Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 20, NWS New Orleans, LA

April 16, 20214 parishes in Louisiana

NWS New Orleans, LA issued this flash flood warning at Apr 16, 2021, 11:46 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
Apr 16, 2021, 11:46 PM CDT (04:46 UTC)
Expired
Apr 17, 2021, 2:45 AM CDT
In force
3 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties East Baton Rouge Parish, LA, Livingston Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 4.8 hours before the alert went out and 121 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 2021-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
828 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
151 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

538 
WGUS54 KLIX 170446
FFWLIX
LAC033-063-091-105-170745-
/O.NEW.KLIX.FF.W.0020.210417T0446Z-210417T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
1146 PM CDT Fri Apr 16 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Northeastern East Baton Rouge Parish in southeastern Louisiana...
  Northern Livingston Parish in southeastern Louisiana...
  Southern St. Helena Parish in southeastern Louisiana...
  Central Tangipahoa Parish in southeastern Louisiana...

* Until 245 AM CDT.

* At 1146 PM 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...
  Baton Rouge, Hammond, Zachary, Baker, Denham Springs, Amite, 
  Walker, Amite City, Livingston, Independence, Albany, Montpelier, 
  Watson, Natalbany, Greenwell Spring, Pride, Merrydale, Robert, 
  Brownfields and Tickfaw.

Additional rainfall amounts of 1 to 2 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.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3044 9119 3053 9119 3069 9122 3072 9091
      3072 9089 3072 9088 3072 9085 3072 9084
      3077 9028 3049 9026

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 2 HOURS 

$$

TE
1 follow-up statement
024 
WGUS74 KLIX 170641
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
141 AM CDT Sat Apr 17 2021

LAC033-063-091-170651-
/O.CAN.KLIX.FF.W.0020.000000T0000Z-210417T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Baton Rouge LA-Livingston LA-St. Helena LA-
141 AM CDT Sat Apr 17 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHEASTERN EAST BATON 
ROUGE, NORTHERN LIVINGSTON AND SOUTHERN ST. HELENA PARISHES...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

A Flash Flood Watch remains in effect until 100 PM CDT Saturday for 
portions of southeast Louisiana and southern Mississippi.

LAT...LON 3074 9057 3077 9028 3049 9026 3047 9055
      3048 9056 3049 9057 3050 9057

$$

LAC105-170745-
/O.CON.KLIX.FF.W.0020.000000T0000Z-210417T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tangipahoa LA-
141 AM CDT Sat Apr 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 AM CDT EARLY THIS 
MORNING FOR CENTRAL TANGIPAHOA PARISH...

At 141 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...
  Hammond, Amite, Amite City, Independence, Natalbany, Robert and 
  Tickfaw.

Additional rainfall amounts of .5 to 1 inches are possible in the 
warned area with this thunderstorm.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3074 9057 3077 9028 3049 9026 3047 9055
      3048 9056 3049 9057 3050 9057

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.25-1 INCH IN 1 HOUR 

$$

TE

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 16, 7:36 PM CDTSpecial Weather StatementLIXLivingston54 min
Apr 16, 8:16 PM CDTSpecial Weather StatementLIXSaint Tammany74 min
Apr 16, 8:19 PM CDTSpecial Marine WarningLIX27 min
Apr 16, 9:10 PM CDTSpecial Marine WarningLIX38 min
Apr 17, 1:11 AM CDTSpecial Marine WarningLIX64 min
Apr 17, 2:23 AM CDTSpecial Marine WarningLIX22 min
Apr 17, 4:05 AM CDTSmall Craft AdvisoryLIX24 hr
Apr 17, 11:57 AM CDTAreal Flood AdvisoryLIXAssumption, Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard and 4 more3 hr
Apr 17, 12:15 PM CDTRiver Flood WarningLIXLivingston46 hr
Apr 17, 12:39 PM CDTSpecial Weather StatementLIXLafourche36 min
Apr 17, 1:25 PM CDTFlash Flood WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard3 hr
Apr 17, 4:55 PM CDTSpecial Marine WarningLIX65 min
Apr 17, 5:13 PM CDTSpecial Marine WarningLIX62 min
Apr 17, 6:14 PM CDTSpecial Marine WarningLIX61 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.