Alert archive / Louisiana / Flash Flood Warnings in 2012

Flash Flood Warning 22, NWS Shreveport, LA

March 30, 2012Grant Parish, Natchitoches Parish, Winn Parish, Louisiana

NWS Shreveport, LA issued this flash flood warning at Mar 30, 2012, 10:00 AM CDT for Grant Parish, Natchitoches Parish, Winn Parish, Louisiana. It was in force for 3 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 30, 2012, 10:00 AM CDT (15:00 UTC)
Expired: Mar 30, 2012, 1:00 PM CDT
In force: 3 hr
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Flood severity: None

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

What was reported inside it

Time	Report	Where	Remark
Mar 30, 10:01 AM CDT	FLASH FLOOD	Natchitoches, LA	CAR NOSED DOWN IN HIGH WATER AT BREDA AND TEXAS STREETS.
Mar 30, 10:06 AM CDT	FLASH FLOOD	Natchitoches, LA	SEVERAL STREETS IN NATCHITOCHES ARE FLOODED DUE TO HEAVY RAINFALL OVER THE PAST HOUR.
Mar 30, 10:20 AM CDT	FLASH FLOOD	Natchitoches, LA	WATER OVER HOODS OF CARS AT MELROSE AND KEYSER IN NATCHITOCHES

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, 3.0 hours before the alert went out and 97 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: 182 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 449 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 85 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.

790 
WGUS54 KSHV 301500
FFWSHV
LAC043-069-127-301800-
/O.NEW.KSHV.FF.W.0022.120330T1500Z-120330T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
1000 AM CDT FRI MAR 30 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL GRANT PARISH IN NORTH CENTRAL LOUISIANA...
  SOUTHWESTERN WINN PARISH IN NORTH CENTRAL LOUISIANA...
  CENTRAL NATCHITOCHES PARISH IN NORTHWEST LOUISIANA...
  THIS INCLUDES THE CITY OF NATCHITOCHES...

* UNTIL 100 PM CDT

* AT 954 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
  VERY HEAVY RAIN FROM A THUNDERSTORM 8 MILES EAST OF NATCHITOCHES...
  MOVING EAST AT 20 MPH. 

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MONTGOMERY...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ESTIMATES OF AROUND TWO INCHES OF RAIN HAVE FALLEN WITH THIS STORM 
AND AN ADDITIONAL ONE TO TWO INCHES OF RAINFALL ARE EXPECTED IN THE 
WARNED AREA.

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 3173 9332 3188 9341 3190 9320 3192 9317
      3189 9262 3166 9263 3163 9332

$$

05

1 follow-up statement

678 
WGUS74 KSHV 301601
FFSSHV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1101 AM CDT FRI MAR 30 2012

LAC043-069-127-301800-
/O.CON.KSHV.FF.W.0022.000000T0000Z-120330T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NATCHITOCHES LA-GRANT LA-WINN LA-
1101 AM CDT FRI MAR 30 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 PM CDT FOR
WINN...GRANT AND NATCHITOCHES PARISHES...

AT 1100 AM CDT...THE THUNDERSTORM PRODUCING FLASH FLOODING ACROSS 
MUCH OF THE WARNED AREA HAS BEEN GRADUALLY DISSIPATING. 
HOWEVER...THE FLASH FLOOD THREAT CONTINUES AS STANDING WATER WILL
BE SLOW TO RECEDE.

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 3173 9332 3188 9341 3190 9320 3192 9317
      3189 9262 3166 9263 3163 9332

$$

05

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.