Alert archive / Louisiana / Flash Flood Warnings in 2016

Flash Flood Warning 72, NWS New Orleans, LA

August 20, 2016Ascension Parish, Iberville Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 20, 2016, 3:58 PM CDT for Ascension Parish, Iberville Parish, 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 20, 2016, 3:58 PM CDT (20:58 UTC)
Expired
Aug 20, 2016, 7:00 PM CDT
In force
3 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties Ascension Parish, LA, Iberville Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.0 hours before the alert went out and 126 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 2016-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1891 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, Slidell Radar S, LA at 12:00Z on 2016-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -53 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
1891 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
715 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-53 m²/s²
0-3 km storm-relative helicity
-34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

573 
WGUS54 KLIX 202058
FFWLIX
LAC005-047-210000-
/O.NEW.KLIX.FF.W.0072.160820T2058Z-160821T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
358 PM CDT SAT AUG 20 2016

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN IBERVILLE PARISH IN SOUTHEASTERN LOUISIANA...
  ASCENSION PARISH IN SOUTHEASTERN LOUISIANA...

* UNTIL 700 PM CDT

* AT 357 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA. AROUND THREE INCHES OF RAIN
  HAVE ALREADY FALLEN. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY
  AND IS OVER AREAS THAT RECENTLY HAD SIGNIFICANT FLOODING.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  GONZALES...DONALDSONVILLE...ST. GABRIEL...SORRENTO...GEISMER AND
  PRAIRIEVILLE.

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 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.

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

&&

LAT...LON 3032 9106 3032 9103 3034 9101 3034 9086
      3033 9085 3013 9084 3011 9091 3007 9096
      3007 9099 3008 9101 3007 9106 3008 9108
      3008 9109 3006 9109 3006 9116

$$

24/RR
1 follow-up statement
651 
WGUS74 KLIX 202244
FFSLIX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
544 PM CDT SAT AUG 20 2016

LAC005-047-202253-
/O.CAN.KLIX.FF.W.0072.000000T0000Z-160821T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
IBERVILLE LA-ASCENSION LA-
544 PM CDT SAT AUG 20 2016

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN IBERVILLE AND ASCENSION
PARISHES IS CANCELLED...

THE HEAVY RAIN HAS ENDED. FLOODING IS NO LONGER EXPECTED TO POSE A
THREAT. 

A FLOOD ADVISORY REMAINS IN EFFECT THROUGH 3 PM CDT MONDAY. 

LAT...LON 3032 9106 3032 9103 3034 9101 3034 9086
      3033 9085 3013 9084 3011 9091 3007 9096
      3007 9099 3008 9101 3007 9106 3008 9108
      3008 9109 3006 9109 3006 9116

$$

24/RR

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 2:59 PM CDTAreal Flood AdvisoryLIXAscension, East Baton Rouge, Iberville, Livingston, Saint James, Saint John the Baptist3 days
Aug 20, 3:23 PM CDTSpecial Weather StatementLIXAscension, East Baton Rouge, Livingston, Saint Helena67 min

Nearby

Flash Flood Warnings in Louisiana, 2016Every flash flood warning in 2016

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.