Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 21, NWS Shreveport, LA

March 21, 2012Grant Parish, Natchitoches Parish, Winn Parish, Louisiana

NWS Shreveport, LA issued this flash flood warning at Mar 21, 2012, 10:51 AM CDT for Grant Parish, Natchitoches Parish, Winn Parish, Louisiana. It was in force for 3 hr. 2 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, 10:51 AM CDT (15:51 UTC)
Expired: Mar 21, 2012, 1:45 PM CDT
In force: 3 hr
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Emergency: Flash flood emergency
Flood severity: None

Counties Grant Parish, LA, Natchitoches Parish, LA, Winn Parish, LA

What was reported inside it

Time	Report	Where	Remark
Mar 21, 10:51 AM CDT	FLASH FLOOD	3 Se Natchitoches, LA	A FEW HOMES BEING EVACUATED DUE TO FLASH FLOODING BETWEEN NATCHITOCHES AND NATCHEZ LOUISIANA. SEVERAL PARISH ROADS STILL FLOODED.
Mar 21, 11:00 AM CDT	FLASH FLOOD	Winnfield, LA	TWO ROADS STILL BARRICADED DUE TO FLOODING IN WINN PARISH

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, 3.9 hours before the alert went out and 121 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: 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.

893 
WGUS54 KSHV 211551
FFWSHV
LAC043-069-127-211845-
/O.NEW.KSHV.FF.W.0021.120321T1551Z-120321T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
1051 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...

* UNTIL 145 PM CDT

* AT 1044 AM CDT...LOCAL LAW ENFORCEMENT AND EMERGENCY 
  MANAGEMENT OFFICIALS REPORTED EXTENSIVE STREET FLOODING
  ACROSS THE PARISH...AND A FEW HOMES BEING EVACUATED NEAR 
  NATCHITOCHES AND NATCHEZ.

  THIS IS A FLASH FLOOD EMERGENCY FOR NATCHITOCHES PARISH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
  NATCHITOCHES 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 3139 9266 3151 9272 3135 9295 3136 9323
      3153 9323 3154 9334 3171 9334 3171 9344
      3192 9344 3189 9327 3197 9323 3198 9313
      3214 9319 3215 9231 3189 9231 3179 9237
      3176 9234 3161 9238 3149 9227 3147 9221

$$

03

1 follow-up statement

045 
WGUS74 KSHV 211811
FFSSHV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
111 PM CDT WED MAR 21 2012

LAC043-069-127-211845-
/O.CON.KSHV.FF.W.0021.000000T0000Z-120321T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NATCHITOCHES LA-GRANT LA-WINN LA-
111 PM CDT WED MAR 21 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 PM CDT FOR
WINN...GRANT AND NATCHITOCHES PARISHES...

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

AT 101 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETERMINED
THAT RESIDUAL FLOODING CONTINUED TO OCCUR ON STREETS OVER THE 
WARNED AREA. HEAVY RAINFALL IS NO LONGER EXPECTED IN THE WARNED
AREA...BUT THE RESDUAL FLOODING OF STREETS AND LOW LYING AREAS
WILL LIKELY CONTINUE FOR SEVERAL MORE HOURS.

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

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. MOVE TO HIGHER GROUND.

&&

LAT...LON 3139 9266 3151 9272 3135 9295 3136 9323
      3153 9323 3154 9334 3171 9334 3171 9344
      3192 9344 3189 9327 3197 9323 3198 9313
      3214 9319 3215 9231 3189 9231 3179 9237
      3176 9234 3161 9238 3149 9227 3147 9221

$$

03

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 20, 8:55 PM CDT	Flash Flood Warning Emergency	SHV	Grant, Natchitoches, Sabine, Winn	10 hr
Mar 20, 9:02 PM CDT	River Flood Warning	SHV	Bienville, Bossier, Red River, Webster	11 days
Mar 20, 9:03 PM CDT	Tornado Warning	SHV	Natchitoches	27 min
Mar 20, 9:15 PM CDT	Flash Flood Warning	SHV	Bienville, De Soto, Red River	9 hr
Mar 20, 9:24 PM CDT	Tornado Warning	SHV	Natchitoches	36 min
Mar 20, 10:20 PM CDT	Tornado Warning	SHV	Grant, Natchitoches	40 min
Mar 20, 10:50 PM CDT	Flash Flood Warning	SHV	Bossier, Claiborne, Webster	10 hr
Mar 21, 1:52 AM CDT	Flash Flood Warning	SHV	Bienville, Jackson, Lincoln, Union	8 hr
Mar 21, 2:49 AM CDT	Tornado Warning	SHV	Grant, Winn	26 min
Mar 21, 3:14 AM CDT	Tornado Warning	SHV	Jackson, Winn	46 min
Mar 21, 5:41 AM CDT	Tornado Warning	SHV	Jackson, Winn	34 min
Mar 21, 6:16 AM CDT	Flash Flood Warning	SHV	Bienville, Red River	3 hr
Mar 21, 6:47 AM CDT	Flash Flood Warning Emergency	SHV	Grant, Natchitoches, Red River, Sabine, Winn	4 hr
Mar 21, 8:44 AM CDT	Flash Flood Warning	SHV	Claiborne	2 hr
Mar 21, 9:36 AM CDT	Flash Flood Warning	SHV	Union	114 min
Mar 21, 1:53 PM CDT	Areal Flood Warning	SHV	Natchitoches	6 hr

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.