Alert archive / Tennessee / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 21, NWS Morristown, TN

February 17, 1998Claiborne County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Feb 17, 1998, 9:49 AM EST for Claiborne County, Tennessee. It was in force for 56 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
Feb 17, 1998, 9:49 AM EST (14:49 UTC)
Expired
Feb 17, 1998, 10:45 AM EST
In force
56 min
Issued by
NWS Morristown, TN
Area
Whole counties

County Claiborne County, TN

The radar

The Knoxville radar (KMRX), 42 km from the middle of the area, began a volume at 14:48 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, 2.8 hours before the alert went out and 266 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, Nashville Metro, TN at 12:00Z on 1998-02-17Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 1998-02-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 276 square meters per square second.193958Sfc1 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
585 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
276 m²/s²
0-3 km storm-relative helicity
348 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

840 
WUUS01 KMRX 171451 RRA
SVRMRX
TNC025-029-171545-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE KNOXVILLE TRI CITIES TN
949 AM EST TUE FEB 17 1998
 
THE NATIONAL WEATHER SERVICE IN KNOXVILLE TRI CITIES HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1045 AM EST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN EAST TENNESSEE
 
   ...CLAIBORNE COUNTY...COCKE COUNTY
 
AT 949 AM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE
OF SEVERE THUNDERSTORMS MOVING NORTH AT 45 MPH INTO CLAIBORNE
AND COCKE COUNTIES. THIS LINE OF STORMS HAS A HISTORY OF PRODUCE
DAMAGING STRAIGHT LINE WINDS AND DIME SIZE HAIL.
 
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DONT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 17, 8:04 AM ESTSevere Thunderstorm WarningMRXMcMinn, Meigs, Rhea41 min
Feb 17, 8:39 AM ESTSevere Thunderstorm WarningMRXLoudon, Monroe, Roane51 min
Feb 17, 8:51 AM ESTSevere Thunderstorm WarningMRXAnderson, Knox, Morgan54 min
Feb 17, 8:51 AM ESTSevere Thunderstorm WarningMRXBlount54 min
Feb 17, 9:10 AM ESTSevere Thunderstorm WarningMRXCampbell, Scott50 min
Feb 17, 9:19 AM ESTSevere Thunderstorm WarningMRXSevier41 min
Feb 17, 9:30 AM ESTSevere Thunderstorm WarningMRXGrainger, Jefferson, Union45 min
Feb 17, 9:40 AM ESTSevere Thunderstorm WarningMRXHamblen40 min
Feb 17, 9:49 AM ESTSevere Thunderstorm WarningMRXCocke56 min
Feb 17, 9:51 AM ESTTornado WarningMRXGrainger, Hamblen39 min
Feb 17, 10:08 AM ESTSevere Thunderstorm WarningMRXHancock, Hawkins52 min
Feb 17, 10:13 AM ESTSevere Thunderstorm WarningMRXGreene47 min
Feb 17, 10:51 AM ESTSevere Thunderstorm WarningMRXSullivan, Washington54 min
Feb 17, 10:55 AM ESTSevere Thunderstorm WarningMRXGreene15 min
Feb 17, 11:00 AM ESTSevere Thunderstorm WarningMRXHawkins10 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 1998Every severe thunderstorm warning in 1998

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.