Alert archive / Texas / Flash Flood Watches in 2020

Flash Flood Watch 7, NWS Shreveport, LA

August 25, 202021 counties in Texas; 17 parishes in Louisiana; 9 counties in Arkansas

NWS Shreveport, LA issued this flash flood watch at Aug 25, 2020, 2:49 PM CDT for 21 counties in Texas; 17 parishes in Louisiana; 9 counties in Arkansas. It took effect at Aug 26, 2020, 7:00 PM CDT. It was in force for 32 hr.

The area

The counties it named.

The facts

Issued: Aug 25, 2020, 2:49 PM CDT (19:49 UTC)
In effect from: Aug 26, 2020, 7:00 PM CDT
Expired: Aug 28, 2020, 3:12 AM CDT
In force: 32 hr
Issued by: NWS Shreveport, LA
Flood severity: None

All 47 counties

Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 16 km from the middle of the area, began a volume at 19:53 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 12:00Z, 7.8 hours before the alert went out and 282 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: 382 J/kg
Mixed-layer CIN: -120 J/kg
Mixed-layer LCL: 737 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -26 m²/s²
0-3 km storm-relative helicity: -1 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 flash flood watch 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 flash flood watch went out at Aug 25, 1:26 PM CDT, 1 hour 23 minutes earlier.

Area forecast discussion, Aug 25, 1:26 PM CDT, 1 hour 23 minutes before

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Hazardous weather outlook, Aug 25, 5:27 AM CDT, 9 hours 22 minutes before

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<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>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
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        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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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 25, 10:47 AM CDT	Hurricane Watch	SHV	Angelina, Nacogdoches, Sabine, San Augustine	11 hr
Aug 25, 10:47 AM CDT	Tropical Storm Watch	SHV	Cherokee, Gregg, Harrison, Marion, Panola, Rusk and 4 more	18 hr

Nearby

Flash Flood Watches in Texas, 2020 Flash Flood Watches in Louisiana, 2020 Flash Flood Watches in Arkansas, 2020 Every flash flood watch 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.