Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 94, NWS Morristown, TN

August 7, 2021Jefferson County, Knox County, Sevier County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Aug 7, 2021, 12:00 PM EDT for Jefferson County, Knox County, Sevier County, Tennessee. It was in force for 45 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 7, 2021, 12:00 PM EDT (16:00 UTC)
Expired: Aug 7, 2021, 12:45 PM EDT
In force: 45 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Jefferson County, TN, Knox County, TN, Sevier County, TN

The radar

The Knoxville radar (KMRX), 23 km from the middle of the area, began a volume at 16:00 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 7, 12:20 PM EDT	TSTM WND DMG	1 Se Strawberry Plains, TN	A FEW TREES 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 12:00Z, 4.0 hours before the alert went out and 266 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: 885 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 963 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: -25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

260 
WUUS54 KMRX 071600
SVRMRX
TNC089-093-155-071645-
/O.NEW.KMRX.SV.W.0094.210807T1600Z-210807T1645Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
1200 PM EDT Sat Aug 7 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Northeastern Knox County in east Tennessee...
  Western Jefferson County in east Tennessee...
  Northwestern Sevier County in east Tennessee...

* Until 1245 PM EDT.

* At 1200 PM EDT, a severe thunderstorm was located near New Market,
  or 9 miles southwest of Jefferson City, moving east at 10 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...
  Sevierville, Jefferson City, Dandridge, New Market, Strawberry
  Plains, Piedmont, Kodak, House Mountain State Park and Mascot.

This includes Interstate 40 in Tennessee between mile markers 400 and
416.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3595 8374 3613 8376 3613 8372 3608 8366
      3612 8368 3612 8365 3610 8365 3610 8363
      3612 8363 3613 8364 3614 8364 3614 8361
      3615 8360 3615 8345 3594 8347
TIME...MOT...LOC 1600Z 265DEG 10KT 3606 8363 

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

$$

BW

2 follow-up statements

178 
WWUS54 KMRX 071629
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
1229 PM EDT Sat Aug 7 2021

TNC155-071639-
/O.CAN.KMRX.SV.W.0094.000000T0000Z-210807T1645Z/
Sevier TN-
1229 PM EDT Sat Aug 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SEVIER 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 3613 8376 3613 8372 3608 8366 3612 8368
      3612 8365 3610 8365 3610 8363 3612 8363
      3614 8364 3613 8361 3614 8361 3615 8360
      3615 8345 3602 8346 3602 8362 3604 8365
      3604 8367 3602 8367 3602 8375
TIME...MOT...LOC 1629Z 265DEG 10KT 3607 8353 

$$

TNC089-093-071645-
/O.CON.KMRX.SV.W.0094.000000T0000Z-210807T1645Z/
Knox TN-Jefferson TN-
1229 PM EDT Sat Aug 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1245 PM EDT
FOR NORTHEASTERN KNOX AND NORTHWESTERN JEFFERSON COUNTIES...

At 1229 PM EDT, a severe thunderstorm was located near New Market, or
near Jefferson City, moving east at 10 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Jefferson City, Dandridge, New Market, Strawberry Plains, Piedmont,
House Mountain State Park and Mascot.

This includes Interstate 40 in Tennessee between mile markers 415 and
416.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3613 8376 3613 8372 3608 8366 3612 8368
      3612 8365 3610 8365 3610 8363 3612 8363
      3614 8364 3613 8361 3614 8361 3615 8360
      3615 8345 3602 8346 3602 8362 3604 8365
      3604 8367 3602 8367 3602 8375
TIME...MOT...LOC 1629Z 265DEG 10KT 3607 8353 

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

$$

BW

653 
WWUS54 KMRX 071637
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
1237 PM EDT Sat Aug 7 2021

TNC089-093-071646-
/O.EXP.KMRX.SV.W.0094.000000T0000Z-210807T1645Z/
Knox TN-Jefferson TN-
1237 PM EDT Sat Aug 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KNOX AND
NORTHWESTERN JEFFERSON COUNTIES WILL EXPIRE AT 1245 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.

LAT...LON 3613 8376 3613 8372 3608 8366 3612 8368
      3612 8365 3610 8365 3610 8363 3612 8363
      3614 8364 3613 8361 3614 8361 3615 8360
      3615 8345 3602 8346 3602 8362 3604 8365
      3604 8367 3602 8367 3602 8375
TIME...MOT...LOC 1636Z 265DEG 10KT 3607 8351 

$$

CED

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 10:51 AM EDT	Areal Flood Advisory	MRX	Sevier	114 min
Aug 7, 11:14 AM EDT	Special Weather Statement	MRX	Sevier	46 min
Aug 7, 11:20 AM EDT	Special Weather Statement	MRX	Rhea	25 min
Aug 7, 11:44 AM EDT	Special Weather Statement	MRX	Jefferson	31 min
Aug 7, 11:54 AM EDT	Special Weather Statement	MRX	Hamilton	36 min
Aug 7, 12:09 PM EDT	Areal Flood Advisory	MRX	Sevier	66 min
Aug 7, 1:08 PM EDT	Special Weather Statement	MRX	Morgan	37 min
Aug 7, 1:13 PM EDT	Special Weather Statement	MRX	Bradley	32 min
Aug 7, 1:23 PM EDT	Areal Flood Advisory	MRX	Knox	112 min
Aug 7, 1:31 PM EDT	Special Weather Statement	MRX	Claiborne	44 min
Aug 7, 1:41 PM EDT	Special Weather Statement	MRX	Hawkins	34 min
Aug 7, 1:53 PM EDT	Special Weather Statement	MRX	Claiborne	37 min
Aug 7, 2:00 PM EDT	Areal Flood Advisory	MRX	Morgan	103 min
Aug 7, 2:03 PM EDT	Special Weather Statement	MRX	Hawkins	27 min
Aug 7, 2:10 PM EDT	Severe Thunderstorm Warning	MRX	Claiborne	30 min
Aug 7, 2:15 PM EDT	Special Weather Statement	MRX	Union	30 min
Aug 7, 2:19 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Hawkins, Sullivan, Washington	30 min
Aug 7, 2:39 PM EDT	Special Weather Statement	MRX	Grainger	36 min
Aug 7, 2:48 PM EDT	Special Weather Statement	MRX	Washington	27 min
Aug 7, 2:52 PM EDT	Special Weather Statement	MRX	Knox	23 min
Aug 7, 3:15 PM EDT	Areal Flood Advisory	MRX	Knox	2 hr
Aug 7, 3:19 PM EDT	Areal Flood Advisory	MRX	Hawkins, Sullivan	3 hr
Aug 7, 3:24 PM EDT	Special Weather Statement	MRX	Sullivan	51 min
Aug 7, 3:30 PM EDT	Special Weather Statement	MRX	Sevier	30 min
Aug 7, 3:33 PM EDT	Areal Flood Advisory	MRX	Sullivan	3 hr
Aug 7, 3:37 PM EDT	Severe Thunderstorm Warning	MRX	Sevier	53 min
Aug 7, 3:53 PM EDT	Special Weather Statement	MRX	Johnson	37 min
Aug 7, 4:06 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Sevier	39 min
Aug 7, 4:14 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Greene	27 min
Aug 7, 4:35 PM EDT	Special Weather Statement	MRX	Cocke	25 min
Aug 7, 5:06 PM EDT	Special Weather Statement	MRX	Hawkins	39 min
Aug 7, 5:43 PM EDT	Special Weather Statement	MRX	Blount	47 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.