Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 102, NWS Morristown, TN

August 9, 2021Morgan County, Scott County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Aug 9, 2021, 5:49 PM EDT for Morgan County, Scott County, Tennessee. It was in force for 41 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
Aug 9, 2021, 5:49 PM EDT (21:49 UTC)
Expired
Aug 9, 2021, 6:30 PM EDT
In force
41 min
Issued by
NWS Morristown, TN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Morgan County, TN, Scott County, TN

The radar

The Knoxville radar (KMRX), 118 km from the middle of the area, began a volume at 21:49 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
Aug 9, 6:05 PM EDTTSTM WND DMGSunbright, TNNUMEROUS TREES WERE BLOWN DOWN AROUND SUNBRIGHT.

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, 9.8 hours before the alert went out and 170 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 2021-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 788 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 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 square meters per square second.1939Sfc1 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
788 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
892 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

204 
WUUS54 KMRX 092149
SVRMRX
TNC129-151-092230-
/O.NEW.KMRX.SV.W.0102.210809T2149Z-210809T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
549 PM EDT Mon Aug 9 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Morgan County in east Tennessee...
  Southwestern Scott County in east Tennessee...

* Until 630 PM EDT.

* At 549 PM EDT, a severe thunderstorm was located 11 miles northwest
  of Wartburg, moving east at 20 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Wartburg, Huntsville, Helenwood, Sunbright, Rugby, High Point,
  Robbins, Rugby State Park, Deerlodge and Elgin.

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.

&&

LAT...LON 3604 8446 3609 8482 3609 8484 3614 8488
      3630 8481 3630 8479 3631 8479 3633 8477
      3633 8476 3634 8474 3635 8474 3635 8473
      3637 8473 3641 8443
TIME...MOT...LOC 2149Z 267DEG 19KT 3621 8474 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DGS
2 follow-up statements
634 
WWUS54 KMRX 092216
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
616 PM EDT Mon Aug 9 2021

TNC129-151-092230-
/O.CON.KMRX.SV.W.0102.000000T0000Z-210809T2230Z/
Morgan TN-Scott TN-
616 PM EDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR CENTRAL MORGAN AND SOUTH CENTRAL SCOTT COUNTIES...

At 616 PM EDT, a severe thunderstorm was located 7 miles north of
Wartburg, moving east at 20 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Wartburg, Frozen Head State Park, Slick Rock, Petros, Elgin and
Coalfield.

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.

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

&&

LAT...LON 3608 8472 3632 8463 3635 8444 3604 8446
TIME...MOT...LOC 2216Z 267DEG 19KT 3622 8456 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DGS
282 
WWUS54 KMRX 092228
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
628 PM EDT Mon Aug 9 2021

TNC129-151-092238-
/O.EXP.KMRX.SV.W.0102.000000T0000Z-210809T2230Z/
Morgan TN-Scott TN-
628 PM EDT Mon Aug 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MORGAN AND SOUTH
CENTRAL SCOTT COUNTIES WILL EXPIRE AT 630 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 3608 8472 3632 8463 3635 8444 3604 8446
TIME...MOT...LOC 2228Z 267DEG 19KT 3622 8450 

$$

DGS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 2:24 PM EDTSpecial Weather StatementMRXBradley36 min
Aug 9, 3:17 PM EDTSpecial Weather StatementMRXScott43 min
Aug 9, 5:29 PM EDTSpecial Weather StatementMRXScott46 min
Aug 9, 5:48 PM EDTSevere Thunderstorm WarningMRXScott42 min
Aug 9, 6:07 PM EDTAreal Flood AdvisoryMRXMorgan3 hr
Aug 9, 7:13 PM EDTSpecial Weather StatementMRXAnderson47 min
Aug 9, 7:55 PM EDTSevere Thunderstorm WarningMRXGrainger, Knox, Union39 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.