Alert archive / Alabama / Tornado Watches in 1998

Tornado Watch 154

April 3, 199851 counties in Alabama; 8 counties in Georgia

The Storm Prediction Center issued this tornado watch at Apr 3, 1998, 7:00 AM CST for 51 counties in Alabama; 8 counties in Georgia. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Apr 3, 1998, 7:00 AM CST (13:00 UTC)
Expired: Apr 3, 1998, 1:00 PM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 59 counties

Autauga County, AL, Bibb County, AL, Blount County, AL, Bullock County, AL, Butler County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Chilton County, AL, Choctaw County, AL, Clay County, AL, Cleburne County, AL, Colbert County, AL, Coosa County, AL, Crenshaw County, AL, Cullman County, AL, Dallas County, AL, DeKalb County, AL, Elmore County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lauderdale County, AL, Lawrence County, AL, Lee County, AL, Limestone County, AL, Lowndes County, AL, Macon County, AL, Madison County, AL, Marengo County, AL, Marion County, AL, Marshall County, AL, Montgomery County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Pike County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL, Walker County, AL, Wilcox County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Floyd County, GA, Haralson County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA

The radar

The Birmingham radar (KBMX), 25 km from the middle of the area, began a volume at 13:02 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

Birmingham, AL (KBMX), launched 12:00Z, 1.0 hours before the alert went out and 25 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: 216 J/kg
Mixed-layer CIN: -127 J/kg
Mixed-layer LCL: 619 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 355 m²/s²
0-3 km storm-relative helicity: 434 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 6.8

Open this sounding in Storm Lab

The text

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

229 
WWUS9 KMKC 031235
SEL4  
MKC WW 031235
ALZ000-031900-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 154
STORM PREDICTION CENTER NORMAN OK
635 AM CST FRI APR 3 1998

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

   ALABAMA                            

EFFECTIVE THIS FRIDAY MORNING AND AFTERNOON FROM 700 AM UNTIL 100
PM CST.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 85 STATUTE MILES EAST AND WEST
OF A LINE FROM 45 MILES SOUTH OF SELMA ALABAMA TO 40 MILES
NORTHEAST OF HUNTSVILLE ALABAMA.

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.


DISCUSSION...THUNDERSTORMS WILL INCREASE AHEAD OF SURFACE TROUGH AS
LOW LEVEL WARM ADVECTION AND DIURNAL HEATING RESULTS IN SURFACE
BASED CAPES ABOVE 2000 J/KG. STORM RELATIVE HELICITY ABOVE 400
M2/SEC2 INDICATES POTENTIAL FOR TORNADIC SUPERCELLS. 

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24040.


...ROGASH

314,0882 350,0874 350,0844 314,0853

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 3, 10:15 AM CST	Severe Thunderstorm Watch	SPC	Russell	5 hr
Apr 3, 1:00 PM CST	Tornado Watch	SPC	Blount, Cherokee, Cullman, DeKalb, Etowah, Jackson and 5 more	6 hr
Apr 3, 3:00 PM CST	Tornado Watch	SPC	Russell	6 hr
Apr 3, 5:00 PM CST	Severe Thunderstorm Watch	SPC	Fannin, Gilmer, Rabun, Towns, Union	6 hr

Nearby

Tornado Watches in Alabama, 1998 Tornado Watches in Georgia, 1998 Every 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.