Alert archive / Mississippi / Flash Flood Warnings in 2026

Flash Flood Warning 18, NWS Jackson, MS

May 21, 20266 counties in Mississippi

NWS Jackson, MS issued this flash flood warning at May 21, 2026, 8:13 AM CDT for 6 counties in Mississippi. 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 21, 2026, 8:13 AM CDT (13:13 UTC)
Expired
May 21, 2026, 11:15 AM CDT
In force
3 hr
Issued by
NWS Jackson, MS
Area
Storm-based polygon
Flood severity
None

Counties Covington County, MS, Forrest County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Marion County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 86 km from the middle of the area, began a volume at 13:16 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 21, 10:00 AM CDTFLASH FLOOD6 S Hebron, MSJones County EMA personnel encountered swift moving water crossing Maybelle Road.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this flash flood warning; the first came 107 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 1.2 hours before the alert went out and 95 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 2026-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 376 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 12:00Z on 2026-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.193958Sfc1 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
376 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
610 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

474 
WGUS54 KJAN 211313
FFWJAN
MSC031-035-065-067-073-091-211615-
/O.NEW.KJAN.FF.W.0018.260521T1313Z-260521T1615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Jackson MS
813 AM CDT Thu May 21 2026

The National Weather Service in Jackson has issued a

* Flash Flood Warning for...
  Southern Jefferson Davis County in south central Mississippi...
  Northern Marion County in south central Mississippi...
  Covington County in southeastern Mississippi...
  Northwestern Forrest County in southeastern Mississippi...
  Western Jones County in southeastern Mississippi...
  Northwestern Lamar County in southeastern Mississippi...

* Until 1115 AM CDT.

* At 813 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 4 inches of rain 
  have fallen. Additional rainfall amounts of 2 to 3 inches 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, Laurel, Ellisville, Collins, Sumrall, Soso, Seminary, 
  Moselle, Bassfield, Eastabuchie, Sanford, Melba, Hebron, Improve, 
  Carson, Bunker Hill, Society Hill and Goss.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3168 8964 3180 8940 3180 8938 3180 8937
      3180 8935 3180 8934 3181 8918 3160 8918
      3145 8920 3133 8965 3131 8974 3135 8997
      3153 8990

FLASH FLOOD...RADAR INDICATED

$$

EC
2 follow-up statements
704 
WGUS74 KJAN 211453
FFSJAN

Flash Flood Statement
National Weather Service Jackson MS
953 AM CDT Thu May 21 2026

MSC031-035-065-067-073-091-211615-
/O.CON.KJAN.FF.W.0018.000000T0000Z-260521T1615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Covington MS-Forrest MS-Jefferson Davis MS-Jones MS-Lamar MS-
Marion MS-
953 AM CDT Thu May 21 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 AM CDT THIS 
MORNING FOR SOUTHERN JEFFERSON DAVIS, NORTHERN MARION, SOUTHERN 
COVINGTON, NORTHWESTERN FORREST, SOUTHWESTERN JONES AND NORTHWESTERN 
LAMAR COUNTIES...

At 953 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 6 inches of rain have 
fallen. Additional rainfall amounts of 1 to 3 inches 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, Collins, Sumrall, Seminary, Moselle, Bassfield, 
  Eastabuchie, Melba, Sanford, Improve, Carson, Bunker Hill, Society 
  Hill and Goss.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3166 8962 3170 8929 3145 8920 3133 8965
      3131 8974 3135 8997 3153 8988

FLASH FLOOD...RADAR INDICATED

$$

EC
813 
WGUS74 KJAN 211613
FFSJAN

Flash Flood Statement
National Weather Service Jackson MS
1113 AM CDT Thu May 21 2026

MSC031-035-065-067-073-091-211623-
/O.EXP.KJAN.FF.W.0018.000000T0000Z-260521T1615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Covington MS-Forrest MS-Jefferson Davis MS-Jones MS-Lamar MS-
Marion MS-
1113 AM CDT Thu May 21 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 1115 AM CDT THIS MORNING FOR 
SOUTHERN JEFFERSON DAVIS, NORTHERN MARION, SOUTHERN COVINGTON, 
NORTHWESTERN FORREST, SOUTHWESTERN JONES AND NORTHWESTERN LAMAR 
COUNTIES...

Rainfall rates have diminished and flash flooding is no longer 
expected to pose an immediate threat. Please continue to heed 
remaining road closures.

&&

LAT...LON 3166 8962 3170 8929 3145 8920 3133 8965
      3131 8974 3135 8997 3153 8988

$$

EC

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Jackson, MS wrote its last area forecast discussion before this flash flood warning went out at May 21, 6:24 AM CDT, 1 hour 49 minutes earlier. Its key messages:

  • The potential for heavy rainfall and flooding will need to be monitored through this weekend.
Area forecast discussion, May 21, 6:24 AM CDT, 1 hour 49 minutes before
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
624 AM CDT Thu May 21 2026

...New AVIATION...

.KEY MESSAGES...

- The potential for heavy rainfall and flooding will need to be
  monitored through this weekend.

&&

.DISCUSSION...
Issued at 131 AM CDT Thu May 21 2026

Today and Tonight:

Longwave trough to ridge pattern of the CONUS will keep rain in the
ArkLaMiss region. A shortwave disturbance moving across Lower MS
Valley will filter in additional moisture into the area, resulting
in PW values in the 99th percentile. Widespread showers and storms
are expected through the evening. With PW values in the 99th
percentile, ample moisture transport, and storm training, flash
flooding will possible today in areas receiving heavy rainfall. /SW/

Friday through next Wednesday...The primary focus through the mid
and extended portions of the forecast will continue to be that of
multiple bouts of rainfall affecting the area.  Under persistent
southwesterly to southerly flow across the region, multiple
disturbances aloft will traverse the forecast area through the
Memorial Day weekend into the middle of next week.  These
disturbances, coupled with the warm and abundantly moist airmass in
place across the area, will yield multiple bouts of moderate to
occasionally heavy rain falling across the forecast area during this
time.

As rainfall continues to accumulate across the area during this
time, in addition to just the daily potential for high rainfall
rates over a short amount of time in localized areas, the threat for
flash flooding could begin to become a concern.  This will need to
be monitored, with flooding hazards potentially being added to the
HWO for portions of, if not all of, the forecast area through this
forecast period.  Otherwise, expect muggy conditions overall with
near seasonable highs for this time of year.  However at night,
expect above normal lows. /19/

&&

.AVIATION...
(12Z TAFS)
Issued at 624 AM CDT Thu May 21 2026

Morning showers with an isolated storms are moving across sites
resulting in a mix of current flight conditions. Patchy fog will be
possible through 14Z. As ceilings improve, flight conditions will
return to VFR. Additional showers/storms are expected through the
evening, lasting through the rest of the period. Flight conditions
are expected to vary between MVFR/IFR flight conditions due to rain
and low ceilings. /SW/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       82  69  81  69 /  70  70  80  50
Meridian      83  69  82  70 /  80  60 100  60
Vicksburg     82  68  81  69 /  80  80 100  30
Hattiesburg   84  70  83  70 /  80  60 100  60
Natchez       84  69  82  70 /  80  80  80  30
Greenville    81  68  81  68 /  60  90  80  40
Greenwood     82  68  81  68 /  80  80  90  50

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&

SW/19/SW

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 1:40 PM CDTSpecial Weather StatementJANLincoln50 min
May 21, 6:20 PM CDTSpecial Weather StatementJANFranklin, Jefferson40 min

Nearby

Flash Flood Warnings in Mississippi, 2026Every flash flood warning in 2026

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.