Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 31, NWS Lake Charles, LA

May 20, 20214 parishes in Louisiana

NWS Lake Charles, LA issued this flash flood warning at May 20, 2021, 5:16 PM CDT for 4 parishes in Louisiana. It was in force for 3 hr. 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 20, 2021, 5:16 PM CDT (22:16 UTC)
Expired: May 20, 2021, 8:15 PM CDT
In force: 3 hr
Issued by: NWS Lake Charles, LA
Area: Storm-based polygon
Flood severity: None

Counties Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Jefferson Davis Parish, LA

The radar

The Lake Charles radar (KLCH), 11 km from the middle of the area, began a volume at 22:19 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, 10.3 hours before the alert went out and 9 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: 138 J/kg
Mixed-layer CIN: -95 J/kg
Mixed-layer LCL: 697 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 220 m²/s²
0-3 km storm-relative helicity: 296 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

506 
WGUS54 KLCH 202216
FFWLCH
LAC011-019-023-053-210115-
/O.NEW.KLCH.FF.W.0031.210520T2216Z-210521T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lake Charles LA
516 PM CDT Thu May 20 2021

The National Weather Service in Lake Charles has issued a

* Flash Flood Warning for...
  Southwestern Beauregard Parish in southwestern Louisiana...
  Calcasieu Parish in southwestern Louisiana...
  Eastern Cameron Parish in southwestern Louisiana...
  Southwestern Jefferson Davis Parish in southwestern Louisiana...

* Until 815 PM CDT.

* At 516 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Lake Charles, Sulphur, Cameron, Westlake, Iowa, Lake Charles 
  Regional Airport, Hayes, Grand Lake, Lacassine National Wildlife 
  Refuge, Moss Bluff, Grand Chenier, Ragley, De Quincy, Rockefeller 
  Wildlife Range, Holmwood, Hacketts Corner, Sweet Lake, Lebleu 
  Settlement, Gibbstown and Heberts Marina.

Additional rainfall amounts of 2 to 4 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3048 9363 3060 9328 3046 9313 3042 9313
      3042 9309 3006 9268 3006 9269 3004 9272
      3004 9267 2960 9270 2978 9320 2988 9326
      3003 9330 3003 9332 2998 9332

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3.5 INCHES IN 3 HOURS 

$$

06

The office that day

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

Issued	Product	Office	Counties	Lasted
May 19, 10:00 PM CDT	Flash Flood Warning	LCH	Cameron	3 hr
May 19, 10:27 PM CDT	Special Marine Warning	LCH		33 min
May 19, 10:29 PM CDT	Special Marine Warning	LCH		31 min
May 19, 10:54 PM CDT	Severe Thunderstorm Warning	LCH	Calcasieu, Cameron, Jefferson Davis	36 min
May 19, 10:56 PM CDT	Special Marine Warning	LCH		34 min
May 19, 11:29 PM CDT	Severe Thunderstorm Warning	LCH	Calcasieu, Cameron, Jefferson Davis	17 min
May 20, 3:55 AM CDT	Coastal Flood Advisory	LCH	Cameron	18 hr
May 20, 9:27 AM CDT	River Flood Warning	LCH	Calcasieu, Cameron	21 days
May 20, 4:04 PM CDT	Flash Flood Warning	LCH	Acadia, Allen, Jefferson Davis, Vermilion	5 hr

Nearby

Flash Flood Warnings in Louisiana, 2021 Every flash flood 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.