Alert archive / Louisiana / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 68, NWS New Orleans, LA

September 4, 1990Orleans Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Sep 4, 1990, 8:55 PM CDT for Orleans Parish, Louisiana. It was in force for 65 min.

The area

The counties it named.

The facts

Issued
Sep 4, 1990, 8:55 PM CDT (01:55 UTC)
Expired
Sep 4, 1990, 10:00 PM CDT
In force
65 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County Orleans 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 00:00Z, 1.9 hours before the alert went out and 30 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 1990-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1824 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 1990-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
1824 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
1659 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.3

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, Sep 4, 8:09 PM CDT, 46 minutes before
LAZ009-050300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BATON ROUGE LA
810 PM CDT TUE SEP 4 1990

...A BAND OF THUNDERSTORMS WERE MOVING TOWARD THE BATON ROUGE METROPOLITAN
AREA...

RADAR SHOWED THUNDERSTORMS FROM NEAR INDIAN MOUND TO MONTPELIER.
MOVING WEST SOUTHWEST AT 15 MPH.

AS THESE THUNDERSTORMS MOVE THROUGH THE AREA...THEY WILL PRODUCE STRONG
GUSTY WINDS...HEAVY RAINS...FREQUENT LIGHTNING WITH SOME SMALL HAIL.
THESE CONDITIONS SHOULD LAST UNTIL 10 PM TONIGHT.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 8:55 PM CDTSevere Thunderstorm WarningLIXJefferson, Saint Charles, Saint John the Baptist65 min
Sep 4, 8:55 PM CDTSevere Thunderstorm WarningLIXTangipahoa65 min
Sep 4, 9:34 PM CDTSevere Thunderstorm WarningLIXLafourche, Saint Charles, Saint John the Baptist56 min
Sep 4, 9:34 PM CDTSevere Thunderstorm WarningLIXSaint James56 min
Sep 4, 10:45 PM CDTSevere Thunderstorm WarningLIXIberia, Saint Martin, St. Mary105 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.