Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 149, NWS Morristown, TN

December 11, 20214 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Dec 11, 2021, 8:18 AM CST for 4 counties in Tennessee. It was in force for 42 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Dec 11, 2021, 8:18 AM CST (14:18 UTC)
Expired: Dec 11, 2021, 9:00 AM CST
In force: 42 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Bledsoe County, TN, Meigs County, TN, Rhea County, TN, Roane County, TN

The radar

The Knoxville radar (KMRX), 137 km from the middle of the area, began a volume at 14:20 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.

What was reported inside it

Time	Report	Where	Remark
Dec 11, 8:40 AM CST	TSTM WND DMG	3 Ene Rockwood, TN	MULTIPLE TREES DOWN SOUTH OF INTERSTATE 40, EXIT 347, ALONG HWY 27.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Dec 11, 3:41 AM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 2.3 hours before the alert went out and 269 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: 182 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 625 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 268 m²/s²
0-3 km storm-relative helicity: 271 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

As transmitted.

534 
WUUS54 KMRX 111418
SVRMRX
TNC007-121-143-145-111500-
/O.NEW.KMRX.SV.W.0149.211211T1418Z-211211T1500Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
918 AM EST Sat Dec 11 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Northern Rhea County in east Tennessee...
  Northeastern Bledsoe County in east Tennessee...
  Northeastern Meigs County in east Tennessee...
  Southwestern Roane County in east Tennessee...

* Until 1000 AM EST/900 AM CST/.

* At 918 AM EST/818 AM CST/, a severe thunderstorm was located 9
  miles southwest of Spring City, or 9 miles north of Dayton, moving
  northeast at 65 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Rockwood, Fairview, Spring City, Midtown, Harriman, Stinging Fork
  Falls State Park, Eagle Furnace, Piney Falls State Park, Grandview
  and Ten Mile.

This includes Interstate 40 in Tennessee between mile markers 341 and
346.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of 
a building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

A Tornado Watch remains in effect until noon EST/1100 AM CST/ for
east Tennessee.

&&

LAT...LON 3559 8511 3573 8513 3577 8504 3575 8503
      3577 8494 3576 8492 3578 8490 3578 8488
      3583 8480 3583 8477 3586 8473 3590 8471
      3593 8465 3594 8461 3568 8452 3565 8458
TIME...MOT...LOC 1418Z 244DEG 57KT 3563 8501 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DGS

2 follow-up statements

953 
WWUS54 KMRX 111432
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
932 AM EST Sat Dec 11 2021

TNC007-111442-
/O.CAN.KMRX.SV.W.0149.000000T0000Z-211211T1500Z/
Bledsoe TN-
932 AM EST Sat Dec 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BLEDSOE COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until noon EST for east Tennessee.

LAT...LON 3562 8493 3574 8494 3578 8490 3578 8488
      3583 8480 3583 8477 3587 8472 3590 8471
      3593 8465 3594 8461 3569 8452 3568 8453
      3568 8452 3565 8458
TIME...MOT...LOC 1432Z 246DEG 54KT 3570 8480 

$$

TNC121-143-145-111500-
/O.CON.KMRX.SV.W.0149.000000T0000Z-211211T1500Z/
Rhea TN-Meigs TN-Roane TN-
932 AM EST Sat Dec 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 AM EST
FOR NORTHEASTERN RHEA...NORTHEASTERN MEIGS AND SOUTHWESTERN ROANE
COUNTIES...

At 932 AM EST, a severe thunderstorm was located near Spring City, or
12 miles north of Decatur, moving northeast at 60 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Rockwood, Fairview, Spring City, Midtown, Harriman, Stinging Fork
Falls State Park, Eagle Furnace, Piney Falls State Park, Grandview
and Ten Mile.

This includes Interstate 40 in Tennessee between mile markers 341 and
346.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of 
a building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

A Tornado Watch remains in effect until noon EST for east Tennessee.

&&

LAT...LON 3562 8493 3574 8494 3578 8490 3578 8488
      3583 8480 3583 8477 3587 8472 3590 8471
      3593 8465 3594 8461 3569 8452 3568 8453
      3568 8452 3565 8458
TIME...MOT...LOC 1432Z 246DEG 54KT 3570 8480 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DGS

336 
WWUS54 KMRX 111457
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
957 AM EST Sat Dec 11 2021

TNC121-143-145-111507-
/O.EXP.KMRX.SV.W.0149.000000T0000Z-211211T1500Z/
Rhea TN-Meigs TN-Roane TN-
957 AM EST Sat Dec 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN RHEA...
NORTHEASTERN MEIGS AND SOUTHWESTERN ROANE COUNTIES WILL EXPIRE AT
1000 AM EST...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until noon EST for east Tennessee.

LAT...LON 3562 8493 3574 8494 3578 8490 3578 8488
      3583 8480 3583 8477 3587 8472 3590 8471
      3593 8465 3594 8461 3569 8452 3568 8453
      3568 8452 3565 8458
TIME...MOT...LOC 1457Z 244DEG 57KT 3586 8439 

$$

DGS

The office that day

Everything else NWS Morristown, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 11, 4:57 AM CST	Severe Thunderstorm Warning	MRX	Campbell, Scott	48 min
Dec 11, 5:39 AM CST	Severe Thunderstorm Warning	MRX	Campbell, Scott	51 min
Dec 11, 6:29 AM CST	Severe Thunderstorm Warning	MRX	Campbell, Scott	46 min
Dec 11, 6:43 AM CST	Flash Flood Warning	MRX	Scott	4 hr
Dec 11, 6:51 AM CST	Special Weather Statement	MRX	Campbell, Morgan	54 min
Dec 11, 7:23 AM CST	Severe Thunderstorm Warning	MRX	Marion, Sequatchie	52 min
Dec 11, 7:23 AM CST	Severe Thunderstorm Warning	MRX	Campbell, Claiborne, Scott	37 min
Dec 11, 8:02 AM CST	Severe Thunderstorm Warning	MRX	Bledsoe, Bradley, Hamilton, McMinn, Meigs, Rhea and 1 more	43 min
Dec 11, 8:18 AM CST	Special Weather Statement	MRX	Hamilton	42 min
Dec 11, 8:34 AM CST	Severe Thunderstorm Warning	MRX	Bradley, Hamilton, Marion	41 min
Dec 11, 8:44 AM CST	Severe Thunderstorm Warning	MRX	Bradley, Loudon, McMinn, Meigs, Monroe, Roane	46 min
Dec 11, 8:51 AM CST	Severe Thunderstorm Warning	MRX	Anderson, Blount, Knox, Loudon, Roane	39 min
Dec 11, 9:15 AM CST	Severe Thunderstorm Warning	MRX	Bradley, McMinn, Monroe, Polk	45 min
Dec 11, 9:21 AM CST	Severe Thunderstorm Warning	MRX	Blount, Grainger, Jefferson, Knox, Sevier	39 min
Dec 11, 9:25 AM CST	Severe Thunderstorm Warning	MRX	Blount, Loudon, McMinn, Monroe	50 min
Dec 11, 9:30 AM CST	Special Weather Statement	MRX	Bradley	45 min
Dec 11, 9:53 AM CST	Severe Thunderstorm Warning	MRX	Cocke, Grainger, Greene, Hamblen, Hawkins, Jefferson	35 min
Dec 11, 9:59 AM CST	Special Weather Statement	MRX	Polk	46 min
Dec 11, 9:59 AM CST	Severe Thunderstorm Warning	MRX	Blount, Cocke, Jefferson, Sevier	30 min
Dec 11, 10:28 AM CST	Special Weather Statement	MRX	Sullivan	47 min
Dec 11, 10:49 AM CST	Special Weather Statement	MRX	Carter, Johnson, Washington	41 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2021 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.