Alert archive / Alabama / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 502, NWS Birmingham, AL

August 20, 1999Lowndes County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Aug 20, 1999, 4:46 PM CDT for Lowndes County, Alabama. It was in force for 34 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 20, 1999, 4:46 PM CDT (21:46 UTC)
Expired
Aug 20, 1999, 5:20 PM CDT
In force
34 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Lowndes County, AL

The nearest sounding before it

Eglin AFB/Valpar, FL (KVPS), launched 12:00Z, 9.8 hours before the alert went out and 187 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, Eglin AFB/Valpar, FL at 12:00Z on 1999-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2396 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, Eglin AFB/Valpar, FL at 12:00Z on 1999-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -75 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
2396 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
802 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-75 m²/s²
0-3 km storm-relative helicity
-45 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 19, 7:43 PM CDTSevere Thunderstorm WarningBMXEtowah47 min
Aug 19, 9:27 PM CDTSevere Thunderstorm WarningBMXMarshall33 min
Aug 20, 2:21 PM CDTSevere Thunderstorm WarningBMXRandolph34 min
Aug 20, 3:54 PM CDTSevere Thunderstorm WarningBMXRussell51 min
Aug 20, 4:24 PM CDTSevere Thunderstorm WarningBMXMontgomery31 min
Aug 20, 4:31 PM CDTSevere Thunderstorm WarningBMXMacon34 min
Aug 20, 5:35 PM CDTFlash Flood WarningBMXMacon2 hr
Aug 20, 5:56 PM CDTSevere Thunderstorm WarningBMXElmore, Montgomery34 min
Aug 20, 6:11 PM CDTSevere Thunderstorm WarningBMXBullock34 min
Aug 20, 2:36 PM CDTSevere Thunderstorm WarningBMXMuscogee29 min
Aug 20, 3:03 PM CDTSevere Thunderstorm WarningBMXMuscogee32 min
Aug 20, 3:36 PM CDTSevere Thunderstorm WarningBMXMuscogee49 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.