Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 17, NWS New Orleans, LA

April 16, 2012Jefferson Parish, Orleans Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Apr 16, 2012, 5:00 PM CDT for Jefferson Parish, Orleans 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: Apr 16, 2012, 5:00 PM CDT (22:00 UTC)
Expired: Apr 16, 2012, 7:29 PM CDT
In force: 2 hr
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Flood severity: None

Counties Jefferson Parish, LA, Orleans Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 10.0 hours before the alert went out and 45 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1887 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 437 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 124 m²/s²
0-3 km storm-relative helicity: 144 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

156 
WGUS54 KLIX 162200
FFWLIX
LAC051-071-170100-
/O.NEW.KLIX.FF.W.0017.120416T2200Z-120417T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
500 PM CDT MON APR 16 2012

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL JEFFERSON PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITIES OF...MARRERO...HARVEY...
  SOUTHWESTERN ORLEANS PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITY OF NEW ORLEANS...

* UNTIL 800 PM CDT

* AT 454 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
  VERY HEAVY RAIN FROM A NEARLY STATIONARY THUNDERSTORM OVER THE 
  NEW ORLEANS AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO THE NEW 
  ORLEANS METRO AREA. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE ACROSS
THE CITY.

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 2990 9019 3003 9017 3003 9011 3004 9010
      3004 9007 3005 9003 3005 9000 3006 8998
      3007 8996 2986 9004

$$

1 follow-up statement

902 
WGUS74 KLIX 170029
FFSLIX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
729 PM CDT MON APR 16 2012

LAC051-071-170040-
/O.CAN.KLIX.FF.W.0017.000000T0000Z-120417T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ORLEANS LA-JEFFERSON LA-
729 PM CDT MON APR 16 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTH CENTRAL
JEFFERSON AND SOUTHWESTERN ORLEANS PARISHES...

LAT...LON 2990 9019 3003 9017 3003 9011 3004 9010
      3004 9007 3005 9003 3005 9000 3006 8998
      3007 8996 2986 9004

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 16, 9:58 AM CDT	Special Marine Warning	LIX		32 min
Apr 16, 1:47 PM CDT	Special Marine Warning	LIX		43 min
Apr 16, 3:23 PM CDT	Special Marine Warning	LIX		22 min
Apr 16, 3:36 PM CDT	Special Marine Warning	LIX		24 min
Apr 16, 4:33 PM CDT	Special Marine Warning	LIX		27 min
Apr 16, 5:30 PM CDT	Special Marine Warning	LIX		30 min
Apr 16, 5:41 PM CDT	Areal Flood Advisory	LIX	Saint Tammany	109 min

Nearby

Flash Flood Warnings in Louisiana, 2012 Every flash flood warning in 2012

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.