Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 42, NWS Morristown, TN

April 8, 2021Campbell County, Claiborne County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Apr 8, 2021, 7:24 PM EDT for Campbell County, Claiborne County, Tennessee. It was in force for 36 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
Apr 8, 2021, 7:24 PM EDT (23:24 UTC)
Expired
Apr 8, 2021, 8:00 PM EDT
In force
36 min
Issued by
NWS Morristown, TN
Area
Storm-based polygon
Tornado
Possible
Hail
1.75 in
Wind
60.0 mph

Counties Campbell County, TN, Claiborne County, TN

The radar

The Knoxville radar (KMRX), 66 km from the middle of the area, began a volume at 23:25 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
Apr 8, 7:35 PM EDTHAIL 1.5Clairfield, TN

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, 11.4 hours before the alert went out and 240 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 2021-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 55 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 2021-04-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 354 square meters per square second.19395878Sfc1 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
55 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
626 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
354 m²/s²
0-3 km storm-relative helicity
375 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

444 
WUUS54 KMRX 082324
SVRMRX
TNC013-025-090000-
/O.NEW.KMRX.SV.W.0042.210408T2324Z-210409T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
724 PM EDT Thu Apr 8 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Northwestern Claiborne County in east Tennessee...
  Northeastern Campbell County in east Tennessee...

* Until 800 PM EDT.

* At 724 PM EDT, a severe thunderstorm was located near Lot, or 12
  miles northeast of La Follette, moving northeast at 30 mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* Locations impacted include...
  Jellico, White Oak and Clairfield. 

This includes Interstate 75 in Tennessee between mile markers 155 and
160.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 3658 8372 3645 8413 3653 8419 3659 8409
TIME...MOT...LOC 2324Z 237DEG 27KT 3654 8403 

TORNADO...POSSIBLE
HAIL...1.75IN
WIND...60MPH
 
$$

DH
1 follow-up statement
422 
WWUS54 KMRX 082339
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
739 PM EDT Thu Apr 8 2021

TNC013-082349-
/O.CAN.KMRX.SV.W.0042.000000T0000Z-210409T0000Z/
Campbell TN-
739 PM EDT Thu Apr 8 2021

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

LAT...LON 3658 8372 3650 8396 3651 8396 3654 8398
      3659 8398
TIME...MOT...LOC 2339Z 245DEG 30KT 3657 8384 

$$

TNC025-090000-
/O.CON.KMRX.SV.W.0042.000000T0000Z-210409T0000Z/
Claiborne TN-
739 PM EDT Thu Apr 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHWESTERN CLAIBORNE COUNTY...

At 739 PM EDT, a severe thunderstorm was located over Fonde, or near
Middlesboro, moving northeast at 35 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Clairfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 3658 8372 3650 8396 3651 8396 3654 8398
      3659 8398
TIME...MOT...LOC 2339Z 245DEG 30KT 3657 8384 

TORNADO...POSSIBLE
HAIL...1.75IN
WIND...60MPH
 
$$

DH

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 8, 3:58 AM EDTWind AdvisoryMRXBlount, Carter, Cocke, Greene, Johnson, Monroe and 2 more19 hr
Apr 8, 4:47 PM EDTTornado WarningMRXMorgan, Scott43 min
Apr 8, 5:21 PM EDTSevere Thunderstorm WarningMRXCampbell, Morgan, Scott39 min
Apr 8, 5:25 PM EDTTornado WarningMRXCampbell, Morgan, Scott35 min
Apr 8, 5:51 PM EDTTornado WarningMRXCampbell, Scott39 min
Apr 8, 5:56 PM EDTTornado WarningMRXScott34 min
Apr 8, 6:16 PM EDTSevere Thunderstorm WarningMRXCampbell, Scott44 min
Apr 8, 6:22 PM EDTTornado WarningMRXCampbell, Claiborne, Scott53 min
Apr 8, 6:44 PM EDTTornado WarningMRXCampbell, Scott46 min
Apr 8, 6:50 PM EDTSevere Thunderstorm WarningMRXCampbell, Claiborne40 min
Apr 8, 6:52 PM EDTTornado WarningMRXCampbell, Claiborne, Scott38 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.