Alert archive / Tennessee / Special Weather Statements in 2021

Special Weather Statement, NWS Morristown, TN

August 25, 2021Knox County, Tennessee

NWS Morristown, TN issued this special weather statement at Aug 25, 2021, 4:21 PM EDT for Knox County, Tennessee. It was in force for 24 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 25, 2021, 4:21 PM EDT (20:21 UTC)
Expired: Aug 25, 2021, 4:45 PM EDT
In force: 24 min
Issued by: NWS Morristown, TN
Hail: 0.25 in
Wind: 40

County Knox County, TN

The radar

The Knoxville radar (KMRX), 50 km from the middle of the area, began a volume at 20:22 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, 8.4 hours before the alert went out and 250 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: 729 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 1368 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: -27 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

514 
WWUS84 KMRX 252021
SPSMRX

Special Weather Statement
National Weather Service Morristown TN
421 PM EDT Wed Aug 25 2021
 
TNZ069-071-073-252045-
Knox TN-North Sevier TN-NW Blount TN-
421 PM EDT Wed Aug 25 2021

...A strong thunderstorm will impact portions of southeastern Knox
County through 445 PM EDT...

At 421 PM EDT, Doppler radar was tracking a strong thunderstorm near
Rockford, or 7 miles southeast of Knoxville. This storm was nearly
stationary.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

Locations impacted include...
Knoxville, Lake Forest, Seymour and Kimberlin Heights. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3588 8392 3593 8390 3599 8370 3576 8375
TIME...MOT...LOC 2021Z 281DEG 4KT 3589 8385 

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

$$

Garuckas

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 25, 2:18 PM EDT	Special Weather Statement	MRX	Carter	42 min
Aug 25, 2:52 PM EDT	Special Weather Statement	MRX	Morgan	38 min
Aug 25, 3:20 PM EDT	Special Weather Statement	MRX	Sevier	40 min
Aug 25, 3:46 PM EDT	Special Weather Statement	MRX	Sevier	44 min
Aug 25, 4:02 PM EDT	Areal Flood Advisory	MRX	Morgan	3 hr
Aug 25, 4:02 PM EDT	Special Weather Statement	MRX	Knox	43 min
Aug 25, 4:07 PM EDT	Special Weather Statement	MRX	Johnson	38 min
Aug 25, 4:13 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Knox	47 min
Aug 25, 4:20 PM EDT	Areal Flood Advisory	MRX	Johnson	3 hr
Aug 25, 4:32 PM EDT	Areal Flood Advisory	MRX	Knox, Loudon	22 min
Aug 25, 4:49 PM EDT	Flash Flood Warning	MRX	Knox, Loudon	3 hr
Aug 25, 5:01 PM EDT	Special Weather Statement	MRX	Grainger	44 min
Aug 25, 5:08 PM EDT	Special Weather Statement	MRX	Knox	52 min
Aug 25, 5:22 PM EDT	Areal Flood Advisory	MRX	Bledsoe	3 hr
Aug 25, 5:26 PM EDT	Areal Flood Advisory	MRX	Blount	3 hr
Aug 25, 5:31 PM EDT	Areal Flood Advisory	MRX	Sullivan	3 hr
Aug 25, 5:38 PM EDT	Areal Flood Advisory	MRX	Grainger, Jefferson, Knox, Sevier, Union	3 hr
Aug 25, 5:49 PM EDT	Special Weather Statement	MRX	Grainger	41 min
Aug 25, 5:53 PM EDT	Special Weather Statement	MRX	Sullivan	52 min
Aug 25, 6:23 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Hamblen	37 min
Aug 25, 6:27 PM EDT	Special Weather Statement	MRX	Greene	33 min
Aug 25, 6:30 PM EDT	Special Weather Statement	MRX	Sullivan	45 min
Aug 25, 6:33 PM EDT	Special Weather Statement	MRX	McMinn	27 min
Aug 25, 6:38 PM EDT	Special Weather Statement	MRX	Union	37 min
Aug 25, 6:41 PM EDT	Severe Thunderstorm Warning	MRX	Greene	34 min
Aug 25, 6:54 PM EDT	Areal Flood Advisory	MRX	Greene, Hamblen, Hawkins	3 hr
Aug 25, 6:54 PM EDT	Special Weather Statement	MRX	Washington	51 min
Aug 25, 7:01 PM EDT	Areal Flood Advisory	MRX	McMinn	3 hr
Aug 25, 7:03 PM EDT	Areal Flood Advisory	MRX	Claiborne, Grainger, Union	3 hr
Aug 25, 7:05 PM EDT	Areal Flood Advisory	MRX	Sullivan	3 hr
Aug 25, 7:29 PM EDT	Special Weather Statement	MRX	Hawkins	46 min
Aug 25, 7:50 PM EDT	Areal Flood Advisory	MRX	Knox, Loudon	70 min
Aug 25, 6:57 PM EDT	Special Weather Statement	MRX	Wise, City of Norton	48 min

Nearby

Special Weather Statements in Tennessee, 2021 Every special weather statement 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.