Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 20, NWS Shreveport, LA

March 21, 2012Union Parish, Louisiana; Union County, Arkansas

NWS Shreveport, LA issued this flash flood warning at Mar 21, 2012, 9:36 AM CDT for Union Parish, Louisiana; Union County, Arkansas. It was in force for 114 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
Mar 21, 2012, 9:36 AM CDT (14:36 UTC)
Expired
Mar 21, 2012, 11:30 AM CDT
In force
114 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon
Flood severity
None

Counties Union County, AR, Union Parish, LA

The radar

The Shreveport radar (KSHV), 147 km from the middle of the area, began a volume at 14:36 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.

What was reported inside it

TimeReportWhereRemark
Mar 21, 9:58 AM CDTFLASH FLOODFarmerville, LASOME 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

Shreveport, LA (KSHV), launched 12:00Z, 2.6 hours before the alert went out and 138 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 12:00Z on 2012-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2012-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -164 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
0 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
-164 m²/s²
0-3 km storm-relative helicity
465 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.

043 
WGUS54 KSHV 211436
FFWSHV
ARC139-LAC111-211630-
/O.NEW.KSHV.FF.W.0020.120321T1436Z-120321T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS EXTENDED THE 

* FLASH FLOOD WARNING FOR...
  UNION PARISH IN NORTH CENTRAL LOUISIANA...
  EASTERN UNION COUNTY IN SOUTH CENTRAL ARKANSAS...
  THIS INCLUDES THE CITIES OF...HUTTIG...EL DORADO...

* UNTIL 1130 AM CDT

* AT 927 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
  MODERATE TO OCCASIONALLY HEAVY RAIN STILL OCCURRING OVER THE 
  WARNED AREA. RESIDUAL STREET FLOODING WILL CONTINUE OVER UNION 
  PARISH LOUISIANA AND EASTERN UNION COUNTY ARKANSAS...THROUGH 
  1130 AM CDT.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO URBANA...
  STRONG...LAWSON...LAPILE AND CALION...

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 3259 9223 3258 9241 3267 9242 3267 9251
      3272 9252 3275 9257 3277 9273 3301 9273
      3301 9268 3337 9266 3337 9265 3337 9254
      3328 9244 3330 9235 3325 9222 3321 9221
      3315 9210 3310 9213 3301 9206 3274 9205

$$

03
1 follow-up statement
648 
WGUS74 KSHV 211527
FFSSHV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1027 AM CDT WED MAR 21 2012

ARC139-LAC111-211630-
/O.CON.KSHV.FF.W.0020.000000T0000Z-120321T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
UNION AR-UNION LA-
1027 AM CDT WED MAR 21 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1130 AM CDT FOR
UNION COUNTY...AND UNION PARISH...

AT 1023 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED RESIDUAL
STREET FLOODING OCCURRING IN RURAL PARTS OF THE UNION PARISH.
RESIDUAL FLOODING IS ALSO LIKELY STILL OCCURRING OVER EASTERN
UNION COUNTY ARKANSAS.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO URBANA...
STRONG...LAWSON...LAPILE...HUTTIG...EL DORADO AND CALION

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 3259 9223 3258 9241 3267 9242 3267 9251
      3272 9252 3275 9257 3277 9273 3301 9273
      3301 9268 3337 9266 3337 9265 3337 9254
      3328 9244 3330 9235 3325 9222 3321 9221
      3315 9210 3310 9213 3301 9206 3274 9205

$$

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, 6:47 AM CDTFlash Flood Warning EmergencySHVGrant, Natchitoches, Red River, Sabine, Winn4 hr
Mar 21, 8:44 AM CDTFlash Flood WarningSHVClaiborne2 hr
Mar 21, 10:51 AM CDTFlash Flood Warning EmergencySHVGrant, Natchitoches, Winn3 hr
Mar 21, 1:53 PM CDTAreal Flood WarningSHVNatchitoches6 hr
Mar 20, 7:27 PM CDTRiver Flood WarningSHVAshley, Union28 days

Nearby

Flash Flood Warnings in Louisiana, 2012Flash Flood Warnings in Arkansas, 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; radar from the NEXRAD Level II archive.