Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 103, NWS Morristown, TN
NWS Morristown, TN issued this severe thunderstorm warning at Aug 9, 2021, 7:55 PM EDT for Grainger County, Knox County, Union County, Tennessee. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 9, 2021, 7:55 PM EDT (23:55 UTC)
- Expired
- Aug 9, 2021, 8:34 PM EDT
- In force
- 39 min
- Issued by
- NWS Morristown, TN
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Grainger County, TN, Knox County, TN, Union County, TN
The radar
The Knoxville radar (KMRX), 33 km from the middle of the area, began a volume at 23:57 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.
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 12:00Z, 11.9 hours before the alert went out and 255 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.
- Mixed-layer CAPE
- 788 J/kg
- Mixed-layer CIN
- -39 J/kg
- Mixed-layer LCL
- 892 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 120 m²/s²
- 0-3 km storm-relative helicity
- 131 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
778
WUUS54 KMRX 092355
SVRMRX
TNC057-093-173-100045-
/O.NEW.KMRX.SV.W.0103.210809T2355Z-210810T0045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
755 PM EDT Mon Aug 9 2021
The National Weather Service in Morristown has issued a
* Severe Thunderstorm Warning for...
Northeastern Knox County in east Tennessee...
Southwestern Union County in east Tennessee...
Southwestern Grainger County in east Tennessee...
* Until 845 PM EDT.
* At 754 PM EDT, a severe thunderstorm was located 9 miles east of
Clinton, moving east at 25 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, Plainview, Halls, Blaine, House Mountain State Park,
Maloneyville, Mascot and Paulette.
This includes the following highways...
Interstate 40 in Tennessee between mile markers 392 and 404.
Interstate 75 in Tennessee between mile markers 112 and 117.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3607 8406 3612 8403 3619 8394 3620 8396
3621 8396 3617 8360 3613 8361 3614 8364
3612 8363 3610 8363 3610 8365 3612 8365
3612 8367 3609 8366 3609 8371 3606 8369
3605 8367 3600 8366 3594 8369 3594 8371
TIME...MOT...LOC 2354Z 280DEG 22KT 3611 8396
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Diegan2 follow-up statements
624
WWUS54 KMRX 100013
SVSMRX
Severe Weather Statement
National Weather Service Morristown TN
813 PM EDT Mon Aug 9 2021
TNC057-093-173-100045-
/O.CON.KMRX.SV.W.0103.000000T0000Z-210810T0045Z/
Knox TN-Union TN-Grainger TN-
813 PM EDT Mon Aug 9 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR NORTHEASTERN KNOX...SOUTH CENTRAL UNION AND SOUTHWESTERN GRAINGER
COUNTIES...
At 813 PM EDT, a severe thunderstorm was located near Plainview, or
10 miles south of Maynardville, moving east at 25 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Knoxville, Plainview, Blaine, Maloneyville, House Mountain State Park
and Mascot.
This includes Interstate 40 in Tennessee between mile markers 395 and
404.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3605 8394 3611 8391 3620 8387 3617 8360
3613 8361 3614 8364 3612 8363 3610 8363
3610 8365 3612 8365 3612 8367 3609 8366
3609 8371 3606 8369 3605 8367 3600 8366
3595 8369
TIME...MOT...LOC 0013Z 280DEG 22KT 3609 8382
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Diegan963
WWUS54 KMRX 100034
SVSMRX
Severe Weather Statement
National Weather Service Morristown TN
834 PM EDT Mon Aug 9 2021
TNC057-093-173-100044-
/O.CAN.KMRX.SV.W.0103.000000T0000Z-210810T0045Z/
Knox TN-Union TN-Grainger TN-
834 PM EDT Mon Aug 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KNOX...SOUTH
CENTRAL UNION AND SOUTHWESTERN GRAINGER COUNTIES IS CANCELLED...
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 has been cancelled.
LAT...LON 3605 8394 3611 8391 3620 8387 3617 8360
3613 8361 3614 8364 3612 8363 3610 8363
3610 8365 3612 8365 3612 8367 3609 8366
3609 8371 3606 8369 3605 8367 3600 8366
3595 8369
TIME...MOT...LOC 0030Z 280DEG 22KT 3607 8366
$$
DieganThe office that day
Everything else NWS Morristown, TN issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 2:24 PM EDT | Special Weather Statement | MRX | Bradley | 36 min |
| Aug 9, 3:17 PM EDT | Special Weather Statement | MRX | Scott | 43 min |
| Aug 9, 5:29 PM EDT | Special Weather Statement | MRX | Scott | 46 min |
| Aug 9, 5:48 PM EDT | Severe Thunderstorm Warning | MRX | Scott | 42 min |
| Aug 9, 5:49 PM EDT | Severe Thunderstorm Warning | MRX | Morgan, Scott | 41 min |
| Aug 9, 6:07 PM EDT | Areal Flood Advisory | MRX | Morgan | 3 hr |
| Aug 9, 7:13 PM EDT | Special Weather Statement | MRX | Anderson | 47 min |
Nearby
Severe Thunderstorm Warnings in Tennessee, 2021Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.