Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 35, NWS Shreveport, LA

August 31, 2012Caldwell Parish, Grant Parish, LaSalle Parish, Louisiana

NWS Shreveport, LA issued this flash flood warning at Aug 31, 2012, 3:55 AM CDT for Caldwell Parish, Grant Parish, LaSalle Parish, Louisiana. It was in force for 6 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
Aug 31, 2012, 3:55 AM CDT (08:55 UTC)
Expired
Aug 31, 2012, 10:00 AM CDT
In force
6 hr
Issued by
NWS Shreveport, LA
Area
Storm-based polygon
Flood severity
None

Counties Caldwell Parish, LA, Grant Parish, LA, LaSalle Parish, LA

What was reported inside it

TimeReportWhereRemark
Aug 31, 7:55 AM CDTFLASH FLOODJena, LAWATER OVER ROADS ACROSS LASALLE COUNTY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 8.9 hours before the alert went out and 167 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, Shreveport, LA at 00:00Z on 2012-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 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, Shreveport, LA at 00:00Z on 2012-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
10 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
474 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
44 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.

615 
WGUS54 KSHV 310855
FFWSHV
LAC021-043-059-311200-
/O.NEW.KSHV.FF.W.0035.120831T0855Z-120831T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
355 AM CDT FRI AUG 31 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CALDWELL PARISH IN NORTH CENTRAL LOUISIANA...
  THIS INCLUDES THE CITY OF COLUMBIA...
  EASTERN GRANT PARISH IN NORTH CENTRAL LOUISIANA...
  LA SALLE PARISH IN NORTH CENTRAL LOUISIANA...

* UNTIL 700 AM CDT

* AT 353 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
  VERY HEAVY RAIN FROM THUNDERSTORMS OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO OLLA...
  GRAYSON AND CLARKS...

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.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 3207 9192 3203 9189 3193 9189 3192 9200
      3133 9200 3132 9208 3147 9220 3139 9259
      3140 9266 3180 9244 3180 9236 3183 9234
      3203 9231 3226 9219 3226 9199 3218 9197
      3217 9190 3210 9186

$$

14
2 follow-up statements
370 
WGUS54 KSHV 311155
FFWSHV
LAC021-043-059-311500-
/O.EXT.KSHV.FF.W.0035.000000T0000Z-120831T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
655 AM CDT FRI AUG 31 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  CALDWELL PARISH IN NORTH CENTRAL LOUISIANA...
  THIS INCLUDES THE CITY OF COLUMBIA...
  EASTERN GRANT PARISH IN NORTH CENTRAL LOUISIANA...
  LA SALLE PARISH IN NORTH CENTRAL LOUISIANA...

* UNTIL 1000 AM CDT

* AT 649 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  JENA...OLLA...POLLOCK AND CLARKS...

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.

&&

LAT...LON 3207 9192 3203 9189 3193 9189 3192 9200
      3133 9200 3132 9208 3147 9220 3139 9259
      3140 9266 3180 9244 3180 9236 3183 9234
      3203 9231 3226 9219 3226 9199 3218 9197
      3217 9190 3210 9186

$$

14
457 
WGUS74 KSHV 311412
FFSSHV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
912 AM CDT FRI AUG 31 2012

LAC021-043-059-311500-
/O.CON.KSHV.FF.W.0035.000000T0000Z-120831T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LA SALLE LA-GRANT LA-CALDWELL LA-
912 AM CDT FRI AUG 31 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 AM CDT FOR
CALDWELL...GRANT AND LA SALLE PARISHES...

BETWEEN 8 AND 9 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED 
FLASH FLOODING OVER SEVERAL ROADS IN LASALLE PARISH. SHOWERS AND 
THUNDERSTORMS LOCATED NEAR JENA AND OVER THE SOUTH PART OF 
LASALLE PARISH...WERE MOVNIG NORTHEAST AT 35 MPH...BUT WERE 
TRAINING OVER THE SAME AREA. THE RAINFALL HAS DECREASED SOME IN 
INTENSITY...BUT RESIDUAL FLASH FLOODING WAS LIKELY STILL 
OCCURRING IN SOME LOCATIONS...MAINLY IN LASALLE PARISH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO OLLA...
AND CLARKS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

&&

LAT...LON 3207 9192 3203 9189 3193 9189 3192 9200
      3133 9200 3132 9208 3147 9220 3139 9259
      3140 9266 3180 9244 3180 9236 3183 9234
      3203 9231 3226 9219 3226 9199 3218 9197
      3217 9190 3210 9186

$$

03

Nearby

Flash Flood Warnings in Louisiana, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.