Alert archive / Tennessee / Frost Advisories in 2021

Frost Advisory 2, NWS Morristown, TN

April 15, 202114 counties in Tennessee; 7 counties in Virginia

NWS Morristown, TN issued this frost advisory at Apr 15, 2021, 7:03 PM EDT for 14 counties in Tennessee; 7 counties in Virginia. It took effect at Apr 16, 2021, 2:00 AM EDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Apr 15, 2021, 7:03 PM EDT (23:03 UTC)
In effect from
Apr 16, 2021, 2:00 AM EDT
Expired
Apr 16, 2021, 9:00 AM EDT
In force
7 hr
Issued by
NWS Morristown, TN
All 21 counties

Anderson County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Morgan County, TN, Scott County, TN, Sullivan 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), 45 km from the middle of the area, began a volume at 23:07 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 12:00Z, 11.1 hours before the alert went out and 290 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-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2021-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2021-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
730 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
90 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

753 
WWUS74 KMRX 152303
NPWMRX

URGENT - WEATHER MESSAGE
National Weather Service Morristown TN
703 PM EDT Thu Apr 15 2021

TNZ012>017-035>039-042-044-046-VAZ001-002-005-006-008-160815-
/O.NEW.KMRX.FR.Y.0002.210416T0600Z-210416T1300Z/
Scott-Campbell-Claiborne-Hancock-Hawkins-Sullivan-Morgan-Anderson-
Union-Grainger-Hamblen-Northwest Greene-Washington-
Northwest Carter-Lee-Wise-Russell-
Including the cities of Big South Fork National, Oneida, 
Smokey Junction, Elgin, Huntsville, Norma, Slick Rock, Fincastle,
La Follette, Elk Valley, Jellico, White Oak, Caryville, 
Royal Blue, Lone Mountain, Sandlick, Springdale, Arthur, 
Harrogate-Shawanee, Clairfield, Howard Quarter, Evanston, 
Sneedville, Treadway, Kyles Ford, Mooresburg, Kingsport, 
Bristol TN, South Holston Dam, Pine Orchard, High Point, Petros, 
Clinton, Maynardville, Norris Lake, Paulette, Rose Hill, 
Sharps Chapel, Luttrell, Bean Station, Alpha, Morristown, 
Russellville, Greeneville, Johnson City, Elizabethton, 
Big Stone Gap, Norton, Wise, Coeburn, Appalachia, Pardee, 
Hiltons, Hansonville, Lebanon, Dye, Castlewood, Honaker, 
Rosedale, Benhams, Bristol VA, and Abingdon
703 PM EDT Thu Apr 15 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM EDT FRIDAY MORNING...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Portions of east Tennessee and southwest Virginia.

* WHEN...From 2 AM to 9 AM EDT Friday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if left
  uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
1 follow-up statement
343 
WWUS74 KMRX 160658
NPWMRX

URGENT - WEATHER MESSAGE
National Weather Service Morristown TN
258 AM EDT Fri Apr 16 2021

TNZ012>017-035>039-042-044-046-VAZ001-002-005-006-008-161300-
/O.CON.KMRX.FR.Y.0002.000000T0000Z-210416T1300Z/
Scott-Campbell-Claiborne-Hancock-Hawkins-Sullivan-Morgan-Anderson-
Union-Grainger-Hamblen-Northwest Greene-Washington-
Northwest Carter-Lee-Wise-Russell-
Including the cities of Big South Fork National, Oneida, 
Smokey Junction, Elgin, Huntsville, Norma, Slick Rock, Fincastle,
La Follette, Elk Valley, Jellico, White Oak, Caryville, 
Royal Blue, Lone Mountain, Sandlick, Springdale, Arthur, 
Harrogate-Shawanee, Clairfield, Howard Quarter, Evanston, 
Sneedville, Treadway, Kyles Ford, Mooresburg, Kingsport, 
Bristol TN, South Holston Dam, Pine Orchard, High Point, Petros, 
Clinton, Maynardville, Norris Lake, Paulette, Rose Hill, 
Sharps Chapel, Luttrell, Bean Station, Alpha, Morristown, 
Russellville, Greeneville, Johnson City, Elizabethton, 
Big Stone Gap, Norton, Wise, Coeburn, Appalachia, Pardee, 
Hiltons, Hansonville, Lebanon, Dye, Castlewood, Honaker, 
Rosedale, Benhams, Bristol VA, and Abingdon
258 AM EDT Fri Apr 16 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM EDT THIS MORNING...

* WHAT...Temperatures as low as the mid 30s will result in frost 
  formation.

* WHERE...Portions of east Tennessee and southwest Virginia.

* WHEN...Through 9 AM EDT this morning.

* IMPACTS...Frost could damage or kill sensitive outdoor 
  vegetation if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Nearby

Frost Advisories in Tennessee, 2021Frost Advisories in Virginia, 2021Every frost 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.