Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 81, NWS Morristown, TN

June 21, 20216 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Jun 21, 2021, 7:41 PM EDT for 6 counties in Tennessee. It was in force for 49 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: Jun 21, 2021, 7:41 PM EDT (23:41 UTC)
Expired: Jun 21, 2021, 8:30 PM EDT
In force: 49 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Anderson County, TN, Blount County, TN, Knox County, TN, Loudon County, TN, Morgan County, TN, Roane County, TN

The radar

The Knoxville radar (KMRX), 79 km from the middle of the area, began a volume at 23:42 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
Jun 21, 8:05 PM EDT	TSTM WND DMG	5 E Oak Ridge, TN	TREE DOWN ON CAMPBELL STATION RD AND POWERLINES DOWN ON GUINN RD.

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

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.7 hours before the alert went out and 214 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: 1530 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 919 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 211 m²/s²
0-3 km storm-relative helicity: 228 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 9.6

Open this sounding in Storm Lab

The text

As transmitted.

024 
WUUS54 KMRX 212341
SVRMRX
TNC001-009-093-105-129-145-220030-
/O.NEW.KMRX.SV.W.0081.210621T2341Z-210622T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
741 PM EDT Mon Jun 21 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  East central Morgan County in east Tennessee...
  Northeastern Loudon County in east Tennessee...
  Western Knox County in east Tennessee...
  Anderson County in east Tennessee...
  Northwestern Blount County in east Tennessee...
  Northeastern Roane County in east Tennessee...

* Until 830 PM EDT.

* At 741 PM EDT, a severe thunderstorm was located over Midtown, or
  near Rockwood, moving east at 45 mph.

  HAZARD...60 mph wind gusts and nickel size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Knoxville, Oak Ridge, Maryville, Clinton, Lenoir City, Alcoa,
  Kingston, Loudon, Farragut and Oliver Springs.

This includes the following highways...
 Interstate 40 in Tennessee between mile markers 358 and 386.
 Interstate 75 in Tennessee between mile markers 76 and 123.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3577 8441 3610 8445 3620 8397 3577 8392
TIME...MOT...LOC 2341Z 261DEG 39KT 3591 8458 

HAIL...0.88IN
WIND...60MPH
 
$$

Garuckas

2 follow-up statements

968 
WWUS54 KMRX 220014
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
814 PM EDT Mon Jun 21 2021

TNC105-129-145-220024-
/O.CAN.KMRX.SV.W.0081.000000T0000Z-210622T0030Z/
Morgan TN-Loudon TN-Roane TN-
814 PM EDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MORGAN...
NORTHEASTERN LOUDON AND NORTHEASTERN ROANE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3577 8418 3581 8417 3583 8419 3614 8426
      3620 8397 3577 8392
TIME...MOT...LOC 0014Z 257DEG 45KT 3598 8407 

$$

TNC001-009-093-220030-
/O.CON.KMRX.SV.W.0081.000000T0000Z-210622T0030Z/
Knox TN-Anderson TN-Blount TN-
814 PM EDT Mon Jun 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM EDT
FOR WESTERN KNOX...CENTRAL ANDERSON AND NORTHWESTERN BLOUNT
COUNTIES...

At 814 PM EDT, a severe thunderstorm was located near Knoxville,
moving east at 50 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Knoxville, Oak Ridge, Maryville, Clinton, Alcoa, Farragut,
Louisville, Rockford, Eagleton Village and Friendsville.

This includes the following highways...
 Interstate 40 in Tennessee between mile markers 372 and 386.
 Interstate 75 in Tennessee between mile markers 108 and 123.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3577 8418 3581 8417 3583 8419 3614 8426
      3620 8397 3577 8392
TIME...MOT...LOC 0014Z 257DEG 45KT 3598 8407 

HAIL...0.75IN
WIND...60MPH
 
$$

Garuckas

486 
WWUS54 KMRX 220028
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
828 PM EDT Mon Jun 21 2021

TNC001-009-093-220038-
/O.EXP.KMRX.SV.W.0081.000000T0000Z-210622T0030Z/
Knox TN-Anderson TN-Blount TN-
828 PM EDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN KNOX...CENTRAL
ANDERSON AND NORTHWESTERN BLOUNT COUNTIES WILL EXPIRE AT 830 PM
EDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 3577 8418 3581 8417 3583 8419 3614 8426
      3620 8397 3577 8392
TIME...MOT...LOC 0028Z 261DEG 39KT 3600 8392 

$$

Garuckas

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 21, 4:21 PM EDT	Special Weather Statement	MRX	Morgan	39 min
Jun 21, 4:29 PM EDT	Severe Thunderstorm Warning	MRX	Campbell, Morgan	46 min
Jun 21, 4:40 PM EDT	Special Weather Statement	MRX	Grainger	50 min
Jun 21, 4:48 PM EDT	Special Weather Statement	MRX	Union	42 min
Jun 21, 4:55 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Morgan, Roane, Scott	65 min
Jun 21, 5:01 PM EDT	Special Weather Statement	MRX	Claiborne	44 min
Jun 21, 5:05 PM EDT	Severe Thunderstorm Warning	MRX	Campbell, Morgan, Scott	40 min
Jun 21, 5:08 PM EDT	Severe Thunderstorm Warning	MRX	Grainger, Hancock, Hawkins	67 min
Jun 21, 5:12 PM EDT	Severe Thunderstorm Warning	MRX	Campbell, Claiborne, Union	48 min
Jun 21, 5:29 PM EDT	Severe Thunderstorm Warning	MRX	Campbell, Grainger, Knox, Union	46 min
Jun 21, 5:34 PM EDT	Special Weather Statement	MRX	Bradley, Hamilton, Marion, Sequatchie	41 min
Jun 21, 5:36 PM EDT	Severe Thunderstorm Warning	MRX	Grainger, Jefferson, Knox	39 min
Jun 21, 5:42 PM EDT	Severe Thunderstorm Warning	MRX	Campbell, Claiborne	48 min
Jun 21, 5:46 PM EDT	Special Weather Statement	MRX	Loudon	44 min
Jun 21, 5:53 PM EDT	Severe Thunderstorm Warning	MRX	Hancock	41 min
Jun 21, 5:57 PM EDT	Severe Thunderstorm Warning	MRX	Claiborne, Grainger, Hancock	48 min
Jun 21, 6:02 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Loudon, McMinn, Monroe, Roane	43 min
Jun 21, 6:02 PM EDT	Severe Thunderstorm Warning	MRX	Claiborne, Cocke, Grainger, Greene, Hamblen, Hawkins and 1 more	58 min
Jun 21, 6:05 PM EDT	Special Weather Statement	MRX	McMinn	40 min
Jun 21, 6:25 PM EDT	Special Weather Statement	MRX	Bradley, McMinn	65 min
Jun 21, 6:33 PM EDT	Special Weather Statement	MRX	Anderson	57 min
Jun 21, 6:50 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Monroe	40 min
Jun 21, 6:54 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Knox, Sevier	51 min
Jun 21, 7:19 PM EDT	Severe Thunderstorm Warning	MRX	Morgan, Rhea, Roane	56 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.