Alert archive / Alabama / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 96, NWS Birmingham, AL

June 21, 1990Blount County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Jun 21, 1990, 10:13 AM CDT for Blount County, Alabama. It was in force for 62 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jun 21, 1990, 10:13 AM CDT (15:13 UTC)
Expired
Jun 21, 1990, 11:15 AM CDT
In force
62 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Blount County, AL

The radar

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

What was reported inside it

TimeReportWhereRemark
Jun 21, 10:30 AM CDTThunderstorm Wind 0Blount, AL

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Centreville/Bibb, AL (KCKL), launched 12:00Z, 3.2 hours before the alert went out and 134 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 211515
SVRBHM
ALC009-211615-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1013 AM CDT THU JUN 21 1990
 
THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1115 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTH ALABAMA
 
   ...BLOUNT COUNTY
 
AT 1010 AM WEATHER SERVICE RADAR INDICATED A SEVERE THUNDERSTORM EAST
OF BLOUNTSVILLE IN NORTHERN BLOUNT COUNTY. OTHER POSSIBLE SEVERE
THUNDERSTORMS WERE MOVING INTO WESTERN BLOUNT COUNTY. THESE
THUNDERSTORMS WERE MOVING EAST AT 20 TO 30 MPH.
 
 
WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING.  DO NOT STAND BY WINDOWS.  DON'T USE TELEPHONES
OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM
HAS PASSED.  MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.

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, 51 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, 7 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, 11:17 AM CDTSevere Thunderstorm WarningBMXSt. Clair58 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.