Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 21, NWS New Orleans, LA

May 2, 2012Ascension Parish, East Baton Rouge Parish, Iberville Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at May 2, 2012, 5:09 PM CDT for Ascension Parish, East Baton Rouge Parish, Iberville Parish, Louisiana. It was in force for 2 hr. 1 report 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 2, 2012, 5:09 PM CDT (22:09 UTC)
Expired: May 2, 2012, 7:15 PM CDT
In force: 2 hr
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Flood severity: None

Counties Ascension Parish, LA, East Baton Rouge Parish, LA, Iberville Parish, LA

What was reported inside it

Time	Report	Where	Remark
May 2, 5:45 PM CDT	FLASH FLOOD	Prairieville, LA	BATON ROUGE ADVOCATE REPORTING THAT 13 HOMES HAD FLOODING FROM EARLIER HEAVY RAINS. ASCENSION PARISH SHERIFFS OFFICE DISPATCH CONFIRMED THE REPORTS.

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, 10.2 hours before the alert went out and 126 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: 2546 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 482 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 49 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

356 
WGUS54 KLIX 022209
FFWLIX
LAC005-033-047-030015-
/O.NEW.KLIX.FF.W.0021.120502T2209Z-120503T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
509 PM CDT WED MAY 2 2012

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL ASCENSION PARISH IN SOUTHEAST LOUISIANA...
  SOUTHEASTERN EAST BATON ROUGE PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITY OF OAK HILLS PLACE...
  EXTREME EAST CENTRAL IBERVILLE PARISH IN SOUTHEAST LOUISIANA...

* UNTIL 715 PM CDT

* AT 504 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  FLASH FLOODING FROM A CLUSTER OF THUNDERSTORMS OVER THE WARNED     
  AREA. RADAR ESTIMATES NEAR 3 INCHES HAVE OCCURRED NEAR PORT        
  VINCENT SINCE 4 PM. DUE TO THE SLOW MOVEMENT...AN ADDITIONAL 1 TO  
  2 INCHES WILL CAUSE FLOODING ACROSS SOUTHERN PORTION OF THE BATON  
  ROUGE METRO AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3044 9113 3043 9098 3041 9096 3040 9097
      3039 9095 3037 9094 3021 9094 3022 9105

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 2, 6:17 AM CDT	Special Marine Warning	LIX		43 min
May 2, 7:42 AM CDT	Special Marine Warning	LIX		63 min
May 2, 8:39 AM CDT	Special Marine Warning	LIX		36 min
May 2, 10:03 AM CDT	Special Marine Warning	LIX		57 min
May 2, 2:13 PM CDT	Areal Flood Advisory	LIX	Tangipahoa	2 hr
May 2, 3:21 PM CDT	Flash Flood Warning	LIX	Tangipahoa	114 min
May 2, 4:15 PM CDT	Areal Flood Advisory	LIX	Ascension, Livingston	2 hr
May 2, 4:38 PM CDT	Areal Flood Advisory	LIX	East Baton Rouge, Iberville	112 min
May 2, 5:04 PM CDT	Flash Flood Warning	LIX	Ascension, Livingston	116 min
May 2, 6:09 PM CDT	Areal Flood Advisory	LIX	Livingston	111 min
May 2, 6:21 PM CDT	Flash Flood Watch	LIX	Assumption, Saint Bernard, Saint James, Saint John the Baptist	6 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.