Alert archive / Louisiana / Tropical Storm Warnings in 2021

Tropical Storm Warning 1009, NWS New Orleans, LA

August 27, 202111 parishes in Louisiana; 5 counties in Mississippi

NWS New Orleans, LA issued this tropical storm warning at Aug 27, 2021, 4:01 PM CDT for 11 parishes in Louisiana; 5 counties in Mississippi. It was in force for 24 days. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 27, 2021, 4:01 PM CDT (21:01 UTC)
Expired: Sep 20, 2021, 10:28 AM CDT
In force: 24 days
Issued by: NWS New Orleans, LA

Counties Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Orleans Parish, LA, Saint Bernard Parish, LA, Saint Helena Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Feliciana Parish, LA, Amite County, MS, Pearl River County, MS, Pike County, MS, Walthall County, MS, Wilkinson County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.0 hours before the alert went out and 89 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: 311 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 965 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -57 m²/s²
0-3 km storm-relative helicity: -13 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this tropical storm warning 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 tropical storm warning went out at Aug 27, 1:04 PM CDT, 2 hours 57 minutes earlier.

Area forecast discussion, Aug 27, 1:04 PM CDT, 2 hours 57 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

Local storm report, Aug 27, 2:44 PM CDT, 1 hour 17 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>

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 26, 10:09 PM CDT	Hurricane Watch	LIX	Assumption, East Baton Rouge, East Feliciana, Iberville, Orleans, Pointe Coupee and 9 more	36 hr
Aug 26, 10:09 PM CDT	Storm Surge Watch	LIX	Assumption, Orleans, Saint Bernard, Saint James, Saint John the Baptist, Saint Tammany	18 hr
Aug 27, 3:34 AM CDT	Special Marine Warning	LIX		116 min
Aug 27, 5:27 AM CDT	Special Marine Warning	LIX		48 min
Aug 27, 6:19 AM CDT	Special Marine Warning	LIX		56 min
Aug 27, 7:12 AM CDT	Special Marine Warning	LIX		63 min
Aug 27, 8:34 AM CDT	Special Marine Warning	LIX		56 min
Aug 27, 10:10 AM CDT	Areal Flood Advisory	LIX	Orleans, Saint Tammany	3 hr
Aug 27, 10:17 AM CDT	Flash Flood Watch	LIX	Orleans, Saint Bernard, Saint James, Saint John the Baptist, Saint Tammany	12 hr
Aug 27, 12:21 PM CDT	Special Marine Warning	LIX		54 min
Aug 27, 4:01 PM CDT	Hurricane Warning	LIX	Assumption, East Baton Rouge, East Feliciana, Iberville, Orleans, Pointe Coupee and 9 more	60 hr
Aug 27, 4:12 PM CDT	Storm Surge Warning	LIX	Assumption, Iberville, Orleans, Saint Bernard, Saint James, Saint John the Baptist and 1 more	3 days
Aug 27, 9:37 AM CDT	River Flood Warning	LIX	Harrison	6 days
Aug 27, 9:37 AM CDT	River Flood Warning	LIX	Hancock	5 days
Aug 27, 9:37 AM CDT	River Flood Warning	LIX	Harrison	5 days
Aug 27, 9:37 AM CDT	River Flood Warning	LIX	Harrison	6 days
Aug 27, 10:46 AM CDT	Tropical Storm Watch	LIX	Amite, Pearl River, Pike, Walthall, Wilkinson	5 hr
Aug 27, 1:28 PM CDT	Areal Flood Advisory	LIX	Harrison, Jackson	3 hr
Aug 27, 1:44 PM CDT	Flash Flood Warning	LIX	Harrison	3 hr

Nearby

Tropical Storm Warnings in Louisiana, 2021 Tropical Storm Warnings in Mississippi, 2021 Every tropical storm warning 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.