Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 56, NWS Morristown, TN

May 28, 20214 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at May 28, 2021, 3:58 PM EDT for 4 counties in Tennessee. It was in force for 47 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 28, 2021, 3:58 PM EDT (19:58 UTC)
Expired: May 28, 2021, 4:45 PM EDT
In force: 47 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Anderson County, TN, Knox County, TN, Morgan County, TN, Roane County, TN

The radar

The Knoxville radar (KMRX), 71 km from the middle of the area, began a volume at 19:59 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 28, 4:11 PM EDT	TSTM WND DMG	3 Wnw Clinton, TN	TREES DOWN IN THE AREA, AND SOME POWER OUTAGES.

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, 8.0 hours before the alert went out and 217 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: 204 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 749 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 182 m²/s²
0-3 km storm-relative helicity: 138 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted.

881 
WUUS54 KMRX 281958
SVRMRX
TNC001-093-129-145-282045-
/O.NEW.KMRX.SV.W.0056.210528T1958Z-210528T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
358 PM EDT Fri May 28 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  East central Morgan County in east Tennessee...
  Central Knox County in east Tennessee...
  Anderson County in east Tennessee...
  Northeastern Roane County in east Tennessee...

* Until 445 PM EDT.

* At 357 PM EDT, a severe thunderstorm was located over Oliver
  Springs, or near Oak Ridge, moving east at 40 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Knoxville, Oak Ridge, Clinton, Oliver Springs, Halls, Norris,
  Coalfield, Powell, Karns and Andersonville.

This includes the following highways...
 Interstate 40 in Tennessee between mile markers 384 and 391.
 Interstate 75 in Tennessee between mile markers 108 and 123.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3609 8446 3621 8397 3619 8394 3596 8386
      3591 8442
TIME...MOT...LOC 1957Z 257DEG 37KT 3602 8434 

HAIL...0.88IN
WIND...60MPH
 
$$

SR

1 follow-up statement

513 
WWUS54 KMRX 282016
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
416 PM EDT Fri May 28 2021

TNC129-145-282026-
/O.CAN.KMRX.SV.W.0056.000000T0000Z-210528T2045Z/
Morgan TN-Roane TN-
416 PM EDT Fri May 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MORGAN AND
NORTHEASTERN ROANE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3615 8421 3621 8397 3619 8394 3599 8387
      3598 8418
TIME...MOT...LOC 2016Z 257DEG 37KT 3606 8410 

$$

TNC001-093-282045-
/O.CON.KMRX.SV.W.0056.000000T0000Z-210528T2045Z/
Knox TN-Anderson TN-
416 PM EDT Fri May 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR NORTHWESTERN KNOX AND SOUTHEASTERN ANDERSON COUNTIES...

At 416 PM EDT, a severe thunderstorm was located over Clinton, moving
east at 45 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, Clinton, Halls, Norris, Powell and
Andersonville.

This includes the following highways...
 Interstate 40 in Tennessee between mile markers 390 and 391.
 Interstate 75 in Tennessee between mile markers 108 and 123.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3615 8421 3621 8397 3619 8394 3599 8387
      3598 8418
TIME...MOT...LOC 2016Z 257DEG 37KT 3606 8410 

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

JLB

The office that day

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

Issued	Product	Office	Counties	Lasted
May 28, 2:44 PM EDT	Special Weather Statement	MRX	Hancock, Hawkins	46 min
May 28, 2:58 PM EDT	Areal Flood Advisory	MRX	Campbell, Morgan, Scott	3 hr
May 28, 3:00 PM EDT	Special Weather Statement	MRX	Grainger	45 min
May 28, 3:08 PM EDT	Special Weather Statement	MRX	Sullivan	37 min
May 28, 3:33 PM EDT	Special Weather Statement	MRX	Campbell, Morgan, Roane, Scott	42 min
May 28, 3:54 PM EDT	Special Weather Statement	MRX	Loudon	36 min
May 28, 4:13 PM EDT	Special Weather Statement	MRX	Anderson, Claiborne, Grainger, Knox, Union	47 min
May 28, 4:18 PM EDT	Special Weather Statement	MRX	Monroe	42 min
May 28, 4:32 PM EDT	Severe Thunderstorm Warning	MRX	Grainger, Jefferson, Knox, Union	43 min
May 28, 4:56 PM EDT	Special Weather Statement	MRX	Grainger, Hamblen, Jefferson	49 min
May 28, 5:02 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Grainger, Greene, Hamblen, Hawkins, Jefferson	43 min
May 28, 5:18 PM EDT	Special Weather Statement	MRX	Greene, Hamblen, Hancock, Hawkins, Jefferson	42 min
May 28, 5:35 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Hawkins	40 min
May 28, 5:40 PM EDT	Special Weather Statement	MRX	Monroe, Polk	65 min
May 28, 5:58 PM EDT	Special Weather Statement	MRX	Carter, Sullivan, Washington	62 min
May 28, 6:42 PM EDT	Special Weather Statement	MRX	Carter, Johnson	48 min
May 28, 6:46 PM EDT	Severe Thunderstorm Warning	MRX	Carter, Johnson	29 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.