Alert archive / Texas / Special Weather Statements in 2021

Special Weather Statement, NWS Shreveport, LA

May 17, 2021Shelby County, Texas; De Soto Parish, Louisiana

NWS Shreveport, LA issued this special weather statement at May 17, 2021, 12:13 PM CDT for Shelby County, Texas; De Soto Parish, Louisiana. It was in force for 47 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
May 17, 2021, 12:13 PM CDT (17:13 UTC)
Expired
May 17, 2021, 1:00 PM CDT
In force
47 min
Issued by
NWS Shreveport, LA

Counties De Soto Parish, LA, Shelby County, TX

The radar

The Shreveport radar (KSHV), 78 km from the middle of the area, began a volume at 17:14 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, 5.2 hours before the alert went out and 84 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, Shreveport, LA at 12:00Z on 2021-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 269 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, Shreveport, LA at 12:00Z on 2021-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 square meters per square second.193958Sfc1 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
269 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
462 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
212 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 May 17, 11:46 AM CDT, 27 minutes earlier.

Area forecast discussion, May 17, 11:46 AM CDT, 27 minutes before
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</head>
<body>
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    <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.
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        Please try again in a few minutes.
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Hazardous weather outlook, May 17, 6:11 AM CDT, 6 hours 2 minutes before
Hazardous Weather Outlook
National Weather Service Shreveport LA
611 AM CDT Mon May 17 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>167-181100-
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-
611 AM CDT Mon May 17 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...

Showers and thunderstorms will increase across the region today,
ahead of an upper level disturbance that will move through the
area. Isolated strong to severe thunderstorms can not be ruled
out, with damaging winds, hail, and brief heavy rainfall possible.
These showers and thunderstorms will diminish this evening with
the departure of this disturbance.

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

Showers and thunderstorms will again return to the region Tuesday
in advance of an upper level storm system that will progress
through the Southern Rockies and into West Texas and the Oklahoma
Panhandle by midweek. The threat for locally heavy rainfall and
flash flooding will increase Tuesday night and Wednesday across
East Texas, Southeast Oklahoma, portions of Southwest Arkansas and
possibly Western Louisiana, as a complex of showers and
thunderstorms moves into these areas. Some of these storms may
also become severe during the late afternoon through the evening
hours Tuesday, before the heavy rain and flash flood threat
increases across these areas Tuesday night and Wednesday.
Widespread rainfall amounts of three to five inches are expected
this week across these areas this week, with isolated higher
amounts in excess of eight inches possible, especially over East
Texas. This rainfall will result in new rises and possible
flooding on area creeks and bayous, rivers and lakes. This
unsettled weather pattern will continue Thursday and Friday,
before gradually diminishing from east to west this weekend.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel...amateur radio
operators...and storm spotters may be needed today across portions
of the region.

15

In the hours before

Local storm report, May 17, 11:18 AM CDT, 55 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1118 AM CDT MON MAY 17 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1017 AM     FLASH FLOOD      PINELAND                31.25N 93.97W
05/17/2021                   SABINE             TX   BROADCAST MEDIA

            SOME ROADS AND AREAS IN SABINE COUNTY ARE
            EXPERIENCING FLOODING: HIGHWAY 87 S
            YELLOWPINE AREA 96 IN BROOKELAND HIGHWAY 21
            TO NACOGDOCHES ANGELINA RIVER.

&&

25
Special weather statement, May 17, 12:13 PM CDT, 0 minutes before
Special Weather Statement
National Weather Service Shreveport LA
1213 PM CDT Mon May 17 2021

LAZ001-010-017-TXZ151>153-166-171800-
De Soto LA-Caddo LA-Sabine LA-Panola TX-Nacogdoches TX-
San Augustine TX-Shelby TX-
1213 PM CDT Mon May 17 2021

...SIGNIFICANT WEATHER ADVISORY FOR DE SOTO...SOUTHWESTERN CADDO AND
NORTHWESTERN SABINE PARISHES...SOUTHEASTERN PANOLA...EAST CENTRAL
NACOGDOCHES...SHELBY AND NORTHERN SAN AUGUSTINE COUNTIES UNTIL 100 PM
CDT...

At 1213 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles south of Deberry to 8 miles northwest
of Joaquin to near Tenaha to 6 miles northeast of Martinsville to
Melrose. Movement was east at 25 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Center, Mansfield, San Augustine, Stonewall, Logansport, Tenaha,
Joaquin, Melrose, Patroon, Martinsville, Bland Lake, Neuville,
Shelbyville, Chireno, Huxley, South Mansfield, Keachi, Grand Cane,
Longstreet and Stanley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3154 9457 3169 9438 3189 9424 3206 9419
      3227 9426 3230 9374 3201 9364 3185 9369
      3165 9383 3160 9389 3157 9398 3152 9398
      3144 9408
TIME...MOT...LOC 1713Z 275DEG 21KT 3220 9420 3206 9414 3189 9420 3169
9433 3159 9446

13

The office that day

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

IssuedProductOfficeCountiesLasted
May 16, 8:47 PM CDTRiver Flood WarningSHVFranklin, Morris, Red River, Titus20 days
May 16, 8:48 PM CDTRiver Flood WarningSHVWood7 days
May 16, 8:50 PM CDTRiver Flood WarningSHVFranklin, Morris, Titus21 days
May 17, 4:34 AM CDTAreal Flood AdvisorySHVSabine, San Augustine4 hr
May 17, 8:49 AM CDTRiver Flood WarningSHVGregg6 days
May 17, 8:54 AM CDTRiver Flood WarningSHVCass, Marion13 days
May 17, 8:56 AM CDTRiver Flood WarningSHVGregg, Harrison, Marion, Upshur10 days
May 17, 11:13 AM CDTAreal Flood WarningSHVAngelina, Nacogdoches, Sabine, San Augustine, Shelby6 hr
May 17, 1:02 PM CDTSpecial Weather StatementSHVSabine43 min
May 17, 1:56 PM CDTFlash Flood WatchSHVAngelina, Bowie, Camp, Cass, Cherokee, Franklin and 15 more5 days
May 17, 2:10 PM CDTRiver Flood WarningSHVPanola, Shelby5 days
May 17, 9:06 AM CDTRiver Flood WarningSHVBienville, Bossier, Red River, Webster29 hr
May 17, 1:59 PM CDTSpecial Weather StatementSHVBienville, Natchitoches, Winn61 min
May 17, 2:55 PM CDTSpecial Weather StatementSHVGrant, Winn65 min

Nearby

Special Weather Statements in Texas, 2021Special 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.