Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 81, NWS New Orleans, LA

August 3, 2021Saint Charles Parish, Saint John the Baptist Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 3, 2021, 3:28 PM CDT for Saint Charles Parish, Saint John the Baptist Parish, Louisiana. It was in force for 2 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 3, 2021, 3:28 PM CDT (20:28 UTC)
Expired
Aug 3, 2021, 5:30 PM CDT
In force
2 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties Saint Charles Parish, LA, Saint John the Baptist Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 8.5 hours before the alert went out and 77 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 2021-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 928 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 2021-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
928 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
708 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

699 
WGUS54 KLIX 032028
FFWLIX
LAC089-095-032330-
/O.NEW.KLIX.FF.W.0081.210803T2028Z-210803T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
328 PM CDT Tue Aug 3 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Northwestern St. Charles Parish in southeastern Louisiana...
  Central St. John The Baptist Parish in southeastern Louisiana...

* Until 630 PM CDT.

* At 328 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 3.5 inches of 
  rain have fallen. Additional rainfall amounts of 1 to 3 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...
  Hahnville, Laplace, Reserve, Norco, Taft, New Sarpy, Montz, 
  Destrehan, Killona, St. Rose, Luling, Ama and Edgard.

This includes the following Interstates...
	Interstate 310 between mile markers 2 and 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 3004 9054 3005 9052 3006 9051 3009 9053
      3011 9052 3008 9042 3004 9044 3002 9041
      3003 9034 2998 9028 2992 9032 2992 9042
      2995 9044 3000 9054

FLASH FLOOD...RADAR INDICATED

$$

CAB
3 follow-up statements
776 
WGUS74 KLIX 032100
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
400 PM CDT Tue Aug 3 2021

LAC095-032110-
/O.CAN.KLIX.FF.W.0081.000000T0000Z-210803T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
St. John The Baptist LA-
400 PM CDT Tue Aug 3 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL ST. JOHN THE BAPTIST 
PARISH...

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

LAT...LON 3001 9050 3001 9048 3002 9041 3001 9039
      2997 9031 2992 9032 2993 9040 2995 9044
      3000 9050

$$

LAC089-032330-
/O.CON.KLIX.FF.W.0081.000000T0000Z-210803T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
St. Charles LA-
400 PM CDT Tue Aug 3 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM CDT THIS 
EVENING FOR NORTHWESTERN ST. CHARLES PARISH...

At 400 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1.5 and 4 inches of rain have 
fallen. Additional rainfall amounts of 0.5 to 1.5 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...
  Hahnville, New Sarpy, Norco, Destrehan, Taft, Montz, Luling, St. 
  Rose, Killona and Ama.

This includes the following Interstates...
	Interstate 310 between mile markers 3 and 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 3001 9050 3001 9048 3002 9041 3001 9039
      2997 9031 2992 9032 2993 9040 2995 9044
      3000 9050

FLASH FLOOD...RADAR INDICATED

$$

CAB
393 
WGUS74 KLIX 032158
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
458 PM CDT Tue Aug 3 2021

LAC089-032330-
/O.CON.KLIX.FF.W.0081.000000T0000Z-210803T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
St. Charles LA-
458 PM CDT Tue Aug 3 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM CDT THIS 
EVENING FOR NORTHWESTERN ST. CHARLES PARISH...

At 458 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1.5 and 4 inches of rain have 
fallen. Additional rainfall amounts of 0.5 to 1.5 inches are 
possible in the warned area. Flash flooding is ongoing or expected 
to begin shortly.

Currently most of the warned area is not seeing rain but there are 
storms only 5 to 10 miles to the west that may still move into the 
warned area. Warning will continue for now unless this activity 
dissipates or moves south.

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...
  Hahnville, New Sarpy, Norco, Destrehan, Taft, Montz, Luling, St. 
  Rose, Killona and Ama.

This includes the following Interstates...
	Interstate 310 between mile markers 4 and 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 3001 9050 3001 9048 3002 9041 3001 9039
      2997 9031 2992 9032 2993 9040 2995 9044
      3000 9050

FLASH FLOOD...RADAR INDICATED

$$

CAB
395 
WGUS74 KLIX 032230
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
530 PM CDT Tue Aug 3 2021

LAC089-032240-
/O.CAN.KLIX.FF.W.0081.000000T0000Z-210803T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
St. Charles LA-
530 PM CDT Tue Aug 3 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN ST. CHARLES 
PARISH...

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

LAT...LON 3001 9050 3001 9048 3002 9041 3001 9039
      2997 9031 2992 9032 2993 9040 2995 9044
      3000 9050

$$

CAB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 4:23 AM CDTSpecial Marine WarningLIX67 min
Aug 3, 6:33 AM CDTSpecial Weather StatementLIXPlaquemines27 min
Aug 3, 6:44 AM CDTSpecial Weather StatementLIXAscension, Lafourche, Saint James61 min
Aug 3, 7:47 AM CDTSpecial Weather StatementLIXSaint Charles, Saint John the Baptist88 min
Aug 3, 8:42 AM CDTSpecial Marine WarningLIX63 min
Aug 3, 8:50 AM CDTAreal Flood AdvisoryLIXOrleans, Saint Bernard19 min
Aug 3, 9:09 AM CDTFlash Flood WarningLIXOrleans2 hr
Aug 3, 10:04 AM CDTSpecial Marine WarningLIX86 min
Aug 3, 10:24 AM CDTSpecial Marine WarningLIX96 min
Aug 3, 10:40 AM CDTAreal Flood AdvisoryLIXAscension, East Baton Rouge, Livingston90 min
Aug 3, 10:53 AM CDTAreal Flood AdvisoryLIXAscension, East Baton Rouge, Livingston77 min
Aug 3, 11:04 AM CDTSpecial Marine WarningLIX116 min
Aug 3, 11:40 AM CDTSpecial Marine WarningLIX110 min
Aug 3, 11:49 AM CDTSpecial Marine WarningLIX86 min
Aug 3, 11:52 AM CDTSpecial Marine WarningLIX113 min
Aug 3, 2:45 PM CDTFlash Flood WarningLIXEast Baton Rouge, Livingston4 hr
Aug 3, 3:00 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans, Saint Charles, Saint John the Baptist3 hr
Aug 3, 3:39 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans, Plaquemines, Saint Bernard119 min
Aug 3, 3:52 PM CDTAreal Flood AdvisoryLIXAscension, Saint Charles, Saint James, Saint John the Baptist103 min
Aug 3, 4:39 PM CDTAreal Flood AdvisoryLIXSaint Charles, Saint James, Saint John the Baptist50 min
Aug 3, 4:53 PM CDTFlash Flood WarningLIXSaint James, Saint John the Baptist39 min
Aug 3, 5:27 PM CDTAreal Flood AdvisoryLIXSaint Tammany, Tangipahoa, Washington3 hr
Aug 3, 5:33 PM CDTAreal Flood AdvisoryLIXSaint Tammany117 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.