Alert archive / Louisiana / Special Weather Statements in 2021

Special Weather Statement, NWS New Orleans, LA

August 1, 2021Orleans Parish, Louisiana

NWS New Orleans, LA issued this special weather statement at Aug 1, 2021, 3:52 PM CDT for Orleans Parish, Louisiana. It was in force for 38 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: Aug 1, 2021, 3:52 PM CDT (20:52 UTC)
Expired: Aug 1, 2021, 4:30 PM CDT
In force: 38 min
Issued by: NWS New Orleans, LA

County Orleans Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 8.9 hours before the alert went out and 48 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1490 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 945 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: -22 m²/s²
0-3 km storm-relative helicity: -4 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 Aug 1, 12:56 PM CDT, 2 hours 56 minutes earlier.

Area forecast discussion, Aug 1, 12:56 PM CDT, 2 hours 56 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.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

In the hours before

Special weather statement, Aug 1, 3:00 PM CDT, 52 minutes before

Special Weather Statement
National Weather Service New Orleans LA
300 PM CDT Sun Aug 1 2021

MSZ070-071-012045-
Pike-Walthall-
300 PM CDT Sun Aug 1 2021

...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL WALTHALL AND
NORTHEASTERN PIKE COUNTIES...

At 259 PM CDT, a strong thunderstorm was located near Summit, or near
Mccomb. The storm is nearly stationary.

Wind gusts of 20 to 25 mph along with heavy rainfall and frequent
lightning are possible with this storm.

Locations impacted include...
Mccomb and Summit.

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

Frequent cloud to ground lightning is also occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 3122 9018 3112 9035 3129 9047 3135 9038
      3135 9031
TIME...MOT...LOC 1959Z 316DEG 4KT 3127 9036

95/DM

Special weather statement, Aug 1, 3:52 PM CDT, 0 minutes before

Special Weather Statement
National Weather Service New Orleans LA
352 PM CDT Sun Aug 1 2021

LAZ061-063-064-077-012130-
Western Orleans-Upper St. Bernard-Upper Plaquemines-Upper Jefferson-
352 PM CDT Sun Aug 1 2021

...A CLUSTER OF STRONG THUNDERSTORMS IS AFFECTING NORTHWESTERN ST.
BERNARD... ORLEANS...NORTHEASTERN JEFFERSON AND NORTHWESTERN
PLAQUEMINES PARISHES...

At 350 PM CDT, a cluster of strong thunderstorms was centered over
New Orleans. The storms are nearly stationary.

Wind gusts of 20 to 25 mph, heavy rainfall and frequent lightning
are possible with these storms.

Locations impacted include...
New Orleans, Chalmette, Marrero, Harvey, Timberlane, Belle Chasse,
Metairie, Jefferson, Gretna, Westwego, Terrytown, Arabi and Meraux.

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

Frequent cloud to ground lightning is also occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 2989 9014 3002 9014 3003 9008 3001 8992
      2985 8994
TIME...MOT...LOC 2050Z 287DEG 1KT 2998 9009

95/DM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 4:30 PM CDT	Special Weather Statement	LIX	Saint Charles	30 min
Aug 1, 4:33 PM CDT	Special Weather Statement	LIX	Saint Helena	27 min
Aug 1, 5:08 PM CDT	Special Weather Statement	LIX	Saint Helena	22 min
Aug 1, 5:13 PM CDT	Special Weather Statement	LIX	East Feliciana	32 min
Aug 1, 5:20 PM CDT	Special Weather Statement	LIX	Saint Tammany	25 min
Aug 1, 5:32 PM CDT	Special Weather Statement	LIX	Saint Tammany	28 min
Aug 1, 5:50 PM CDT	Special Marine Warning	LIX		55 min
Aug 1, 6:40 PM CDT	Special Marine Warning	LIX		50 min
Aug 1, 6:40 PM CDT	Special Marine Warning	LIX		65 min
Aug 1, 6:58 PM CDT	Special Weather Statement	LIX	West Feliciana	32 min
Aug 1, 3:00 PM CDT	Special Weather Statement	LIX	Pike	45 min
Aug 1, 3:58 PM CDT	Special Weather Statement	LIX	Pike	32 min
Aug 1, 4:11 PM CDT	Special Weather Statement	LIX	Wilkinson	49 min
Aug 1, 4:43 PM CDT	Special Weather Statement	LIX	Pearl River	32 min
Aug 1, 5:26 PM CDT	Special Weather Statement	LIX	Harrison	34 min
Aug 1, 6:03 PM CDT	Special Weather Statement	LIX	Hancock	27 min
Aug 1, 6:26 PM CDT	Special Weather Statement	LIX	Harrison	34 min

Nearby

Special Weather Statements in Louisiana, 2021 Every 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.