Alert archive / Tennessee / Winter Weather Advisories in 2021

Winter Weather Advisory 9, NWS Morristown, TN

February 12, 20216 counties in Tennessee; Wise County, City of Norton, Virginia

NWS Morristown, TN issued this winter weather advisory at Feb 12, 2021, 1:47 PM CST for 6 counties in Tennessee; Wise County, City of Norton, Virginia. It took effect at Feb 12, 2021, 11:00 PM CST. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued: Feb 12, 2021, 1:47 PM CST (19:47 UTC)
In effect from: Feb 12, 2021, 11:00 PM CST
Expired: Feb 13, 2021, 9:00 AM CST
In force: 10 hr
Issued by: NWS Morristown, TN

Counties Bledsoe County, TN, Campbell County, TN, Marion County, TN, Morgan County, TN, Scott County, TN, Sequatchie County, TN, City of Norton, VA, Wise County, VA

The radar

The Knoxville radar (KMRX), 85 km from the middle of the area, began a volume at 19:49 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, 7.8 hours before the alert went out and 202 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: 4 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 433 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -54 m²/s²
0-3 km storm-relative helicity: 18 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 winter weather advisory 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 winter weather advisory went out at Feb 12, 11:23 AM CST, 2 hours 24 minutes earlier.

Area forecast discussion, Feb 12, 11:23 AM CST, 2 hours 24 minutes before

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Hazardous weather outlook, Feb 12, 9:06 AM CST, 4 hours 41 minutes before

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      <h1 id="headline">This service is currently unavailable.</h1>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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        Please try again in a few minutes.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 12, 2:36 AM CST	Winter Weather Advisory	MRX	Russell, Wise, City of Norton	6 hr

Nearby

Winter Weather Advisories in Tennessee, 2021 Winter Weather Advisories in Virginia, 2021 Every winter weather advisory 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.