Alert archive / Tennessee / Freeze Warnings in 2018

Freeze Warning 9, NWS Morristown, TN

October 21, 201821 counties in Tennessee; 7 counties in Virginia; Cherokee County, Clay County, North Carolina

NWS Morristown, TN issued this freeze warning at Oct 21, 2018, 3:35 AM EDT for 21 counties in Tennessee; 7 counties in Virginia; Cherokee County, Clay County, North Carolina. It took effect at Oct 22, 2018, 2:00 AM EDT. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Oct 21, 2018, 3:35 AM EDT (07:35 UTC)
In effect from: Oct 22, 2018, 2:00 AM EDT
Expired: Oct 22, 2018, 9:00 AM EDT
In force: 7 hr
Issued by: NWS Morristown, TN

All 30 counties

Cherokee County, NC, Clay County, NC, Blount County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Scott County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Washington County, TN, City of Bristol, VA, City of Norton, VA, Lee County, VA, Russell County, VA, Scott County, VA, Washington County, VA, Wise County, VA

The radar

The Knoxville radar (KMRX), 20 km from the middle of the area, began a volume at 07:35 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 7.6 hours before the alert went out and 296 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1756 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 99 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 freeze 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 freeze warning went out at Oct 20, 7:40 PM EDT, 7 hours 55 minutes earlier.

Area forecast discussion, Oct 20, 7:40 PM EDT, 7 hours 55 minutes before

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Hazardous weather outlook, Oct 20, 2:56 PM EDT, 12 hours 39 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
Oct 21, 3:35 AM EDT	Frost Advisory	MRX	Anderson, Bledsoe, Blount, Bradley, Hamilton, Knox and 10 more	29 hr

Nearby

Freeze Warnings in Tennessee, 2018 Freeze Warnings in Virginia, 2018 Freeze Warnings in North Carolina, 2018 Every freeze warning in 2018

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.