Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 50, NWS Morristown, TN

May 4, 20215 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at May 4, 2021, 10:03 AM EDT for 5 counties in Tennessee. It was in force for 13 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: May 4, 2021, 10:03 AM EDT (14:03 UTC)
Expired: May 4, 2021, 10:16 AM EDT
In force: 13 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Anderson County, TN, Blount County, TN, Knox County, TN, Loudon County, TN, Roane County, TN

The radar

The Knoxville radar (KMRX), 95 km from the middle of the area, began a volume at 14:04 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
May 4, 10:10 AM EDT	TSTM WND DMG	3 Ssw Oak Ridge, TN	COUPLE TREES DOWN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 4, 9:37 AM EDT	Severe Thunderstorm Watch	SPC	3 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 2.1 hours before the alert went out and 269 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: 590 J/kg
Mixed-layer CIN: -114 J/kg
Mixed-layer LCL: 753 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 207 m²/s²
0-3 km storm-relative helicity: 213 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

313 
WUUS54 KMRX 041403
SVRMRX
TNC001-009-093-105-145-041430-
/O.NEW.KMRX.SV.W.0050.210504T1403Z-210504T1430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
1003 AM EDT Tue May 4 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Loudon County in east Tennessee...
  Southern Knox County in east Tennessee...
  Southwestern Anderson County in east Tennessee...
  Northwestern Blount County in east Tennessee...
  Roane County in east Tennessee...

* Until 1030 AM EDT.

* At 1002 AM EDT, severe thunderstorms were located along a line
  extending from Oliver Springs to near Kingston to near Fairview,
  moving east at 55 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Knoxville, Oak Ridge, Maryville, Lenoir City, Alcoa, Kingston,
  Loudon, Farragut, Fairview and Oliver Springs.

This includes the following highways...
 Interstate 40 in Tennessee between mile markers 354 and 388.
 Interstate 75 in Tennessee between mile markers 67 and 84.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3567 8443 3566 8448 3577 8475 3588 8450
      3600 8442 3605 8434 3608 8436 3595 8379
      3577 8395 3564 8429 3567 8432 3567 8435
      3564 8438 3564 8440
TIME...MOT...LOC 1402Z 282DEG 47KT 3602 8431 3587 8441 3580 8465 

HAIL...0.75IN
WIND...60MPH
 
$$

BW

1 follow-up statement

005 
WWUS54 KMRX 041416
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
1016 AM EDT Tue May 4 2021

TNC001-009-093-105-145-041426-
/O.CAN.KMRX.SV.W.0050.000000T0000Z-210504T1430Z/
Loudon TN-Knox TN-Anderson TN-Blount TN-Roane TN-
1016 AM EDT Tue May 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR LOUDON...SOUTHERN KNOX...
SOUTHWESTERN ANDERSON...NORTHWESTERN BLOUNT AND ROANE COUNTIES IS
CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled. However, gusty winds are 
still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 200 PM EDT for
east Tennessee.

LAT...LON 3567 8443 3566 8448 3577 8475 3588 8450
      3600 8442 3605 8434 3608 8436 3595 8379
      3577 8395 3564 8429 3567 8432 3567 8435
      3564 8438 3564 8440
TIME...MOT...LOC 1415Z 282DEG 47KT 3598 8410 3583 8420 3576 8444 

$$

BW

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 8:29 PM EDT	Special Weather Statement	MRX	Greene, Unicoi, Washington	46 min
May 3, 8:47 PM EDT	Special Weather Statement	MRX	Hamblen, Jefferson	43 min
May 4, 3:10 AM EDT	Severe Thunderstorm Warning	MRX	Morgan, Roane	50 min
May 4, 3:53 AM EDT	Severe Thunderstorm Warning	MRX	Anderson, Morgan, Roane	52 min
May 4, 3:56 AM EDT	Special Weather Statement	MRX	Morgan	49 min
May 4, 4:12 AM EDT	Special Weather Statement	MRX	Morgan	48 min
May 4, 4:40 AM EDT	Severe Thunderstorm Warning	MRX	Anderson, Knox	30 min
May 4, 4:45 AM EDT	Special Weather Statement	MRX	Blount	45 min
May 4, 4:57 AM EDT	Areal Flood Advisory	MRX	Anderson, Morgan, Roane	3 hr
May 4, 5:14 AM EDT	Special Weather Statement	MRX	Knox	46 min
May 4, 5:34 AM EDT	Special Weather Statement	MRX	Blount	41 min
May 4, 6:05 AM EDT	Severe Thunderstorm Warning	MRX	Blount, Sevier	30 min
May 4, 6:11 AM EDT	Areal Flood Advisory	MRX	Anderson, Knox	3 hr
May 4, 6:16 AM EDT	Areal Flood Advisory	MRX	Blount	3 hr
May 4, 6:52 AM EDT	Special Weather Statement	MRX	Sevier	53 min
May 4, 7:00 AM EDT	Flash Flood Warning	MRX	Blount, Sevier	3 hr
May 4, 7:24 AM EDT	Areal Flood Advisory	MRX	Scott	3 hr
May 4, 7:58 AM EDT	Special Weather Statement	MRX	Cocke	47 min
May 4, 9:05 AM EDT	Special Weather Statement	MRX	Morgan, Scott	40 min
May 4, 9:18 AM EDT	Special Weather Statement	MRX	Hamilton	27 min
May 4, 9:37 AM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Morgan, Rhea, Roane	38 min
May 4, 9:48 AM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Rhea	27 min
May 4, 9:50 AM EDT	Special Weather Statement	MRX	Anderson, Campbell, Claiborne, Union	40 min
May 4, 9:53 AM EDT	Special Weather Statement	MRX	Hamilton, Marion, Sequatchie	67 min
May 4, 10:18 AM EDT	Special Weather Statement	MRX	McMinn, Meigs	57 min
May 4, 10:24 AM EDT	Special Weather Statement	MRX	Blount, Knox	36 min
May 4, 10:37 AM EDT	Special Weather Statement	MRX	Hamblen	38 min
May 4, 10:41 AM EDT	Severe Thunderstorm Warning	MRX	Blount, Jefferson, Knox, Sevier	34 min
May 4, 10:45 AM EDT	Severe Thunderstorm Warning	MRX	Blount, Monroe	30 min
May 4, 11:10 AM EDT	Severe Thunderstorm Warning	MRX	Cocke, Jefferson, Sevier	22 min
May 4, 11:11 AM EDT	Flash Flood Warning	MRX	Hamilton, Marion, Sequatchie	3 hr
May 4, 11:29 AM EDT	Areal Flood Warning	MRX	Blount, Sevier	6 hr
May 4, 11:44 AM EDT	Areal Flood Advisory	MRX	Blount, Monroe	2 hr
May 4, 11:47 AM EDT	Areal Flood Advisory	MRX	Blount, Sevier	118 min
May 4, 12:06 PM EDT	Special Weather Statement	MRX	Polk	24 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.