Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 131, NWS Morristown, TN
NWS Morristown, TN issued this severe thunderstorm warning at Aug 15, 2021, 4:27 PM EDT for Anderson County, Knox County, Union County, Tennessee. It was in force for 33 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
- Aug 15, 2021, 4:27 PM EDT (20:27 UTC)
- Expired
- Aug 15, 2021, 5:00 PM EDT
- In force
- 33 min
- Issued by
- NWS Morristown, TN
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Anderson County, TN, Knox County, TN, Union County, TN
The radar
The Knoxville radar (KMRX), 52 km from the middle of the area, began a volume at 20:31 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 |
|---|---|---|---|
| Aug 15, 4:30 PM EDT | TSTM WND DMG | Powell, TN | TIME ESTIMATED BY RADAR. AWNING ON HOME DAMAGED AND TOSSED ONTO ROOF. |
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, 8.5 hours before the alert went out and 235 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
- 152 J/kg
- Mixed-layer CIN
- -98 J/kg
- Mixed-layer LCL
- 697 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 23 m²/s²
- 0-3 km storm-relative helicity
- 36 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
685 WUUS54 KMRX 152027 SVRMRX TNC001-093-173-152100- /O.NEW.KMRX.SV.W.0131.210815T2027Z-210815T2100Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Morristown TN 427 PM EDT Sun Aug 15 2021 The National Weather Service in Morristown has issued a * Severe Thunderstorm Warning for... North central Knox County in east Tennessee... Northeastern Anderson County in east Tennessee... Southwestern Union County in east Tennessee... * Until 500 PM EDT. * At 427 PM EDT, a severe thunderstorm was located 8 miles east of Clinton, moving north at 10 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, Clinton, Halls, Rocky Top, Norris, Andersonville, Powell, Paulette, Norris Dam State Park and Big Ridge State Park. This includes Interstate 75 in Tennessee between mile markers 110 and 127. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3624 8388 3602 8391 3601 8406 3622 8418 TIME...MOT...LOC 2027Z 173DEG 11KT 3609 8398 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...0.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ JLB
2 follow-up statements
095 WWUS54 KMRX 152044 SVSMRX Severe Weather Statement National Weather Service Morristown TN 444 PM EDT Sun Aug 15 2021 TNC001-093-173-152100- /O.CON.KMRX.SV.W.0131.000000T0000Z-210815T2100Z/ Knox TN-Anderson TN-Union TN- 444 PM EDT Sun Aug 15 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT FOR NORTH CENTRAL KNOX...NORTHEASTERN ANDERSON AND SOUTHWESTERN UNION COUNTIES... At 443 PM EDT, a severe thunderstorm was located 8 miles east of Clinton, moving north at 15 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... Clinton, Rocky Top, Norris, Andersonville, Paulette, Norris Dam State Park and Big Ridge State Park. This includes Interstate 75 in Tennessee between mile markers 115 and 127. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3624 8388 3610 8390 3607 8405 3622 8415 TIME...MOT...LOC 2043Z 173DEG 11KT 3614 8399 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ JLB
838
WWUS54 KMRX 152055
SVSMRX
Severe Weather Statement
National Weather Service Morristown TN
455 PM EDT Sun Aug 15 2021
TNC001-093-173-152105-
/O.EXP.KMRX.SV.W.0131.000000T0000Z-210815T2100Z/
Knox TN-Anderson TN-Union TN-
455 PM EDT Sun Aug 15 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL KNOX...
NORTHEASTERN ANDERSON AND SOUTHWESTERN UNION COUNTIES WILL EXPIRE AT
500 PM EDT...
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 will be allowed to expire. However gusty
winds and heavy rain are still possible with this thunderstorm.
LAT...LON 3624 8388 3610 8390 3607 8405 3622 8415
TIME...MOT...LOC 2055Z 173DEG 11KT 3616 8399
$$
JLBThe office that day
Everything else NWS Morristown, TN issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 14, 8:13 PM EDT | Severe Thunderstorm Warning | MRX | Knox | 32 min |
| Aug 14, 8:25 PM EDT | Special Weather Statement | MRX | Jefferson | 50 min |
| Aug 14, 8:33 PM EDT | Special Weather Statement | MRX | Blount | 42 min |
| Aug 14, 8:35 PM EDT | Areal Flood Advisory | MRX | Knox | 3 hr |
| Aug 14, 8:36 PM EDT | Flash Flood Warning | MRX | Monroe | 3 hr |
| Aug 14, 8:42 PM EDT | Severe Thunderstorm Warning | MRX | Knox | 33 min |
| Aug 14, 8:49 PM EDT | Areal Flood Advisory | MRX | McMinn, Monroe, Polk | 3 hr |
| Aug 14, 8:49 PM EDT | Severe Thunderstorm Warning | MRX | Blount | 41 min |
| Aug 14, 8:59 PM EDT | Areal Flood Advisory | MRX | Blount | 3 hr |
| Aug 14, 9:12 PM EDT | Special Weather Statement | MRX | Knox | 48 min |
| Aug 14, 11:24 PM EDT | Areal Flood Advisory | MRX | Anderson, Campbell, Claiborne, Union | 3 hr |
| Aug 15, 3:34 PM EDT | Special Weather Statement | MRX | Knox | 26 min |
| Aug 15, 4:09 PM EDT | Special Weather Statement | MRX | Knox | 36 min |
| Aug 15, 4:35 PM EDT | Special Weather Statement | MRX | Meigs, Rhea | 25 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.