Alert archive / Alabama / Tornado Warnings in 1998

Tornado Warning 84, NWS Birmingham, AL

April 18, 1998Shelby County, Alabama

NWS Birmingham, AL issued this tornado warning at Apr 18, 1998, 7:55 PM CDT for Shelby County, Alabama. It was in force for 20 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, 7:55 PM CDT (00:55 UTC)
Expired
Apr 18, 1998, 8:15 PM CDT
In force
20 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Shelby 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, 0.9 hours before the alert went out and 14 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 190055 RRA
TORBHM
ALC117-190115-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
755 PM CDT SAT APR 18 1998

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN SHELBY COUNTY... IN CENTRAL ALABAMA

* UNTIL 815 PM CDT

* AT 754 PM CDT... A POSSIBLE TORNADO WAS DETECTED...BY NATIONAL
  WEATHER SERVICE DOPPLER RADAR MOVING OUT OF CHILTON COUNTY.  THIS
  STORM WILL PASS OVER THE TOWN OF SHELBY BY 805 PM CDT.  MOVEMENT OF
THIS STORM WAS TO THE NORTHEAST AT 35 MILES PER HOUR.

IF YOU ARE IN A MULTIPLE STORY BUILDING...GO TO A SMALL INTERIOR ROOM
AWAY FROM WINDOWS.

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, 7:58 PM CDTSevere Thunderstorm WarningBMXCalhoun47 min
Apr 18, 8:23 PM CDTTornado WarningBMXTalladega62 min
Apr 18, 9:06 PM CDTSevere Thunderstorm WarningBMXCherokee19 min

Nearby

Tornado Warnings in Alabama, 1998Every tornado warning in 1998Tornadoes 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.