Flash Flood Warning 38, NWS St. Louis, MO

363 
WGUS73 KLSX 212238
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
538 PM CDT Sun Jun 21 2026

ILC051-220045-
/O.CON.KLSX.FF.W.0038.000000T0000Z-260622T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fayette IL-
538 PM CDT Sun Jun 21 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM CDT THIS
EVENING FOR FAYETTE COUNTY...

At 538 PM CDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 2 and 5 inches of rain have
fallen. Additional rainfall amounts of 2 to 3 inches are possible in
the warned area..

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

SOURCE...Radar indicated.

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

Some locations that will experience flash flooding include...
  Vandalia, St. Elmo, Brownstown, Farina, Shobonier, Wrights Corner,
  Avena, La Clede, Pittsburg, St. Peter, St. Paul, St. James,
  Loogootee and Hagerstown.

This includes the following State Parks...
Carlyle Lake State Fish and Wildlife Area.

This includes the following highways...
Interstate 70 in Illinois between exits 68 and 76. Interstate 57 in
Illinois near exit 135.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3892 8926 3897 8906 3922 8892 3922 8881
      3891 8881 3891 8870 3883 8870 3882 8900
      3882 8914 3874 8914 3874 8925 3884 8926

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Carney

125 
WGUS53 KLSX 220018
FFWLSX
ILC051-220245-
/O.EXT.KLSX.FF.W.0038.000000T0000Z-260622T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
718 PM CDT Sun Jun 21 2026

The National Weather Service in St Louis has extended the

* Flash Flood Warning for...
  Southern Fayette County in south central Illinois...

* Until 945 PM CDT.

* At 718 PM CDT, Doppler radar indicated thunderstorms have produced
  heavy rain across the warned area. Between 4 and 6 inches of rain
  have fallen. Life threatening flash flooding is occurring.

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

  SOURCE...Radar indicated.

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

* Some locations that will experience flash flooding include...
  Farina, Shobonier, La Clede, Pittsburg, St. Peter, St. Paul,
  Loogootee and St. James.

This includes the following State Parks...
Carlyle Lake State Fish and Wildlife Area.

This includes Interstate 57 in Illinois near exit 135.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3891 8926 3899 8881 3891 8881 3891 8870
      3883 8870 3882 8887 3882 8914 3874 8914
      3874 8925 3879 8925

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Jaja

Area Forecast Discussion
National Weather Service Saint Louis MO
324 PM CDT Sun Jun 21 2026

.KEY MESSAGES...

- Damaging winds and tornadoes are possible through this evening
  across east central and southeast Missouri into southwest Illinois.

- Locally heavy rainfall is also possible through early tonight.

- Seasonably cool conditions are forecast this work week.

&&

.SHORT TERM...  (Through Late Tonight)
Issued at 324 PM CDT Sun Jun 21 2026

A remnant MCV is currently in southwest Illinois and moving
east/northeast. There has been a very slow and gradual uptick in
convection out ahead of this feature across southwest and south-
central Illinois as diurnal instability continues to increase.
Low- level shear and helicity remain quite strong, so mini
supercells may be capable of producing tornadoes. This threat will
continue at least over the next few hours as the MCV progress
through south- central Illinois.

Farther southwest, additional showers and thunderstorms are expected
to develop farther southwest along the trailing cold front. Exactly
where and when is not certain, but my best guess would be near the
Missouri-Kansas border where surface convergence is located. At
least scattered storms should develop farther northeast eventually
along the boundary, with storms moving east/southeast in time. How
organized this convection will be is also uncertain as there are a
couple of limiting factors including: 1) weak surface convergence
along the boundary and 2) modest height rises behind the MCV. In
addition, the prior storms have at least helped limit instability
slightly, with MLCAPE values of 1000-1500 J/kg. Effective shear also
decreases behind the MCV, though is still near 30 knots. A mixed
mode of convection seems most likely, with multicellular clusters,
small bowing segments, and transient supercells all possible.
Damaging winds and a tornado or two are possible through late
evening before storms begin to move out to the southeast. Locally
heavy rainfall is also possible given high precipitable water values
(~1.9"). Afternoon/evening storms are however focused farther
southwest. Storms also should be progressive, so overall I think the
flash flood threat is low and likely would be isolated to any areas
that do experience some training.

Gosselin

&&

.LONG TERM...  (Monday through Next Sunday)
Issued at 324 PM CDT Sun Jun 21 2026

(Monday - Monday Night)

Cooler weather along with northerly winds and clouds are
expected on Monday. High temperatures are only expected to reach
into the mid 70s, or about 10 degrees below normal for the date.
Lows Monday night are forecast to drop into the mid 50s to near the
60 degree mark.

(Tuesday - Next Sunday)

Not much has changed with respect to the work week forecast with
broad northwest flow aloft across the Mississippi Valley. There is
high confidence in seasonally cool temperatures with mostly dry
weather expected outside of a cold frontal passage
Wednesday/Wednesday night.

Moderating temperatures are forecast heading into next weekend with
flow aloft becoming more zonal. That means increasing
moisture/instability as well and increasing chances of showers and
thunderstorms.

Gosselin

&&

.AVIATION...  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1227 PM CDT Sun Jun 21 2026

Showers and thunderstorms are expected to move out of the metro
St. Louis terminals over the next 2 hours. Additional development
is expected later this afternoon, but may be just south of both
central Missouri and St. Louis terminals. The actual cold front
should move through from northwest to southeast through tonight,
with winds veering from the southwest to the northwest and
eventually north/northeast through the period. Low stratus is also
forecast behind this front, with a period of IFR ceilings likely.

Gosselin

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flood Watch until 1 AM CDT Monday for Franklin MO-Saint Charles
     MO-Saint Louis City MO-Saint Louis MO.

     Flood Watch through Monday morning for Crawford MO-Iron MO-
     Jefferson MO-Madison MO-Reynolds MO-Saint Francois MO-
     Sainte Genevieve MO-Washington MO.

     Flood Watch until 7 PM CDT this evening for Boone MO-Callaway MO-
     Cole MO-Gasconade MO-Lincoln MO-Moniteau MO-Montgomery MO-
     Osage MO-Warren MO.

IL...Flood Watch until 1 AM CDT Monday for Bond IL-Fayette IL-Greene
     IL-Jersey IL-Macoupin IL-Madison IL-Montgomery IL.

     Flood Watch through Monday morning for Clinton IL-Marion IL-
     Monroe IL-Randolph IL-Saint Clair IL-Washington IL.

     Flood Watch until 7 PM CDT this evening for Calhoun IL.

&&

WFO LSX

Preliminary Local Storm Report
National Weather Service St Louis MO
242 PM CDT Sun Jun 21 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0225 PM     Non-Tstm Wnd Dmg 1 SW Warson Woods       38.60N 90.40W
06/21/2026                   St. Louis          MO   Trained Spotter

            Power lines down near North Woodlawn and
            Manchester Road.

&&

JPG

Preliminary Local Storm Report
National Weather Service St Louis MO
318 PM CDT Sun Jun 21 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0225 PM     Non-Tstm Wnd Dmg 1 SW Warson Woods       38.60N 90.40W
06/21/2026                   St. Louis          MO   Trained Spotter

            Corrects previous non-tstm wnd dmg report
            from 1 SW Warson Woods. Power lines down
            near North Woodlawn and Manchester Road.
            Downed lines caught cars in a car dealership
            on fire on Manchester and Woodlawn.

&&

LSJ