Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 78, NWS Morristown, TN

June 21, 2021Blount County, Knox County, Sevier County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Jun 21, 2021, 6:54 PM EDT for Blount County, Knox County, Sevier County, Tennessee. It was in force for 51 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, 6:54 PM EDT (22:54 UTC)
Expired
Jun 21, 2021, 7:45 PM EDT
In force
51 min
Issued by
NWS Morristown, TN
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Blount County, TN, Knox County, TN, Sevier County, TN

The radar

The Knoxville radar (KMRX), 59 km from the middle of the area, began a volume at 22:56 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

TimeReportWhereRemark
Jun 21, 7:12 PM EDTTSTM WND DMG5 N Alcoa, TNSEVERAL TREES DOWN ACROSS THE COUNTY.

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, 10.9 hours before the alert went out and 244 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-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2021-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1530 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2021-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 211 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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.

347 
WUUS54 KMRX 212254
SVRMRX
TNC009-093-155-212345-
/O.NEW.KMRX.SV.W.0078.210621T2254Z-210621T2345Z/

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

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Southeastern Knox County in east Tennessee...
  Northern Blount County in east Tennessee...
  Northwestern Sevier County in east Tennessee...

* Until 745 PM EDT.

* At 653 PM EDT, a severe thunderstorm was located near Louisville,
  or near Alcoa, moving east at 20 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, Maryville, Alcoa, Pigeon Forge, Louisville, Rockford,
  Eagleton Village, Friendsville, Kimberlin Heights and Wildwood.

This includes Interstate 40 in Tennessee between mile markers 378 and
389, and between mile markers 400 and 406.
 
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 3572 8411 3596 8410 3602 8363 3575 8360
TIME...MOT...LOC 2253Z 271DEG 19KT 3585 8401 

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

Garuckas
2 follow-up statements
187 
WWUS54 KMRX 212313
SVSMRX

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

TNC009-093-155-212345-
/O.CON.KMRX.SV.W.0078.000000T0000Z-210621T2345Z/
Knox TN-Blount TN-Sevier TN-
713 PM EDT Mon Jun 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR SOUTHEASTERN KNOX...NORTHEASTERN BLOUNT AND NORTHWESTERN SEVIER
COUNTIES...

At 713 PM EDT, a severe thunderstorm was located near Rockford, or 8
miles northeast of Alcoa, moving east at 25 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, Pigeon Forge, Rockford, Eagleton Village, McMahan, Lake
Forest, Seymour, Kodak, Kimberlin Heights and Wildwood.

This includes Interstate 40 in Tennessee between mile markers 388 and
389, and between mile markers 400 and 406.
 
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 3573 8391 3598 8394 3602 8363 3575 8360
TIME...MOT...LOC 2313Z 265DEG 23KT 3585 8384 

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

Garuckas
556 
WWUS54 KMRX 212337
SVSMRX

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

TNC009-093-155-212346-
/O.EXP.KMRX.SV.W.0078.000000T0000Z-210621T2345Z/
Knox TN-Blount TN-Sevier TN-
737 PM EDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN KNOX...
NORTHEASTERN BLOUNT AND NORTHWESTERN SEVIER COUNTIES WILL EXPIRE AT
745 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 3573 8391 3598 8394 3602 8363 3575 8360
TIME...MOT...LOC 2336Z 271DEG 19KT 3585 8371 

$$

Garuckas

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 4:21 PM EDTSpecial Weather StatementMRXMorgan39 min
Jun 21, 4:29 PM EDTSevere Thunderstorm WarningMRXCampbell, Morgan46 min
Jun 21, 4:40 PM EDTSpecial Weather StatementMRXGrainger50 min
Jun 21, 4:48 PM EDTSpecial Weather StatementMRXUnion42 min
Jun 21, 4:55 PM EDTSevere Thunderstorm WarningMRXAnderson, Campbell, Morgan, Roane, Scott65 min
Jun 21, 5:01 PM EDTSpecial Weather StatementMRXClaiborne44 min
Jun 21, 5:05 PM EDTSevere Thunderstorm WarningMRXCampbell, Morgan, Scott40 min
Jun 21, 5:08 PM EDTSevere Thunderstorm WarningMRXGrainger, Hancock, Hawkins67 min
Jun 21, 5:12 PM EDTSevere Thunderstorm WarningMRXCampbell, Claiborne, Union48 min
Jun 21, 5:29 PM EDTSevere Thunderstorm WarningMRXCampbell, Grainger, Knox, Union46 min
Jun 21, 5:34 PM EDTSpecial Weather StatementMRXBradley, Hamilton, Marion, Sequatchie41 min
Jun 21, 5:36 PM EDTSevere Thunderstorm WarningMRXGrainger, Jefferson, Knox39 min
Jun 21, 5:42 PM EDTSevere Thunderstorm WarningMRXCampbell, Claiborne48 min
Jun 21, 5:46 PM EDTSpecial Weather StatementMRXLoudon44 min
Jun 21, 5:53 PM EDTSevere Thunderstorm WarningMRXHancock41 min
Jun 21, 5:57 PM EDTSevere Thunderstorm WarningMRXClaiborne, Grainger, Hancock48 min
Jun 21, 6:02 PM EDTSevere Thunderstorm WarningMRXBlount, Loudon, McMinn, Monroe, Roane43 min
Jun 21, 6:02 PM EDTSevere Thunderstorm WarningMRXClaiborne, Cocke, Grainger, Greene, Hamblen, Hawkins and 1 more58 min
Jun 21, 6:05 PM EDTSpecial Weather StatementMRXMcMinn40 min
Jun 21, 6:25 PM EDTSpecial Weather StatementMRXBradley, McMinn65 min
Jun 21, 6:33 PM EDTSpecial Weather StatementMRXAnderson57 min
Jun 21, 6:50 PM EDTSevere Thunderstorm WarningMRXBlount, Monroe40 min
Jun 21, 7:19 PM EDTSevere Thunderstorm WarningMRXMorgan, Rhea, Roane56 min
Jun 21, 7:41 PM EDTSevere Thunderstorm WarningMRXAnderson, Blount, Knox, Loudon, Morgan, Roane49 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2021Every 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.