Alert archive / Tennessee / Freeze Warnings in 2018

Freeze Warning 1, NWS Morristown, TN

March 21, 201831 counties in Tennessee

NWS Morristown, TN issued this freeze warning at Mar 21, 2018, 3:40 AM EDT for 31 counties in Tennessee. It took effect at Mar 22, 2018, 2:00 AM EDT. It was in force for 8 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: Mar 21, 2018, 3:40 AM EDT (07:40 UTC)
In effect from: Mar 22, 2018, 2:00 AM EDT
Expired: Mar 22, 2018, 10:00 AM EDT
In force: 8 hr
Issued by: NWS Morristown, TN

All 31 counties

Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Sullivan County, TN, Union County, TN, Washington County, TN

The radar

The Knoxville radar (KMRX), 61 km from the middle of the area, began a volume at 07:41 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, 7.7 hours before the alert went out and 235 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: 701 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 46 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 Mar 21, 1:17 AM EDT, 2 hours 23 minutes earlier.

Area forecast discussion, Mar 21, 1:17 AM EDT, 2 hours 23 minutes before

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Hazardous weather outlook, Mar 21, 3:25 AM EDT, 15 minutes before

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Nearby

Freeze Warnings in Tennessee, 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.