Alert archive / Alabama / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 64, NWS Birmingham, AL

May 20, 1990Etowah County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at May 20, 1990, 11:47 AM CDT for Etowah County, Alabama. It was in force for 43 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
May 20, 1990, 11:47 AM CDT (16:47 UTC)
Expired
May 20, 1990, 12:30 PM CDT
In force
43 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Etowah 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
May 20, 12:18 PM CDTThunderstorm Wind 52Etowah, 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, 4.8 hours before the alert went out and 167 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 201649
SVRBHM
ALC055-117-115-201730-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1147 AM CDT SUN MAY 20 1990
 
THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1230 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTH ALABAMA
 
   ...ETOWAH COUNTY...SHELBY COUNTY...ST.CLAIR COUNTY
 
AT 11:45 AM CDT WEATHER SERVICE RADAR INDICATED A LINE OF SEVERE
THUNDERSTORMS IN EASTERN JEFFERSON AND BLOUNT COUNTIES. THIS LINE WAS
MOVING TO THE EAST AT 30 MPH. SEVERAL REPORTS OF DAMAGE HAVE BEEN
REPORTED WITH THIS LINE OF THUNDERSTORMS IN JEFFERSON AND WALKER
COUNTIES.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO ARE+AS WHERE WATER COVERS THE ROAD.

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, 10:36 AM CDTSevere Thunderstorm WarningBMXWalker54 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, 11:55 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.