Alert archive / Alabama / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 470, NWS Birmingham, AL

August 12, 1999Blount County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Aug 12, 1999, 5:39 PM CDT for Blount County, Alabama. It was in force for 36 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 12, 1999, 5:39 PM CDT (22:39 UTC)
Expired
Aug 12, 1999, 6:15 PM CDT
In force
36 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Blount County, AL

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 10.7 hours before the alert went out and 91 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 1999-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2056 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 1999-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 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
2056 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
1175 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Aug 12, 1:56 PM CDTSevere Thunderstorm WarningBMXMontgomery34 min
Aug 12, 2:56 PM CDTSevere Thunderstorm WarningBMXShelby34 min
Aug 12, 3:00 PM CDTSevere Thunderstorm WarningBMXLimestone, Madison50 min
Aug 12, 3:20 PM CDTSevere Thunderstorm WarningBMXLimestone35 min
Aug 12, 3:52 PM CDTSevere Thunderstorm WarningBMXLimestone18 min
Aug 12, 4:23 PM CDTSevere Thunderstorm WarningBMXMadison32 min
Aug 12, 4:58 PM CDTSevere Thunderstorm WarningBMXJackson32 min
Aug 12, 6:07 PM CDTSevere Thunderstorm WarningBMXLimestone33 min
Aug 12, 5:18 PM CDTSevere Thunderstorm WarningBMXChattahoochee, Muscogee32 min
Aug 12, 5:49 PM CDTSevere Thunderstorm WarningBMXChattahoochee, Muscogee31 min
Aug 12, 6:01 PM CDTSevere Thunderstorm WarningBMXStewart49 min
Aug 12, 6:24 PM CDTSevere Thunderstorm WarningBMXChattahoochee, Muscogee31 min
Aug 12, 6:54 PM CDTSevere Thunderstorm WarningBMXChattahoochee, Muscogee31 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.