Alert archive / Louisiana / Special Weather Statements in 2021

Special Weather Statement, NWS Shreveport, LA

July 12, 2021LaSalle Parish, Louisiana

NWS Shreveport, LA issued this special weather statement at Jul 12, 2021, 6:15 AM CDT for LaSalle Parish, Louisiana. It was in force for 30 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
Jul 12, 2021, 6:15 AM CDT (11:15 UTC)
Expired
Jul 12, 2021, 6:45 AM CDT
In force
30 min
Issued by
NWS Shreveport, LA

County LaSalle Parish, LA

The radar

The Ft Polk radar (KPOE), 86 km from the middle of the area, began a volume at 11:18 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

Lake Charles Mun, LA (KLCH), launched 00:00Z, 11.3 hours before the alert went out and 177 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, Lake Charles Mun, LA at 00:00Z on 2021-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2736 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, Lake Charles Mun, LA at 00:00Z on 2021-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
2736 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
874 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
103 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 Shreveport, LA wrote its last area forecast discussion before this special weather statement went out at Jul 12, 4:30 AM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Jul 12, 4:30 AM CDT, 1 hour 45 minutes before
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<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
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  <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.
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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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Hazardous weather outlook, Jul 12, 6:06 AM CDT, 9 minutes before
Hazardous Weather Outlook
National Weather Service Shreveport LA
606 AM CDT Mon Jul 12 2021

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-
TXZ096-097-108>112-124>126-136>138-149>153-165>167-131115-
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-
606 AM CDT Mon Jul 12 2021

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...

Isolated to widely scattered showers and thunderstorms will remain
possible across much of the region today into this evening as an
upper level trough and stalled frontal boundary continue to linger.
Although no organized severe threat exists, any storms that manage
to develop may produce some gusty winds and brief heavy downpours.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday...

Diurnally driven showers and thunderstorms will remain possible
each day through the remainder of this week and into the weekend.
Stronger storms may be capable of producing gusty winds and brief
heavy downpours, generally more of a concern during the hours of
afternoon peak heating.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel, amateur radio
operators and storm spotters should not be needed through tonight.

19

In the hours before

Special weather statement, Jul 12, 6:15 AM CDT, 0 minutes before
Special Weather Statement
National Weather Service Shreveport LA
615 AM CDT Mon Jul 12 2021

LAZ020-022-121145-
La Salle LA-Grant LA-
615 AM CDT Mon Jul 12 2021

...SPECIAL WEATHER STATEMENT...

At 614 AM CDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Walters, or 16 miles northwest of Larto, moving
northeast at 55 mph.

Winds in excess of 30 mph will be possible with this storm.

Locations impacted include...
Nebo, Rogers and Catahoula Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

If on or near Catahoula Lake, get out of the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3134 9204 3132 9208 3134 9209 3135 9207
      3136 9208 3138 9212 3141 9215 3143 9216
      3145 9216 3146 9217 3147 9216 3148 9221
      3146 9232 3156 9230 3166 9201 3133 9201
TIME...MOT...LOC 1114Z 245DEG 46KT 3152 9213

24

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:23 PM CDTSpecial Weather StatementSHVRusk52 min
Jul 11, 8:25 PM CDTAreal Flood AdvisorySHVRusk110 min
Jul 11, 8:31 PM CDTSpecial Weather StatementSHVRusk44 min
Jul 11, 8:40 PM CDTSpecial Weather StatementSHVCherokee50 min
Jul 11, 9:10 PM CDTFlash Flood Warning Considerable damage threatSHVCherokee, Panola, Rusk, Shelby, Smith3 hr
Jul 11, 9:49 PM CDTSpecial Weather StatementSHVCherokee41 min
Jul 11, 10:27 PM CDTSpecial Weather StatementSHVNacogdoches48 min
Jul 11, 10:50 PM CDTSpecial Weather StatementSHVSmith40 min
Jul 11, 11:12 PM CDTSpecial Weather StatementSHVSmith48 min
Jul 11, 11:15 PM CDTSpecial Weather StatementSHVGregg45 min
Jul 12, 12:13 AM CDTFlash Flood WarningSHVCherokee, Rusk, Smith4 hr
Jul 12, 2:10 AM CDTAreal Flood AdvisorySHVCherokee, Nacogdoches3 hr
Jul 12, 6:28 AM CDTRiver Flood WarningSHVAnderson, Cherokee, Houston, Trinity21 days
Jul 12, 6:28 AM CDTRiver Flood WarningSHVNacogdoches, Rusk25 hr
Jul 12, 8:20 AM CDTRiver Flood WarningSHVAngelina, Houston, Polk, Trinity, Tyler11 days
Jul 12, 1:56 PM CDTSpecial Weather StatementSHVWood49 min
Jul 12, 2:37 PM CDTSevere Thunderstorm WarningSHVWood43 min
Jul 11, 7:12 PM CDTSpecial Weather StatementSHVRed River48 min
Jul 11, 8:03 PM CDTSpecial Weather StatementSHVWebster42 min
Jul 11, 8:53 PM CDTSpecial Weather StatementSHVCaddo52 min
Jul 12, 2:28 PM CDTSpecial Weather StatementSHVLafayette47 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; radar from the NEXRAD Level II archive.