Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 12, NWS Morristown, TN

March 27, 2021Grainger County, Knox County, Union County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Mar 27, 2021, 9:18 AM EDT for Grainger County, Knox County, Union County, Tennessee. It was in force for 42 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: Mar 27, 2021, 9:18 AM EDT (13:18 UTC)
Expired: Mar 27, 2021, 10:00 AM EDT
In force: 42 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Grainger County, TN, Knox County, TN, Union County, TN

The radar

The Knoxville radar (KMRX), 25 km from the middle of the area, began a volume at 13:19 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
Mar 27, 9:23 AM EDT	HAIL 0.75	Halls, TN	REPORT FROM MPING: DIME (0.75 IN.).
Mar 27, 9:28 AM EDT	HAIL 0.5	3 Nw Maloneyville, TN

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, 1.3 hours before the alert went out and 263 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 710 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 347 m²/s²
0-3 km storm-relative helicity: 316 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

713 
WUUS54 KMRX 271318
SVRMRX
TNC057-093-173-271400-
/O.NEW.KMRX.SV.W.0012.210327T1318Z-210327T1400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
918 AM EDT Sat Mar 27 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Northeastern Knox County in east Tennessee...
  Southwestern Grainger County in east Tennessee...
  Southeastern Union County in east Tennessee...

* Until 1000 AM EDT.

* At 918 AM EDT, a severe thunderstorm was located 8 miles east of
  Clinton, moving northeast at 40 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Knoxville, Maynardville, Plainview, Halls, Blaine, Luttrell, Rose
  Hill, Paulette, House Mountain State Park and Maloneyville.

This includes Interstate 75 in Tennessee between mile markers 109 and
118.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3636 8368 3616 8352 3619 8356 3617 8356
      3617 8358 3615 8359 3616 8360 3613 8361
      3615 8364 3613 8364 3612 8363 3612 8367
      3611 8367 3600 8398 3610 8406 3636 8375
      3634 8373 3636 8370
TIME...MOT...LOC 1318Z 238DEG 35KT 3610 8397 

HAIL...1.00IN
WIND...<50MPH
 
$$

DGS

2 follow-up statements

308 
WWUS54 KMRX 271331
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
931 AM EDT Sat Mar 27 2021

TNC057-093-173-271400-
/O.CON.KMRX.SV.W.0012.000000T0000Z-210327T1400Z/
Knox TN-Grainger TN-Union TN-
931 AM EDT Sat Mar 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 AM EDT
FOR NORTHEASTERN KNOX...SOUTHWESTERN GRAINGER AND SOUTHEASTERN UNION
COUNTIES...

At 931 AM EDT, a severe thunderstorm was located over Plainview, or
near Maynardville, moving northeast at 40 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Knoxville, Maynardville, Plainview, Halls, Blaine, Luttrell, Rose
Hill, Paulette, House Mountain State Park and Maloneyville.

This includes Interstate 75 in Tennessee between mile markers 109 and
118.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 3636 8368 3616 8352 3619 8356 3617 8356
      3617 8358 3615 8359 3616 8360 3613 8361
      3615 8364 3613 8364 3612 8363 3612 8367
      3611 8367 3600 8398 3610 8406 3636 8375
      3634 8373 3636 8370
TIME...MOT...LOC 1331Z 243DEG 36KT 3615 8381 

HAIL...1.00IN
WIND...<50MPH
 
$$

DGS

855 
WWUS54 KMRX 271341
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
941 AM EDT Sat Mar 27 2021

TNC093-271351-
/O.CAN.KMRX.SV.W.0012.000000T0000Z-210327T1400Z/
Knox TN-
941 AM EDT Sat Mar 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KNOX 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 3616 8352 3619 8356 3617 8356 3617 8358
      3616 8359 3616 8360 3613 8361 3615 8364
      3612 8363 3612 8367 3611 8367 3611 8369
      3617 8374 3617 8381 3626 8385 3636 8375
      3634 8373 3636 8368
TIME...MOT...LOC 1341Z 238DEG 35KT 3620 8370 

$$

TNC057-173-271400-
/O.CON.KMRX.SV.W.0012.000000T0000Z-210327T1400Z/
Grainger TN-Union TN-
941 AM EDT Sat Mar 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 AM EDT
FOR SOUTHWESTERN GRAINGER AND SOUTHEASTERN UNION COUNTIES...

At 941 AM EDT, a severe thunderstorm was located near Plainview, or
near Maynardville, moving northeast at 40 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Maynardville, Plainview, Blaine, Luttrell, Joppa, Rose Hill and
Buffalo Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 3616 8352 3619 8356 3617 8356 3617 8358
      3616 8359 3616 8360 3613 8361 3615 8364
      3612 8363 3612 8367 3611 8367 3611 8369
      3617 8374 3617 8381 3626 8385 3636 8375
      3634 8373 3636 8368
TIME...MOT...LOC 1341Z 238DEG 35KT 3620 8370 

HAIL...1.00IN
WIND...<50MPH
 
$$

DGS

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 27, 5:03 AM EDT	Special Weather Statement	MRX	Marion, Sequatchie	42 min
Mar 27, 5:23 AM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Hamilton, Marion, Sequatchie	39 min
Mar 27, 5:47 AM EDT	Special Weather Statement	MRX	Hamilton	43 min
Mar 27, 6:08 AM EDT	Severe Thunderstorm Warning	MRX	Bradley, Hamilton	52 min
Mar 27, 6:41 AM EDT	Severe Thunderstorm Warning	MRX	Bradley, Polk	49 min
Mar 27, 7:46 AM EDT	Special Weather Statement	MRX	Roane	44 min
Mar 27, 7:58 AM EDT	Severe Thunderstorm Warning	MRX	Morgan	47 min
Mar 27, 8:27 AM EDT	Special Weather Statement	MRX	Scott	48 min
Mar 27, 8:37 AM EDT	Special Weather Statement	MRX	Knox	38 min
Mar 27, 8:42 AM EDT	Severe Thunderstorm Warning	MRX	Scott	26 min
Mar 27, 8:58 AM EDT	Special Weather Statement	MRX	Knox, Loudon	47 min
Mar 27, 9:39 AM EDT	Severe Thunderstorm Warning	MRX	Knox, Sevier	30 min
Mar 27, 9:43 AM EDT	Severe Thunderstorm Warning	MRX	Claiborne, Grainger, Hancock, Hawkins	47 min
Mar 27, 10:00 AM EDT	Severe Thunderstorm Warning	MRX	Cocke, Hamblen, Jefferson	45 min
Mar 27, 10:06 AM EDT	Severe Thunderstorm Warning	MRX	Campbell, Scott	54 min
Mar 27, 10:14 AM EDT	Special Weather Statement	MRX	Anderson, Campbell, Morgan, Scott	46 min
Mar 27, 10:30 AM EDT	Special Weather Statement	MRX	Hawkins	45 min
Mar 27, 10:33 AM EDT	Severe Thunderstorm Warning	MRX	Greene	42 min
Mar 27, 10:33 AM EDT	Severe Thunderstorm Warning	MRX	Campbell, Claiborne	42 min
Mar 27, 10:36 AM EDT	Flash Flood Warning	MRX	Morgan, Scott	4 hr
Mar 27, 10:41 AM EDT	Severe Thunderstorm Warning	MRX	Hawkins	49 min
Mar 27, 10:51 AM EDT	Special Weather Statement	MRX	Anderson, Morgan	39 min
Mar 27, 11:00 AM EDT	Special Weather Statement	MRX	Claiborne	45 min
Mar 27, 11:07 AM EDT	Severe Thunderstorm Warning	MRX	Sullivan	38 min
Mar 27, 11:11 AM EDT	Severe Thunderstorm Warning	MRX	Unicoi, Washington	35 min
Mar 27, 11:20 AM EDT	Special Weather Statement	MRX	Grainger, Hamblen, Union	40 min
Mar 27, 11:30 AM EDT	Severe Thunderstorm Warning	MRX	Claiborne, Hancock	22 min
Mar 27, 11:32 AM EDT	Severe Thunderstorm Warning	MRX	Carter, Johnson, Sullivan, Unicoi, Washington	43 min
Mar 27, 11:45 AM EDT	Areal Flood Advisory	MRX	Hawkins, Sullivan	3 hr
Mar 27, 11:46 AM EDT	Special Weather Statement	MRX	Hamblen, Jefferson	44 min
Mar 27, 11:48 AM EDT	Areal Flood Advisory	MRX	Campbell, Claiborne	3 hr
Mar 27, 11:50 AM EDT	Areal Flood Advisory	MRX	Carter, Greene, Washington	3 hr
Mar 27, 11:56 AM EDT	Special Weather Statement	MRX	Monroe	49 min
Mar 27, 12:07 PM EDT	Areal Flood Advisory	MRX	Anderson, Knox	3 hr
Mar 27, 12:12 PM EDT	Areal Flood Advisory	MRX	Claiborne, Hancock	3 hr
Mar 27, 12:17 PM EDT	Special Weather Statement	MRX	Johnson	43 min
Mar 27, 12:23 PM EDT	Special Weather Statement	MRX	Hawkins	52 min
Mar 27, 1:01 PM EDT	Severe Thunderstorm Warning	MRX	Carter, Johnson, Sullivan, Unicoi, Washington	44 min
Mar 27, 3:13 PM EDT	Wind Advisory	MRX	Blount, Carter, Cocke, Greene, Johnson, Monroe and 2 more	23 hr
Mar 27, 3:34 PM EDT	Special Weather Statement	MRX	Campbell, Morgan	41 min
Mar 27, 5:05 PM EDT	Areal Flood Warning	MRX	Anderson, Campbell, Claiborne, Morgan, Scott, Union	3 hr
Mar 27, 5:38 PM EDT	Areal Flood Warning	MRX	Claiborne, Grainger, Hancock, Hawkins, Union	3 hr
Mar 27, 5:49 PM EDT	Special Weather Statement	MRX	Anderson, Morgan	41 min
Mar 27, 6:13 PM EDT	Areal Flood Warning	MRX	Blount, Sevier	3 hr
Mar 27, 6:59 PM EDT	Special Weather Statement	MRX	Morgan, Scott	46 min
Mar 27, 7:02 PM EDT	Special Weather Statement	MRX	Marion, Sequatchie	43 min
Mar 27, 7:15 PM EDT	Severe Thunderstorm Warning	MRX	Campbell, Scott	45 min
Mar 27, 7:34 PM EDT	Special Weather Statement	MRX	Hancock	41 min
Mar 27, 7:36 PM EDT	Special Weather Statement	MRX	Meigs	39 min
Mar 27, 7:40 PM EDT	Special Weather Statement	MRX	Campbell, Scott	50 min
Mar 27, 7:43 PM EDT	Severe Thunderstorm Warning	MRX	Marion	47 min
Mar 27, 7:52 PM EDT	Special Weather Statement	MRX	Campbell	53 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.