Alert archive / Alabama / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 520, NWS Birmingham, AL

August 25, 1999Etowah County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Aug 25, 1999, 6:37 PM CDT for Etowah County, Alabama. It was in force for 48 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
Aug 25, 1999, 6:37 PM CDT (23:37 UTC)
Expired
Aug 25, 1999, 7:25 PM CDT
In force
48 min
Issued by
NWS Birmingham, AL
Area
Whole counties

County Etowah County, AL

What was reported inside it

TimeReportWhereRemark
Aug 25, 6:51 PM CDTThunderstorm Wind 50Attalla, ALTrees were blown down at US 431 near Kelly's Auto Auction just north of Attalla.

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.

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 11.6 hours before the alert went out and 118 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 1999-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 648 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 1999-08-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
648 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
787 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.3

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
Aug 25, 2:20 PM CDTSevere Thunderstorm WarningBMXPike35 min
Aug 25, 3:30 PM CDTSevere Thunderstorm WarningBMXHale, Marengo30 min
Aug 25, 4:11 PM CDTTornado WarningBMXDallas34 min
Aug 25, 4:43 PM CDTTornado WarningBMXDallas32 min
Aug 25, 5:11 PM CDTSevere Thunderstorm WarningBMXMarengo34 min
Aug 25, 3:18 PM CDTSevere Thunderstorm WarningBMXStewart27 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.