Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 41, NWS Morristown, TN

April 8, 2021Campbell County, Claiborne County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Apr 8, 2021, 6:50 PM EDT for Campbell County, Claiborne County, Tennessee. It was in force for 40 min. 2 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
Apr 8, 2021, 6:50 PM EDT (22:50 UTC)
Expired
Apr 8, 2021, 7:30 PM EDT
In force
40 min
Issued by
NWS Morristown, TN
Area
Storm-based polygon
Tornado
Possible
Hail
1.25 in
Wind
60.0 mph

Counties Campbell County, TN, Claiborne County, TN

The radar

The Knoxville radar (KMRX), 67 km from the middle of the area, began a volume at 22:52 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, 7:15 PM EDTHAIL 1.751 Sw Duff, TN
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, 10.8 hours before the alert went out and 230 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°0°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.

788 
WUUS54 KMRX 082250
SVRMRX
TNC013-025-082330-
/O.NEW.KMRX.SV.W.0041.210408T2250Z-210408T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
650 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...
  Northern Campbell County in east Tennessee...

* Until 730 PM EDT.

* At 649 PM EDT, a severe thunderstorm was located 8 miles northwest
  of Jacksboro, or 11 miles west of La Follette, moving east at 25
  mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  La Follette, Jellico, Caryville, Elk Valley, Clairfield, Fincastle,
  Royal Blue and White Oak.

This includes Interstate 75 in Tennessee between mile markers 140 and
154.
 
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 3659 8388 3643 8381 3643 8386 3642 8388
      3643 8389 3642 8389 3642 8391 3635 8433
      3639 8433 3639 8431 3642 8435 3645 8434
      3646 8435 3659 8399
TIME...MOT...LOC 2249Z 249DEG 22KT 3640 8433 

TORNADO...POSSIBLE
HAIL...1.25IN
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, 6:52 PM EDTTornado WarningMRXCampbell, Claiborne, Scott38 min
Apr 8, 7:24 PM EDTSevere Thunderstorm WarningMRXCampbell, Claiborne36 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.