Alert archive / Tennessee / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 191

April 20, 200015 counties in Alabama; 8 counties in Georgia; 33 counties in Tennessee

The Storm Prediction Center issued this severe thunderstorm watch at Apr 20, 2000, 8:35 PM CDT for 15 counties in Alabama; 8 counties in Georgia; 33 counties in Tennessee. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Apr 20, 2000, 8:35 PM CDT (01:35 UTC)
Expired: Apr 21, 2000, 12:00 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 56 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Jackson County, AL, Jefferson County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, St. Clair County, AL, Walker County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Floyd County, GA, Gordon County, GA, Murray County, GA, Walker County, GA, Whitfield County, GA, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Claiborne County, TN, Cumberland County, TN, Fentress County, TN, Franklin County, TN, Grainger County, TN, Grundy 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, Union County, TN, Van Buren County, TN, Warren County, TN, White County, TN

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Apr 20, 8:36 PM CDT	Severe Thunderstorm Warning	MRX	Campbell, Scott	44 min
Apr 20, 8:38 PM CDT	Severe Thunderstorm Warning	BMX	Cullman, Winston	37 min
Apr 20, 8:44 PM CDT	Tornado Warning	MRX	Sequatchie	46 min
Apr 20, 8:45 PM CDT	Tornado Warning	MRX	Campbell, Scott	30 min
Apr 20, 8:48 PM CDT	Severe Thunderstorm Warning	MRX	Marion	62 min
Apr 20, 8:50 PM CDT	Severe Thunderstorm Warning	OHX	Grundy	25 min
Apr 20, 9:01 PM CDT	Severe Thunderstorm Warning	MRX	Hamilton, Meigs, Rhea	59 min
Apr 20, 9:02 PM CDT	Tornado Warning	BMX	Cullman	28 min
Apr 20, 9:12 PM CDT	Tornado Warning	MRX	Claiborne	48 min
Apr 20, 9:51 PM CDT	Severe Thunderstorm Warning	MRX	Bradley	59 min
Apr 20, 10:39 PM CDT	Severe Thunderstorm Warning	FFC	Murray, Whitfield	36 min
Apr 20, 10:44 PM CDT	Severe Thunderstorm Warning	MRX	Monroe	61 min

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 00:00Z, 1.6 hours before the alert went out and 169 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: 1081 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 1023 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 156 m²/s²
0-3 km storm-relative helicity: 274 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 2.8

Open this sounding in Storm Lab

The text

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

249 
WWUS9 KMKC 210113
SEL1  
MKC WW 210113
ALZ000-GAZ000-TNZ000-210500-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 191
STORM PREDICTION CENTER NORMAN OK
913 PM EDT THU APR 20 2000

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   NORTH ALABAMA                            
   EXTREME NORTHWEST GEORGIA                            
   EASTERN TENNESSEE                          

EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 935 PM UNTIL
100 AM EDT.

HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 65 STATUTE MILES
EAST AND WEST OF A LINE FROM 25 MILES WEST SOUTHWEST OF BIRMINGHAM
ALABAMA TO 60 MILES NORTH NORTHEAST OF KNOXVILLE TENNESSEE.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
TORNADO WATCH NUMBER 189.  WATCH NUMBER 189 WILL NOT BE IN EFFECT
AFTER 935 PM EDT.  CONTINUE...WW 190...

DISCUSSION...LINE OF THUNDERSTORMS WITH EMBEDDED SUPERCELLS IS
EXPECTED TO CONTINUE MOVING EWD TOWARD THE APPALACHIANS WHILE
BUILDING SWD INTO PARTS OF AL. STRONG DEEP LAYER SHEAR WILL
CONTINUE TO SUPPORT MAINLY DAMAGING WINDS AND SOME HAIL GIVEN STEEP
LAPSE RATES AND STRONG DEEP LAYER SHEAR.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM
MOTION VECTOR 26035.

...VESCIO

363,0822 332,0860 332,0881 363,0844

Nearby

Severe Thunderstorm Watches in Tennessee, 2000 Severe Thunderstorm Watches in Alabama, 2000 Severe Thunderstorm Watches in Georgia, 2000 Every severe thunderstorm watch in 2000

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.