Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 77, NWS New Orleans, LA

August 31, 2012Ascension Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 31, 2012, 11:56 AM CDT for Ascension Parish, Louisiana. It was in force for 3 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 31, 2012, 11:56 AM CDT (16:56 UTC)
Expired: Aug 31, 2012, 2:45 PM CDT
In force: 3 hr
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Flood severity: None

County Ascension Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 4.9 hours before the alert went out and 104 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: 1794 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 580 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 78 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.

954 
WGUS54 KLIX 311656
FFWLIX
LAC005-311945-
/O.NEW.KLIX.FF.W.0077.120831T1656Z-120831T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1156 AM CDT FRI AUG 31 2012

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL ASCENSION PARISH IN SOUTHEAST LOUISIANA...

* UNTIL 245 PM CDT

* AT 1143 AM CDT...EMERGENCY MANAGEMENT IN ASCENSION PARISH REPORTED 
  THAT RISING WATER MAY OVERTOP A PUMPING STATION STRUCTURE. IF THE  
  STRUCTURE IS OVERTOPPED...FLASH FLOODING IS EXPECTED.

* AS A PRECAUTIONARY MEASURE...A VOLUNTARY EVACUATION HAS BEEN       
  ORDERED FOR PORTIONS OF EASTERN ASCENSION PARISH INCLUDING THE     
  COMMUNITIES ST. AMANT...ACY AND SORRENTO. PLEASE CONSULT LOCAL LAW 
  ENFORCEMENT OR LOCAL EMERGENCY MANAGEMENT FOR ADDITIONAL DETAILS   
  CONCERNING THE VOLUNTARY EVACUATION.

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 3027 9080 3024 9077 3024 9076 3022 9073
      3021 9074 3021 9073 3020 9072 3016 9082
      3019 9091

$$

95/DM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 30, 7:04 PM CDT	Flash Flood Warning	LIX	Ascension, Livingston, Tangipahoa	3 hr
Aug 30, 8:41 PM CDT	Flash Flood Warning	LIX	Washington	3 hr
Aug 31, 2:39 PM CDT	Flash Flood Warning	LIX	Livingston, Saint Helena, Tangipahoa, Washington	4 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; the sounding from the Mesonet's radiosonde archive.