Alert archive / Alabama / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 511, NWS Birmingham, AL

August 23, 1999Montgomery County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Aug 23, 1999, 6:39 PM CDT for Montgomery County, Alabama. It was in force for 31 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
Aug 23, 1999, 6:39 PM CDT (23:39 UTC)
Expired
Aug 23, 1999, 7:10 PM CDT
In force
31 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Montgomery County, AL

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 11.7 hours before the alert went out and 119 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 12:00Z on 1999-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1708 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 12:00Z on 1999-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
1708 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
825 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBHM 232339 RRA
SVRBHM
ALC101-240010-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
639 PM CDT MON AUG 23 1999

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED...A

* SEVERE THUNDERSTORM WARNING FOR...
  MONTGOMERY COUNTY...IN CENTRAL ALABAMA...

* UNTIL 710 PM CDT.

* AT 637 PM CDT... WEATHER RADAR SHOWED A SEVERE THUNDERSTORM...
MOVING INTO THE CITY OF MONTGOMERY.  THIS STORM WAS MOVING EAST AT
25 MPH...AND WAS LIKELY PRODUCING DAMAGING WINDS.

THIS IS A DANGEROUS STORM. STAY INDOORS AWAY FROM WINDOWS.

IF YOU ARE CAUGHT OUTSIDE... SEEK REFUGE FROM THE STORM IN A
STRONG BUILDING. BOATERS ON AREA LAKES SHOULD TAKE SHELTER.
DAMAGING WIND... LARGE HAIL... VERY HEAVY RAIN... AND DANGEROUS
LIGHTNING ARE ALL LIKELY. DO NOT SEEK SHELTER UNDER TREES OR OTHER
ISOLATED TALL OBJECTS. THESE ATTRACT LIGHTNING. DO NOT DRIVE INTO
AREAS WHERE WATER COVERS THE ROAD.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 4:01 PM CDTSevere Thunderstorm WarningBMXPerry34 min
Aug 23, 4:33 PM CDTSevere Thunderstorm WarningBMXTalladega47 min
Aug 23, 4:46 PM CDTSevere Thunderstorm WarningBMXDeKalb49 min
Aug 23, 5:52 PM CDTSevere Thunderstorm WarningBMXTallapoosa43 min

Nearby

Severe Thunderstorm Warnings in Alabama, 1999Every severe thunderstorm warning in 1999

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.