Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 70, NWS Morristown, TN

June 21, 20214 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Jun 21, 2021, 5:29 PM EDT for 4 counties in Tennessee. It was in force for 46 min. 3 reports 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, 5:29 PM EDT (21:29 UTC)
Expired: Jun 21, 2021, 6:15 PM EDT
In force: 46 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Campbell County, TN, Grainger County, TN, Knox County, TN, Union County, TN

The radar

The Knoxville radar (KMRX), 28 km from the middle of the area, began a volume at 21:31 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, 5:50 PM EDT	TSTM WND DMG	3 Nne Halls, TN	NUMEROUS TREES DOWN ACROSS NORTH KNOX COUNTY.
Jun 21, 6:07 PM EDT	TSTM WND DMG	2 Sw Norris Lake, TN	A FEW TREES DOWN.
Jun 21, 6:12 PM EDT	TSTM WND DMG	2 Ne Rutledge, TN	SEVERE TREES DOWN.

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, 9.5 hours before the alert went out and 260 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.

587 
WUUS54 KMRX 212129
SVRMRX
TNC013-057-093-173-212215-
/O.NEW.KMRX.SV.W.0070.210621T2129Z-210621T2215Z/

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

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Northeastern Knox County in east Tennessee...
  Southeastern Campbell County in east Tennessee...
  Union County in east Tennessee...
  Grainger County in east Tennessee...

* Until 615 PM EDT.

* At 528 PM EDT, a severe thunderstorm was located 7 miles northeast
  of Clinton, moving east at 40 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Maynardville, Rutledge, Plainview, Halls, Blaine, Luttrell, Rose
  Hill, Buffalo Springs, Paulette and Big Ridge State Park.

This includes Interstate 75 in Tennessee between mile markers 114 and
117.
 
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 3637 8345 3621 8343 3617 8348 3616 8353
      3619 8356 3613 8361 3614 8364 3610 8363
      3612 8368 3609 8366 3607 8409 3619 8394
      3630 8403 3622 8409 3635 8409 3634 8371
      3636 8369 3633 8366 3637 8359
TIME...MOT...LOC 2128Z 262DEG 33KT 3617 8403 

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

Garuckas

2 follow-up statements

963 
WWUS54 KMRX 212139
SVSMRX

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

TNC013-057-093-173-212215-
/O.CON.KMRX.SV.W.0070.000000T0000Z-210621T2215Z/
Knox TN-Campbell TN-Union TN-Grainger TN-
539 PM EDT Mon Jun 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR NORTHEASTERN KNOX...SOUTHEASTERN CAMPBELL...UNION AND GRAINGER
COUNTIES...

At 539 PM EDT, a severe thunderstorm was located near Plainview, or
near Maynardville, moving east at 40 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Maynardville, Rutledge, Plainview, Halls, Blaine, Luttrell, Rose
Hill, Buffalo Springs, Paulette and Big Ridge State Park.

This includes Interstate 75 in Tennessee between mile markers 114 and
117.
 
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 3637 8345 3621 8343 3617 8348 3616 8353
      3619 8356 3613 8361 3614 8364 3610 8363
      3612 8368 3609 8366 3607 8409 3619 8394
      3630 8403 3622 8409 3635 8409 3634 8371
      3636 8369 3633 8366 3637 8359
TIME...MOT...LOC 2139Z 262DEG 33KT 3618 8390 

HAIL...0.75IN
WIND...70MPH
 
$$

Garuckas

965 
WWUS54 KMRX 212207
SVSMRX

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

TNC013-093-173-212217-
/O.CAN.KMRX.SV.W.0070.000000T0000Z-210621T2215Z/
Knox TN-Campbell TN-Union TN-
607 PM EDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KNOX...
SOUTHEASTERN CAMPBELL AND UNION 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 3637 8345 3621 8343 3622 8344 3620 8345
      3617 8350 3618 8352 3616 8353 3619 8356
      3613 8361 3614 8364 3610 8363 3611 8365
      3617 8366 3622 8370 3633 8368 3634 8364
      3637 8359 3635 8353 3637 8351
TIME...MOT...LOC 2207Z 262DEG 33KT 3622 8358 

$$

TNC057-212215-
/O.CON.KMRX.SV.W.0070.000000T0000Z-210621T2215Z/
Grainger TN-
607 PM EDT Mon Jun 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR WESTERN GRAINGER COUNTY...

At 607 PM EDT, a severe thunderstorm was located near Rutledge,
moving east at 40 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Rutledge, Joppa and Buffalo Springs. 

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 3637 8345 3621 8343 3622 8344 3620 8345
      3617 8350 3618 8352 3616 8353 3619 8356
      3613 8361 3614 8364 3610 8363 3611 8365
      3617 8366 3622 8370 3633 8368 3634 8364
      3637 8359 3635 8353 3637 8351
TIME...MOT...LOC 2207Z 262DEG 33KT 3622 8358 

HAIL...0.75IN
WIND...70MPH
 
$$

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, 5:34 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
Jun 21, 7:41 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Blount, Knox, Loudon, Morgan, Roane	49 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.