Alert archive / Mississippi / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 229, NWS New Orleans, LA

August 25, 1999Walthall County, Mississippi

NWS New Orleans, LA issued this severe thunderstorm warning at Aug 25, 1999, 11:31 PM CDT for Walthall County, Mississippi. 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 25, 1999, 11:31 PM CDT (04:31 UTC)
Expired
Aug 26, 1999, 12:05 AM CDT
In force
34 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County Walthall County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 4.5 hours before the alert went out and 107 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, Slidell Radar S, LA at 00:00Z on 1999-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1620 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, Slidell Radar S, LA at 00:00Z on 1999-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
1620 J/kg
Mixed-layer CIN
-63 J/kg
Mixed-layer LCL
1336 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
94 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 New Orleans, LA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 26, 2:04 PM CDTSevere Thunderstorm WarningLIXPlaquemines26 min
Aug 26, 2:30 PM CDTSevere Thunderstorm WarningLIXPlaquemines30 min
Aug 26, 3:16 PM CDTSevere Thunderstorm WarningLIXAscension, Saint James29 min
Aug 26, 3:48 PM CDTSevere Thunderstorm WarningLIXSaint Charles27 min
Aug 25, 10:18 PM CDTSevere Thunderstorm WarningLIXPearl River62 min
Aug 25, 11:11 PM CDTSevere Thunderstorm WarningLIXHancock, Harrison59 min

Nearby

Severe Thunderstorm Warnings in Mississippi, 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.