Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 18, NWS Shreveport, LA

March 21, 20125 parishes in Louisiana

NWS Shreveport, LA issued this flash flood warning at Mar 21, 2012, 6:47 AM CDT for 5 parishes in Louisiana. It was in force for 4 hr. 3 reports 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
Mar 21, 2012, 6:47 AM CDT (11:47 UTC)
Expired
Mar 21, 2012, 10:45 AM CDT
In force
4 hr
Issued by
NWS Shreveport, LA
Area
Storm-based polygon
Emergency
Flash flood emergency
Flood severity
None

Counties Grant Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Winn Parish, LA

What was reported inside it

TimeReportWhereRemark
Mar 21, 7:05 AM CDTFLASH FLOOD20 Ssw Natchitoches, LASEVERAL CREEKS ARE OUT OF THE BANKS...AND SHADY GROVE RD IS FLOODED EAST OF HWY 117
Mar 21, 7:40 AM CDTFLASH FLOODNatchitoches, LAWATER COMPLETELY COVERING HWY 3191...TEXAS STREET...AT SIBLEY LAKE BOAT LAUNCH. BOAT HOUSES ON CANE RIVER ARE FLOODED AND HIGH WATER IS APPROACHING ROGUE HOUSE IN THE DOWNTOWN AREA.
Mar 21, 10:51 AM CDTFLASH FLOOD3 Se Natchitoches, LAA FEW HOMES BEING EVACUATED DUE TO FLASH FLOODING BETWEEN NATCHITOCHES AND NATCHEZ LOUISIANA. SEVERAL PARISH ROADS STILL FLOODED.

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

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 11.8 hours before the alert went out and 310 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, Jackson, MS at 00:00Z on 2012-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 267 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 00:00Z on 2012-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 square meters per square second.193958Sfc1 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
267 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1256 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
145 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.

102 
WGUS54 KSHV 211147
FFWSHV
LAC043-069-081-085-127-211545-
/O.NEW.KSHV.FF.W.0018.120321T1147Z-120321T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
647 AM CDT WED MAR 21 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  GRANT PARISH IN NORTH CENTRAL LOUISIANA...
  WINN PARISH IN NORTH CENTRAL LOUISIANA...
  THIS INCLUDES THE CITY OF WINNFIELD...
  NATCHITOCHES PARISH IN NORTHWEST LOUISIANA...
  THIS INCLUDES THE CITY OF NATCHITOCHES...
  SOUTHEASTERN RED RIVER PARISH IN NORTHWEST LOUISIANA...
  SABINE PARISH IN NORTHWEST LOUISIANA...

* UNTIL 1045 AM CDT

* AT 637 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED 
TO DETECT AREAS OF MODERATE AND HEAVY RAIN FROM SHOWER AND 
THUNDERSTORM ACTIVITY PASSING OVER THE WARNED AREA. LOCAL LAW 
ENFORCEMENT AND EMERGENCY MANAGEMENT OFFICIALS CONTINUE TO RELAY 
REPORTS OF FLASH FLOODING OVER THE WARNED AREA. SURFACE REPORTS AND 
RADAR ESTIMATES INDICATE THAT GENERAL RAINFALL AMOUNTS OF FIVE TO 
SEVEN INCHES HAVE FALLEN ACROSS THE WARNED AREA...WITH HIGHER 
AMOUNTS OF EIGHT TO TEN INCHES ACROSS NATCHITOCHES PARISH. THE 
KISATCHIE RANGER STATION IN NATCHITOCHES PARISH REPORTED A TOTAL OF 
10.19 INCHES THIS MORNING. NUMEROUS ROADS ARE FLOODED AND 
CLOSED...WITH WATER ENTERING HOMES IN NATCHITOCHES. ADDITIONAL HEAVY 
RAINFALL WILL CONTINUE TO MOVE ACROSS THE WARNED AREA THIS MORNING 
AND INTO DAYBREAK...AND ONLY CONTINUE TO EXACERBATE FLASH FLOODING. 
THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION! 
TRAVEL IS STRONGLY DISCOURAGED THIS MORNING!

  A FLASH FLOOD EMERGENCY CONTINUES FOR NATCHITOCHES PARISH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ZWOLLE...
  MONTGOMERY...MANY...CONVERSE...COLFAX AND CAMPTI...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF ONE TO THREE INCHES ARE POSSIBLE IN 
THE WARNED AREA.

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.

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.

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 3117 9360 3137 9364 3147 9375 3151 9372
      3160 9384 3170 9380 3184 9387 3184 9345
      3194 9342 3201 9315 3211 9316 3215 9318
      3214 9231 3161 9238 3147 9221 3139 9266
      3151 9272 3135 9295 3136 9339 3116 9359

$$

ELEVEN
1 follow-up statement
170 
WGUS74 KSHV 211453
FFSSHV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
953 AM CDT WED MAR 21 2012

LAC043-069-081-085-127-211545-
/O.CON.KSHV.FF.W.0018.000000T0000Z-120321T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SABINE LA-RED RIVER LA-NATCHITOCHES LA-GRANT LA-WINN LA-
953 AM CDT WED MAR 21 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 AM CDT FOR
WINN...GRANT...NATCHITOCHES...RED RIVER AND SABINE PARISHES...

...A FLASH FLOOD EMERGENCY FOR NATCHITOCHES PARISH...

AT 940 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED A
THUNDERSTORM PRODUCING FLASH FLOODING OVER THE WARNED AREA.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ZWOLLE...
WINNFIELD...NATCHITOCHES...MONTGOMERY...CONVERSE AND CAMPTI

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.

&&

LAT...LON 3117 9360 3137 9364 3147 9375 3151 9372
      3160 9384 3170 9380 3184 9387 3184 9345
      3194 9342 3201 9315 3211 9316 3215 9318
      3214 9231 3161 9238 3147 9221 3139 9266
      3151 9272 3135 9295 3136 9339 3116 9359

$$

03

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 20, 8:55 PM CDTFlash Flood Warning EmergencySHVGrant, Natchitoches, Sabine, Winn10 hr
Mar 20, 9:02 PM CDTRiver Flood WarningSHVBienville, Bossier, Red River, Webster11 days
Mar 20, 9:03 PM CDTTornado WarningSHVNatchitoches27 min
Mar 20, 9:15 PM CDTFlash Flood WarningSHVBienville, De Soto, Red River9 hr
Mar 20, 9:24 PM CDTTornado WarningSHVNatchitoches36 min
Mar 20, 10:20 PM CDTTornado WarningSHVGrant, Natchitoches40 min
Mar 20, 10:50 PM CDTFlash Flood WarningSHVBossier, Claiborne, Webster10 hr
Mar 21, 1:52 AM CDTFlash Flood WarningSHVBienville, Jackson, Lincoln, Union8 hr
Mar 21, 2:49 AM CDTTornado WarningSHVGrant, Winn26 min
Mar 21, 3:14 AM CDTTornado WarningSHVJackson, Winn46 min
Mar 21, 5:41 AM CDTTornado WarningSHVJackson, Winn34 min
Mar 21, 6:16 AM CDTFlash Flood WarningSHVBienville, Red River3 hr
Mar 21, 8:44 AM CDTFlash Flood WarningSHVClaiborne2 hr
Mar 21, 9:36 AM CDTFlash Flood WarningSHVUnion114 min
Mar 21, 10:51 AM CDTFlash Flood Warning EmergencySHVGrant, Natchitoches, Winn3 hr
Mar 21, 1:53 PM CDTAreal Flood WarningSHVNatchitoches6 hr

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.