Alert archive / Louisiana / Flash Flood Warnings in 2023

Flash Flood Warning 46, NWS New Orleans, LA

September 25, 2023Jefferson Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Sep 25, 2023, 3:38 PM CDT for Jefferson Parish, Louisiana. It was in force for 112 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 25, 2023, 3:38 PM CDT (20:38 UTC)
Expired
Sep 25, 2023, 5:30 PM CDT
In force
112 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

County Jefferson Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 8.6 hours before the alert went out and 74 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 2023-09-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 400 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2023-09-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
400 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1001 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 25, 5:39 AM CDTFlash Flood WarningLIXTangipahoa111 min
Sep 25, 12:48 PM CDTSpecial Weather StatementLIXTangipahoa42 min
Sep 25, 3:10 PM CDTAreal Flood AdvisoryLIXJefferson28 min
Sep 25, 3:46 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans3 hr
Sep 25, 4:55 PM CDTSpecial Weather StatementLIXSaint Charles35 min
Sep 25, 5:21 PM CDTFlash Flood WarningLIXJefferson61 min
Sep 25, 6:50 PM CDTSpecial Weather StatementLIXAssumption25 min

Nearby

Flash Flood Warnings in Louisiana, 2023Every flash flood warning in 2023

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.