Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 28, NWS Shreveport, LA

July 11, 20124 parishes in Louisiana

NWS Shreveport, LA issued this flash flood warning at Jul 11, 2012, 4:35 PM CDT for 4 parishes in 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: Jul 11, 2012, 4:35 PM CDT (21:35 UTC)
Expired: Jul 11, 2012, 7:30 PM CDT
In force: 3 hr
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Flood severity: None

Counties Bienville Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Winn Parish, LA

The radar

The Shreveport radar (KSHV), 87 km from the middle of the area, began a volume at 21:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 9.6 hours before the alert went out and 81 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: 1004 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 479 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 8 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.

047 
WGUS54 KSHV 112135
FFWSHV
LAC013-069-081-127-120030-
/O.NEW.KSHV.FF.W.0028.120711T2135Z-120712T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
435 PM CDT WED JUL 11 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN WINN PARISH IN NORTH CENTRAL LOUISIANA...
  SOUTH CENTRAL BIENVILLE PARISH IN NORTHWEST LOUISIANA...
  NORTH CENTRAL NATCHITOCHES PARISH IN NORTHWEST LOUISIANA...
  EASTERN RED RIVER PARISH IN NORTHWEST LOUISIANA...

* UNTIL 730 PM CDT.

* AT 426 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
  VERY HEAVY RAIN FROM A CLUSTER OF THUNDERSTORMS FROM NEAR          
  MARTIN...TO CHESTNUT...TO GOLDONNA...TO NEAR CEDAR LAKE. RADAR     
  ESTIMATES INDICATE THAT RAIN RATES WITH THIS THUNDERSTORM ARE      
  EXCEEDING TWO INCHES PER HOUR...AND LOCAL EMERGENCY MANAGEMENT IN  
  NATCHITOCHES PARISH HAS REPORTED WATER OVER ROADS IN THE NORTHERN  
  PORTION OF THE PARISH. AN ADDITIONAL TWO TO FOUR INCHES OF RAIN    
  MAY BE POSSIBLE OVER THE NEXT COUPLE OF HOURS...WHICH WILL WORSEN  
  ANY ONGOING FLOODING CONCERNS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WOMACK...
  SALINE...MARTIN...CHESTNUT AND ASHLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. REMEMBER...TURN AROUND DONT DROWN.

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

&&

LAT...LON 3219 9326 3219 9286 3199 9285 3187 9286
      3188 9321

$$

12

1 follow-up statement

593 
WGUS74 KSHV 112311
FFSSHV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
611 PM CDT WED JUL 11 2012

LAC013-069-081-127-120030-
/O.CON.KSHV.FF.W.0028.000000T0000Z-120712T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RED RIVER LA-NATCHITOCHES LA-BIENVILLE LA-WINN LA-
611 PM CDT WED JUL 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR
WINN...BIENVILLE...NATCHITOCHES AND RED RIVER PARISHES...

AT 558 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT RANFALL ACROSS NORTHERN NATCHITOCHES PARISH...EASTERN RED 
RIVER PARISH...AND WESTERN WINN PARISH. ALTHOUGH THE RAIN HAS LET UP 
SOME...FLOODING MAY CONTINUE FOR ANOTHER COUPLE OF HOURS OR SO...AS 
RUNOFF MAY BE SLOW DUE TO SATURATED SOILS. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WOMACK...
SALINE...MARTIN...CHESTNUT AND ASHLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

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

&&

LAT...LON 3219 9326 3219 9286 3199 9285 3187 9286
      3188 9321

$$

12

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 10, 10:12 PM CDT	Areal Flood Advisory	SHV	Bossier, Caddo	63 min
Jul 11, 11:29 AM CDT	Areal Flood Advisory	SHV	Bienville, Claiborne, Webster	2 hr
Jul 11, 2:13 PM CDT	Flash Flood Warning	SHV	Bossier, Caddo, Claiborne, Union, Webster	4 hr
Jul 11, 3:24 PM CDT	Flash Flood Warning	SHV	Bienville, Jackson, Winn	3 hr
Jul 11, 4:49 PM CDT	Flash Flood Warning	SHV	Jackson, Ouachita	3 hr
Jul 11, 6:31 PM CDT	Areal Flood Advisory	SHV	Bossier, Caddo, De Soto	119 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; radar from the NEXRAD Level II archive.