Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 16, NWS Jackson, MS

April 10, 2021Catahoula Parish, Louisiana

NWS Jackson, MS issued this flash flood warning at Apr 10, 2021, 2:14 AM CDT for Catahoula Parish, Louisiana. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 10, 2021, 2:14 AM CDT (07:14 UTC)
Expired: Apr 10, 2021, 4:52 AM CDT
In force: 3 hr
Issued by: NWS Jackson, MS
Area: Storm-based polygon
Flood severity: None

County Catahoula Parish, LA

The radar

The Ft Polk radar (KPOE), 108 km from the middle of the area, began a volume at 07:14 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.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 7.2 hours before the alert went out and 191 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: 2773 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 733 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 111 m²/s²
0-3 km storm-relative helicity: 149 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 7.7

Open this sounding in Storm Lab

The text

As transmitted.

203 
WGUS54 KJAN 100714
FFWJAN
LAC025-101015-
/O.NEW.KJAN.FF.W.0016.210410T0714Z-210410T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Jackson MS
214 AM CDT Sat Apr 10 2021

The National Weather Service in Jackson has issued a

* Flash Flood Warning for...
  Southwestern Catahoula Parish in northeastern Louisiana...

* Until 515 AM CDT.

* At 214 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Larto and Mayna.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks, country roads, farm land, and other low lying areas.

&&

LAT...LON 3153 9201 3163 9181 3157 9183 3152 9178
      3148 9180 3144 9172 3144 9181 3150 9183
      3150 9186 3142 9185 3139 9178 3136 9186
      3131 9187 3128 9182 3129 9193 3127 9195
      3123 9192 3123 9199 3128 9202 3130 9200

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR 

$$

GRG

1 follow-up statement

995 
WGUS74 KJAN 100952
FFSJAN

Flash Flood Statement
National Weather Service Jackson MS
452 AM CDT Sat Apr 10 2021

LAC025-101002-
/O.CAN.KJAN.FF.W.0016.000000T0000Z-210410T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Catahoula LA-
452 AM CDT Sat Apr 10 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN CATAHOULA 
PARISH...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3153 9201 3163 9181 3157 9183 3152 9178
      3148 9180 3144 9172 3144 9181 3150 9183
      3150 9186 3142 9185 3139 9178 3136 9186
      3131 9187 3128 9182 3129 9193 3127 9195
      3123 9192 3123 9199 3128 9202 3130 9200

$$

GRG

The office that day

Everything else NWS Jackson, MS issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 9, 7:49 PM CDT	Severe Thunderstorm Warning	JAN	Morehouse, Richland	39 min
Apr 9, 8:10 PM CDT	Severe Thunderstorm Warning	JAN	Franklin, Richland	50 min
Apr 9, 8:49 PM CDT	Severe Thunderstorm Warning	JAN	East Carroll, Madison	41 min
Apr 9, 10:03 PM CDT	Special Weather Statement	JAN	Madison, Tensas	27 min
Apr 9, 10:11 PM CDT	Severe Thunderstorm Warning	JAN	Catahoula, Concordia, Franklin	49 min
Apr 10, 12:01 AM CDT	Flash Flood Warning	JAN	Concordia	3 hr
Apr 10, 12:59 AM CDT	Special Weather Statement	JAN	Catahoula	46 min
Apr 10, 1:24 AM CDT	Severe Thunderstorm Warning	JAN	Catahoula, Concordia	51 min
Apr 10, 2:53 AM CDT	Flash Flood Warning	JAN	Concordia	118 min

Nearby

Flash Flood Warnings in Louisiana, 2021 Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.