Flash Flood Warning 41, NWS St. Louis, MO

960 
WGUS73 KLSX 260426
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
1126 PM CDT Thu Jun 25 2026

ILC157-260600-
/O.CON.KLSX.FF.W.0041.000000T0000Z-260626T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Randolph IL-
1126 PM CDT Thu Jun 25 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 AM CDT FRIDAY FOR
RANDOLPH COUNTY...

At 1126 PM CDT, Doppler radar indicated the heavy rain has largely
ended. However,  between 2 and 5 inches of rain have fallen, and
flash flooding from this heavy rain is continuing

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

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...
  Chester, Sparta, Bremen, Steeleville, Percy, Evansville, Eden,
  Preston, Blair, Prairie Du Rocher, Ellis Grove, Ruma, Rockwood,
  Kaskaskia, New Palestine, Walsh, Welge and Roots.

This includes the following State Parks...
Piney Creek Ravine State Natural Area, Randolph County State
Recreation Area and Turkey Bluffs State Fish and Wildlife Area.

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.

&&

LAT...LON 3816 9003 3814 8959 3796 8960 3782 8968
      3780 8967 3785 8974 3785 8979 3788 8980
      3791 8984 3787 8990 3787 8994 3793 8997
      3796 8993 3797 8994 3796 9000 3801 9006
      3803 9011 3806 9013 3809 9020 3814 9004

FLASH FLOOD...RADAR INDICATED

$$

Carney

665 
WGUS73 KLSX 260556
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
1256 AM CDT Fri Jun 26 2026

ILC157-260606-
/O.EXP.KLSX.FF.W.0041.000000T0000Z-260626T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Randolph IL-
1256 AM CDT Fri Jun 26 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 1 AM CDT EARLY THIS MORNING FOR
RANDOLPH COUNTY...

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

A Flood Watch remains in effect until 700 PM CDT Friday for portions
of Illinois and Missouri.

&&

LAT...LON 3816 9003 3814 8959 3796 8960 3782 8968
      3780 8967 3785 8974 3785 8979 3788 8980
      3791 8984 3787 8990 3787 8994 3793 8997
      3796 8993 3797 8994 3796 9000 3801 9006
      3803 9011 3806 9013 3809 9020 3814 9004

$$

Gosselin

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
645 PM CDT Thu Jun 25 2026

.KEY MESSAGES...

- Showers and thunderstorms capable primarily of heavy rainfall
  are expected through Friday evening, with a Flash Flood Watch
  remaining in effect for much of the area.

- Thunderstorms both Thursday and Friday afternoon and early
  evening will also be capable of isolated instances of damaging
  wind gusts and large hail.

- Dangerous heat and humidity will build into the region on
  Sunday and continue through much of next week.

&&

.SHORT TERM...  (Through Late Friday Night)
Issued at 304 PM CDT Thu Jun 25 2026

A cold front has settled into the region, with current surface
observations showing it roughly along/just north of I-70; just north
of the cumulus field seen in visible satellite. Ample insolation
south of the front has yielded upwards of 2,000 J/kg of MLCAPE.
Thanks to subtle lift from an approaching disturbance, forcing from
the front, and the building instability, isolated to scattered
showers and thunderstorms have developed along the I-70 corridor
across both Missouri and Illinois. Effective bulk shear is around 30
kts along the portion of the front in Illinois, but is expected to
increase to that value across Missouri through the rest of this
afternoon. This favors an updraft or two becoming organized, with a
threat of brief supercellular structures. The strongest updrafts
will be capable of large hail and damaging wind gusts.

The previously described convective activity will be occurring ahead
of an approaching shortwave and associated convective complex
currently seen over eastern Kansas. As this complex moves into the
CWA this evening, PWAT is forecast to be around 1.75", paired with
slow storm motions and deep warm cloud layers to support a threat of
heavy rainfall. With thunderstorms repeatedly impacting the same
areas, the threat of flash flooding remains a concern through early
Friday morning.

Convective trends become increasingly uncertain mid-morning Friday
onward, with guidance diverging in the strength on the strength of
the surface low associated with this initial disturbance. A minority
of guidance shows a stronger low that would push the front south of
the CWA and greatly limit the chance for additional convection
across much of the CWA tomorrow. A majority of guidance favors a
weaker low, that will have little impact on the position of the
front as a trailing MCV moves across the region during the day
tomorrow. This solution will keep the warm sector mainly along and
south of I-70, with the MCV enhancing lift and shear as it moves
through the CWA. The current expected trajectory of the MCV
highlights southeastern Missouri and southwestern Illinois for
isolated to scattered severe thunderstorms capable mainly of
damaging wind gusts and large hail, with a low chance for tornadoes.
Given that a majority of guidance favors this solution, it is
reflected in the current forecast. The atmosphere over the CWA will
remain conducive for heavy rainfall with this solution as well, with
the Flash Flood Watch now being extended through Friday evening.
Subsidence in the wake of the MCV and diminishing instability will
lead to a downward trend in convection during the early evening
Friday, with a lull expected during the overnight hours.

Elmore

&&

.LONG TERM...  (Saturday through Next Thursday)
Issued at 304 PM CDT Thu Jun 25 2026

On Saturday, upper-level ridging will gradually build into the
Midwest. This will push the stationary front that will have been
draped across the area in the previous days northward; however,
confidence is low in how quickly this will happen through the day.
The speed of the now warm front lifting northward will impact
placement of convective potential through the day and primarily
during the afternoon. While height rises thanks to the building
ridge would suppress convection, there is enough of a consensus
among deterministic guidance in a weak shortwave cresting the ridge
during the afternoon that will amplify lift along the front and lead
to a 30-50% chance for scattered showers and thunderstorms. If the
front is slower to lift north, this chance for showers and
thunderstorms will be across a majority of the CWA, while a faster
front will limit convective potential roughly along and eastward of
the Mississippi River.

For Sunday onward, the main focus will the threat of dangerous
levels of heat and humidity. Guidance consensus remains strong in
the upper-level ridge rapidly building northward across the Midwest
as 850mb temperatures surge to into the mid-20s C. The result at the
surface will be temperatures in the mid-90s, with uninhibited flow
from the Gulf and local evapotranspiration supporting dew points in
the mid 70s. These temperatures and dew points will combine to push
heat index values at least into the 100-105 degree F range (80%
chance) through Thursday. The ridge is forecast to be strong enough
to minimize convective impacts to the heat, and nearly every
ensemble member keeps the area dry through this portion of the
period.

Elmore

&&

.AVIATION...  (For the 00z TAFs through 00z Friday Evening)
Issued at 636 PM CDT Thu Jun 25 2026

Showers and thunderstorms are expected to affect the terminals
periodically throughout the period. Showers will likely become
more steady with occasional thunderstorms between 04-14Z with
either low MVFR or IFR ceilings and visibilities with occasional
moderate to heavy rainfall. Visibilities are expected to improve
to VFR by 18Z with more dry time, though additional scattered
showers and thunderstorms is expected to develop and be in around
the terminals on Friday afternoon.

Britt

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flood Watch through Friday evening for Audrain MO-Boone MO-
     Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Jefferson MO-Lincoln MO-Madison MO-Moniteau MO-
     Montgomery MO-Osage MO-Pike MO-Reynolds MO-Saint Charles MO-
     Saint Francois MO-Saint Louis City MO-Saint Louis MO-Sainte
     Genevieve MO-Warren MO-Washington MO.

IL...Flood Watch through Friday evening for Bond IL-Calhoun IL-
     Clinton IL-Fayette IL-Greene IL-Jersey IL-Macoupin IL-
     Madison IL-Marion IL-Monroe IL-Montgomery IL-Pike IL-
     Randolph IL-Saint Clair IL-Washington IL.

&&

WFO LSX

Preliminary Local Storm Report
National Weather Service St Louis MO
347 PM CDT Thu Jun 25 2026

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

0340 PM     Flood            Saint Peters            38.79N 90.59W
06/25/2026                   St. Charles        MO   Public

            Street flooding reported in Saint Peters
            along Mexico Road.

&&

Carney

Preliminary Local Storm Report
National Weather Service St Louis MO
406 PM CDT Thu Jun 25 2026

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

0340 PM     Hail             Saint Peters            38.79N 90.60W
06/25/2026  E0.75 Inch       St. Charles        MO   Public

&&

Carney

Preliminary Local Storm Report
National Weather Service St Louis MO
454 PM CDT Thu Jun 25 2026

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

0448 PM     Flood            1 WSW Saint Charles     38.78N 90.53W
06/25/2026                   St. Charles        MO   Public

            Zumbehl Rd covered with running water. Do
            not know how high. There is a creek nearby.
            Rain still falling.

&&

LSJ

Preliminary Local Storm Report
National Weather Service St Louis MO
456 PM CDT Thu Jun 25 2026

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

0445 PM     Flood            2 NNE Saint Charles     38.82N 90.50W
06/25/2026                   St. Charles        MO   Public

            Elm Point Industrial Road covered with
            stagnant water about 4 inches high. There is
            a creek nearby.

&&

LSJ

Preliminary Local Storm Report
National Weather Service St Louis MO
458 PM CDT Thu Jun 25 2026

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

0352 PM     Flash Flood      1 ESE Saint Charles     38.79N 90.50W
06/25/2026                   St. Charles        MO   Public

            4 to 5 inches of swift moving water on
            Kingshighway in front of Lindenwood.

&&

LSJ

Preliminary Local Storm Report
National Weather Service St Louis MO
501 PM CDT Thu Jun 25 2026

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

0352 PM     Flash Flood      1 ESE Saint Charles     38.79N 90.50W
06/25/2026                   St. Charles        MO   Broadcast Media

            Corrects previous flash flood report from 1
            ESE Saint Charles. 4 to 5 inches of swift
            moving water on Kingshighway in front of
            Lindenwood.

&&

LSJ