Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 51, NWS Morristown, TN

May 4, 20214 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at May 4, 2021, 10:41 AM EDT for 4 counties in Tennessee. It was in force for 34 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: May 4, 2021, 10:41 AM EDT (14:41 UTC)
Expired: May 4, 2021, 11:15 AM EDT
In force: 34 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

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

The radar

The Knoxville radar (KMRX), 56 km from the middle of the area, began a volume at 14:42 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, 10:55 AM EDT	TSTM WND DMG	1 Nnw Happy Valley, TN	TREES DOWN ALONG THE FOOTHILLS PARKWAY.
May 4, 11:00 AM EDT	TSTM WND DMG	Sevierville, TN	SEVERAL TREES DOWN IN THE SEVIERVILLE AREA.

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, 2.7 hours before the alert went out and 273 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.

693 
WUUS54 KMRX 041441
SVRMRX
TNC009-089-093-155-041515-
/O.NEW.KMRX.SV.W.0051.210504T1441Z-210504T1515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
1041 AM EDT Tue May 4 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Southeastern Knox County in east Tennessee...
  Eastern Blount County in east Tennessee...
  Southwestern Jefferson County in east Tennessee...
  Sevier County in east Tennessee...

* Until 1115 AM EDT.

* At 1041 AM EDT, severe thunderstorms were located along a line
  extending from 8 miles northeast of Knoxville to 7 miles east of
  Rockford to near Eagleton Village to 7 miles south of Maryville,
  moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Knoxville, Sevierville, Gatlinburg, Dandridge, Pigeon Forge, Smoky
  Mountains-Fontana Area, Townsend, Walland, Kimberlin Heights and
  Wildwood.

This includes Interstate 40 in Tennessee between mile markers 392 and
417.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3564 8404 3577 8390 3587 8387 3606 8388
      3605 8344 3583 8342 3569 8349 3557 8367
      3556 8376 3555 8378
TIME...MOT...LOC 1441Z 280DEG 36KT 3604 8382 3587 8381 3575 8387 3564
8401

HAIL...<.75IN
WIND...60MPH
 
$$

CED

1 follow-up statement

878 
WWUS54 KMRX 041457
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
1057 AM EDT Tue May 4 2021

TNC093-041506-
/O.CAN.KMRX.SV.W.0051.000000T0000Z-210504T1515Z/
Knox TN-
1057 AM EDT Tue May 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN KNOX COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 3558 8387 3573 8376 3584 8370 3594 8370
      3594 8368 3595 8369 3597 8365 3599 8365
      3600 8367 3605 8368 3605 8344 3583 8342
      3569 8349 3557 8367 3556 8376 3555 8378
TIME...MOT...LOC 1456Z 280DEG 36KT 3602 8366 3585 8365 3573 8371 3562
8385

$$

TNC009-089-155-041515-
/O.CON.KMRX.SV.W.0051.000000T0000Z-210504T1515Z/
Blount TN-Jefferson TN-Sevier TN-
1057 AM EDT Tue May 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 AM EDT
FOR SOUTHEASTERN BLOUNT...SOUTHWESTERN JEFFERSON AND CENTRAL SEVIER
COUNTIES...

At 1056 AM EDT, severe thunderstorms were located along a line
extending from 8 miles southwest of New Market to near Sevierville to
9 miles southwest of Pigeon Forge to 8 miles north of Smoky
Mountains-Twentymile Creek, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Sevierville, Gatlinburg, Dandridge, Pigeon Forge, Smoky
Mountains-Fontana Area, Townsend, McMahan, Wears Valley, Cades Cove
and Harrisburg.

This includes Interstate 40 in Tennessee between mile markers 406 and
417.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3558 8387 3573 8376 3584 8370 3594 8370
      3594 8368 3595 8369 3597 8365 3599 8365
      3600 8367 3605 8368 3605 8344 3583 8342
      3569 8349 3557 8367 3556 8376 3555 8378
TIME...MOT...LOC 1456Z 280DEG 36KT 3602 8366 3585 8365 3573 8371 3562
8385

HAIL...<.75IN
WIND...60MPH
 
$$

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, 10:03 AM EDT	Severe Thunderstorm Warning	MRX	Anderson, Blount, Knox, Loudon, Roane	13 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, 10:45 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.