Alert archive / Alabama / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 59, NWS Birmingham, AL

May 20, 1990Walker County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at May 20, 1990, 10:36 AM CDT for Walker County, Alabama. It was in force for 54 min.

The area

The counties it named.

The facts

Issued
May 20, 1990, 10:36 AM CDT (15:36 UTC)
Expired
May 20, 1990, 11:30 AM CDT
In force
54 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Walker 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, 3.6 hours before the alert went out and 101 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 1990-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 429 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 1990-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 square meters per square second.193958Sfc1 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
429 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
689 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
93 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBHM 201540
SVRBHM
ALC127-201630-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1036 AM CDT SUN MAY 20 1990
 
THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1130 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTH ALABAMA
 
   ...WALKER COUNTY
 
AT 1036 AM CDT RADAR INDICATED AT SEVERE THUNDERSTORM IN WALKER
COUNTY. THIS THUNDERSTORM IS MOVING EAST AT 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 7DRIVE INTO LOW WATER CROSSINGS.

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 1:22 AM CDTFlash Flood WarningBMXMarion2 hr
May 20, 10:06 AM CDTSevere Thunderstorm WarningBMXFayette, Lamar69 min
May 20, 11:03 AM CDTSevere Thunderstorm WarningBMXBlount, Cullman57 min
May 20, 11:08 AM CDTSevere Thunderstorm WarningBMXJefferson67 min
May 20, 11:12 AM CDTSevere Thunderstorm WarningBMXTuscaloosa48 min
May 20, 11:47 AM CDTSevere Thunderstorm WarningBMXSt. Clair, Shelby43 min
May 20, 11:47 AM CDTSevere Thunderstorm WarningBMXEtowah43 min
May 20, 11:55 AM CDTSevere Thunderstorm WarningBMXMarshall35 min
May 20, 12:15 PM CDTSevere Thunderstorm WarningBMXChilton45 min
May 20, 12:28 PM CDTSevere Thunderstorm WarningBMXCalhoun, Talladega62 min
May 20, 12:28 PM CDTSevere Thunderstorm WarningBMXCherokee, Etowah62 min
May 20, 12:45 PM CDTSevere Thunderstorm WarningBMXClay, Cleburne60 min
May 20, 1:07 PM CDTSevere Thunderstorm WarningBMXRandolph53 min
May 20, 3:29 PM CDTSevere Thunderstorm WarningBMXPickens, Tuscaloosa46 min
May 20, 4:07 PM CDTTornado WarningBMXTuscaloosa53 min
May 20, 4:57 PM CDTSevere Thunderstorm WarningBMXTuscaloosa63 min
May 20, 6:05 PM CDTSevere Thunderstorm WarningBMXBibb55 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.