Alert archive / Mississippi / Flash Flood Warnings in 2021

Flash Flood Warning 99, NWS Jackson, MS

September 18, 2021Forrest County, Lamar County, Mississippi

NWS Jackson, MS issued this flash flood warning at Sep 18, 2021, 4:35 PM CDT for Forrest County, Lamar County, Mississippi. It was in force for 42 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 18, 2021, 4:35 PM CDT (21:35 UTC)
Expired
Sep 18, 2021, 5:17 PM CDT
In force
42 min
Issued by
NWS Jackson, MS
Area
Storm-based polygon
Flood severity
None

Counties Forrest County, MS, Lamar County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 121 km from the middle of the area, began a volume at 21:38 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.6 hours before the alert went out and 123 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, Slidell Radar S, LA at 12:00Z on 2021-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1642 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, Slidell Radar S, LA at 12:00Z on 2021-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.1939Sfc1 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
1642 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
550 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

696 
WGUS54 KJAN 182135
FFWJAN
MSC035-073-182300-
/O.NEW.KJAN.FF.W.0099.210918T2135Z-210918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Jackson MS
435 PM CDT Sat Sep 18 2021

The National Weather Service in Jackson has issued a

* Flash Flood Warning for...
  Northwestern Forrest County in southeastern Mississippi...
  Northeastern Lamar County in southeastern Mississippi...

* Until 600 PM CDT.

* At 435 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen. Additional rainfall amounts up to 1 inch are possible 
  in the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Hattiesburg, Petal, West Hattiesburg, Oak Grove and Rawls Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3135 8945 3138 8945 3139 8941 3135 8925
      3126 8924 3125 8933 3126 8945

FLASH FLOOD...RADAR INDICATED

$$

DL
1 follow-up statement
088 
WGUS74 KJAN 182217
FFSJAN

Flash Flood Statement
National Weather Service Jackson MS
517 PM CDT Sat Sep 18 2021

MSC035-073-182227-
/O.CAN.KJAN.FF.W.0099.000000T0000Z-210918T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Forrest MS-Lamar MS-
517 PM CDT Sat Sep 18 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN FORREST AND 
NORTHEASTERN LAMAR COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat.

LAT...LON 3135 8945 3138 8945 3139 8941 3135 8925
      3126 8924 3125 8933 3126 8945

$$

DL

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 17, 7:30 PM CDTSpecial Weather StatementJANClay60 min
Sep 17, 7:48 PM CDTSpecial Weather StatementJANBolivar57 min
Sep 17, 9:27 PM CDTFlash Flood WarningJANLowndes93 min
Sep 17, 10:05 PM CDTFlash Flood WarningJANIssaquena, Sharkey2 hr
Sep 18, 2:30 PM CDTSpecial Weather StatementJANLowndes45 min
Sep 18, 3:41 PM CDTSpecial Weather StatementJANForrest49 min
Sep 18, 4:49 PM CDTSpecial Weather StatementJANWinston41 min

Nearby

Flash Flood Warnings in Mississippi, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.