Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 78, NWS New Orleans, LA

August 31, 2012Amite County, Pike County, Walthall County, Mississippi; 4 parishes in Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 31, 2012, 2:39 PM CDT for Amite County, Pike County, Walthall County, Mississippi; 4 parishes in Louisiana. It was in force for 4 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, 2:39 PM CDT (19:39 UTC)
Expired
Aug 31, 2012, 6:30 PM CDT
In force
4 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties Livingston Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, Amite County, MS, Pike County, MS, Walthall County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 7.7 hours before the alert went out and 109 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 2012-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1794 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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 2012-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 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
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.

264 
WGUS54 KLIX 311939
FFWLIX
LAC063-091-105-117-MSC005-113-147-312330-
/O.NEW.KLIX.FF.W.0078.120831T1939Z-120831T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN LIVINGSTON PARISH IN SOUTHEAST LOUISIANA...
  ST. HELENA PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITY OF GREENSBURG...
  TANGIPAHOA PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITIES OF...HAMMOND...AMITE...
  NORTHWESTERN WASHINGTON PARISH IN SOUTHEAST LOUISIANA...
  EASTERN AMITE COUNTY IN SOUTHERN MISSISSIPPI...
  PIKE COUNTY IN SOUTHERN MISSISSIPPI...
  THIS INCLUDES THE CITY OF MCCOMB...
  WESTERN WALTHALL COUNTY IN SOUTHERN MISSISSIPPI...

* UNTIL 630 PM CDT

* AT 234 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
  VERY HEAVY RAIN FROM THUNDERSTORMS CONTINUING TO DEVELOP AND MOVE  
  NORTHEAST OVER THE WARNED AREA. ONE TO TWO INCHES OF RAIN HAS      
  FALLEN OVER THE WARNED AREA OVER THE LAST THREE HOURS AND          
  ADDITIONAL RAINFALL AMOUNTS OF TWO TO FOUR INCHES IS POSSIBLE      
  THROUGH THE AFTERNOON. IN ADDITION...THE GROUND IS ALREADY         
  SATURATED FROM SIGNIFICANT RAINFALL OVER THE LAST SEVERAL DAYS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MOUNT      
  HERMAN...SUMMIT...OSYKA...MAGNOLIA AND GILLSBERG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY 
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN NEW 
ORLEANS.

&&

LAT...LON 3134 9009 3047 9033 3048 9084 3135 9067
      3136 9011

$$

98/SO

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 8:41 PM CDTFlash Flood WarningLIXWalthall3 hr
Aug 30, 8:44 PM CDTTornado WarningLIXWalthall31 min
Aug 30, 7:04 PM CDTFlash Flood WarningLIXAscension, Livingston, Tangipahoa3 hr
Aug 31, 11:56 AM CDTFlash Flood WarningLIXAscension3 hr

Nearby

Flash Flood Warnings in Louisiana, 2012Flash Flood Warnings in Mississippi, 2012Every 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.