Alert archive / Alabama / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 397, NWS Birmingham, AL

June 30, 1999St. Clair County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Jun 30, 1999, 5:29 PM CDT for St. Clair 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
Jun 30, 1999, 5:29 PM CDT (22:29 UTC)
Expired
Jun 30, 1999, 6:00 PM CDT
In force
31 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County St. Clair County, AL

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 10.5 hours before the alert went out and 74 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 1999-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 953 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 1999-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
953 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
1000 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 10:24 AM CDTSevere Thunderstorm WarningBMXChilton, Coosa31 min
Jun 30, 10:57 AM CDTSevere Thunderstorm WarningBMXCoosa33 min
Jun 30, 3:26 PM CDTFlash Flood WarningBMXBibb, Perry119 min
Jun 30, 4:27 PM CDTSevere Thunderstorm WarningBMXAutauga48 min
Jun 30, 4:50 PM CDTSevere Thunderstorm WarningBMXElmore, Montgomery60 min
Jun 30, 5:22 PM CDTFlash Flood WarningBMXAutauga, Elmore, Montgomery2 hr

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.