Alert archive / Tennessee / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 115, NWS Morristown, TN

July 21, 2020Campbell County, Scott County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Jul 21, 2020, 8:45 PM EDT for Campbell County, Scott County, Tennessee. It was in force for 45 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 21, 2020, 8:45 PM EDT (00:45 UTC)
Expired: Jul 21, 2020, 9:30 PM EDT
In force: 45 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Campbell County, TN, Scott County, TN

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 00:00Z, 0.8 hours before the alert went out and 206 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: 669 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 1684 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Morristown, TN wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 7:39 PM EDT, 1 hour 6 minutes earlier.

Area forecast discussion, Jul 21, 7:39 PM EDT, 1 hour 6 minutes before

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Hazardous weather outlook, Jul 21, 3:15 AM EDT, 17 hours 30 minutes before

Hazardous Weather Outlook
National Weather Service Morristown TN
315 AM EDT Tue Jul 21 2020

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-220715-
Cherokee-Clay-Scott-Campbell-Claiborne-Hancock-Hawkins-Sullivan-
Johnson-Morgan-Anderson-Union-Grainger-Hamblen-Northwest Cocke-
Cocke Smoky Mountains-Northwest Greene-Southeast Greene-
Washington-Unicoi-Northwest Carter-Southeast Carter-Roane-Loudon-
Knox-Jefferson-Northwest Blount-Blount Smoky Mountains-
North Sevier-Sevier Smoky Mountains-Sequatchie-Bledsoe-Rhea-Meigs-
McMinn-Northwest Monroe-Southeast Monroe-Marion-Hamilton-Bradley-
West Polk-East Polk-Lee-Wise-Russell-
315 AM EDT Tue Jul 21 2020 /215 AM CDT Tue Jul 21 2020/

This Hazardous Weather Outlook is for portions of southwest North
Carolina...east Tennessee and southwest Virginia.

.DAY ONE...Today and Tonight

Scattered to numerous thunderstorms are in the forecast today, a
few of which could produce damaging winds and brief heavy rainfall.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Scattered thunderstorms are expected Wednesday through Friday
with a strong to marginally severe storm or two possible on
Wednesday and Thursday. Localized flash flooding and isolated
damaging wind gusts are the main threats, especially north of
I-40.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not needed at this time.

In the hours before

Local storm report, Jul 21, 5:09 PM EDT, 3 hours 36 minutes before

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Special weather statement, Jul 21, 5:18 PM EDT, 3 hours 27 minutes before

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Special weather statement, Jul 21, 7:52 PM EDT, 53 minutes before

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Special weather statement, Jul 21, 8:05 PM EDT, 40 minutes before

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Special weather statement, Jul 21, 8:29 PM EDT, 16 minutes before

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Special weather statement, Jul 21, 8:42 PM EDT, 3 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 8:05 PM EDT	Special Weather Statement	MRX	Scott	40 min
Jul 21, 8:29 PM EDT	Special Weather Statement	MRX	Campbell	46 min
Jul 21, 8:42 PM EDT	Special Weather Statement	MRX	Scott	48 min
Jul 21, 9:23 PM EDT	Areal Flood Advisory	MRX	Campbell, Scott	3 hr
Jul 22, 1:16 PM EDT	Special Weather Statement	MRX	Rhea	29 min
Jul 22, 2:31 PM EDT	Special Weather Statement	MRX	Cocke	29 min
Jul 22, 3:45 PM EDT	Special Weather Statement	MRX	Campbell	30 min
Jul 22, 4:23 PM EDT	Special Weather Statement	MRX	Washington	52 min
Jul 22, 4:48 PM EDT	Special Weather Statement	MRX	Sullivan	42 min
Jul 22, 5:11 PM EDT	Special Weather Statement	MRX	McMinn	49 min
Jul 22, 6:03 PM EDT	Special Weather Statement	MRX	Loudon	42 min
Jul 22, 6:47 PM EDT	Special Weather Statement	MRX	Knox, Union	43 min
Jul 22, 7:11 PM EDT	Areal Flood Advisory	MRX	Knox	3 hr
Jul 22, 7:46 PM EDT	Special Weather Statement	MRX	Hamblen	44 min
Jul 22, 7:47 PM EDT	Special Weather Statement	MRX	Hamblen	43 min
Jul 21, 10:34 PM EDT	Special Weather Statement	MRX	Lee	41 min
Jul 22, 5:27 PM EDT	Special Weather Statement	MRX	City of Bristol	48 min
Jul 22, 6:06 PM EDT	Special Weather Statement	MRX	Russell	39 min
Jul 22, 6:26 PM EDT	Special Weather Statement	MRX	Russell	34 min
Jul 22, 7:04 PM EDT	Special Weather Statement	MRX	Russell	26 min
Jul 22, 3:16 PM EDT	Special Weather Statement	MRX	Cherokee	44 min
Jul 22, 3:49 PM EDT	Special Weather Statement	MRX	Clay	26 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2020 Every severe thunderstorm warning in 2020

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.