Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 37, NWS New Orleans, LA

July 20, 2012Lafourche Parish, Terrebonne Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Jul 20, 2012, 12:56 PM CDT for Lafourche Parish, Terrebonne Parish, Louisiana. It was in force for 94 min. 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: Jul 20, 2012, 12:56 PM CDT (17:56 UTC)
Expired: Jul 20, 2012, 2:30 PM CDT
In force: 94 min
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Flood severity: None

Counties Lafourche Parish, LA, Terrebonne Parish, LA

What was reported inside it

Time	Report	Where	Remark
Jul 20, 1:26 PM CDT	FLASH FLOOD	Houma, LA	SIGNIFICANT STREET FLOODING IN THE HOUMA AREA.

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, 5.9 hours before the alert went out and 147 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: 1085 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 694 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 62 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.

053 
WGUS54 KLIX 201756
FFWLIX
LAC057-109-201930-
/O.NEW.KLIX.FF.W.0037.120720T1756Z-120720T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1256 PM CDT FRI JUL 20 2012

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN LAFOURCHE PARISH IN SOUTHEAST LOUISIANA...
  TERREBONNE PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITY OF HOUMA...

* UNTIL 230 PM CDT

* AT 1254 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
  VERY HEAVY RAIN FROM THUNDERSTORMS ALONG A LINE EXTENDING FROM
  RACELAND TO 6 MILES SOUTHEAST OF MONTEGUT...OR ALONG A LINE
  EXTENDING FROM 10 MILES SOUTHEAST OF THIBODAUX TO 12 MILES WEST OF
  GALLIANO...MOVING SOUTHWEST AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  CHAUVIN...SCHRIEVER...GRAY...BAYOU CANE...DULAC AND COCODRIE

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 2 TO 4 ARE POSSIBLE IN THE WARNED 
AREA BEFORE 230 PM.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

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 2916 9094 2938 9107 2968 9101 2988 9066
      2938 9040 2927 9048 2927 9057 2926 9058
      2923 9052 2919 9055 2920 9059 2917 9060
      2918 9063 2919 9063 2913 9064 2914 9067
      2910 9071 2912 9073 2909 9077 2908 9086

$$


24/RR

3 follow-up statements

066 
WGUS74 KLIX 201829
FFSLIX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
129 PM CDT FRI JUL 20 2012

LAC057-109-201930-
/O.CON.KLIX.FF.W.0037.000000T0000Z-120720T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TERREBONNE LA-LAFOURCHE LA-
129 PM CDT FRI JUL 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM CDT FOR
NORTHWESTERN LAFOURCHE AND TERREBONNE PARISHES...

AT 126 PM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED SEVERAL 
STREETS FLOODING IN PORTIONS OF TERREBONNE PARISH. STORMS WERE 
LOCATED ALONG A LINE EXTENDING FROM SCHRIEVER TO 8 MILES WEST OF 
DULAC TO COCODRIE...OR ALONG A LINE EXTENDING FROM THIBODAUX TO 14 
MILES SOUTHWEST OF HOUMA TO 24 MILES SOUTH OF HOUMA...MOVING 
SOUTHWEST AT 25 MPH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

&&

LAT...LON 2938 9107 2967 9102 2988 9066 2939 9041
      2927 9048 2927 9057 2925 9057 2923 9052
      2919 9055 2920 9059 2917 9061 2918 9063
      2913 9064 2914 9067 2912 9068 2908 9086

$$


24/RR

282 
WGUS74 KLIX 201859
FFSLIX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
159 PM CDT FRI JUL 20 2012

LAC057-109-201930-
/O.CON.KLIX.FF.W.0037.000000T0000Z-120720T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TERREBONNE LA-LAFOURCHE LA-
159 PM CDT FRI JUL 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM CDT FOR
NORTHWESTERN LAFOURCHE AND TERREBONNE PARISHES...

AT 154 PM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH 
FLOODING IN HOUMA AND IN OTHER PORTIONS OF TERREBONNE PARISH. THESE 
STORMS WERE LOCATED ALONG A LINE EXTENDING FROM 8 MILES WEST OF 
SCHRIEVER TO 16 MILES WEST OF DULAC TO 8 MILES WEST OF COCODRIE...OR 
ALONG A LINE EXTENDING FROM 9 MILES SOUTHWEST OF THIBODAUX TO 21 
MILES SOUTHWEST OF HOUMA TO 24 MILES SOUTH OF HOUMA...MOVING 
SOUTHWEST AT 15 MPH.

THUNDERSTORMS PRODUCING FLASH FLOODING WILL BE NEAR...
  9 MILES WEST OF SCHRIEVER AND 9 MILES WEST OF COCODRIE BY 200 PM
  CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS 
SAFELY. MOVE TO HIGHER GROUND. LOCAL EMERGENCY MANAGEMENT OFFICIALS 
ARE URGING CITIZENS TO NOT DRIVE IN THE AFFECTED AREAS. POSTPONE ANY 
UNNECESSARY TRAVEL UNTIL THE DANGER OF FLOODING HAS ENDED. 

&&

LAT...LON 2938 9107 2967 9102 2988 9066 2939 9041
      2927 9048 2927 9057 2925 9057 2923 9052
      2919 9055 2920 9059 2917 9061 2918 9063
      2913 9064 2914 9067 2912 9068 2908 9086

$$


24/RR

973 
WGUS74 KLIX 201928
FFSLIX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
228 PM CDT FRI JUL 20 2012

LAC057-109-201935-
/O.EXP.KLIX.FF.W.0037.000000T0000Z-120720T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TERREBONNE LA-LAFOURCHE LA-
228 PM CDT FRI JUL 20 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 230 PM CDT FOR NORTHWESTERN
LAFOURCHE AND TERREBONNE PARISHES...

THE RAINS ARE INDICATED TO BE WEAKENING IN INTENSITY ACROSS THE 
WARNED AREA. SEVERAL STREETS MAY CONTINUE TO BE FLOODED THROUGH 4 
PM. AREA BAYOUS AND STREAMS MAY REMAIN OUT OF BANKS BUT SHOULD BEGIN 
TO LOWER THROUGH THE REMAINDER OF THE AFTERNOON.

TRAVEL IS STRONGLY DISCOURAGED ACROSS THE HOUMA AREA AND SURROUNDING 
PORTIONS OF TERREBONNE AND LAFOURCHE PARISHES. DO NOT DRIVE UNLESS 
IT IS NECESSARY UNTIL FLOOD WATERS RECEDE. 

LAT...LON 2938 9107 2967 9102 2988 9066 2939 9041
      2927 9048 2927 9057 2925 9057 2923 9052
      2919 9055 2920 9059 2917 9061 2918 9063
      2913 9064 2914 9067 2912 9068 2908 9086

$$


24/RR

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 7:48 PM CDT	Areal Flood Advisory	LIX	East Feliciana, Pointe Coupee, West Feliciana	117 min
Jul 20, 7:11 AM CDT	Special Marine Warning	LIX		34 min
Jul 20, 7:19 AM CDT	Special Marine Warning	LIX		26 min
Jul 20, 7:51 AM CDT	Special Marine Warning	LIX		24 min
Jul 20, 7:54 AM CDT	Special Marine Warning	LIX		36 min
Jul 20, 10:53 AM CDT	Areal Flood Advisory	LIX	Jefferson, Orleans	52 min
Jul 20, 11:28 AM CDT	Flash Flood Warning	LIX	Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles	3 hr
Jul 20, 12:22 PM CDT	Areal Flood Advisory	LIX	Saint Tammany, Tangipahoa	113 min
Jul 20, 1:08 PM CDT	Special Marine Warning	LIX		37 min
Jul 20, 1:24 PM CDT	Severe Thunderstorm Warning	LIX	Terrebonne	36 min
Jul 20, 1:46 PM CDT	Flash Flood Warning	LIX	Ascension, Jefferson, Lafourche, Saint Charles, Saint James, Saint John the Baptist	4 hr
Jul 20, 2:15 PM CDT	Areal Flood Advisory	LIX	Saint Tammany	60 min
Jul 20, 2:19 PM CDT	Flash Flood Warning	LIX	Ascension, Assumption, Iberville, Lafourche, Saint James, Terrebonne	116 min
Jul 20, 2:35 PM CDT	Special Marine Warning	LIX		40 min
Jul 20, 2:42 PM CDT	Areal Flood Advisory	LIX	Jefferson, Orleans, Plaquemines, Saint Bernard	16 min
Jul 20, 2:52 PM CDT	Severe Thunderstorm Warning	LIX	Jefferson, Orleans, Plaquemines, Saint Bernard	38 min
Jul 20, 2:56 PM CDT	Flash Flood Warning	LIX	Jefferson, Orleans, Plaquemines, Saint Bernard	64 min
Jul 20, 3:24 PM CDT	Areal Flood Advisory	LIX	East Baton Rouge, Livingston, Saint Helena, Saint Tammany, Tangipahoa, Washington	111 min
Jul 20, 3:28 PM CDT	Special Marine Warning	LIX		32 min
Jul 20, 3:47 PM CDT	Flash Flood Warning	LIX	Livingston, Saint Helena, Tangipahoa, Washington	3 hr
Jul 20, 4:02 PM CDT	Flash Flood Warning	LIX	Ascension, Assumption, East Baton Rouge, Iberville, West Baton Rouge	2 hr
Jul 20, 5:04 PM CDT	Flash Flood Warning	LIX	East Baton Rouge, East Feliciana, Livingston, Saint Helena	116 min
Jul 20, 5:16 PM CDT	Areal Flood Advisory	LIX	East Feliciana, Saint Helena, Tangipahoa	119 min
Jul 20, 5:46 PM CDT	Severe Thunderstorm Warning	LIX	East Feliciana, Pointe Coupee, West Feliciana	31 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.