Alert archive / Louisiana / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 52, NWS Shreveport, LA

April 12, 2020Grant Parish, LaSalle Parish, Natchitoches Parish, Louisiana

NWS Shreveport, LA issued this severe thunderstorm warning at Apr 12, 2020, 3:42 PM CDT for Grant Parish, LaSalle Parish, Natchitoches Parish, Louisiana. It was in force for 63 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 12, 2020, 3:42 PM CDT (20:42 UTC)
Expired: Apr 12, 2020, 4:45 PM CDT
In force: 63 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Grant Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA

The radar

The Ft Polk radar (KPOE), 67 km from the middle of the area, began a volume at 20:46 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 8.7 hours before the alert went out and 141 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: 605 J/kg
Mixed-layer CIN: -277 J/kg
Mixed-layer LCL: 681 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 255 m²/s²
0-3 km storm-relative helicity: 308 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

Open this sounding in Storm Lab

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.

NWS Shreveport, LA wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 12, 1:03 PM CDT, 2 hours 39 minutes earlier.

Area forecast discussion, Apr 12, 1:03 PM CDT, 2 hours 39 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>

Hazardous weather outlook, Apr 12, 5:14 AM CDT, 10 hours 28 minutes before

Hazardous Weather Outlook
National Weather Service Shreveport LA
514 AM CDT Sun Apr 12 2020

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-
TXZ096-097-108>112-124>126-136>138-149>153-165>167-131200-
Sevier-Howard-Little River-Hempstead-Nevada-Miller-Lafayette-
Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-De Soto-
Red River-Bienville-Jackson-Ouachita-Sabine-Natchitoches-Winn-
Grant-Caldwell-La Salle-McCurtain-Bowie-Franklin-Titus-Camp-
Morris-Cass-Wood-Upshur-Marion-Smith-Gregg-Harrison-Cherokee-Rusk-
Panola-Nacogdoches-Shelby-Angelina-San Augustine-
514 AM CDT Sun Apr 12 2020

This Hazardous Weather Outlook is for portions of south central
Arkansas, southwest Arkansas, north central Louisiana, northwest
Louisiana, southeast Oklahoma, east Texas and northeast Texas.

.DAY ONE...Today and Tonight...

A volatile airmass will be in place across much of the Four State
Region. An upper level disturbance will move our way from the
west, interact with this airmass and the end result will be severe
thunderstorms, some of which will produce very large hail,
destructive thunderstorm wind gusts and isolated tornadoes, some
of which could be long tracked tornadoes. This threat will begin
to taper off somewhat early this afternoon but rematerialize near
and north of the Interstate 20 Corridor of Northeast Texas,
Southeast Oklahoma, Southwest Arkansas and extreme Northern
Louisiana as the upper trough itself moves overhead. The severe
weather theat will then diminish late this evening across the
entire Four State Region.

.DAYS TWO THROUGH SEVEN...Monday through Saturday...

No hazardous weather is anticipated at this time.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel...amateur radio
operators...and storm spotters will be needed today into this
evening for severe thunderstorms. Please relay any information
about observed severe weather to the NWS while following all
local, state, and CDC guidelines.

13

In the hours before

Local storm report, Apr 12, 1:51 PM CDT, 1 hour 51 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>

Special weather statement, Apr 12, 2:24 PM CDT, 1 hour 18 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>

Special weather statement, Apr 12, 3:19 PM CDT, 23 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>

Local storm report, Apr 12, 3:20 PM CDT, 22 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>

Local storm report, Apr 12, 3:34 PM CDT, 8 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>

Special weather statement, Apr 12, 3:37 PM CDT, 5 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 Shreveport, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 12, 2:45 AM CDT	Lake Wind Advisory	SHV	Angelina, Bowie, Camp, Cass, Cherokee, Franklin and 15 more	21 hr
Apr 12, 5:41 AM CDT	Special Weather Statement	SHV	Gregg, Smith	49 min
Apr 12, 6:33 AM CDT	Special Weather Statement	SHV	Harrison	42 min
Apr 12, 7:03 AM CDT	Severe Thunderstorm Warning	SHV	Cherokee, Gregg, Rusk, Smith, Upshur	57 min
Apr 12, 7:12 AM CDT	Tornado Warning	SHV	Cherokee, Gregg, Rusk, Smith	48 min
Apr 12, 7:32 AM CDT	Severe Thunderstorm Warning	SHV	Cherokee, Rusk, Smith	58 min
Apr 12, 7:48 AM CDT	Flash Flood Warning	SHV	Cherokee, Gregg, Rusk, Smith	3 hr
Apr 12, 7:51 AM CDT	Tornado Warning	SHV	Gregg, Harrison, Panola, Rusk, Smith, Upshur	39 min
Apr 12, 7:56 AM CDT	Tornado Warning	SHV	Cherokee, Gregg, Rusk, Smith	34 min
Apr 12, 8:21 AM CDT	Severe Thunderstorm Warning	SHV	Gregg, Harrison, Panola, Rusk, Shelby	54 min
Apr 12, 8:28 AM CDT	Severe Thunderstorm Warning	SHV	Gregg, Harrison, Marion, Upshur	47 min
Apr 12, 8:31 AM CDT	Severe Thunderstorm Warning	SHV	Angelina, Cherokee, Nacogdoches, Panola, Rusk, San Augustine and 1 more	44 min
Apr 12, 8:46 AM CDT	Flash Flood Warning Considerable damage threat	SHV	Cass, Gregg, Harrison, Marion, Panola, Rusk	2 hr
Apr 12, 9:04 AM CDT	Tornado Warning	SHV	Panola, Shelby	26 min
Apr 12, 9:12 AM CDT	Severe Thunderstorm Warning	SHV	Cass	63 min
Apr 12, 9:15 AM CDT	Severe Thunderstorm Warning	SHV	Harrison, Panola	45 min
Apr 12, 9:15 AM CDT	Tornado Warning	SHV	Harrison	30 min
Apr 12, 9:20 AM CDT	Severe Thunderstorm Warning	SHV	Panola, Shelby	40 min
Apr 12, 11:05 AM CDT	Areal Flood Warning	SHV	Smith	115 min
Apr 12, 12:00 PM CDT	Special Weather Statement	SHV	Panola	30 min
Apr 12, 12:06 PM CDT	River Flood Warning	SHV	Gregg	44 hr
Apr 12, 12:16 PM CDT	Severe Thunderstorm Warning	SHV	Panola	27 min
Apr 12, 2:02 PM CDT	River Flood Warning	SHV	Franklin, Morris, Red River, Titus	71 hr
Apr 12, 2:10 PM CDT	River Flood Warning	SHV	Cass, Marion	6 days
Apr 12, 2:12 PM CDT	River Flood Warning	SHV	Anderson, Cherokee, Houston, Trinity	21 days
Apr 12, 4:44 PM CDT	Special Weather Statement	SHV	Bowie, Titus	46 min
Apr 12, 4:51 PM CDT	Severe Thunderstorm Warning	SHV	Red River	54 min
Apr 12, 4:55 PM CDT	Severe Thunderstorm Warning	SHV	Bowie, Morris, Red River, Titus	65 min
Apr 12, 5:03 PM CDT	Special Weather Statement	SHV	Red River	42 min
Apr 12, 5:39 PM CDT	Severe Thunderstorm Warning	SHV	Bowie, Red River	66 min
Apr 12, 5:49 PM CDT	Severe Thunderstorm Warning	SHV	Bowie, Cass	41 min
Apr 12, 6:19 PM CDT	Severe Thunderstorm Warning	SHV	Cass	56 min
Apr 12, 6:30 PM CDT	Special Weather Statement	SHV	Bowie	60 min
Apr 12, 6:48 PM CDT	Severe Thunderstorm Warning	SHV	Gregg, Harrison, Marion, Rusk, Smith, Upshur and 1 more	57 min
Apr 12, 6:50 PM CDT	Special Weather Statement	SHV	Cass	55 min
Apr 12, 6:55 PM CDT	Severe Thunderstorm Warning	SHV	Bowie, Cass, Marion	50 min
Apr 12, 8:28 AM CDT	Severe Thunderstorm Warning	SHV	Ouachita	17 min
Apr 12, 9:30 AM CDT	Tornado Warning	SHV	De Soto	30 min
Apr 12, 9:41 AM CDT	Tornado Warning	SHV	Bossier, Caddo	28 min
Apr 12, 9:51 AM CDT	Tornado Warning Tornado observedConsiderable damage threat	SHV	Bienville, Bossier, Caddo, De Soto, Red River, Webster	24 min
Apr 12, 9:53 AM CDT	Tornado Warning	SHV	Bossier, Caddo, De Soto, Red River	29 min
Apr 12, 9:58 AM CDT	Severe Thunderstorm Warning	SHV	Bienville, Bossier, De Soto, Natchitoches, Red River, Sabine and 1 more	62 min
Apr 12, 10:00 AM CDT	Severe Thunderstorm Warning	SHV	Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 2 more	60 min
Apr 12, 10:04 AM CDT	Tornado Warning	SHV	Bossier, Claiborne, Webster	19 min
Apr 12, 10:07 AM CDT	Tornado Warning	SHV	Bienville, Natchitoches, Red River	23 min
Apr 12, 10:10 AM CDT	Tornado Warning Tornado observed	SHV	Bienville, Bossier, Red River, Webster	39 min
Apr 12, 10:13 AM CDT	Tornado Warning	SHV	Bienville, Claiborne, Lincoln, Webster	47 min
Apr 12, 10:28 AM CDT	Tornado Warning	SHV	Bienville, Natchitoches	47 min
Apr 12, 10:46 AM CDT	Tornado Warning	SHV	Bienville, Jackson	29 min
Apr 12, 10:47 AM CDT	Severe Thunderstorm Warning	SHV	Claiborne, Jackson, Lincoln, Ouachita, Union	58 min
Apr 12, 10:56 AM CDT	Tornado Warning Tornado observed	SHV	Bienville, Claiborne, Lincoln, Union	24 min
Apr 12, 11:16 AM CDT	Tornado Warning	SHV	Lincoln, Ouachita, Union	29 min
Apr 12, 11:33 AM CDT	Tornado Warning Emergency	SHV	Ouachita	29 min
Apr 12, 11:42 AM CDT	Tornado Warning Tornado observedConsiderable damage threat	SHV	Ouachita	18 min
Apr 12, 12:54 PM CDT	Special Weather Statement	SHV	Claiborne, Webster	51 min
Apr 12, 1:25 PM CDT	Special Weather Statement	SHV	Union	35 min
Apr 12, 1:50 PM CDT	Special Weather Statement	SHV	Caldwell	40 min
Apr 12, 1:55 PM CDT	Severe Thunderstorm Warning	SHV	Caldwell, LaSalle, Ouachita, Winn	24 min
Apr 12, 2:24 PM CDT	Special Weather Statement	SHV	Natchitoches	51 min
Apr 12, 3:19 PM CDT	Special Weather Statement	SHV	Natchitoches, Winn	41 min
Apr 12, 3:37 PM CDT	Special Weather Statement	SHV	Jackson, Ouachita	38 min
Apr 12, 3:59 PM CDT	Severe Thunderstorm Warning	SHV	Caldwell, Grant, LaSalle, Winn	46 min
Apr 12, 6:35 PM CDT	Special Weather Statement	SHV	Ouachita	40 min
Apr 12, 6:41 PM CDT	Special Weather Statement	SHV	Claiborne	49 min
Apr 12, 8:05 AM CDT	Special Weather Statement	SHV	Columbia, Union	40 min
Apr 12, 6:24 PM CDT	Severe Thunderstorm Warning	SHV	Hempstead, Howard, Little River, Sevier	51 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2020 Every severe thunderstorm warning in 2020

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; radar from the NEXRAD Level II archive.