Alert archive / Louisiana / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 59, NWS New Orleans, LA

August 30, 19904 parishes in Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Aug 30, 1990, 6:48 PM CDT for 4 parishes in Louisiana. It was in force for 57 min.

The area

The counties it named.

The facts

Issued
Aug 30, 1990, 6:48 PM CDT (23:48 UTC)
Expired
Aug 30, 1990, 7:45 PM CDT
In force
57 min
Issued by
NWS New Orleans, LA
Area
Whole counties

Counties Jefferson Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.8 hours before the alert went out and 55 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 1990-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2438 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 1990-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
2438 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
889 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
6 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.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Aug 30, 3:44 PM CDT, 3 hours 4 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-302200-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
340 PM CDT THU AUG 30 1990

...SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 9 PM CDT FOR ALL OF
SOUTHEAST LOUISIANA...

SCATTERED THUNDERSTORMS CONTINUED TO DEVELOP ACROSS SOUTHEAST LOUISIANA
AND SOUTH MISSISSIPPI FROM BETWEEN HAMMOND AND MCCOMB EAST BETWEEN
POPLARVILLE AND LAUREL AND CONTINUED EAST INTO SOUTHWEST ALABAM#A.

THE STRONGEST THUNDERSTORMS WERE LOCATED BETWEEN BOGALUSA LOUISIANA AND
HATTIESBURG MISSISSIPPI AND EXTENDED EAST TO THE MOBILE AREA.

MOVEMENT WAS SOUTHEAST AT 20 MILES AN HOUR.

The office that day

Everything else NWS New Orleans, LA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 30, 2:28 PM CDTSevere Thunderstorm WarningLIXCatahoula, Concordia62 min
Aug 30, 3:16 PM CDTSevere Thunderstorm WarningLIXAvoyelles59 min
Aug 30, 4:01 PM CDTSevere Thunderstorm WarningLIXSaint Tammany59 min
Aug 30, 4:58 PM CDTSevere Thunderstorm WarningLIXSaint Tammany47 min
Aug 30, 5:46 PM CDTSevere Thunderstorm WarningLIXSaint Tammany29 min
Aug 30, 6:02 PM CDTSevere Thunderstorm WarningLIXJefferson, Orleans, Saint Bernard58 min
Aug 30, 6:15 PM CDTSevere Thunderstorm WarningLIXTangipahoa60 min
Aug 30, 6:48 PM CDTSevere Thunderstorm WarningLIXSaint Charles57 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1990Every severe thunderstorm warning in 1990

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.