Alert archive / Louisiana / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 23, NWS New Orleans, LA

May 21, 1990Saint Bernard Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at May 21, 1990, 4:11 PM CDT for Saint Bernard Parish, Louisiana. It was in force for 49 min.

The area

The counties it named.

The facts

Issued
May 21, 1990, 4:11 PM CDT (21:11 UTC)
Expired
May 21, 1990, 5:00 PM CDT
In force
49 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County 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, 9.2 hours before the alert went out and 43 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 1990-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2055 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 1990-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
2055 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
807 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.4

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, May 21, 12:53 PM CDT, 3 hours 18 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-211900-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1235 PM CDT MON MAY 21 1990

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR TANGIPAHOA AND WASHINGTON
PARISHES IN SOUTHEAST LOUISIANA UNTIL 5PM CDT...

AN AREA OF THUNDERSTORMS WERE OCCURRING OVER SOUTHERN MISSISSIPPI
BETWEEN JACKSON AND NATCHEZ EXTENDING EAST TO NEAR MERIDIAN. THE
AREA WAS MOVING SOUTH AT 25 MILES AN HOUR.

SCATTERED PATCHES OF LIGHT RAIN AND SHOWERS WERE ALSO OCCURRING OVER
EXTREME SOUTHEAST MISSISSIPPI AND SOUTHWEST ALABAMA.

THERE ARE NO THUNDERSTORMS OVER SOUTHEAST LOUISIANA AT THE PRESENT
TIME HOWEVER THUNDERSTORM ACTIVITY MAY DEVELOP AC/ROSS THE AREA THIS
AFTERNOON. THESE THUNDERSTORMS COULD BE CAPABLE OF PRODUCING STRONG
GUSTY WINDS...FREQUENT LIGHTNING...POSSIBLE HAIL AND HEAVY RAINS.
Special weather statement, May 21, 1:55 PM CDT, 2 hours 16 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-212000-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
145 PM CDT MON MAY 21 1990

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR TANGIPAHOA AND WASHINGTON
PARISHES IN SOUTHEAST LOUISIANA UNTIL 5PM CDT...

A LINE OF THUNDERSTORMS WAS OCCURRING FROM SOUTH OF MERIDIAN EXTENDING
SOUTHWEST TO BETWEEN HAZELHURST AND MC COMB AND CONTINUING SOUTHWEST TO
BETWEEN NATCHEZ MISSISSIPPI AND SIMMESPORT LOUISIANA.

OTHERWISE PATCHES OF LIGHT RAIN WITH SHOWERS AND THUNDESTORMS CONTINUED
ACROSS SOUTHERN MISSISSIPPI AND SOUTHWEST ALABAMA.

THERE IS NO THUNDERSTORM ACTIVITY OVER SOUTHEAST LOUISIANA HOWEVER
PRECIPITATION IS DEVELOPING NEAR THE AREA AND THE THUNDERSTORM ACTIVITY
OVER MISSISSIPPI IS SOUTH. THUNDERSTORMS ARE POSSIBLE AND WILL BE
CAPABLE OF PRODUCING STRONG GUSTY WINDS...FREQUENT LIGHTNING...POSSIBLE
HAIL AND HEAVY RAINS.
Special weather statement, May 21, 1:59 PM CDT, 2 hours 12 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-212000-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
145 PM CDT MON MAY 21 1990

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR TANGIPAHOA AND WASHINGTON
PARISHES IN SOUTHEAST LOUISIANA UNTIL 5PM CDT...

A LINE OF THUNDERSTORMS WAS OCCURRING FROM SOUTH OF MERIDIAN EXTENDING
SOUTHWEST TO BETWEEN HAZELHURST AND MC COMB AND CONTINUING SOUTHWEST TO
BETWEEN NATCHEZ MISSISSIPPI AND SIMMESPORT LOUISIANA.

OTHERWISE PATCHES OF LIGHT RAIN WITH SHOWERS AND THUNDESTORMS CONTINUED
ACROSS SOUTHERN MISSISSIPPI AND SOUTHWEST ALABAMA.

THERE IS NO THUNDERSTORM ACTIVITY OVER SOUTHEAST LOUISIANA HOWEVER
PRECIPITATION IS DEVELOPING NEAR THE AREA AND THE THUNDERSTORM ACTIVITY
OVER MISSISSIPPI IS MOVING SOUTH. THUNDERSTORMS ARE POSSIBLE AND WILL
BE CAPABLE OF PRODUCING STRONG GUSTY WINDS...FREQUENT LIGHTNING...
POSSIBLE HAIL AND HEAVY RAINS.
Special weather statement, May 21, 2:31 PM CDT, 1 hour 40 minutes before
LAZ009-212030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BATON ROUGE LA
230 PM CDT MON MAY 21 1990

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 5 PM CDT FOR EAST
CENTRAL LOUISIANA EXCEPT FOR ASCENSION PARISH...

RADAR SHOWED AN AREA OF THUNDERSTORMS EXTENDING EAST TO WEST ALONG THE
MISSISSIPPI/LOUISIANA BORDER FROM NORTHEAST OF KENTWOOD WESTWARD NORTH
OF ANGOLA CONTINUING INTO LOUISIANA NEAR JUST NORTH OF MARKSVILLE.  THE
THUNDERSTORMS WERE MOVING SOUTHWARD AROUND 25 MPH.

THESE THUNDERSTORMS WILL PRODUCE STRONG GUSTY WINDS AND SMALL HAIL AS
THEY MOVE INTO EAST AND WEST FELICIANA AND ST. HELENA PARISHES DURING
THE NEXT HOUR.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE
FOR SEVERE THUNDERSTORMS IN...AND CLOSE TO...THE WATCH AREA.  PERSONS
IN EAST CENTRAL LOUISIANA SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND/OR WARNINGS.
Local storm report, May 21, 3:01 PM CDT, 1 hour 10 minutes before
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Special weather statement, May 21, 3:49 PM CDT, 22 minutes before
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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 12:31 PM CDTSevere Thunderstorm WarningLIXCatahoula, Concordia74 min
May 21, 2:42 PM CDTSevere Thunderstorm WarningLIXTangipahoa, Washington63 min
May 21, 2:51 PM CDTSevere Thunderstorm WarningLIXEast Feliciana, West Feliciana69 min
May 21, 2:51 PM CDTSevere Thunderstorm WarningLIXSaint Helena69 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.