan, Knott, Knox, Leslie and 3 more2 hr

Nearby

Mesoscale Discussions in Tennessee, 2023Mesoscale Discussions in Kentucky, 2023Mesoscale Discussions in Alabama, 2023Every 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.