Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 106, NWS New Orleans, LA

August 30, 20215 parishes in Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 30, 2021, 7:45 AM CDT for 5 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
Aug 30, 2021, 7:45 AM CDT (12:45 UTC)
Expired
Aug 30, 2021, 10:45 AM CDT
In force
3 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties Livingston Parish, LA, Saint Helena Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 0.8 hours before the alert went out and 94 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 12:00Z on 2021-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 881 joules per kilogram.LCLEL10008507005003002001001 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, Slidell Radar S, LA at 12:00Z on 2021-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 386 square meters per square second.19395878Sfc1 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
881 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
560 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
386 m²/s²
0-3 km storm-relative helicity
386 m²/s²
Significant tornado parameter
1.1
Supercell composite
9.7

Open this sounding in Storm Lab

The text

As transmitted.

442 
WGUS54 KLIX 301245
FFWLIX
LAC063-091-103-105-117-301545-
/O.NEW.KLIX.FF.W.0106.210830T1245Z-210830T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
Issued by National Weather Service Lake Charles LA
745 AM CDT Mon Aug 30 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Northern Livingston Parish in southeastern Louisiana...
  Eastern St. Helena Parish in southeastern Louisiana...
  Northwestern St. Tammany Parish in southeastern Louisiana...
  Northern Tangipahoa Parish in southeastern Louisiana...
  Western Washington Parish in southeastern Louisiana...

* Until 1045 AM CDT.

* At 745 AM CDT, While heavy rainfall has ended, gauge reports 
  indicated continued rapidly rising water across the warned area. 
  Between 4 and 8 inches of rain have fallen. Flash flooding is 
  already occurring.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Gauges reported.

  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...
  Franklinton, Greensburg, Amite, Amite City, Kentwood, 
  Independence, Roseland, Folsom, Sun, Osyka, Wilmer, Mount Herman, 
  Easleyville, Darlington and Tangipahoa.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3081 9063 3081 9065 3081 9080 3099 9082
      3100 9062 3100 9019 3089 9018 3071 9009
      3064 8993 3060 9005 3060 9062

FLASH FLOOD...GAUGE INDICATED

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 7:48 PM CDTFlash Flood Warning Considerable damage threatLIXSaint Charles, Saint John the Baptist2 hr
Aug 29, 8:00 PM CDTSpecial Marine WarningLIX30 min
Aug 29, 8:22 PM CDTTornado WarningLIXSaint Tammany38 min
Aug 29, 8:35 PM CDTFlash Flood Warning EmergencyCatastrophic damage threatLIXSaint Charles, Saint John the Baptist6 hr
Aug 29, 8:55 PM CDTFlash Flood Warning EmergencyConsiderable damage threatLIXLivingston, Tangipahoa3 hr
Aug 29, 9:05 PM CDTRiver Flood WarningLIXSaint Tammany12 days
Aug 29, 9:05 PM CDTRiver Flood WarningLIXSaint Tammany21 days
Aug 29, 9:05 PM CDTRiver Flood WarningLIXWashington63 hr
Aug 29, 9:05 PM CDTRiver Flood WarningLIXSaint Tammany, Washington11 days
Aug 29, 10:39 PM CDTSpecial Marine WarningLIX51 min
Aug 29, 10:48 PM CDTFlash Flood Warning EmergencyCatastrophic damage threatLIXJefferson15 hr
Aug 29, 10:55 PM CDTSpecial Marine WarningLIX20 min
Aug 29, 11:45 PM CDTFlash Flood Warning EmergencyCatastrophic damage threatLIXPlaquemines10 hr
Aug 29, 11:50 PM CDTFlash Flood Warning Considerable damage threatLIXLivingston, Saint Helena, Saint Tammany, Tangipahoa, Washington3 hr
Aug 30, 12:05 AM CDTFlash Flood Warning EmergencyCatastrophic damage threatLIXLivingston, Tangipahoa12 hr
Aug 30, 1:24 AM CDTFlash Flood WarningLIXLivingston, Saint Helena8 hr
Aug 30, 2:24 AM CDTFlash Flood Warning EmergencyCatastrophic damage threatLIXSaint Charles, Saint John the Baptist8 hr
Aug 30, 2:39 AM CDTFlash Flood Warning Considerable damage threatLIXSaint Tammany9 hr
Aug 30, 2:55 AM CDTFlash Flood Warning Considerable damage threatLIXLivingston, Saint Helena, Saint Tammany, Tangipahoa, Washington5 hr
Aug 30, 3:55 AM CDTFlash Flood WarningLIXEast Feliciana, Saint Helena, Tangipahoa, Washington5 hr
Aug 30, 4:19 AM CDTSmall Craft AdvisoryLIX39 hr
Aug 30, 4:51 AM CDTCoastal Flood AdvisoryLIXAssumption15 hr
Aug 30, 7:15 AM CDTSpecial Marine WarningLIX30 min
Aug 30, 7:18 AM CDTSpecial Marine WarningLIX27 min
Aug 30, 9:01 AM CDTSpecial Marine WarningLIX89 min
Aug 30, 9:58 AM CDTAreal Flood WarningLIXJefferson, Lafourche, Livingston, Plaquemines, Saint Charles, Saint James and 1 more60 hr
Aug 30, 10:53 AM CDTAreal Flood WarningLIXSaint Tammany, Tangipahoa, Washington35 hr
Aug 30, 11:04 AM CDTAreal Flood WarningLIXSaint Helena, Saint Tammany, Tangipahoa, Washington35 hr
Aug 30, 11:34 AM CDTAreal Flood WarningLIXSaint Tammany, Washington34 hr
Aug 30, 12:24 PM CDTAreal Flood WarningLIXAscension, Livingston, Saint John the Baptist, Saint Tammany, Tangipahoa33 hr
Aug 30, 2:57 PM CDTHeat AdvisoryLIXAssumption, East Baton Rouge, Iberville, Orleans, Saint Bernard, Saint James and 2 more26 hr
Aug 30, 6:10 PM CDTSpecial Marine WarningLIX95 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.