Alert archive / Louisiana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 185, NWS Shreveport, LA

August 12, 2021Natchitoches Parish, Louisiana

NWS Shreveport, LA issued this severe thunderstorm warning at Aug 12, 2021, 7:10 PM CDT for Natchitoches Parish, Louisiana. It was in force for 35 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 12, 2021, 7:10 PM CDT (00:10 UTC)
Expired
Aug 12, 2021, 7:45 PM CDT
In force
35 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Natchitoches Parish, LA

The radar

The Ft Polk radar (KPOE), 62 km from the middle of the area, began a volume at 00:08 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.

What was reported inside it

TimeReportWhereRemark
Aug 12, 7:21 PM CDTHAIL 0.882 Sw Natchitoches, LANICKEL SIZED HAIL REPORTED AT PARCH NATCHITOCHES.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 0.2 hours before the alert went out and 106 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 00:00Z on 2021-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1821 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Shreveport, LA at 00:00Z on 2021-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 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
1821 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
1706 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

877 
WUUS54 KSHV 130010
SVRSHV
LAC069-130045-
/O.NEW.KSHV.SV.W.0185.210813T0010Z-210813T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Shreveport LA
710 PM CDT Thu Aug 12 2021

The National Weather Service in Shreveport has issued a

* Severe Thunderstorm Warning for...
  Central Natchitoches Parish in northwestern Louisiana...

* Until 745 PM CDT.

* At 709 PM CDT, a severe thunderstorm was located just south of 
  Natchitoches, moving northwest at 10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Natchitoches, Provencal, Natchez and Hagewood. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3170 9298 3162 9307 3167 9329 3183 9318
TIME...MOT...LOC 0007Z 130DEG 7KT 3170 9308 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

15
1 follow-up statement
018 
WWUS54 KSHV 130037
SVSSHV

Severe Weather Statement
National Weather Service Shreveport LA
737 PM CDT Thu Aug 12 2021

LAC069-130045-
/O.CON.KSHV.SV.W.0185.000000T0000Z-210813T0045Z/
Natchitoches LA-
737 PM CDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR CENTRAL NATCHITOCHES PARISH...

At 737 PM CDT, a severe thunderstorm was located 5 miles west of 
Natchitoches, moving northwest at 10 mph. This storm has begun to 
weaken, but still may produce locally gusty winds along Interstate 
49 northwest of Natchitoches during the next 10 minutes. 

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Natchitoches and Hagewood. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3178 9312 3170 9317 3171 9326 3183 9318
TIME...MOT...LOC 0035Z 121DEG 10KT 3175 9320 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

15

Nearby

Severe Thunderstorm Warnings in Louisiana, 2021Every severe thunderstorm 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.