Alert archive / Louisiana / Special Weather Statements in 2021

Special Weather Statement, NWS New Orleans, LA

June 29, 2021Saint John the Baptist Parish, Louisiana

NWS New Orleans, LA issued this special weather statement at Jun 29, 2021, 5:28 PM CDT for Saint John the Baptist Parish, Louisiana. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 29, 2021, 5:28 PM CDT (22:28 UTC)
Expired
Jun 29, 2021, 6:15 PM CDT
In force
47 min
Issued by
NWS New Orleans, LA

County Saint John the Baptist Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 10.5 hours before the alert went out and 78 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 2021-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1396 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 2021-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -41 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
1396 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
740 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-41 m²/s²
0-3 km storm-relative helicity
-28 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

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

NWS New Orleans, LA wrote its last area forecast discussion before this special weather statement went out at Jun 29, 3:09 PM CDT, 2 hours 19 minutes earlier.

Area forecast discussion, Jun 29, 3:09 PM CDT, 2 hours 19 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <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.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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In the hours before

Special weather statement, Jun 29, 12:36 PM CDT, 4 hours 52 minutes before
Special Weather Statement
National Weather Service New Orleans LA
1236 PM CDT Tue Jun 29 2021

LAZ056-291800-
Assumption-
1236 PM CDT Tue Jun 29 2021

...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL ASSUMPTION
PARISH...

At 1235 PM CDT, a strong thunderstorm was located over Belle River,
moving west at 20 mph.

Winds in excess of 40 mph are possible with this storm.

This storm will remain over mainly rural areas of west central
Assumption Parish.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 2993 9110 2984 9113 2985 9118 2986 9120
      2990 9121 2992 9123 2993 9123 2995 9125
      2999 9126
TIME...MOT...LOC 1735Z 104DEG 16KT 2991 9122

KLG
Special weather statement, Jun 29, 2:14 PM CDT, 3 hours 14 minutes before
Special Weather Statement
National Weather Service New Orleans LA
214 PM CDT Tue Jun 29 2021

LAZ037-071-291945-
St. Helena-Northern Tangipahoa-
214 PM CDT Tue Jun 29 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN ST. HELENA AND
NORTHERN TANGIPAHOA PARISHES...

At 214 PM CDT, a strong thunderstorm was located near Wilmer, or 7
miles northeast of Amite, moving northwest at 25 mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
Greensburg, Amite City, Kentwood, Roseland, Wilmer and Tangipahoa.

This includes Interstate 55 in Louisiana between mile markers 49 and
64.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 3081 9031 3072 9036 3078 9068 3084 9073
      3100 9064 3100 9054
TIME...MOT...LOC 1914Z 117DEG 23KT 3079 9041

KLG
Special weather statement, Jun 29, 4:35 PM CDT, 53 minutes before
Special Weather Statement
National Weather Service New Orleans LA
435 PM CDT Tue Jun 29 2021

LAZ060-061-063-068-069-292215-
Lower Plaquemines-St. Charles-Lower Jefferson-Upper Plaquemines-Upper
Jefferson-
435 PM CDT Tue Jun 29 2021

...A STRONG THUNDERSTORM WILL AFFECT ST. CHARLES...NORTHERN
JEFFERSON AND NORTHWESTERN PLAQUEMINES PARISHES...

At 434 PM CDT, a strong thunderstorm was located near Luling, or 7
miles west of Avondale, moving northwest at 10 mph.

A Waterspout was reported over Lake Cataouatche, and additional
waterspouts or weak tropical funnel clouds will be possible in these
storms.

Locations impacted include... Avondale, Hahnville, Marrero, Belle
Chasse, Harvey, Harahan, Westwego, Jean Lafitte, Montz, Luling,
Boutte, Ama, Destrehan, Estelle, St. Rose, Woodmere, Killona, Norco,
Paradis and Lafitte.

This includes Interstate 310 between mile markers 2 and 11.

Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 2979 9046 2985 9048 2987 9050 2986 9051
      2989 9054 2991 9053 2999 9055 3001 9054
      3003 9049 3003 9045 3005 9043 2978 8989
      2959 8997
TIME...MOT...LOC 2134Z 134DEG 8KT 2988 9031

KLG
Local storm report, Jun 29, 4:54 PM CDT, 34 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
454 PM CDT TUE JUN 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0429 PM     WATER SPOUT      6 W BARATARIA           29.73N 90.23W
06/29/2021                   ST. CHARLES        LA   EMERGENCY MNGR

            RELAYED REPORT OF A WATERSPOUT OVER LAKE
            SALVADOR.

&&

TD
Special weather statement, Jun 29, 5:05 PM CDT, 23 minutes before
Special Weather Statement
National Weather Service New Orleans LA
505 PM CDT Tue Jun 29 2021

LAZ060-061-292230-
St. Charles-Upper Jefferson-
505 PM CDT Tue Jun 29 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL ST. CHARLES AND
NORTHWESTERN JEFFERSON PARISHES...

At 505 PM CDT, a strong thunderstorm was located near New Sarpy, or
near Hahnville, moving northwest at 25 mph.

A funnel cloud and winds in excess of 40 mph are possible with this
storm.

Locations impacted include...
Hahnville, Laplace, Norco, Ama, Destrehan, New Sarpy, St. Rose,
Montz, Taft, Luling and New Orleans Armstrong Airport.

This includes the following Interstates...
 Interstate 10 in Louisiana between mile markers 213 and 223.
 Interstate 310 between mile markers 1 and 7.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 3003 9047 3003 9045 3006 9043 3008 9041
      3006 9037 3005 9027 3000 9023 2994 9028
      2994 9038
TIME...MOT...LOC 2205Z 135DEG 22KT 3002 9033

KLG
Special weather statement, Jun 29, 5:28 PM CDT, 0 minutes before
Special Weather Statement
National Weather Service New Orleans LA
528 PM CDT Tue Jun 29 2021

LAZ049-058-292315-
Ascension-St. John The Baptist-
528 PM CDT Tue Jun 29 2021

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL ST. JOHN THE BAPTIST AND
EAST CENTRAL ASCENSION PARISHES...

At 527 PM CDT, a strong thunderstorm was located near Laplace, moving
northwest at 25 mph.

Winds in excess of 40 mph and isolated waterspouts or funnel
clouds are possible with these storms.

Locations impacted include...
Laplace, Reserve, Montz and Edgard.

This includes the following Interstates...
 Interstate 10 in Louisiana between mile markers 202 and 211.
 Interstate 55 in Louisiana between mile markers 1 and 14.

LAT...LON 3023 9064 3021 9061 3023 9058 3019 9060
      3017 9057 3017 9050 3022 9044 3029 9040
      3030 9031 3026 9034 3022 9041 3019 9043
      3008 9041 3003 9045 3003 9047 3019 9068
      3021 9068
TIME...MOT...LOC 2227Z 138DEG 22KT 3011 9043

KLG

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 28, 10:58 PM CDTSpecial Marine WarningLIX62 min
Jun 29, 12:04 PM CDTSpecial Weather StatementLIXSaint Helena41 min
Jun 29, 12:36 PM CDTSpecial Weather StatementLIXAssumption24 min
Jun 29, 2:14 PM CDTSpecial Weather StatementLIXSaint Helena31 min
Jun 29, 4:35 PM CDTSpecial Weather StatementLIXSaint Charles40 min
Jun 29, 5:05 PM CDTSpecial Weather StatementLIXSaint Charles25 min
Jun 29, 5:23 PM CDTSpecial Marine WarningLIX25 min

Nearby

Special Weather Statements in Louisiana, 2021Every special weather statement in 2021

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.