Alert archive / Tennessee / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 9, NWS Atlanta, GA

February 13, 1991Polk County, Tennessee

NWS Atlanta, GA issued this severe thunderstorm warning at Feb 13, 1991, 11:46 PM EST for Polk County, Tennessee. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Feb 13, 1991, 11:46 PM EST (04:46 UTC)
Expired
Feb 14, 1991, 12:30 AM EST
In force
44 min
Issued by
NWS Atlanta, GA
Area
Whole counties

County Polk County, TN

What was reported inside it

TimeReportWhereRemark
Feb 13, 11:58 PM ESTHail 0.75Polk, TN

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Athens Municipal, GA (KAHN), launched 00:00Z, 4.8 hours before the alert went out and 172 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, Athens Municipal, GA at 00:00Z on 1991-02-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 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, Athens Municipal, GA at 00:00Z on 1991-02-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 560 square meters per square second.1939587897117136Sfc1 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
587 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
560 m²/s²
0-3 km storm-relative helicity
718 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.

000 
TTAA00 KCHA 140442
SVRCHA
TNC139-140530-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHATTANOOGA TENNESSEE
1146 PM EST WED FEB 13 1991
 
THE NATIONAL WEATHER SERVICE IN CHATTANOOGA TENNESSEE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1230 AM EST
FOR PEOPLE IN THE FOLLOWING LOCATIONS
 
IN SOUTHEAST TENNESSEE
 
   ...POLK COUNTY
 
AT 1145 PM EDT THE CHATTANOOGA WEATHER RADAR INDICATED A SEVERE
THUNDERSTORM MOVING INTO WESTERN POLK COUNTY.
 
THIS STORM HAS PRODUCED HAIL AND HIGH WINDS IN BRADLEY COUNTY
AROUND CLEVELAND DURING THE PAST SEVERAL MINUTES.
 
THE THUNDERSTORM IS MOVING TO THE EAST AT 55 TO 60 MILES PER HOUR.
 
 
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
DON'T DRIVE INTO AREWAS WHERE WATER COVERS THE ROAD.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Feb 13, 11:08 PM EST, 38 minutes before
GAZ001-002-140600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ATLANTA  GA
1110 PM EST WED FEB 13 1991

...STRONG THUNDERSTORMS AIMING AT EXTREME NORTH GEORGIA...

AT 11 PM EST RADAR SHOWED A BAND OF STRONG THUNDERSTORMS
IN EXTREME SOUTHEAST TENNESSEE. SOME OF THE STORMS HAVE BEEN
SEVERE...PRODUCING LARGE HAIL AND DAMAGING WINDS.

AT 11 PM THE STORMS WERE IN THE CHATTANOOGA AREA MOVING
SOUTHEAST AT AROUND 50 MPH. AT THIS SPEED THE STORMS WILL
MOVE INTO THE CHATSWORTH...ELLIJAY AND BLUE RIDGE AREAS
BEFORE MIDNIGHT.

RESIDENTS OF MURRAY...FANNIN...AND GILMER COUNTIES...ESPECIALLY
THOSE LIVING IN AREAS CLOSE TO THE TENNESSEE BORDER...SHOULD
BE PREPARED TO TAKE SHELTER QUICKLY IF THREATENING WEATHER
APPROACHES.

The office that day

Everything else NWS Atlanta, GA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 13, 10:28 PM ESTSevere Thunderstorm WarningFFCGrundy47 min
Feb 13, 10:44 PM ESTSevere Thunderstorm WarningFFCMarion46 min
Feb 13, 10:56 PM ESTSevere Thunderstorm WarningFFCSequatchie34 min
Feb 13, 11:05 PM ESTSevere Thunderstorm WarningFFCHamilton40 min
Feb 13, 11:33 PM ESTSevere Thunderstorm WarningFFCBradley42 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 1991Every severe thunderstorm warning in 1991

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.