Alert archive / Missouri / River Flood Warnings in 2026
River Flood Warning 65, NWS St. Louis, MO
NWS St. Louis, MO issued this river flood warning at May 20, 2026, 10:30 AM CDT for Gasconade County, Montgomery County, Missouri. It took effect at May 21, 2026, 10:00 AM CDT. It was in force for 48 hr.
The area
The outline as issued.
The facts
- Issued
- May 20, 2026, 10:30 AM CDT (15:30 UTC)
- In effect from
- May 21, 2026, 10:00 AM CDT
- Expired
- May 23, 2026, 9:50 AM CDT
- In force
- 48 hr
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Flood severity
- Minor
Counties Gasconade County, MO, Montgomery County, MO
The radar
The St Louis radar (KLSX), 65 km from the middle of the area, began a volume at 15:30 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 river
Written for the forecast point Missouri River at Hermann (HRNM7). The gauge peaked at 22.02 ft at May 22, 2026, 5:00 AM CDT.
- Action stage
- 19 ft
- Minor stage
- 21 ft
- Moderate stage
- 26 ft
- Major stage
- 33 ft
This gauge today: stage, forecast and historic crests
Stage from the USGS instantaneous record for site 06934500, one reading an hour, from a day before the product to a day after it ended. Flood stages are today's.
The text
As transmitted.
566
WGUS43 KLSX 201530
FLWLSX
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service St Louis MO
1030 AM CDT Wed May 20 2026
...The National Weather Service in St Louis has issued a Flood
Warning for the following rivers in Missouri...
Missouri River at Hermann.
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.
Rainfall heavier than forecast could cause river levels to rise even
higher than predicted. The National Weather Service will monitor this
developing situation and issue follow up statements as conditions
change.
This product, along with additional weather and stream information,
is available at https://water.noaa.gov/wfo/lsx
&&
MOC073-139-220330-
/O.NEW.KLSX.FL.W.0065.260521T1800Z-260525T0800Z/
/HRNM7.1.ER.260521T1800Z.260523T1200Z.260524T0130Z.NO/
1030 AM CDT Wed May 20 2026
...FLOOD WARNING IN EFFECT FROM THURSDAY AFTERNOON TO LATE SUNDAY
NIGHT...
* WHAT...Minor flooding is forecast.
* WHERE...Missouri River at Hermann.
* WHEN...From Thursday afternoon to late Sunday night.
* IMPACTS...At 21.3 feet, The southern end of School House Road south
of Rhineland begins flooding near this height.
* ADDITIONAL DETAILS...
- At 9:30 AM CDT Wednesday the stage was 20.0 feet.
- Forecast...The river will rise above flood stage early tomorrow
afternoon to 21.6 feet Friday morning. It will then fall early
Friday afternoon. It will rise to 21.8 feet Saturday morning. It
will then fall below flood stage Saturday evening.
- Flood stage is 21.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Thu Fri Sat Sun Mon
Missouri River
Hermann 21.0 20.0 20.7 21.6 21.8 20.2 18.5
&&
LAT...LON 3873 9160 3875 9136 3866 9119 3859 9119
3867 9144 3865 9160
$$
Fuchs6 follow-up statements
778
WGUS83 KLSX 210144
FLSLSX
Flood Statement
National Weather Service St Louis MO
844 PM CDT Wed May 20 2026
...The Flood Warning is extended for the following rivers in
Missouri...
Missouri River near Chamois.
Missouri River at Hermann.
River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
This product, along with additional weather and stream information,
is available at https://water.noaa.gov/wfo/lsx
&&
MOC027-151-221345-
/O.EXT.KLSX.FL.W.0064.000000T0000Z-260526T0130Z/
/CMSM7.1.ER.260520T1732Z.260523T1200Z.260524T1330Z.NO/
844 PM CDT Wed May 20 2026
...FLOOD WARNING NOW IN EFFECT UNTIL MONDAY EVENING...
* WHAT...Minor flooding is forecast.
* WHERE...Missouri River near Chamois.
* WHEN...Until Monday evening.
* IMPACTS...At 17.0 feet, Flood Stage: Lower lying bottom land
begins to flood.
* ADDITIONAL DETAILS...
- At 11:11 AM CDT Tuesday, May 19 the stage was 11.5 feet.
- Forecast...The river will rise above flood stage just after
midnight tonight to 18.4 feet early Friday morning. It will then
fall early Friday afternoon. It will rise to 18.8 feet Saturday
morning. It will then fall below flood stage Sunday morning.
- Flood stage is 17.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Fri Sat Sun Mon Tue
Missouri River
Chamois 17.0 11.5 18.3 18.8 17.1 15.6 MSG
&&
LAT...LON 3864 9198 3871 9185 3873 9160 3865 9160
3864 9181 3858 9194
$$
MOC073-139-221345-
/O.EXT.KLSX.FL.W.0065.260521T1500Z-260525T1200Z/
/HRNM7.1.ER.260521T1500Z.260523T1200Z.260524T0600Z.NO/
844 PM CDT Wed May 20 2026
...FLOOD WARNING NOW IN EFFECT FROM THURSDAY MORNING TO MONDAY
MORNING...
* WHAT...Minor flooding is forecast.
* WHERE...Missouri River at Hermann.
* WHEN...From Thursday morning to Monday morning.
* IMPACTS...At 22.3 feet, Southern portions of Old Rock Road and
Twisters Road south of Rhineland begin flooding near this height.
* ADDITIONAL DETAILS...
- At 8:30 PM CDT Wednesday the stage was 20.3 feet.
- Forecast...The river is expected to rise above flood stage late
tomorrow morning to a crest of 21.9 feet Saturday morning. It
will then fall below flood stage early Sunday morning.
- Flood stage is 21.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Fri Sat Sun Mon Tue
Missouri River
Hermann 21.0 20.3 21.5 21.9 20.5 18.8 16.2
&&
LAT...LON 3873 9160 3875 9136 3866 9119 3859 9119
3867 9144 3865 9160
$$
Jaja078
WGUS83 KLSX 211701
FLSLSX
Flood Statement
National Weather Service St Louis MO
1201 PM CDT Thu May 21 2026
...The Flood Warning is extended for the following rivers in
Missouri...Illinois...
Missouri River at Hermann.
Missouri River near Chamois.
Bourbeuse River at Union.
Kaskaskia River at Carlyle.
River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Motorists should not attempt to drive around barricades or drive cars
through flooded areas.
This product, along with additional weather and stream information,
is available at https://water.noaa.gov/wfo/lsx
&&
MOC073-139-230515-
/O.EXT.KLSX.FL.W.0065.000000T0000Z-260525T1330Z/
/HRNM7.1.ER.260521T1225Z.260522T1200Z.260524T0730Z.NO/
1201 PM CDT Thu May 21 2026
...FLOOD WARNING NOW IN EFFECT UNTIL MONDAY MORNING...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Missouri River at Hermann.
* WHEN...Until Monday morning.
* IMPACTS...At 22.3 feet, Southern portions of Old Rock Road and
Twisters Road south of Rhineland begin flooding near this height.
* ADDITIONAL DETAILS...
- At 11:30 AM CDT Thursday the stage was 21.4 feet.
- Recent Activity...The maximum river stage in the 24 hours ending
at 11:30 AM CDT Thursday was 21.4 feet.
- Forecast...The river will fall to 21.3 feet this afternoon. It
will then rise to 21.9 feet tomorrow morning. It will fall to
21.6 feet tomorrow evening. It will then rise to 21.8 feet
Saturday morning. It will fall below flood stage early Sunday
morning.
- Flood stage is 21.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Fri Sat Sun Mon Tue
Missouri River
Hermann 21.0 21.4 21.9 21.8 20.7 19.1 16.9
&&
LAT...LON 3873 9160 3875 9136 3866 9119 3859 9119
3867 9144 3865 9160
$$
MOC027-151-230515-
/O.EXT.KLSX.FL.W.0064.000000T0000Z-260526T0600Z/
/CMSM7.1.ER.260520T1732Z.260522T0600Z.260524T1800Z.NO/
1201 PM CDT Thu May 21 2026
...FLOOD WARNING NOW IN EFFECT UNTIL LATE MONDAY NIGHT...
* WHAT...Minor flooding is forecast.
* WHERE...Missouri River near Chamois.
* WHEN...Until late Monday night.
* IMPACTS...At 17.0 feet, Flood Stage: Lower lying bottom land
begins to flood.
* ADDITIONAL DETAILS...
- There is no current observed data.
- Forecast...The river will rise to 18.9 feet tomorrow morning. It
will then fall tomorrow evening. It will rise to 18.8 feet
Saturday morning. It will then fall below flood stage early
Sunday afternoon.
- Flood stage is 17.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Fri Sat Sun Mon Tue
Missouri River
Chamois 17.0 MSG 18.9 18.8 17.4 16.0 13.5
&&
LAT...LON 3864 9198 3871 9185 3873 9160 3865 9160
3864 9181 3858 9194
$$
MOC071-230515-
/O.EXT.KLSX.FL.W.0063.000000T0000Z-260523T0732Z/
/UNNM7.1.UU.260520T0837Z.260521T1415Z.260522T0132Z.NO/
1201 PM CDT Thu May 21 2026
...FLOOD WARNING NOW IN EFFECT UNTIL LATE FRIDAY NIGHT...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Bourbeuse River at Union.
* WHEN...Until late Friday night.
* ADDITIONAL DETAILS...
- At 11:30 AM CDT Thursday the stage was 17.5 feet.
- Recent Activity...The maximum river stage in the 24 hours ending
at 11:30 AM CDT Thursday was 17.7 feet.
- Forecast...The river is expected to fall below flood stage this
evening and continue falling to 3.7 feet Thursday, May 28.
- Flood stage is 15.0 feet.
&&
LAT...LON 3832 9113 3836 9113 3840 9107 3843 9106
3848 9096 3843 9085 3841 9089 3839 9089
3839 9092 3843 9093 3837 9101
$$
ILC027-230515-
/O.EXT.KLSX.FL.W.0060.000000T0000Z-260523T0800Z/
/KCAI2.1.ER.260507T1459Z.260512T1800Z.260522T0200Z.NO/
1201 PM CDT Thu May 21 2026
...FLOOD WARNING NOW IN EFFECT UNTIL LATE FRIDAY NIGHT...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Kaskaskia River at Carlyle.
* WHEN...Until late Friday night.
* IMPACTS...At 16.5 feet, Near this height, downstream agricultural
fields begin flooding.
* ADDITIONAL DETAILS...
- At 11:30 AM CDT Thursday the stage was 17.0 feet.
- Recent Activity...The maximum river stage in the 24 hours ending
at 11:30 AM CDT Thursday was 17.2 feet.
- Forecast...The river is expected to rise to a crest of 17.1 feet
this afternoon. It will then fall below flood stage late this
evening.
- Flood stage is 16.5 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Fri Sat Sun Mon Tue
Kaskaskia River
Carlyle 16.5 17.0 16.2 16.2 16.2 16.2 16.2
&&
LAT...LON 3862 8936 3861 8933 3851 8937 3849 8942
3854 8942
$$
Delia645
WGUS83 KLSX 220108
FLSLSX
Flood Statement
National Weather Service St Louis MO
808 PM CDT Thu May 21 2026
...The Flood Warning continues for the following locations along the
Missouri River...
Missouri River at Hermann.
Missouri River near Chamois.
River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Motorists should not attempt to drive around barricades or drive cars
through flooded areas.
This product, along with additional weather and stream information,
is available at https://water.noaa.gov/wfo/lsx
&&
MOC073-139-231315-
/O.EXT.KLSX.FL.W.0065.000000T0000Z-260525T0000Z/
/HRNM7.1.ER.260521T1225Z.260522T1200Z.260523T1800Z.NO/
808 PM CDT Thu May 21 2026
...FLOOD WARNING NOW IN EFFECT UNTIL SUNDAY EVENING...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Missouri River at Hermann.
* WHEN...Until Sunday evening.
* IMPACTS...At 22.3 feet, Southern portions of Old Rock Road and
Twisters Road south of Rhineland begin flooding near this height.
* ADDITIONAL DETAILS...
- At 7:30 PM CDT Thursday the stage was 21.8 feet.
- Forecast...The river is expected to rise to a crest of 22.2 feet
tomorrow morning. It will then fall below flood stage early
Saturday afternoon.
- Flood stage is 21.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Fri Sat Sun Mon Tue Wed
Missouri River
Hermann 21.0 21.8 22.2 21.2 20.0 18.9 16.9 13.5
&&
LAT...LON 3873 9160 3875 9136 3866 9119 3859 9119
3867 9144 3865 9160
$$
MOC027-151-231315-
/O.EXT.KLSX.FL.W.0064.000000T0000Z-260525T2200Z/
/CMSM7.1.ER.260520T1732Z.260522T0600Z.260524T1000Z.NO/
808 PM CDT Thu May 21 2026
...FLOOD WARNING NOW IN EFFECT UNTIL MONDAY AFTERNOON...
* WHAT...Minor flooding is forecast.
* WHERE...Missouri River near Chamois.
* WHEN...Until Monday afternoon.
* ADDITIONAL DETAILS...
- At 700 PM CDT Thursday, May 19, the estimated stage was 19.2
feet.
- Forecast...The river is expected to fall below flood stage early
Sunday morning and continue falling to 11.7 feet Tuesday evening.
- Flood stage is 17.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Fri Sat Sun Mon Tue
Missouri River
Chamois 17.0 MSG 19.2 18.1 16.9 15.9 13.5
&&
LAT...LON 3864 9198 3871 9185 3873 9160 3865 9160
3864 9181 3858 9194
$$
Carney448
WGUS83 KLSX 221543
FLSLSX
Flood Statement
National Weather Service St Louis MO
1043 AM CDT Fri May 22 2026
...The Flood Warning continues for the following rivers in
Missouri...
Missouri River at Hermann.
Missouri River near Chamois.
River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Motorists should not attempt to drive around barricades or drive cars
through flooded areas.
This product, along with additional weather and stream information,
is available at https://water.noaa.gov/wfo/lsx
&&
MOC073-139-240345-
/O.EXT.KLSX.FL.W.0065.000000T0000Z-260524T2200Z/
/HRNM7.1.ER.260521T1225Z.260522T0630Z.260523T1600Z.NO/
1043 AM CDT Fri May 22 2026
...FLOOD WARNING NOW IN EFFECT UNTIL SUNDAY AFTERNOON...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Missouri River at Hermann.
* WHEN...Until Sunday afternoon.
* IMPACTS...At 22.3 feet, Southern portions of Old Rock Road and
Twisters Road south of Rhineland begin flooding near this height.
* ADDITIONAL DETAILS...
- At 9:30 AM CDT Friday the stage was 21.8 feet.
- Recent Activity...The maximum river stage in the 24 hours ending
at 9:30 AM CDT Friday was 22.0 feet.
- Forecast...The river is expected to rise to a crest of 21.9 feet
this afternoon. It will then fall below flood stage late tomorrow
morning.
- Flood stage is 21.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Sat Sun Mon Tue Wed
Missouri River
Hermann 21.0 21.8 21.2 19.7 18.1 15.3 12.9
&&
LAT...LON 3873 9160 3875 9136 3866 9119 3859 9119
3867 9144 3865 9160
$$
MOC027-151-240345-
/O.EXT.KLSX.FL.W.0064.000000T0000Z-260525T1630Z/
/CMSM7.1.ER.260520T1732Z.260522T1800Z.260524T0430Z.NO/
1043 AM CDT Fri May 22 2026
...FLOOD WARNING NOW IN EFFECT UNTIL MONDAY MORNING...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Missouri River near Chamois.
* WHEN...Until Monday morning.
* IMPACTS...At 17.0 feet, Flood Stage: Lower lying bottom land
begins to flood.
* ADDITIONAL DETAILS...
- At 12:42 PM CDT Thursday the stage was 18.5 feet.
- Recent Activity...The maximum river stage in the 24 hours ending
at 12:42 PM CDT Thursday was 18.5 feet.
- Forecast...The river is expected to rise to a crest of 18.8 feet
this afternoon. It will then fall below flood stage late tomorrow
evening.
- Flood stage is 17.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Sat Sun Mon Tue Wed
Missouri River
Chamois 17.0 18.5 18.1 16.5 14.8 12.0 9.5
&&
LAT...LON 3864 9198 3871 9185 3873 9160 3865 9160
3864 9181 3858 9194
$$
Elmore091
WGUS83 KLSX 230111
FLSLSX
Flood Statement
National Weather Service St Louis MO
811 PM CDT Fri May 22 2026
...The Flood Warning continues for the Missouri river at the
following locations...
Missouri River near Chamois.
Missouri River at Hermann.
River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Motorists should not attempt to drive around barricades or drive cars
through flooded areas.
This product, along with additional weather and stream information,
is available at https://water.noaa.gov/wfo/lsx
&&
MOC027-151-241315-
/O.EXT.KLSX.FL.W.0064.000000T0000Z-260525T1400Z/
/CMSM7.1.ER.260520T1732Z.260521T1742Z.260524T0200Z.NO/
811 PM CDT Fri May 22 2026
...FLOOD WARNING NOW IN EFFECT UNTIL MONDAY MORNING...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Missouri River near Chamois.
* WHEN...Until Monday morning.
* ADDITIONAL DETAILS...
- At 12:42 PM CDT Thursday, May 21 the stage was 18.5 feet.
- Forecast...The river is expected to fall below flood stage late
tomorrow evening and continue falling to 8.8 feet Wednesday
evening.
- Flood stage is 17.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Sat Sun Mon Tue Wed
Missouri River
Chamois 17.0 18.5 18.0 16.1 14.1 11.0 9.3
&&
LAT...LON 3864 9198 3871 9185 3873 9160 3865 9160
3864 9181 3858 9194
$$
MOC073-139-241315-
/O.CON.KLSX.FL.W.0065.000000T0000Z-260524T2200Z/
/HRNM7.1.ER.260521T1225Z.260522T0630Z.260523T1600Z.NO/
811 PM CDT Fri May 22 2026
...FLOOD WARNING REMAINS IN EFFECT UNTIL SUNDAY AFTERNOON...
* WHAT...Minor flooding is occurring and minor flooding is forecast.
* WHERE...Missouri River at Hermann.
* WHEN...Until Sunday afternoon.
* ADDITIONAL DETAILS...
- At 7:30 PM CDT Friday the stage was 21.6 feet.
- Forecast...The river is expected to fall below flood stage late
tomorrow morning and continue falling to 11.7 feet Friday, May
29.
- Flood stage is 21.0 feet.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Sat Sun Mon Tue Wed Thu
Missouri River
Hermann 21.0 21.6 21.2 19.2 17.4 14.4 12.8 12.0
&&
LAT...LON 3873 9160 3875 9136 3866 9119 3859 9119
3867 9144 3865 9160
$$
Carney515
WGUS83 KLSX 231450
FLSLSX
Flood Statement
National Weather Service St Louis MO
950 AM CDT Sat May 23 2026
...The Flood Warning is cancelled for the following river in
Missouri...
Missouri River at Hermann.
River forecasts are based on observed precipitation and forecast
precipitation for the next 24 hours.
MOC073-139-231600-
/O.CAN.KLSX.FL.W.0065.000000T0000Z-260523T1450Z/
/HRNM7.1.ER.260521T1225Z.260522T0630Z.260523T1352Z.NO/
950 AM CDT Sat May 23 2026
...FLOOD WARNING IS CANCELLED...
The Flood Warning is cancelled for
the Missouri River at Hermann.
* ADDITIONAL DETAILS...
- At 9:30 AM CDT Saturday the stage was 21.0 feet.
- Forecast...The river is expected to continue to fall to near 16.6
feet Monday morning.
&&
All Times CDT Fld Observed Forecasts (7:00 am)
Location Stg Stage Sun Mon Tue Wed Thu
Missouri River
Hermann 21.0 21.0 19.4 16.6 14.0 12.4 11.8
&&
LAT...LON 3873 9160 3875 9136 3866 9119 3859 9119
3867 9144 3865 9160
$$
GosselinWhat forecasters said that day
The local office's own words before this river flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS St. Louis, MO wrote its last area forecast discussion before this river flood warning went out at May 20, 6:20 AM CDT, 4 hours 10 minutes earlier. Its key messages:
- Cooler temperatures are expected through Friday.
- There will be several chances for showers and thunderstorms over the upcoming Memorial Day weekend.
Area forecast discussion, May 20, 6:20 AM CDT, 4 hours 10 minutes before
Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 620 AM CDT Wed May 20 2026 .KEY MESSAGES... - Cooler temperatures are expected through Friday. - There will be several chances for showers and thunderstorms over the upcoming Memorial Day weekend. && .SHORT TERM... (Through Late Thursday Afternoon) Issued at 332 AM CDT Wed May 20 2026 Temperatures have dropped into the 50s early this morning behind the cold front that has now moved south of Missouri and Illinois. There are scattered showers that continue to form to the north of the front by low level frontogenesis that will gradually move south of the CWA through mid-late morning. The HREF is then showing a short wave ridge building over the Midwest later today into tonight which will keep the forecast dry into early Thursday. At the same time a large surface high will slowly move east across the Great Lakes causing the surface winds to slowly shift from northerly to easterly by tomorrow. Model guidance is showing that we will likely stay mainly cloudy through tomorrow, with lower ceilings in the southern half of the CWA today which favors cooler temperatures. Highs will likely stay in the 60s today and range from the mid 60s to mid 70s on Thursday. Britt && .LONG TERM... (Thursday Night through Tuesday) Issued at 332 AM CDT Wed May 20 2026 After the brief dry period on Wednesday night and Thursday, the chances for showers and thunderstorms increases over the Memorial Day weekend into next week as the LREF is showing southwesterly upper flow over Missouri and Illinois. Model guidance is consistent with a trough moving across the area late Thursday night into Friday which is when the LREF has 60-90% of its members are producing rain over the area. This is also the period when PWATS will be the highest (near 2.0") and WPC has highlighted the southern half of the CWA in a marginal risk of excessive rainfall. There are lower chances on Friday night, but two or three more shortwaves will move across the area over the weekend bringing additional chances for showers and thunderstorms the rest of the weekend. At this point, the LREF/NBM members are keeping the better chances (40-60%) over southeast Missouri into southwest Illinois which is closer to where a surface front will be during the extended weekend. Temperatures will start to warm back up over the weekend, though as pointed out by the previous discussion, the NBM is on the warmest side of guidance. While upper heights will be building over the area which favors the warmer temperatures, they will be tempered by the clouds and rain chances which should keep highs in the 70s. Britt && .AVIATION... (For the 12z TAFs through 12z Thursday Morning) Issued at 604 AM CDT Wed May 20 2026 Mainly dry conditions are expected through the period. Ceilings near 3000 feet at JEF, STL, and CPS are expected to gradually lift to near 5000 feet by 15Z. Ceilings at UIN are expected to stay above 10000 feet through the period. Northerly winds will veer out of the northeast while staying below 10 knots. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && WFO LSX
Hazardous weather outlook, May 20, 5:55 AM CDT, 4 hours 35 minutes before
Hazardous Weather Outlook National Weather Service St Louis MO 555 AM CDT Wed May 20 2026 ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027- 034>036-041-042-047>052-059>065-072>075-084-085-099-211100- Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL- Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL- Calhoun IL-Jersey IL-Madison IL-Saint Clair IL-Monroe IL-Knox MO- Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO- Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO- Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO- Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO- Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO- Madison MO-Reynolds MO- 555 AM CDT Wed May 20 2026 This Hazardous Weather Outlook is for portions of eastern and central Missouri as well as west central and southwest Illinois. .DAYS ONE THROUGH SEVEN...Today through Tuesday. More detailed information can be accessed at: https://www.weather.gov/media/lsx/DssPacket.pdf The Area Forecast Discussion is available at: https://forecast.weather.gov/ product.php?issuedby=LSX&product=AFD&site=lsx .KEY MESSAGES... - Cooler temperatures are expected through Friday. - There will be several chances for showers and thunderstorms over the upcoming Memorial Day weekend. NOTE: Starting May 29, 2026, this outlook product will be discontinued. Please see the above products for more detailed forecast information. WFO LSX
Nearby
River Flood Warnings in Missouri, 2026Every river 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; radar from the NEXRAD Level II archive; the gauge from the NWS water service and the USGS.