Alert archive / Mississippi / Flash Flood Warnings in 2021

Flash Flood Warning 90, NWS New Orleans, LA

August 29, 2021Saint Tammany Parish, Louisiana; Hancock County, Harrison County, Mississippi

NWS New Orleans, LA issued this flash flood warning at Aug 29, 2021, 6:09 PM CDT for Saint Tammany Parish, Louisiana; Hancock County, Harrison County, Mississippi. It was in force for 8 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 29, 2021, 6:09 PM CDT (23:09 UTC)
Expired
Aug 30, 2021, 2:30 AM CDT
In force
8 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties Saint Tammany Parish, LA, Hancock County, MS, Harrison County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.2 hours before the alert went out and 29 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 2021-08-29Temperature 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 12:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -55 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3256 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-55 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

As transmitted.

709 
WGUS54 KLIX 292309
FFWLIX
LAC103-MSC045-047-300130-
/O.NEW.KLIX.FF.W.0090.210829T2309Z-210830T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
609 PM CDT Sun Aug 29 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Eastern St. Tammany Parish in southeastern Louisiana...
  Hancock County in southern Mississippi...
  Southwestern Harrison County in southern Mississippi...

* Until 830 PM CDT.

* At 609 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2.5 and 4 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...
  Long Beach, Bay St. Louis, Waveland, Diamondhead, Kiln, Shoreline 
  Park, Stennis Space Center and Pearlington.

This includes the following Interstates...
	Interstate 10 in Mississippi between mile markers 2 and 26.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3039 8966 3044 8964 3052 8947 3062 8944
      3063 8932 3033 8918 3031 8928 3035 8927
      3036 8928 3038 8932 3037 8935 3034 8938
      3034 8933 3032 8932 3030 8933 3025 8942
      3019 8948 3019 8958 3024 8961 3031 8962

FLASH FLOOD...RADAR INDICATED

$$

TD
3 follow-up statements
671 
WGUS54 KLIX 300123
FFWLIX
LAC103-MSC045-047-300330-
/O.EXT.KLIX.FF.W.0090.000000T0000Z-210830T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
823 PM CDT Sun Aug 29 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Eastern St. Tammany Parish in southeastern Louisiana...
  Hancock County in southern Mississippi...
  Southwestern Harrison County in southern Mississippi...

* Until 1030 PM CDT.

* At 823 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2.5 and 4 inches of 
  rain have fallen. Additional rainfall amounts of 2 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...
  Long Beach, Bay St. Louis, Waveland, Diamondhead, Kiln, Shoreline 
  Park, Stennis Space Center and Pearlington.

This includes the following Interstates...
	Interstate 10 in Mississippi between mile markers 2 and 26.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3039 8966 3044 8964 3052 8947 3062 8944
      3063 8932 3033 8918 3031 8928 3035 8927
      3036 8928 3038 8932 3037 8935 3034 8938
      3034 8933 3032 8932 3030 8933 3025 8942
      3019 8948 3019 8958 3024 8961 3031 8962

FLASH FLOOD...RADAR INDICATED

$$

CAB
575 
WGUS54 KLIX 300320
FFWLIX
LAC103-MSC045-047-300530-
/O.EXT.KLIX.FF.W.0090.000000T0000Z-210830T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
1020 PM CDT Sun Aug 29 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Eastern St. Tammany Parish in southeastern Louisiana...
  Hancock County in southern Mississippi...
  Southwestern Harrison County in southern Mississippi...

* Until 1230 AM CDT.

* At 1020 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 3 and 6 inches of rain 
  have fallen. Additional rainfall amounts of 2 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...
  Long Beach, Bay St. Louis, Waveland, Diamondhead, Kiln, Shoreline 
  Park, Stennis Space Center and Pearlington.

This includes the following Interstates...
	Interstate 10 in Mississippi between mile markers 2 and 26.

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 3039 8966 3044 8964 3052 8947 3062 8944
      3063 8932 3033 8918 3031 8928 3035 8927
      3036 8928 3038 8932 3037 8935 3034 8938
      3034 8933 3032 8932 3030 8933 3025 8942
      3019 8948 3019 8958 3024 8961 3031 8962

FLASH FLOOD...RADAR INDICATED

$$

CAB
774 
WGUS54 KLIX 300513
FFWLIX
LAC103-MSC045-047-300730-
/O.EXT.KLIX.FF.W.0090.000000T0000Z-210830T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
1213 AM CDT Mon Aug 30 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Eastern St. Tammany Parish in southeastern Louisiana...
  Hancock County in southern Mississippi...
  Southwestern Harrison County in southern Mississippi...

* Until 230 AM CDT.

* At 1213 AM CDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  3 and 7 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 and automated gauges.

  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...
  Long Beach, Bay St. Louis, Waveland, Diamondhead, Kiln, Shoreline 
  Park, Stennis Space Center and Pearlington.

This includes the following Interstates...
	Interstate 10 in Mississippi between mile markers 2 and 26.

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 3039 8966 3044 8964 3052 8947 3062 8944
      3063 8932 3033 8918 3031 8928 3035 8927
      3036 8928 3038 8932 3037 8935 3034 8938
      3034 8933 3032 8932 3030 8933 3025 8942
      3019 8948 3019 8958 3024 8961 3031 8962

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

CAB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 6:23 AM CDTSpecial Marine WarningLIX22 min
Aug 29, 7:49 AM CDTExtreme Wind WarningLIXJefferson, Lafourche, Plaquemines, Saint Bernard, Saint Charles, Terrebonne3 hr
Aug 29, 10:30 AM CDTExtreme Wind WarningLIXJefferson, Lafourche, Plaquemines, Saint Bernard, Saint Charles, Terrebonne3 hr
Aug 29, 1:26 PM CDTExtreme Wind WarningLIXAssumption, Jefferson, Lafourche, Plaquemines, Saint Charles, Saint James and 2 more3 hr
Aug 29, 2:42 PM CDTSpecial Marine WarningLIX18 min
Aug 29, 3:39 PM CDTFlash Flood WarningLIXLafourche, Terrebonne7 hr
Aug 29, 4:08 PM CDTFlash Flood Warning EmergencyLIXJefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles, Saint John the Baptist8 hr
Aug 29, 4:23 PM CDTExtreme Wind WarningLIXJefferson, Lafourche, Saint Charles, Saint James, Saint John the Baptist, Terrebonne2 hr
Aug 29, 5:01 PM CDTFlash Flood Warning EmergencyCatastrophic damage threatLIXPlaquemines6 hr
Aug 29, 5:04 PM CDTSpecial Marine WarningLIX26 min
Aug 29, 6:04 PM CDTSpecial Marine WarningLIX26 min
Aug 29, 6:21 PM CDTFlash Flood WarningLIXSaint Tammany16 hr
Aug 29, 6:25 PM CDTTornado WarningLIXOrleans, Saint Bernard, Saint Tammany35 min
Aug 29, 6:33 PM CDTSpecial Marine WarningLIX57 min
Aug 29, 6:54 PM CDTTornado WarningLIXSaint Tammany36 min
Aug 29, 6:21 AM CDTTornado WarningLIXHancock, Harrison24 min
Aug 29, 8:10 AM CDTTornado WarningLIXJackson24 min
Aug 29, 2:15 PM CDTTornado WarningLIXHancock, Harrison, Pearl River15 min
Aug 29, 3:07 PM CDTTornado WarningLIXHancock23 min
Aug 29, 5:12 PM CDTTornado WarningLIXHarrison33 min
Aug 29, 5:20 PM CDTFlash Flood WarningLIXHarrison5 hr

Nearby

Flash Flood Warnings in Mississippi, 2021Flash 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.