Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 19, NWS Jackson, MS

May 4, 2021Morehouse Parish, West Carroll Parish, Louisiana; Ashley County, Chicot County, Arkansas

NWS Jackson, MS issued this flash flood warning at May 4, 2021, 12:37 PM CDT for Morehouse Parish, West Carroll Parish, Louisiana; Ashley County, Chicot County, Arkansas. It was in force for 3 hr. 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
May 4, 2021, 12:37 PM CDT (17:37 UTC)
Expired
May 4, 2021, 3:30 PM CDT
In force
3 hr
Issued by
NWS Jackson, MS
Area
Storm-based polygon
Flood severity
None

Counties Ashley County, AR, Chicot County, AR, Morehouse Parish, LA, West Carroll Parish, LA

The radar

The Jackson/Brandon,MS radar (KDGX), 175 km from the middle of the area, began a volume at 17:41 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
May 4, 1:35 PM CDTFLASH FLOODDermott, ARFLOODING DESCRIBED AS MAJOR WITH TWO FEET OF WATER COVERING HIGHWAYS AND BARRICADES GOING UP - REPORTED BY DERMOTT EM.

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 12:00Z, 5.6 hours before the alert went out and 165 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 12:00Z on 2021-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2428 joules per kilogram.LCLLFCEL10008507005003002001001 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, Jackson, MS at 12:00Z on 2021-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.19395878Sfc1 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
2428 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
646 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
235 m²/s²
Significant tornado parameter
2.8
Supercell composite
13.2

Open this sounding in Storm Lab

The text

As transmitted.

275 
WGUS54 KJAN 041737
FFWJAN
ARC003-017-LAC067-123-042030-
/O.NEW.KJAN.FF.W.0019.210504T1737Z-210504T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Jackson MS
1237 PM CDT Tue May 4 2021

The National Weather Service in Jackson has issued a

* Flash Flood Warning for...
  Ashley County in southeastern Arkansas...
  Chicot County in southeastern Arkansas...
  Morehouse Parish in northeastern Louisiana...
  Northern West Carroll Parish in northeastern Louisiana...

* Until 330 PM CDT.

* At 1236 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 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...
  Bastrop, Crossett, Hamburg, Lake Village, Dermott, Eudora, Wilmot, 
  North Crossett, West Crossett, Oak Grove, Portland, Montrose, 
  Parkdale, Fountain Hill, Jones, Berlin, Snyder, Galion, Beekman 
  and Goodwill.

Additional rainfall amounts of 2 to 3 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3319 9214 3338 9196 3340 9199 3339 9146
      3356 9143 3345 9112 3344 9112 3340 9121
      3338 9117 3345 9106 3335 9114 3329 9106
      3314 9109 3311 9120 3304 9112 3252 9186
      3257 9193 3265 9191 3271 9204 3269 9205

FLASH FLOOD...RADAR INDICATED

$$

DC
1 follow-up statement
510 
WGUS74 KJAN 041859
FFSJAN

Flash Flood Statement
National Weather Service Jackson MS
159 PM CDT Tue May 4 2021

ARC003-017-LAC067-123-042030-
/O.CON.KJAN.FF.W.0019.000000T0000Z-210504T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ashley AR-Chicot AR-Morehouse LA-West Carroll LA-
159 PM CDT Tue May 4 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM CDT THIS 
AFTERNOON FOR ASHLEY AND CHICOT COUNTIES AND MOREHOUSE AND NORTHERN 
WEST CARROLL PARISHES...

At 157 PM CDT, Doppler radar indicated moderate to heavy rain 
continuing to move across the warned area. Between 2 and 3 inches of 
rain have fallen. Flash flooding is already occurring. Additional 
rainfall of up to an inch is expected for the next one to two hours.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Doppler radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Bastrop, Crossett, Hamburg, Lake Village, Dermott, Eudora, Wilmot, 
  North Crossett, West Crossett, Oak Grove, Portland, Montrose, 
  Parkdale, Fountain Hill, Jones, Berlin, Snyder, Galion, Beekman 
  and Goodwill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3319 9214 3338 9196 3340 9199 3339 9146
      3356 9143 3345 9112 3344 9112 3340 9121
      3338 9117 3345 9106 3335 9114 3329 9106
      3314 9109 3311 9120 3304 9112 3252 9186
      3257 9193 3265 9191 3271 9204 3269 9205

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.5-1 INCH IN 2 HOURS 

$$

EC

The office that day

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

IssuedProductOfficeCountiesLasted
May 4, 11:57 AM CDTSevere Thunderstorm WarningJANMorehouse78 min
May 4, 12:30 PM CDTSevere Thunderstorm WarningJANEast Carroll, West Carroll75 min
May 4, 12:57 PM CDTSevere Thunderstorm WarningJANEast Carroll, Franklin, Madison, Richland, West Carroll76 min
May 4, 1:15 PM CDTSevere Thunderstorm WarningJANCatahoula, Concordia, Franklin, Tensas75 min
May 4, 1:37 PM CDTSevere Thunderstorm WarningJANEast Carroll, Madison53 min
May 4, 1:57 PM CDTSevere Thunderstorm WarningJANTensas78 min
May 4, 3:51 PM CDTAreal Flood WarningJANMorehouse, West Carroll6 hr
May 4, 12:18 PM CDTSevere Thunderstorm WarningJANChicot72 min

Nearby

Flash Flood Warnings in Louisiana, 2021Flash Flood Warnings in Arkansas, 2021Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.