Alert archive / Louisiana / Flash Flood Warnings in 2021
Flash Flood Warning 32, NWS New Orleans, LA
NWS New Orleans, LA issued this flash flood warning at May 17, 2021, 6:50 PM CDT for Ascension Parish, Assumption Parish, Iberville Parish, Louisiana. It was in force for 5 hr. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- May 17, 2021, 6:50 PM CDT (23:50 UTC)
- Expired
- May 18, 2021, 12:00 AM CDT
- In force
- 5 hr
- Issued by
- NWS New Orleans, LA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Ascension Parish, LA, Assumption Parish, LA, Iberville Parish, LA
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 17, 9:04 PM CDT | FLASH FLOOD | Geismar, LA | HWY 75 CLOSED AT WATERLOO DR DUE TO HIGH WATER. |
| May 17, 9:09 PM CDT | FLASH FLOOD | 3 Sw Prairieville, LA | BLUFF ROAD AT C BRAUD RD CLOSED DUE TO HIGH WATER. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 12:00Z, 11.8 hours before the alert went out and 125 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.
- Mixed-layer CAPE
- 646 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 616 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 108 m²/s²
- 0-3 km storm-relative helicity
- 160 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.8
The text
As transmitted.
681
WGUS54 KLIX 172350
FFWLIX
LAC005-007-047-180300-
/O.NEW.KLIX.FF.W.0032.210517T2350Z-210518T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
650 PM CDT Mon May 17 2021
The National Weather Service in New Orleans has issued a
* Flash Flood Warning for...
Western Ascension Parish in southeastern Louisiana...
North Central Assumption Parish in southeastern Louisiana...
Southeastern Iberville Parish in southeastern Louisiana...
* Until 1000 PM CDT.
* At 650 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...
Gonzales, Donaldsonville, St. Gabriel, Sorrento, Geismar, Belle
Rose, Paincourtville and Prairieville.
This includes the following Interstates...
Interstate 10 in Louisiana between mile markers 171 and 186.
Additional rainfall amounts of 2 to 4 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.
&&
LAT...LON 3007 9122 3028 9103 3033 9097 3015 9081
3013 9085 3011 9092 3009 9094 3007 9096
3005 9096 2998 9106
FLASH FLOOD...RADAR INDICATED
$$
BL1 follow-up statement
331
WGUS54 KLIX 180248
FFWLIX
LAC005-007-047-180500-
/O.EXT.KLIX.FF.W.0032.000000T0000Z-210518T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
948 PM CDT Mon May 17 2021
The National Weather Service in New Orleans has extended the
* Flash Flood Warning for...
Western Ascension Parish in southeastern Louisiana...
North Central Assumption Parish in southeastern Louisiana...
Southeastern Iberville Parish in southeastern Louisiana...
* Until midnight CDT.
* At 948 PM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 4 and 6 inches of rain
have fallen. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Doppler radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flash flooding include...
Gonzales, Donaldsonville, St. Gabriel, Sorrento, Geismar, Belle
Rose, Paincourtville and Prairieville.
This includes the following Interstates...
Interstate 10 in Louisiana between mile markers 171 and 186.
Additional rainfall amounts of 2 to 4 inches are possible in the
warned area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3007 9122 3028 9103 3033 9097 3015 9081
3013 9085 3011 9092 3009 9094 3007 9096
3005 9096 2998 9106
FLASH FLOOD...RADAR INDICATED
$$
BLThe office that day
Everything else NWS New Orleans, LA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 17, 2:48 AM CDT | Coastal Flood Advisory | LIX | Orleans, Saint Bernard, Saint James, Saint John the Baptist, Saint Tammany | 7 days |
| May 17, 4:38 AM CDT | Small Craft Advisory | LIX | 5 days | |
| May 17, 2:00 PM CDT | Areal Flood Advisory | LIX | Saint Tammany | 3 hr |
| May 17, 2:56 PM CDT | Flash Flood Watch | LIX | Assumption, East Baton Rouge, East Feliciana, Iberville, Orleans, Pointe Coupee and 9 more | 4 days |
| May 17, 6:50 PM CDT | Tornado Warning | LIX | Ascension, East Baton Rouge, Iberville | 25 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.