River Flood Warning 112, NWS St. Louis, MO

Issued

Sep 20, 2026, 11:48 AM CDT (16:48 UTC)

In effect from

Sep 23, 2026, 7:00 PM CDT

Expired

Sep 20, 2026, 9:21 PM CDT

In force

Issued by

NWS St. Louis, MO

Area

Storm-based polygon

Flood severity

Minor

Counties Adams County, IL, Lewis County, MO

The St Louis radar (KLSX), 164 km from the middle of the area, began a volume at 16:52 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.

Written for the forecast point Mississippi River at LaGrange (LGRM7).

Action stage

16 ft

Minor stage

17 ft

Moderate stage

23 ft

Major stage

25 ft

This gauge today: stage, forecast and historic crests

Stage from the USGS instantaneous record, one reading an hour, from a day before the product to a day after it ended. Flood stages are today's.

241 
WGUS43 KLSX 201648
FLWLSX

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service St Louis MO
1148 AM CDT Sun Sep 20 2026

...The National Weather Service in St Louis has issued a Flood
Warning for the following rivers in Missouri...Illinois...

  Mississippi River at Canton.

  Mississippi River at Clarksville.

  Mississippi River at Saverton.

  Mississippi River at LaGrange.

  Mississippi River at Hannibal.

  Mississippi River at Winfield.

River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This product, along with additional weather and stream information,
is available at https://water.noaa.gov/wfo/lsx

&&

ILC001-MOC111-220500-
/O.NEW.KLSX.FL.W.0109.260923T1600Z-260927T1700Z/
/CANM7.1.ER.260923T1600Z.260925T0000Z.260926T1048Z.NO/
1148 AM CDT Sun Sep 20 2026

...FLOOD WARNING IN EFFECT FROM WEDNESDAY MORNING TO SUNDAY
AFTERNOON...

* WHAT...Minor flooding is forecast.

* WHERE...Mississippi River at Canton.

* WHEN...From Wednesday morning to Sunday afternoon.

* IMPACTS...At 16.6 feet, Front Street leading to the campground and
  Corps park campgrounds flood at this height.

* ADDITIONAL DETAILS...
  - At 10:00 AM CDT Sunday the stage was 7.0 feet.
  - Forecast...The river is expected to rise above flood stage late
    Wednesday morning to a crest of 16.6 feet Thursday evening. It
    will then fall below flood stage early Saturday morning.
  - Flood stage is 15.0 feet.



&&


All Times CDT    Fld   Observed  Forecasts (1 pm)
Location         Stg     Stage   Mon   Tue   Wed   Thu   Fri

Mississippi River
 Canton          15.0    7.0     9.6   12.5  15.2  16.5  16.1



&&

LAT...LON 4022 9154 4022 9142 4008 9139 4008 9153


$$

ILC013-MOC163-220500-
/O.NEW.KLSX.FL.W.0110.260923T1930Z-000000T0000Z/
/CLKM7.1.ER.260923T1930Z.260925T1200Z.000000T0000Z.NO/
1148 AM CDT Sun Sep 20 2026

...FLOOD WARNING IN EFFECT FROM WEDNESDAY AFTERNOON UNTIL FURTHER
NOTICE...

* WHAT...Minor flooding is forecast.

* WHERE...Mississippi River at Clarksville.

* WHEN...From Wednesday afternoon until further notice.

* IMPACTS...At 29.0 feet, Water enters the parking lot entrance at
  the Clarksville Riverfront Park.

* ADDITIONAL DETAILS...
  - At 11:30 AM CDT Sunday the stage was 17.8 feet.
  - Forecast...The river is expected to rise above flood stage early
    Wednesday afternoon and continue rising to a crest of 28.2 feet
    Friday morning.
  - Flood stage is 25.0 feet.



&&


All Times CDT    Fld   Observed  Forecasts (1 pm)
Location         Stg     Stage   Mon   Tue   Wed   Thu   Fri

Mississippi River
 Clarksville     25.0    17.8    19.2  21.5  24.8  27.4  28.2



&&

LAT...LON 3939 9097 3946 9088 3940 9081 3932 9075
      3925 9071 3925 9083 3930 9090 3932 9088
      3936 9092 3935 9095


$$

ILC149-MOC173-220500-
/O.NEW.KLSX.FL.W.0111.260923T1942Z-260928T0200Z/
/SVRM7.1.ER.260923T1942Z.260925T0600Z.260926T2000Z.NO/
1148 AM CDT Sun Sep 20 2026

...FLOOD WARNING IN EFFECT FROM WEDNESDAY AFTERNOON TO SUNDAY
EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Mississippi River at Saverton.

* WHEN...From Wednesday afternoon to Sunday evening.

* IMPACTS...At 15.5 feet, An access road to riverside raised homes on
  the riverward side of the Sny levee begins to flood near this
  level.

* ADDITIONAL DETAILS...
  - At 10:00 AM CDT Sunday the stage was 7.7 feet.
  - Forecast...The river is expected to rise above flood stage early
    Wednesday afternoon to a crest of 18.2 feet early Friday morning.
    It will then fall below flood stage Saturday afternoon.
  - Flood stage is 16.0 feet.



&&


All Times CDT    Fld   Observed  Forecasts (1 pm)
Location         Stg     Stage   Mon   Tue   Wed   Thu   Fri

Mississippi River
 Saverton        16.0    7.7     9.6   12.6  15.8  17.9  18.0



&&

LAT...LON 3967 9132 3974 9121 3970 9114 3953 9099
      3946 9110 3960 9122


$$

ILC001-MOC111-220500-
/O.NEW.KLSX.FL.W.0112.260924T0000Z-260927T0800Z/
/LGRM7.1.ER.260924T0000Z.260924T1800Z.260926T0130Z.NO/
1148 AM CDT Sun Sep 20 2026

...FLOOD WARNING IN EFFECT FROM WEDNESDAY EVENING TO LATE SATURDAY
NIGHT...

* WHAT...Minor flooding is forecast.

* WHERE...Mississippi River at LaGrange.

* WHEN...From Wednesday evening to late Saturday night.

* IMPACTS...At 18.0 feet, The entrance to the lower parking lot at
  the Mark Twain Casino begins flooding near this height, requiring
  the use of an alternate entrance.

* ADDITIONAL DETAILS...
  - At 11:00 AM CDT Sunday the stage was 8.6 feet.
  - Forecast...The river is expected to rise above flood stage
    Wednesday evening to a crest of 17.9 feet early Thursday
    afternoon. It will then fall below flood stage Friday evening.
  - Flood stage is 17.0 feet.



&&


All Times CDT    Fld   Observed  Forecasts (1 pm)
Location         Stg     Stage   Mon   Tue   Wed   Thu   Fri

Mississippi River
 LaGrange        17.0    8.6     11.0  13.9  16.6  17.9  17.5



&&

LAT...LON 4008 9153 4008 9139 3999 9140 3999 9153


$$

ILC149-MOC127-220500-
/O.NEW.KLSX.FL.W.0113.260924T0224Z-260927T1800Z/
/HNNM7.1.ER.260924T0224Z.260925T0600Z.260926T1200Z.NO/
1148 AM CDT Sun Sep 20 2026

...FLOOD WARNING IN EFFECT FROM WEDNESDAY EVENING TO SUNDAY
AFTERNOON...

* WHAT...Minor flooding is forecast.

* WHERE...Mississippi River at Hannibal.

* WHEN...From Wednesday evening to Sunday afternoon.

* IMPACTS...At 18.0 feet, The northern end of Southside Recreation #2
  Park along Bear Creek begins flooding at this height. Gate wells
  are shut down to prevent the sewers from backing up.  Also at this
  level pumps are set to standby.

* ADDITIONAL DETAILS...
  - At 11:15 AM CDT Sunday the stage was 11.6 feet.
  - Forecast...The river is expected to rise above flood stage late
    Wednesday evening to a crest of 18.2 feet early Friday morning.
    It will then fall below flood stage Saturday morning.
  - Flood stage is 17.0 feet.



&&


All Times CDT    Fld   Observed  Forecasts (1 pm)
Location         Stg     Stage   Mon   Tue   Wed   Thu   Fri

Mississippi River
 Hannibal        17.0    11.6    12.3  14.2  16.2  17.9  18.0



&&

LAT...LON 3983 9148 3983 9135 3974 9121 3967 9132
      3969 9134 3968 9139 3971 9136


$$

ILC013-MOC113-220500-
/O.NEW.KLSX.FL.W.0114.260924T2100Z-000000T0000Z/
/CAGM7.1.ER.260924T2100Z.260926T0000Z.000000T0000Z.NO/
1148 AM CDT Sun Sep 20 2026

...FLOOD WARNING IN EFFECT FROM THURSDAY AFTERNOON UNTIL FURTHER
NOTICE...

* WHAT...Minor flooding is forecast.

* WHERE...Mississippi River at Winfield.

* WHEN...From Thursday afternoon until further notice.

* IMPACTS...At 27.5 feet, At this stage, Lock and Dam 25 will
  stockpile 200 tons of sand, 12,000 sandbags, and 10,000 square feet
  of polyethylene plastic as a precaution.

* ADDITIONAL DETAILS...
  - At 11:30 AM CDT Sunday the stage was 18.0 feet.
  - Forecast...The river is expected to rise above flood stage
    Thursday afternoon and continue rising to a crest of 27.4 feet
    Friday evening.
  - Flood stage is 26.0 feet.



&&


All Times CDT    Fld   Observed  Forecasts (1 pm)
Location         Stg     Stage   Mon   Tue   Wed   Thu   Fri

Mississippi River
 Winfield        26.0    18.0    18.8  21.2  24.1  25.8  27.3



&&

LAT...LON 3925 9083 3925 9071 3912 9065 3896 9065
      3888 9057 3880 9057 3885 9073 3910 9076


$$

BRC

515 
WGUS83 KLSX 210221 RRA
FLSLSX

Flood Statement
National Weather Service St Louis MO
921 PM CDT Sun Sep 20 2026

...The Flood Warning is cancelled for the following rivers in
Missouri...Illinois...

  Mississippi River at LaGrange.

River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.

ILC001-MOC111-210330-
/O.CAN.KLSX.FL.W.0112.260924T0000Z-260921T0221Z/
/LGRM7.1.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
921 PM CDT Sun Sep 20 2026

...FLOOD WARNING IS CANCELLED...

The Flood Warning is cancelled for
  the Mississippi River at LaGrange.

* ADDITIONAL DETAILS...
  - At 9:00 PM CDT Sunday the stage was 9.2 feet.
  - Forecast...The river is expected to rise to a crest of 16.7 feet
    early Friday morning.



&&


All Times CDT    Fld   Observed  Forecasts (7 pm)
Location         Stg     Stage   Mon   Tue   Wed   Thu   Fri

Mississippi River
 LaGrange        17.0    9.2     11.4  13.4  15.2  16.6  16.4



&&

LAT...LON 4008 9153 4008 9139 3999 9140 3999 9153


$$

Carney

NWS St. Louis, MO wrote its last area forecast discussion before this river flood warning went out at Sep 20, 6:48 AM CDT, 5 hours earlier. Its key messages:

• A cold front begins slowly moving through the region today bringing cooler temperatures the rest of the week.
• Thunderstorms along the front tonight bring the best chance for rain all week.

Area Forecast Discussion
National Weather Service St Louis MO
648 AM CDT Sun Sep 20 2026

.KEY MESSAGES...

- A cold front begins slowly moving through the region today
  bringing cooler temperatures the rest of the week.

- Thunderstorms along the front tonight bring the best chance
  for rain all week.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 315 AM CDT Sun Sep 20 2026

Showers and thunderstorms are currently moving northeast through
northern MO and southeastern IA along a cold front and along the
nose of the low-level jet. As they progress, the convection in
northern MO is moving into a region with less favorable
conditions and a weakening low-level jet to continue to support
their development. As a result, these storms don't pose a
threat to our area aside from a stray shower in our northern
counties during the early morning hours.

An upper level ridge, which has been the driver behind the heat
and humidity during the last several days, is beginning to be
suppressed by an upper level trough as it moves east. This
trough will push the cold front into our area starting today.
Temperatures today will still be hot and humid to the south of
the front as it begins its slow push through the region. This
will lower high temperatures into the 70s and 80s in northern
MO, while southeastern MO will remain well into the 90s. Thanks
to slightly more moderate humidity values in the region,
widespread 100+ heat index values are not expected. Mondays
high temperatures are slated to be even lower as the front makes
its trek south through the region. However, there still remains
some uncertainty in the exact high temperatures for Monday.
Latest NBM guidances interquartile range for the high
temperatures is 6-10 degrees across the region due to the
uncertainty in the fronts exact position and speed. That being
said, behind the front we can expect high temperatures in the
70s and 80s with some areas in northern MO experiencing upper
60s for high temperatures.

Showers and thunderstorms are expected along and behind the cold
front tonight into Monday morning. While the confidence is low
on the exact timing and location of this convection, HREF
guidance shows there is a 80-100% chance across the region of
measurable rainfall during this period, and 30-70% chance of
seeing 0.25 inches of rain. These showers and thunderstorms will
be multi-cellular with the strongest thunderstorms possibly
producing heavy localized rainfall and gusty winds in regions
where CAPE is sufficient (~1500-2000 J/kg). Due to the limited
nature of the severe threat, the severe potential is not being
messaged for this event.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 315 AM CDT Sun Sep 20 2026

The end of the relentless heat is in sight. Behind the front
temperatures are expected to be much cooler. For Tuesday and
Wednesday, NBM guidance shows that high temperatures will be in
the low to mid 70s, with the northern portions of the area
possibly staying in the upper 60s for their high temperatures
(60-80% chance). Low temperatures will also dip into the 50s.
This air mass will continue to dominate for the rest of the week
with a gradual warming through the 70s, reaching the low 80s by
next weekend.

The GFS and ECMWF both show a mid-level ridge building over the
Great Lakes and into the southeastern Canada region with a
center of low pressure over the Ohio Valley by mid week. The
ridge should remain fairly stationary over southeastern Canada,
while the low pressure center will slowly move to the east coast
of the CONUS. This pattern will allow for continued westerly and
northwesterly flow to help moderate our temperatures into next
weekend and limit the moisture transported into the region,
preventing another return of the heat and humidity this week.

&&

.AVIATION /12Z TAFS THROUGH 18Z MONDAY/...
Issued at 647 AM CDT Sun Sep 20 2026

A cold front is moving south through the area bringing chances
of showers and thunderstorms. UIN, JEF, and COU will be impacted
by some showers this morning, but the best chances for
thunderstorms for all terminals will be tonight. There lies some
uncertainty with the exact coverage and timing of the
convection, so TEMPOs and PROB30s were included for the time
periods with the highest confidence. VFR conditions are expected
ahead of the front, but ceilings are expected to drop quickly to
IFR after it passes the terminals.

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.

&&

SHORT TERM...Asel/Kimble
LONG TERM...Asel/Kimble
AVIATION...Asel/Kimble

River Flood Warnings in Illinois, 2026River Flood Warnings in Missouri, 2026Every river flood warning in 2026

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive; the gauge from the NWS water service and the USGS.