Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 84, NWS New Orleans, LA

August 23, 2021Ascension Parish, East Baton Rouge Parish, Iberville Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 23, 2021, 7:13 PM CDT for Ascension Parish, East Baton Rouge Parish, Iberville Parish, Louisiana. It was in force for 57 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
Aug 23, 2021, 7:13 PM CDT (00:13 UTC)
Expired
Aug 23, 2021, 8:10 PM CDT
In force
57 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties Ascension Parish, LA, East Baton Rouge Parish, LA, Iberville Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 0.2 hours before the alert went out and 128 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, Slidell Radar S, LA at 00:00Z on 2021-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 999 joules per kilogram.LCLLFCEL10008507005003002001001 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, Slidell Radar S, LA at 00:00Z on 2021-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
999 J/kg
Mixed-layer CIN
-99 J/kg
Mixed-layer LCL
1430 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
19 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

140 
WGUS54 KLIX 240013
FFWLIX
LAC005-033-047-240315-
/O.NEW.KLIX.FF.W.0084.210824T0013Z-210824T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
713 PM CDT Mon Aug 23 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Northwestern Ascension Parish in southeastern Louisiana...
  Southeastern East Baton Rouge Parish in southeastern Louisiana...
  Eastern Iberville Parish in southeastern Louisiana...

* Until 1015 PM CDT.

* At 713 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  St. Gabriel, Prairieville, Old Jefferson and Village St. George.

This includes the following Interstates...
	Interstate 10 in Louisiana between mile markers 166 and 173.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3033 9106 3034 9106 3035 9106 3036 9105
      3037 9105 3037 9103 3037 9101 3037 9100
      3036 9100 3036 9099 3033 9098 3030 9097
      3027 9096 3026 9102 3025 9103 3028 9105
      3029 9105 3030 9106

FLASH FLOOD...RADAR INDICATED

$$

TD
1 follow-up statement
068 
WGUS74 KLIX 240110
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
810 PM CDT Mon Aug 23 2021

LAC005-033-047-240120-
/O.CAN.KLIX.FF.W.0084.000000T0000Z-210824T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ascension LA-East Baton Rouge LA-Iberville LA-
810 PM CDT Mon Aug 23 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN ASCENSION, 
SOUTHEASTERN EAST BATON ROUGE AND EASTERN IBERVILLE PARISHES...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3033 9106 3034 9106 3035 9106 3036 9105
      3037 9105 3037 9103 3037 9101 3037 9100
      3036 9100 3036 9099 3033 9098 3030 9097
      3027 9096 3026 9102 3025 9103 3028 9105
      3029 9105 3030 9106

$$

TD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 7:00 PM CDTSpecial Weather StatementLIXIberville30 min
Aug 23, 7:03 PM CDTSpecial Weather StatementLIXSaint Charles27 min
Aug 23, 7:18 PM CDTSpecial Marine WarningLIX117 min
Aug 23, 7:28 PM CDTSpecial Weather StatementLIXJefferson47 min
Aug 23, 8:37 PM CDTSpecial Weather StatementLIXLafourche38 min
Aug 23, 9:08 PM CDTSpecial Marine WarningLIX97 min
Aug 23, 10:29 PM CDTSpecial Marine WarningLIX91 min
Aug 23, 11:56 PM CDTSpecial Marine WarningLIX94 min
Aug 24, 4:27 AM CDTSpecial Weather StatementLIXLafourche48 min
Aug 24, 2:49 PM CDTSpecial Weather StatementLIXEast Feliciana26 min
Aug 24, 3:19 PM CDTSpecial Weather StatementLIXIberville26 min
Aug 24, 3:26 PM CDTSpecial Weather StatementLIXEast Feliciana49 min
Aug 24, 3:27 PM CDTSpecial Weather StatementLIXTerrebonne33 min
Aug 24, 3:41 PM CDTSpecial Weather StatementLIXEast Baton Rouge34 min
Aug 24, 4:05 PM CDTSpecial Weather StatementLIXPointe Coupee40 min
Aug 24, 4:07 PM CDTSpecial Weather StatementLIXIberville38 min
Aug 24, 4:07 PM CDTSpecial Weather StatementLIXTerrebonne38 min
Aug 24, 4:18 PM CDTSpecial Weather StatementLIXIberville27 min
Aug 24, 4:31 PM CDTSpecial Weather StatementLIXAssumption44 min
Aug 24, 4:51 PM CDTSpecial Weather StatementLIXLafourche39 min
Aug 24, 5:52 PM CDTSpecial Marine WarningLIX38 min

Nearby

Flash Flood Warnings in Louisiana, 2021Every 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.