Alert archive / Georgia / Tornado Watches in 1998

Tornado Watch 247

April 18, 199864 counties in Georgia; 10 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Apr 18, 1998, 8:45 PM EDT for 64 counties in Georgia; 10 counties in South Carolina. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 18, 1998, 8:45 PM EDT (00:45 UTC)
Expired
Apr 19, 1998, 3:00 AM EDT
In force
6 hr
Issued by
the Storm Prediction Center
All 74 counties

Banks County, GA, Barrow County, GA, Bartow County, GA, Burke County, GA, Butts County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Columbia County, GA, Coweta County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fannin County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Gilmer County, GA, Glascock County, GA, Gordon County, GA, Greene County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Hancock County, GA, Haralson County, GA, Hart County, GA, Henry County, GA, Jackson County, GA, Jasper County, GA, Jefferson County, GA, Lincoln County, GA, Lumpkin County, GA, Madison County, GA, McDuffie County, GA, Morgan County, GA, Murray County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Putnam County, GA, Richmond County, GA, Rockdale County, GA, Spalding County, GA, Stephens County, GA, Taliaferro County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, Warren County, GA, White County, GA, Whitfield County, GA, Wilkes County, GA, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Edgefield County, SC, Greenwood County, SC, Laurens County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Saluda County, SC

The radar

The Atlanta radar (KFFC), 115 km from the middle of the area, began a volume at 00:48 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 18, 8:50 PM EDTTornado WarningFFCCatoosa, Walker50 min
Apr 18, 9:40 PM EDTTornado WarningFFCWalker, Whitfield35 min
Apr 18, 10:16 PM EDTTornado WarningFFCFloyd34 min
Apr 18, 10:50 PM EDTSevere Thunderstorm WarningFFCGordon35 min
Apr 18, 11:03 PM EDTTornado WarningFFCGordon32 min
Apr 18, 11:54 PM EDTFlash Flood WarningFFCWhitfield2 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.8 hours before the alert went out and 111 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, Peachtre/Fal Fld, GA at 00:00Z on 1998-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 589 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, Peachtre/Fal Fld, GA at 00:00Z on 1998-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.1939587897Sfc1 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
589 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
1082 m above ground
0-6 km bulk shear
79 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
280 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.5

Open this sounding in Storm Lab

The text

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

048 
WWUS9 KMKC 190018
SEL7  
MKC WW 190018
GAZ000-SCZ000-190700-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 247
STORM PREDICTION CENTER NORMAN OK
818 PM EDT SAT APR 18 1998

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   NORTHERN GEORGIA                            
   WESTERN SOUTH CAROLINA                     

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 845 PM UNTIL
300 AM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 60 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 20 MILES WEST SOUTHWEST OF ROME GEORGIA TO 40
MILES NORTHEAST OF AUGUSTA GEORGIA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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...  CONTINUE...WW 246...

DISCUSSION...SURFACE WARM FRONT EXTENDS FROM NERN AL ACROSS NRN GA
TO THE SC COAST.  AIRMASS S OF FRONT IS MODERATELY UNSTABLE WITH
SURFACE-BASED CAPE VALUES TO 2000 J/KG.  00Z SOUNDINGS AND WSR-88DS
INDICATE STORM-RELATIVE HELICITY VALUES APPROACHING 400 M2/S2. 
THUNDERSTORMS WERE DEVELOPING ALONG WARM FRONT WITH ADDITIONAL
STORMS OVER AL EXPECTED TO MOVE INTO WW DURING NEXT FEW HOURS.    
INSTABILITY AND SHEAR WERE COMBINING TO PRODUCE AN ENVIRONMENT
CONDUCIVE FOR SUPERCELL DEVELOPMENT WITH ISOLATED TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 21040.


...HOVIS

350,0852 343,0812 325,0812 332,0852

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 3:30 PM EDTTornado WatchSPCColumbia, Lincoln, McDuffie, Warren6 hr
Apr 19, 3:00 PM EDTTornado WatchSPCYork6 hr

Nearby

Tornado Watches in Georgia, 1998Tornado Watches in South Carolina, 1998Every tornado watch 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.