Alert archive / Alabama / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 267, NWS Birmingham, AL

April 18, 1998Calhoun County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Apr 18, 1998, 7:58 PM CDT for Calhoun County, Alabama. It was in force for 47 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
Apr 18, 1998, 7:58 PM CDT (00:58 UTC)
Expired
Apr 18, 1998, 8:45 PM CDT
In force
47 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Calhoun County, AL

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 18, 5:45 PM CDTTornado WatchSPC5 hr

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 1.0 hours before the alert went out and 110 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, Birmingham, AL at 00:00Z on 1998-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 782 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, Birmingham, AL at 00:00Z on 1998-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 229 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
782 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
612 m above ground
0-6 km bulk shear
83 kt
0-1 km storm-relative helicity
229 m²/s²
0-3 km storm-relative helicity
393 m²/s²
Significant tornado parameter
1.7
Supercell composite
13.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBHM 190058 RRA
SVRBHM
ALC015-190145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
758 PM CDT SAT APR 18 1998

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CALHOUN COUNTY... IN EAST CENTRAL ALABAMA

* UNTIL 845 PM CDT

* AT 756 PM CDT... A LINE OF SEVERE THUNDERSTORMS WAS SHOWN...BY
WEATHER RADAR MOVING OUT OF ST. CLAIR AND TALLEDEGA COUNTIES INTO
CALHOUN. THE STROMS WERE MOVING NORTHEAST AROUND 40 MILES AN HOUR.

* THE SEVERE THUNDERSTORMS WILL AFFECT MOST COMMUNITIES IN CALHOUN
COUNTY THROUGH 845 PM...

GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS! A TORNADO
WATCH IS IN EFFECT. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO
PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING.

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, Apr 18, 7:20 PM CDT, 38 minutes before
ALZ023-032-039-190125-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
720 PM CDT SAT APR 18 1998

THE TORNADO WATCH NUMBER 246 HAS BEEN CANCELLED FOR THE FOLLOWING
COUNTIES...

IN ALABAMA

   ...TUSCALOOSA... HALE... MARENGO

The office that day

Everything else NWS Birmingham, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 18, 7:01 PM CDTTornado WarningBMXMarshall19 min
Apr 18, 7:02 PM CDTTornado WarningBMXJefferson33 min
Apr 18, 7:13 PM CDTSevere Thunderstorm WarningBMXChilton62 min
Apr 18, 7:26 PM CDTFlash Flood WarningBMXDeKalb4 hr
Apr 18, 7:26 PM CDTSevere Thunderstorm WarningBMXSt. Clair, Talladega64 min
Apr 18, 7:30 PM CDTTornado WarningBMXLowndes50 min
Apr 18, 7:36 PM CDTTornado WarningBMXDeKalb44 min
Apr 18, 7:39 PM CDTTornado WarningBMXChilton31 min
Apr 18, 7:44 PM CDTTornado WarningBMXCherokee46 min
Apr 18, 7:55 PM CDTTornado WarningBMXShelby20 min
Apr 18, 8:23 PM CDTTornado WarningBMXTalladega62 min
Apr 18, 9:06 PM CDTSevere Thunderstorm WarningBMXCherokee19 min

Nearby

Severe Thunderstorm Warnings in Alabama, 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.