Alert archive / Tennessee / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 25, NWS Morristown, TN

March 12, 2020Campbell County, Claiborne County, Tennessee; Lee County, Virginia

NWS Morristown, TN issued this severe thunderstorm warning at Mar 12, 2020, 10:43 PM EDT for Campbell County, Claiborne County, Tennessee; Lee County, Virginia. It was in force for 23 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: Mar 12, 2020, 10:43 PM EDT (02:43 UTC)
Expired: Mar 12, 2020, 11:06 PM EDT
In force: 23 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Tornado: Possible
Hail: 1.0 in
Wind: 60.0 mph

Counties Campbell County, TN, Claiborne County, TN, Lee County, VA

The radar

The Knoxville radar (KMRX), 46 km from the middle of the area, began a volume at 02:46 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 00:00Z, 2.7 hours before the alert went out and 268 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: 130 J/kg
Mixed-layer CIN: -136 J/kg
Mixed-layer LCL: 1005 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 550 m²/s²
0-3 km storm-relative helicity: 879 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.9

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 Mar 12, 7:48 PM EDT, 2 hours 55 minutes earlier.

Area forecast discussion, Mar 12, 7:48 PM EDT, 2 hours 55 minutes before

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Hazardous weather outlook, Mar 12, 3:46 PM EDT, 6 hours 57 minutes before

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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 12, 11:27 PM EDT	Special Weather Statement	MRX	Claiborne, Hancock	48 min
Mar 12, 11:28 PM EDT	Special Weather Statement	MRX	Bledsoe	47 min
Mar 12, 11:53 PM EDT	Areal Flood Advisory	MRX	Campbell, Claiborne, Hancock	2 hr

Nearby

Severe Thunderstorm Warnings in Tennessee, 2020 Severe Thunderstorm Warnings in Virginia, 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; radar from the NEXRAD Level II archive.