Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 128, NWS Morristown, TN

August 14, 2021Blount County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Aug 14, 2021, 8:49 PM EDT for Blount 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 14, 2021, 8:49 PM EDT (00:49 UTC)
Expired: Aug 14, 2021, 9:30 PM EDT
In force: 41 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Blount County, TN

The radar

The Knoxville radar (KMRX), 87 km from the middle of the area, began a volume at 00:52 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

Time	Report	Where	Remark
Aug 14, 8:55 PM EDT	TSTM WND DMG	5 Nnw Talassee, TN	TREE 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 00:00Z, 0.8 hours before the alert went out and 233 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: 1476 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 941 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: -3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

536 
WUUS54 KMRX 150049
SVRMRX
TNC009-150130-
/O.NEW.KMRX.SV.W.0128.210815T0049Z-210815T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
849 PM EDT Sat Aug 14 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Southwestern Blount County in east Tennessee...

* Until 930 PM EDT.

* At 848 PM EDT, a severe thunderstorm was located 9 miles south of
  Maryville, moving northwest at 5 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Maryville, Greenback, Clover Hill and Happy Valley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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.

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

&&

LAT...LON 3557 8409 3557 8410 3558 8410 3563 8416
      3565 8413 3566 8413 3567 8416 3570 8416
      3577 8400 3559 8395 3555 8406 3555 8408
TIME...MOT...LOC 0048Z 146DEG 5KT 3562 8403 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Garuckas

2 follow-up statements

044 
WWUS54 KMRX 150102
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
902 PM EDT Sat Aug 14 2021

TNC009-150130-
/O.CON.KMRX.SV.W.0128.000000T0000Z-210815T0130Z/
Blount TN-
902 PM EDT Sat Aug 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR SOUTHWESTERN BLOUNT COUNTY...

At 902 PM EDT, a severe thunderstorm was located 8 miles southwest of
Maryville, moving northwest at 5 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Maryville, Greenback, Clover Hill and Happy Valley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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.

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

&&

LAT...LON 3557 8409 3557 8410 3558 8410 3563 8416
      3565 8413 3566 8413 3567 8416 3570 8416
      3577 8400 3559 8395 3555 8406 3555 8408
TIME...MOT...LOC 0102Z 146DEG 5KT 3564 8404 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Garuckas

484 
WWUS54 KMRX 150121
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
921 PM EDT Sat Aug 14 2021

TNC009-150130-
/O.EXP.KMRX.SV.W.0128.000000T0000Z-210815T0130Z/
Blount TN-
921 PM EDT Sat Aug 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN BLOUNT COUNTY
WILL EXPIRE AT 930 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 3557 8409 3557 8410 3558 8410 3563 8416
      3565 8413 3566 8413 3567 8416 3570 8416
      3577 8400 3559 8395 3555 8406 3555 8408
TIME...MOT...LOC 0120Z 146DEG 5KT 3566 8405 

$$

Garuckas

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 14, 8:13 PM EDT	Severe Thunderstorm Warning	MRX	Knox	32 min
Aug 14, 8:25 PM EDT	Special Weather Statement	MRX	Jefferson	50 min
Aug 14, 8:33 PM EDT	Special Weather Statement	MRX	Blount	42 min
Aug 14, 8:35 PM EDT	Areal Flood Advisory	MRX	Knox	3 hr
Aug 14, 8:36 PM EDT	Flash Flood Warning	MRX	Monroe	3 hr
Aug 14, 8:42 PM EDT	Severe Thunderstorm Warning	MRX	Knox	33 min
Aug 14, 8:49 PM EDT	Areal Flood Advisory	MRX	McMinn, Monroe, Polk	3 hr
Aug 14, 8:59 PM EDT	Areal Flood Advisory	MRX	Blount	3 hr
Aug 14, 9:12 PM EDT	Special Weather Statement	MRX	Knox	48 min
Aug 14, 11:24 PM EDT	Areal Flood Advisory	MRX	Anderson, Campbell, Claiborne, Union	3 hr
Aug 15, 3:34 PM EDT	Special Weather Statement	MRX	Knox	26 min
Aug 15, 4:09 PM EDT	Special Weather Statement	MRX	Knox	36 min
Aug 15, 4:27 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Knox, Union	33 min
Aug 15, 4:35 PM EDT	Special Weather Statement	MRX	Meigs, Rhea	25 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.