Alert archive / Alabama / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 97, NWS Birmingham, AL

June 21, 1990St. Clair County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Jun 21, 1990, 11:17 AM CDT for St. Clair County, Alabama. It was in force for 58 min.

The area

The counties it named.

The facts

Issued
Jun 21, 1990, 11:17 AM CDT (16:17 UTC)
Expired
Jun 21, 1990, 12:15 PM CDT
In force
58 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County St. Clair County, AL

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Centreville/Bibb, AL (KCKL), launched 12:00Z, 4.3 hours before the alert went out and 122 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, Centreville/Bibb, AL at 12:00Z on 1990-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1904 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, Centreville/Bibb, AL at 12:00Z on 1990-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 square meters per square second.1939Sfc1 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
1904 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
1025 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
-10 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBHM 211618
SVRBHM
ALC115-211715-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1117 AM CDT THU JUN 21 1990
 
THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1215 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTH ALABAMA
 
   ...ST.CLAIR COUNTY
 
AT 1116 AM CDT WEATHER SERVICE RADAR INDICATED A SEVERE THUNDERSTORM
ENTERING NORTHERN ST CLAIR COUNTY FROM BLOUNT COUNTY.
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.
STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

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, Jun 21, 9:22 AM CDT, 1 hour 55 minutes before
ALZ004>007-011-181530-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
920 AM CDT THU JUN 21 1990

...STRONG THUNDERSTORMS FORMING IN NORTH CENTRAL ALABAMA...

AT 917 AM NATIONAL WEATHER SERVICE RADAR SHOWED A BROKEN LINE OF
SHOWERS AND THUNDERSTORMS FORMING RAPIDLY IN NORTH CENTRAL ALABAMA...
STRETCHING FROM BLOUNT COUNTY INTO CULLMAN...WALKER...AND FAYETTE
COUNTIES. THE STRONGEST STORM AT THAT TIME WAS IN EXTREME NORTHERN
BLOUNT COUNTY. THESE SHOWERS AND THUNDERSTORMS WERE MOVING TO THE EAST
AT AROUND 25 MPH.

THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING STRONG GUSTY WIND...BRIEF
HEAVY DOWNPOURS...DANGEROUS LIGHTNING...AND POSSIBLY SOME HAIL...AND
RESIDENTS IN THE EFFECsTED AREAS SHOULD REMAIN ALERT TO RAPIDLY CHANGING
WEATHER CONDITIONS.
Special weather statement, Jun 21, 10:06 AM CDT, 1 hour 11 minutes before
ALZ004>007-011-181600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1005 AM CDT THU JUN 21 1990

...STRONG THUNDERSTORMS IN NORTH CENTRAL ALABAMA...

AT 1003 AM NATIONAL WEATHER SERVICE RADAR INDICATED AN AREA OF SHOWERS
AND THUNDERSTORMS IN NORTH CENTRAL ALABAMA...MOVING INTO ETOWAH COUNTY
AND STRETCHING SOUTHWESTWARD INTO BLOUNT...CULLMAN...AND WALKER
COUNTIES. THE STRONGEST STORMS AT THAT TIME WERE IN NORTHERN BLOUNT
COUNTY JUST EAST OF BLOUNTSVILLE...IN SOUTHERN CULLMAN COUNTY NEAR
SMITH DAM...AND IN SOUTHERN WALKER COUNTY NEAR OAKMAN.

THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING STRONG GUSTY WIND...BRIEF
HEAVY DOWNPOURS...FREQUENT LIGHTNING...AND POSSIBLE SOME HAIL...AS THEY
MOVE TO THE EAST AT AROUND 25 MPH. PERSONS IN THESE AREAS SHOULD REMAIN
ALERT...AND STAYED TUNED FOR LATER STATEMENTS.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 10:13 AM CDTSevere Thunderstorm WarningBMXBlount62 min
Jun 21, 12:55 PM CDTSevere Thunderstorm WarningBMXShelby35 min
Jun 21, 1:07 PM CDTSevere Thunderstorm WarningBMXCullman68 min
Jun 21, 1:28 PM CDTSevere Thunderstorm WarningBMXJefferson, Shelby47 min
Jun 21, 2:20 PM CDTSevere Thunderstorm WarningBMXLawrence55 min
Jun 21, 2:24 PM CDTSevere Thunderstorm WarningBMXShelby51 min
Jun 21, 3:23 PM CDTSevere Thunderstorm WarningBMXFayette, Walker67 min
Jun 21, 3:23 PM CDTSevere Thunderstorm WarningBMXTuscaloosa41 min
Jun 21, 4:55 PM CDTSevere Thunderstorm WarningBMXLamar35 min
Jun 21, 5:45 PM CDTSevere Thunderstorm WarningBMXFranklin60 min

Nearby

Severe Thunderstorm Warnings in Alabama, 1990Every severe thunderstorm warning in 1990

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.