Alert archive / Louisiana / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 20, NWS New Orleans, LA

January 22, 1999Livingston Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Jan 22, 1999, 5:46 PM CST for Livingston Parish, Louisiana. 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
Jan 22, 1999, 5:46 PM CST (23:46 UTC)
Expired
Jan 22, 1999, 6:20 PM CST
In force
34 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County Livingston Parish, LA

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jan 22, 3:00 PM CSTTornado WatchSPC6 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.8 hours before the alert went out and 101 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 12:00Z on 1999-01-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1281 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 12:00Z on 1999-01-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 386 square meters per square second.1939587897Sfc1 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
1281 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
515 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
386 m²/s²
0-3 km storm-relative helicity
445 m²/s²
Significant tornado parameter
2.4
Supercell composite
12.2

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
Jan 22, 2:50 PM CSTSevere Thunderstorm WarningLIXWest Feliciana30 min
Jan 22, 3:33 PM CSTSevere Thunderstorm WarningLIXIberville32 min
Jan 22, 3:51 PM CSTSevere Thunderstorm WarningLIXEast Baton Rouge, West Baton Rouge49 min
Jan 22, 4:05 PM CSTSevere Thunderstorm WarningLIXEast Feliciana, Livingston, Saint Helena35 min
Jan 22, 4:40 PM CSTSevere Thunderstorm WarningLIXSaint Helena, Tangipahoa45 min
Jan 22, 5:33 PM CSTSevere Thunderstorm WarningLIXAscension, Assumption, Saint James42 min
Jan 22, 5:55 PM CSTSevere Thunderstorm WarningLIXLafourche, Terrebonne30 min
Jan 22, 3:06 PM CSTTornado WarningLIXWilkinson34 min
Jan 22, 5:07 PM CSTTornado WarningLIXPike33 min
Jan 22, 5:18 PM CSTTornado WarningLIXWalthall32 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 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.