Alert archive / Louisiana / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 99, NWS New Orleans, LA

April 29, 1991Terrebonne Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Apr 29, 1991, 5:57 PM CDT for Terrebonne Parish, Louisiana. It was in force for 63 min.

The area

The counties it named.

The facts

Issued
Apr 29, 1991, 5:57 PM CDT (22:57 UTC)
Expired
Apr 29, 1991, 7:00 PM CDT
In force
63 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County Terrebonne Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.0 hours before the alert went out and 150 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 1991-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2664 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 1991-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 193 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
2664 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
578 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
193 m²/s²
0-3 km storm-relative helicity
211 m²/s²
Significant tornado parameter
2.6
Supercell composite
12.9

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
Apr 28, 7:01 PM CDTSevere Thunderstorm WarningLIXPointe Coupee, West Feliciana44 min
Apr 29, 5:52 PM CDTSevere Thunderstorm WarningLIXIberville68 min
Apr 29, 6:22 PM CDTSevere Thunderstorm WarningLIXAscension, East Baton Rouge68 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1991Every severe thunderstorm warning in 1991

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.