Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 44, NWS New Orleans, LA

May 20, 20214 parishes in Louisiana; Amite County, Wilkinson County, Mississippi

NWS New Orleans, LA issued this flash flood warning at May 20, 2021, 9:45 AM CDT for 4 parishes in Louisiana; Amite County, Wilkinson County, Mississippi. It was in force for 11 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 20, 2021, 9:45 AM CDT (14:45 UTC)
Expired
May 20, 2021, 8:45 PM CDT
In force
11 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties East Baton Rouge Parish, LA, East Feliciana Parish, LA, Saint Helena Parish, LA, West Feliciana Parish, LA, Amite County, MS, Wilkinson County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 2.8 hours before the alert went out and 154 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 2021-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 622 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 12:00Z on 2021-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 152 square meters per square second.193958Sfc1 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
622 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
599 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

131 
WGUS54 KLIX 201445
FFWLIX
LAC033-037-091-125-MSC005-157-201745-
/O.NEW.KLIX.FF.W.0044.210520T1445Z-210520T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
945 AM CDT Thu May 20 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Northeastern East Baton Rouge Parish in southeastern Louisiana...
  East Feliciana Parish in southeastern Louisiana...
  Western St. Helena Parish in southeastern Louisiana...
  Eastern West Feliciana Parish in southeastern Louisiana...
  Southwestern Amite County in southern Mississippi...
  Southeastern Wilkinson County in southern Mississippi...

* Until 1245 PM CDT.

* At 945 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2.5 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...
  Zachary, Jackson, Clinton, Centreville, Woodville, Slaughter, 
  Wilson, Norwood, Spillman and Pride.

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.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3101 9137 3115 9129 3115 9106 3115 9099
      3071 9084 3065 9091 3068 9092 3068 9128

FLASH FLOOD...RADAR INDICATED

$$

CAB
4 follow-up statements
126 
WGUS54 KLIX 201732
FFWLIX
LAC033-037-091-125-MSC005-157-201945-
/O.EXT.KLIX.FF.W.0044.000000T0000Z-210520T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
1232 PM CDT Thu May 20 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Northeastern East Baton Rouge Parish in southeastern Louisiana...
  East Feliciana Parish in southeastern Louisiana...
  Western St. Helena Parish in southeastern Louisiana...
  Eastern West Feliciana Parish in southeastern Louisiana...
  Southwestern Amite County in southern Mississippi...
  Southeastern Wilkinson County in southern Mississippi...

* Until 245 PM CDT.

* At 1232 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 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...
  Zachary, Jackson, Clinton, Centreville, Woodville, Slaughter, 
  Wilson, Norwood, Spillman and Pride.

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.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3101 9137 3115 9129 3115 9106 3115 9099
      3071 9084 3065 9091 3068 9092 3068 9128

FLASH FLOOD...RADAR INDICATED

$$

CAB
403 
WGUS54 KLIX 201931
FFWLIX
LAC033-037-091-125-MSC005-157-202145-
/O.EXT.KLIX.FF.W.0044.000000T0000Z-210520T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
231 PM CDT Thu May 20 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Northeastern East Baton Rouge Parish in southeastern Louisiana...
  East Feliciana Parish in southeastern Louisiana...
  Western St. Helena Parish in southeastern Louisiana...
  Eastern West Feliciana Parish in southeastern Louisiana...
  Southwestern Amite County in southern Mississippi...
  Southeastern Wilkinson County in southern Mississippi...

* Until 445 PM CDT.

* At 231 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 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...
  Zachary, Jackson, Clinton, Centreville, Woodville, Slaughter, 
  Wilson, Norwood, Spillman and Pride.

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.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3101 9137 3115 9129 3115 9106 3115 9099
      3071 9084 3065 9091 3068 9092 3068 9128

FLASH FLOOD...RADAR INDICATED

$$

CAB
143 
WGUS54 KLIX 202132
FFWLIX
LAC033-037-091-125-MSC005-157-202345-
/O.EXT.KLIX.FF.W.0044.000000T0000Z-210520T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
432 PM CDT Thu May 20 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Northeastern East Baton Rouge Parish in southeastern Louisiana...
  East Feliciana Parish in southeastern Louisiana...
  Western St. Helena Parish in southeastern Louisiana...
  Eastern West Feliciana Parish in southeastern Louisiana...
  Southwestern Amite County in southern Mississippi...
  Southeastern Wilkinson County in southern Mississippi...

* Until 645 PM CDT.

* At 432 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 5 and 8 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...
  Zachary, Jackson, Clinton, Centreville, Woodville, Slaughter, 
  Wilson, Norwood, Spillman and Pride.

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.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3101 9137 3115 9129 3115 9106 3115 9099
      3071 9084 3065 9091 3068 9092 3068 9128

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

$$
357 
WGUS54 KLIX 202338
FFWLIX
LAC033-037-091-125-MSC005-157-210145-
/O.EXT.KLIX.FF.W.0044.000000T0000Z-210521T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
638 PM CDT Thu May 20 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Northeastern East Baton Rouge Parish in southeastern Louisiana...
  East Feliciana Parish in southeastern Louisiana...
  Western St. Helena Parish in southeastern Louisiana...
  Eastern West Feliciana Parish in southeastern Louisiana...
  Southwestern Amite County in southern Mississippi...
  Southeastern Wilkinson County in southern Mississippi...

* Until 845 PM CDT.

* At 638 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 5 and 8 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...
  Zachary, Jackson, Clinton, Centreville, Woodville, Slaughter, 
  Wilson, Norwood, Spillman and Pride.

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.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3101 9137 3115 9129 3115 9106 3115 9099
      3071 9084 3065 9091 3068 9092 3068 9128

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

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 7:03 PM CDTSpecial Weather StatementLIXSaint Tammany42 min
May 19, 7:24 PM CDTSpecial Marine WarningLIX81 min
May 19, 8:00 PM CDTSevere Thunderstorm WarningLIXSaint Charles, Saint John the Baptist25 min
May 19, 8:30 PM CDTSpecial Marine WarningLIX30 min
May 19, 9:19 PM CDTAreal Flood AdvisoryLIXAscension, East Baton Rouge, Iberville, Livingston116 min
May 20, 3:42 AM CDTSpecial Weather StatementLIXAscension, Assumption, Iberville, Jefferson, Plaquemines, Saint Charles and 3 more63 min
May 20, 4:05 AM CDTSpecial Marine WarningLIX55 min
May 20, 4:18 AM CDTSpecial Marine WarningLIX57 min
May 20, 5:03 AM CDTSpecial Marine WarningLIX57 min
May 20, 5:33 AM CDTSpecial Marine WarningLIX57 min
May 20, 7:00 AM CDTSpecial Weather StatementLIXAssumption, Jefferson, Lafourche, Saint Charles, Saint James60 min
May 20, 7:39 AM CDTTornado WarningLIXJefferson8 min
May 20, 7:42 AM CDTSpecial Marine WarningLIX33 min
May 20, 8:27 AM CDTSpecial Marine WarningLIX63 min
May 20, 8:37 AM CDTAreal Flood AdvisoryLIXAscension, Assumption, East Baton Rouge, Iberville, Lafourche, Livingston and 3 more52 min
May 20, 8:58 AM CDTTornado WarningLIXEast Feliciana13 min
May 20, 9:29 AM CDTFlash Flood WarningLIXAscension, East Baton Rouge, Iberville, Livingston, West Baton Rouge9 hr
May 20, 10:04 AM CDTFlash Flood WarningLIXAscension, Assumption, Iberville, Lafourche, Livingston, Saint James and 1 more13 hr
May 20, 10:52 AM CDTSevere Thunderstorm WarningLIXSaint Charles, Saint John the Baptist19 min
May 20, 11:22 AM CDTSpecial Marine WarningLIX38 min
May 20, 11:26 AM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, East Feliciana, Livingston, Saint Helena94 min
May 20, 2:16 PM CDTRiver Flood WarningLIXEast Baton Rouge, Livingston68 hr
May 20, 2:22 PM CDTRiver Flood WarningLIXAscension, Livingston4 days
May 20, 2:33 PM CDTSpecial Marine WarningLIX57 min
May 20, 2:40 PM CDTRiver Flood WarningLIXEast Baton Rouge61 hr
May 20, 3:29 PM CDTSpecial Marine WarningLIX61 min
May 20, 3:56 PM CDTGale WarningLIX19 hr
May 20, 3:56 PM CDTSmall Craft AdvisoryLIX60 hr
May 20, 3:56 PM CDTWind AdvisoryLIXOrleans, Saint Bernard, Saint John the Baptist, Saint Tammany27 hr
May 20, 4:30 PM CDTSpecial Marine WarningLIX90 min
May 20, 4:58 PM CDTSpecial Weather StatementLIXLafourche, Terrebonne47 min
May 20, 5:16 PM CDTAreal Flood AdvisoryLIXAssumption, Jefferson, Lafourche, Terrebonne3 hr
May 20, 6:42 PM CDTFlash Flood WarningLIXAscension, East Baton Rouge, Iberville, Livingston, Saint Helena, West Baton Rouge4 hr

Nearby

Flash Flood Warnings in Louisiana, 2021Flash Flood Warnings in Mississippi, 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.