Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 7, NWS Lake Charles, LA

May 11, 20214 parishes in Louisiana

NWS Lake Charles, LA issued this flash flood warning at May 11, 2021, 8:52 AM 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 11, 2021, 8:52 AM CDT (13:52 UTC)
Expired: May 11, 2021, 12:00 PM CDT
In force: 3 hr
Issued by: NWS Lake Charles, LA
Area: Storm-based polygon
Flood severity: None

Counties Acadia Parish, LA, Lafayette Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA

The radar

The Lake Charles radar (KLCH), 135 km from the middle of the area, began a volume at 13:53 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, 1.9 hours before the alert went out and 133 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: 2925 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 472 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 11.9

Open this sounding in Storm Lab

The text

As transmitted.

151 
WGUS54 KLCH 111352
FFWLCH
LAC001-055-097-099-111700-
/O.NEW.KLCH.FF.W.0007.210511T1352Z-210511T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lake Charles LA
852 AM CDT Tue May 11 2021

The National Weather Service in Lake Charles has issued a

* Flash Flood Warning for...
  Southern St. Landry Parish in central Louisiana...
  Lafayette Parish in south central Louisiana...
  Northwestern St. Martin Parish in south central Louisiana...
  Central Acadia Parish in southwestern Louisiana...

* Until noon CDT.

* At 852 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 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...
  Lafayette, Crowley, Catahoula, Scott, Breaux Bridge, Rayne, 
  Carencro, Church Point, Iota, Arnaudville, Broussard, Sunset, 
  Duson, Henderson, Grand Coteau, Cankton, Mire, Branch, Cecilia and 
  Richard.

This includes the following highways...
	Interstate 10 in Louisiana between mile markers 75 and 126.
	Interstate 49 between mile markers 1 and 13.

Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 3050 9228 3040 9190 3039 9163 3037 9164
      3037 9165 3035 9163 3031 9162 3028 9159
      3026 9159 3024 9156 3024 9151 3023 9148
      3021 9149 3020 9149 3017 9199 3017 9241
      3023 9249 3038 9253

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-3 INCHES IN 1 HOUR 

$$

Brazzell

1 follow-up statement

891 
WGUS74 KLCH 111609
FFSLCH

Flash Flood Statement
National Weather Service Lake Charles LA
1109 AM CDT Tue May 11 2021

LAC001-055-097-099-111700-
/O.CON.KLCH.FF.W.0007.000000T0000Z-210511T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Acadia LA-Lafayette LA-St. Landry LA-St. Martin LA-
1109 AM CDT Tue May 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON CDT TODAY FOR 
SOUTHEASTERN ST. LANDRY, NORTHERN LAFAYETTE, NORTHWESTERN ST. MARTIN 
AND EAST CENTRAL ACADIA PARISHES...

At 1109 AM CDT, Doppler radar indicated thunderstorms have moved out 
of the warned area. Between 2 and 4 inches of rain have fallen 
earlier this morning.

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...
  Lafayette, Catahoula, Scott, Breaux Bridge, Carencro, Arnaudville, 
  Broussard, Sunset, Duson, Henderson, Grand Coteau, Cankton, 
  Cecilia, Atchafalaya Welcome Center, Butte La Rose and Parks.

This includes the following highways...
	Interstate 10 in Louisiana between mile markers 91 and 126.
	Interstate 49 between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 3022 9224 3033 9217 3043 9206 3040 9190
      3039 9163 3037 9164 3037 9165 3035 9163
      3031 9162 3028 9159 3026 9159 3024 9156
      3024 9151 3023 9148 3020 9149 3017 9199
      3020 9223

FLASH FLOOD...RADAR INDICATED

$$

Brazzell

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 9:59 PM CDT	River Flood Warning	LCH	Acadia, Evangeline, Saint Landry	23 hr
May 11, 3:20 AM CDT	Flash Flood Watch	LCH	Allen, Avoyelles, Beauregard, Cameron, Evangeline, Lafayette and 4 more	34 hr
May 11, 6:14 AM CDT	Special Weather Statement	LCH	Saint Martin	16 min
May 11, 6:29 AM CDT	Special Weather Statement	LCH	Vernon	31 min
May 11, 6:50 AM CDT	Special Weather Statement	LCH	Vernon	25 min
May 11, 6:55 AM CDT	Severe Thunderstorm Warning	LCH	Rapides, Vernon	18 min
May 11, 7:17 AM CDT	Special Weather Statement	LCH	Acadia	43 min
May 11, 7:22 AM CDT	Special Weather Statement	LCH	Rapides	23 min
May 11, 7:48 AM CDT	Severe Thunderstorm Warning	LCH	Lafayette, Saint Landry	16 min
May 11, 8:04 AM CDT	Special Weather Statement	LCH	Acadia, Lafayette	41 min
May 11, 8:40 AM CDT	Severe Thunderstorm Warning	LCH	Allen, Jefferson Davis	33 min
May 11, 10:24 AM CDT	River Flood Watch	LCH	Allen, Evangeline	25 hr
May 11, 10:24 AM CDT	River Flood Warning	LCH	Lafayette, Saint Landry, Saint Martin	4 days
May 11, 10:24 AM CDT	River Flood Warning	LCH	Lafayette, Saint Martin, Vermilion	33 days
May 11, 10:24 AM CDT	River Flood Warning	LCH	Allen, Calcasieu, Jefferson Davis	18 days
May 11, 10:24 AM CDT	River Flood Warning	LCH	Allen, Beauregard	21 days
May 11, 10:24 AM CDT	River Flood Warning	LCH	Allen, Beauregard	4 days
May 11, 6:43 PM CDT	Special Weather Statement	LCH	Saint Martin	47 min
May 11, 6:57 PM CDT	Tornado Warning	LCH	Iberia, St. Mary	33 min

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.