Alert archive / Louisiana / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 91, NWS New Orleans, LA

May 4, 1999Saint James Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at May 4, 1999, 2:16 PM CDT for Saint James Parish, Louisiana. It was in force for 49 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
May 4, 1999, 2:16 PM CDT (19:16 UTC)
Expired
May 4, 1999, 3:05 PM CDT
In force
49 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County Saint James Parish, LA

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 7.3 hours before the alert went out and 264 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, Jackson, MS at 12:00Z on 1999-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 111 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, Jackson, MS at 12:00Z on 1999-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 155 square meters per square second.19395878Sfc1 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
111 J/kg
Mixed-layer CIN
-567 J/kg
Mixed-layer LCL
807 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
211 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

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
May 4, 1:42 PM CDTSevere Thunderstorm WarningLIXAssumption48 min
May 4, 1:51 PM CDTSevere Thunderstorm WarningLIXLafourche, Terrebonne49 min
May 4, 2:16 PM CDTSevere Thunderstorm WarningLIXSaint Charles, Saint John the Baptist49 min
May 4, 3:10 PM CDTSevere Thunderstorm WarningLIXSaint John the Baptist35 min
May 4, 3:18 PM CDTSevere Thunderstorm WarningLIXLivingston, Tangipahoa62 min
May 4, 3:27 PM CDTSevere Thunderstorm WarningLIXSaint Tammany48 min
May 4, 2:55 PM CDTSevere Thunderstorm WarningLIXHarrison, Jackson50 min
May 4, 4:27 PM CDTSevere Thunderstorm WarningLIXHancock, Pearl River33 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.