Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 150, NWS Morristown, TN

December 11, 2021Bradley County, Hamilton County, Marion County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Dec 11, 2021, 9:34 AM EST for Bradley County, Hamilton County, Marion County, Tennessee. It was in force for 41 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, 9:34 AM EST (14:34 UTC)
Expired: Dec 11, 2021, 10:15 AM EST
In force: 41 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Bradley County, TN, Hamilton County, TN, Marion County, TN

The radar

The Northeast Alabama radar (KHTX), 111 km from the middle of the area, began a volume at 14:36 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, 9:45 AM EST	TSTM WND DMG	7 Nne Chattanooga, TN	FEW TREES DOWN.

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, 4:41 AM EST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 2.6 hours before the alert went out and 205 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.

324 
WUUS54 KMRX 111434
SVRMRX
TNC011-065-115-111515-
/O.NEW.KMRX.SV.W.0150.211211T1434Z-211211T1515Z/

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

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Bradley County in east Tennessee...
  Southeastern Marion County in east Tennessee...
  Southern Hamilton County in east Tennessee...

* Until 1015 AM EST/915 AM CST/.

* At 934 AM EST/834 AM CST/, severe thunderstorms were located along
  a line extending from near Walden to near Trenton, moving east at
  55 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Chattanooga, Cleveland, Soddy-Daisy, Signal Mountain, Lakesite,
  Charleston, Ridgeside, South Cleveland, Harrison and East
  Cleveland.

This includes Interstate 75 in Tennessee between mile markers 1 and
31.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3499 8555 3523 8517 3529 8472 3528 8475
      3525 8473 3526 8471 3525 8470 3524 8471
      3523 8470 3520 8470 3499 8491
TIME...MOT...LOC 1434Z 254DEG 46KT 3515 8524 3494 8553 

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

$$

SR

1 follow-up statement

491 
WWUS54 KMRX 111500
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
1000 AM EST Sat Dec 11 2021

TNC115-111510-
/O.CAN.KMRX.SV.W.0150.000000T0000Z-211211T1515Z/
Marion TN-
1000 AM EST Sat Dec 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MARION COUNTY IS
CANCELLED...

The storms which prompted the warning have 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 3499 8540 3526 8498 3529 8472 3528 8475
      3525 8473 3526 8471 3525 8470 3524 8471
      3523 8470 3520 8470 3499 8491
TIME...MOT...LOC 1500Z 254DEG 46KT 3524 8487 3503 8516 

$$

TNC011-065-111515-
/O.CON.KMRX.SV.W.0150.000000T0000Z-211211T1515Z/
Bradley TN-Hamilton TN-
1000 AM EST Sat Dec 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 AM EST
FOR BRADLEY AND SOUTHEASTERN HAMILTON COUNTIES...

At 1000 AM EST, severe thunderstorms were located along a line
extending from near Cleveland to near Ridgeside, moving east at 55
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Chattanooga, Cleveland, Charleston, Ridgeside, South Cleveland,
Harrison, East Cleveland, Wildwood Lake, Collegedale and Waterville.

This includes Interstate 75 in Tennessee between mile markers 1 and
31.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3499 8540 3526 8498 3529 8472 3528 8475
      3525 8473 3526 8471 3525 8470 3524 8471
      3523 8470 3520 8470 3499 8491
TIME...MOT...LOC 1500Z 254DEG 46KT 3524 8487 3503 8516 

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

$$

SR

The office that day

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

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