Alert archive / Kentucky / Mesoscale Discussions in 2021
Mesoscale Discussion 2018
The Storm Prediction Center issued this mesoscale discussion at Dec 11, 2021, 6:32 AM EST for 24 counties in Kentucky; 8 counties in Tennessee. It was in force for 88 min.
The area
The outline as issued.
The facts
- Issued
- Dec 11, 2021, 6:32 AM EST (11:32 UTC)
- Expired
- Dec 11, 2021, 8:00 AM EST
- In force
- 88 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 561...562
All 32 counties
Bell County, KY, Breathitt County, KY, Clark County, KY, Clay County, KY, Estill County, KY, Jackson County, KY, Knox County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Madison County, KY, Magoffin County, KY, McCreary County, KY, Menifee County, KY, Montgomery County, KY, Morgan County, KY, Owsley County, KY, Perry County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Wayne County, KY, Whitley County, KY, Wolfe County, KY, Anderson County, TN, Campbell County, TN, Claiborne County, TN, Fentress County, TN, Morgan County, TN, Pickett County, TN, Scott County, TN, Union County, TN
The radar
The Jackson,KY radar (KJKL), 89 km from the middle of the area, began a volume at 11:34 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
Nashville Metro, TN (KBNA), launched 00:00Z, 11.5 hours before the alert went out and 251 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.
- Mixed-layer CAPE
- 182 J/kg
- Mixed-layer CIN
- -168 J/kg
- Mixed-layer LCL
- 593 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 391 m²/s²
- 0-3 km storm-relative helicity
- 370 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted.
600
ACUS11 KWNS 111133
SWOMCD
SPC MCD 111132
KYZ000-VAZ000-TNZ000-111300-
Mesoscale Discussion 2018
NWS Storm Prediction Center Norman OK
0532 AM CST Sat Dec 11 2021
Areas affected...eastern KY into eastern TN
Concerning...Tornado Watch 561...562...
Valid 111132Z - 111300Z
The severe weather threat for Tornado Watch 561, 562 continues.
SUMMARY...Sporadic strong wind gusts or a brief spin-up are possible
in the short term across parts of eastern KY into northeast TN.
DISCUSSION...Convection continues to decrease in intensity across
portions of eastern KY into adjacent portions of northeast TN early
this morning. This is evident in both radar presentation and
lightning trends. Instability has become very weak while surface
inhibition has increased over the past hour. A few observation sites
have also seen a decrease in surface dewpoints as well. Deep-layer
flow is becoming increasingly veered as well per VWP data from KJKL.
While sporadic strong gusts or a brief spin-up remain possible in
the short term, the overall severe threat is expected to rapidly
diminish with eastward extent. A new watch downstream from WW 561
and 562 across eastern KY/northeast TN is not expected at this time.
..Leitman.. 12/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MRX...JKL...LMK...OHX...
LAT...LON 36478355 36188378 35968413 35888448 35988497 36178519
36468521 37198486 37648447 37968419 38098382 38098369
38078322 37888296 37568292 37098316 36478355SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 7:21 PM EST | Tornado Watch | SPC | Allen, Anderson, Barren, Breckinridge, Bullitt, Butler and 28 more | 10 hr |
| Dec 10, 7:22 PM EST | Mesoscale Discussion | SPC | Fulton, Graves, Hickman | 53 min |
| Dec 10, 8:41 PM EST | Mesoscale Discussion | SPC | Fulton | 64 min |
| Dec 10, 9:35 PM EST | Mesoscale Discussion | SPC | Allen, Barren, Breckinridge, Bullitt, Butler, Caldwell and 26 more | 85 min |
| Dec 10, 9:48 PM EST | Mesoscale Discussion | SPC | Carlisle, Fulton, Graves, Hickman, Lyon, Marshall | 57 min |
| Dec 10, 10:48 PM EST | Mesoscale Discussion | SPC | Caldwell, Graves, Hopkins, Lyon, Marshall | 57 min |
| Dec 10, 11:09 PM EST | Mesoscale Discussion | SPC | Ballard, Caldwell, Calloway, Carlisle, Crittenden, Fulton and 7 more | 96 min |
| Dec 10, 11:44 PM EST | Mesoscale Discussion | SPC | Caldwell, Grayson, Hopkins, McLean, Muhlenberg, Ohio | 61 min |
| Dec 11, 12:03 AM EST | Tornado Watch | SPC | Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more | 5 hr |
| Dec 11, 12:08 AM EST | Mesoscale Discussion | SPC | Boone, Bracken, Campbell, Carroll, Gallatin, Grant and 8 more | 67 min |
| Dec 11, 12:20 AM EST | Tornado Watch | SPC | Boone, Bracken, Campbell, Carroll, Gallatin, Grant and 6 more | 6 hr |
| Dec 11, 12:28 AM EST | Mesoscale Discussion | SPC | Union | 92 min |
| Dec 11, 12:36 AM EST | Mesoscale Discussion | SPC | Calloway, Christian, Logan, Simpson, Todd, Trigg | 54 min |
| Dec 11, 12:53 AM EST | Mesoscale Discussion | SPC | Breckinridge, Bullitt, Grayson, Hardin, Jefferson, Meade and 3 more | 67 min |
| Dec 11, 2:02 AM EST | Mesoscale Discussion | SPC | Adair, Allen, Anderson, Barren, Bath, Bourbon and 51 more | 88 min |
| Dec 11, 2:05 AM EST | Mesoscale Discussion | SPC | Barren, Butler, Edmonson, Green, Hart, Logan and 2 more | 55 min |
| Dec 11, 2:27 AM EST | Tornado Watch | SPC | Adair, Allen, Anderson, Barren, Bath, Bourbon and 51 more | 7 hr |
| Dec 11, 3:51 AM EST | Mesoscale Discussion | SPC | Boyle, Casey, Clark, Estill, Garrard, Jessamine and 4 more | 54 min |
| Dec 10, 10:40 PM EST | Mesoscale Discussion | SPC | Benton, Carroll, Cheatham, Chester, Crockett, Decatur and 24 more | 2 hr |
| Dec 10, 11:44 PM EST | Tornado Watch | SPC | Benton, Carroll, Cheatham, Chester, Crockett, Davidson and 34 more | 6 hr |
| Dec 11, 3:00 AM EST | Mesoscale Discussion | SPC | Bedford, Benton, Cannon, Carroll, Cheatham, Chester and 41 more | 90 min |
| Dec 11, 3:51 AM EST | Mesoscale Discussion | SPC | Cheatham, Davidson, Rutherford, Williamson, Wilson | 84 min |
| Dec 11, 4:41 AM EST | Tornado Watch | SPC | Bedford, Bledsoe, Cannon, Clay, Coffee, Cumberland and 26 more | 6 hr |
| Dec 11, 7:15 AM EST | Mesoscale Discussion | SPC | Bedford, Bledsoe, Cannon, Coffee, Cumberland, DeKalb and 12 more | 90 min |
Nearby
Mesoscale Discussions in Kentucky, 2021Mesoscale Discussions in Tennessee, 2021Every mesoscale discussion in 2021
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.