River Flood Warning 20, NWS St. Louis, MO

137 
WGUS83 KLSX 240133
FLSLSX

Flood Statement
National Weather Service St Louis MO
833 PM CDT Thu Mar 23 2023

...The Flood Warning continues for the following rivers in 
Missouri...

  Black River near Annapolis.

  Big River at Byrnesville.

  Bourbeuse River at Union.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC179-251345-
/O.CON.KLSX.FL.W.0021.230324T1227Z-230328T0600Z/
/ANNM7.2.ER.230324T1227Z.230325T0600Z.230327T0000Z.NO/
833 PM CDT Thu Mar 23 2023

...FLOOD WARNING REMAINS IN EFFECT FROM FRIDAY MORNING TO EARLY 
TUESDAY MORNING...

* WHAT...Moderate flooding is forecast.

* WHERE...Black River near Annapolis.

* WHEN...From Friday morning to early Tuesday morning.

* IMPACTS...At 17.0 feet, when the Black River gets to this level, 
  the Highway 21 bridge upstream in Lesterville on the East Fork of 
  the Black River may start flooding about 6 to 8 hours earlier.

* ADDITIONAL DETAILS...
  - At 11:15 AM CDT Thursday the stage was 5.0 feet.
  - Forecast...The river is expected to rise above flood stage
    tomorrow morning to a crest of 16.5 feet early Saturday
    morning. It will then fall below flood stage Sunday evening.
  - Flood stage is 8.0 feet.


&&

             Fld   Observed  Forecasts (7:00 am)
Location     Stg    Stage    Sat   Sun   Mon   Tue   Wed

Black River
  Annapolis  8.0     5.0     16.0  9.0   7.4   6.6   MSG


&&

LAT...LON 3743 9087 3745 9078 3724 9074 3724 9079


$$

MOC099-251345-
/O.CON.KLSX.FL.W.0020.230324T2204Z-230328T2121Z/
/BYRM7.2.ER.230324T2204Z.230326T1200Z.230327T2120Z.UU/
833 PM CDT Thu Mar 23 2023

...FLOOD WARNING REMAINS IN EFFECT FROM FRIDAY AFTERNOON TO TUESDAY 
AFTERNOON...

* WHAT...Moderate flooding is forecast.

* WHERE...Big River at Byrnesville.

* WHEN...From Friday afternoon to Tuesday afternoon.

* IMPACTS...At 22.4 feet, At this level, Twin Rivers Bridge Road 
  must be closed.

* ADDITIONAL DETAILS...
  - At 10:45 AM CDT Thursday the stage was 3.9 feet.
  - Forecast...The river is expected to rise above flood stage
    tomorrow afternoon to a crest of 24.4 feet Sunday morning. It
    will then fall below flood stage Monday afternoon.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Big River
  Byrnesville  16.0    3.9     18.2  22.5  18.0  10.6  8.1


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

MOC071-251345-
/O.CON.KLSX.FL.W.0019.230326T0015Z-230329T0333Z/
/UNNM7.1.ER.230326T0015Z.230327T0000Z.230327T2132Z.NO/
833 PM CDT Thu Mar 23 2023

...FLOOD WARNING REMAINS IN EFFECT FROM SATURDAY EVENING TO LATE 
TUESDAY EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Bourbeuse River at Union.

* WHEN...From Saturday evening to late Tuesday evening.

* IMPACTS...At 19.8 feet, Near this height, Missouri State Route UU 
  is closed in both directions.

* ADDITIONAL DETAILS...
  - At 10:30 AM CDT Thursday the stage was 2.8 feet.
  - Forecast...The river is expected to rise above flood stage
    Saturday evening to a crest of 19.8 feet Sunday evening. It
    will then fall below flood stage Monday afternoon.
  - Flood stage is 15.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Sat   Sun   Mon   Tue   Wed

Bourbeuse River
  Union          15.0    2.8     10.4  18.2  17.7  9.4   5.4


&&

LAT...LON 3826 9123 3832 9133 3838 9137 3848 9094
      3842 9087


$$

MRM

494 
WGUS83 KLSX 240203
FLSLSX

Flood Statement
National Weather Service St Louis MO
903 PM CDT Thu Mar 23 2023

...The Flood Warning continues for the following rivers in 
Missouri...

  Meramec River near Sullivan.

  Meramec River near Steelville.

  Big River at Byrnesville.

  Bourbeuse River at Union.

  Meramec River near Eureka.

  Meramec River at Pacific.

  Meramec River at Valley Park.

  Meramec River at Fenton.

  Meramec River near Arnold.

  Black River near Annapolis.

...The Flood Warning is extended for the following rivers in 
Illinois...

  Kaskaskia River at Vandalia.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC055-221-251415-
/O.EXT.KLSX.FL.W.0012.230324T2111Z-230329T0036Z/
/SLLM7.1.ER.230324T2111Z.230326T0000Z.230327T1836Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM FRIDAY AFTERNOON TO TUESDAY 
EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Meramec River near Sullivan.

* WHEN...From Friday afternoon to Tuesday evening.

* IMPACTS...At 18.5 feet, Near this height, Missouri Route N will be 
  closed in both directions.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was 4.3 feet.
  - Forecast...The river is expected to rise above flood stage
    tomorrow afternoon to a crest of 19.9 feet Saturday evening.
    It will then fall below flood stage early Monday afternoon.
  - Flood stage is 11.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Sullivan     11.0    4.3     18.0  18.3  12.3  8.7   7.2


&&

LAT...LON 3800 9120 3806 9125 3829 9109 3840 9090
      3837 9082


$$

MOC055-251415-
/O.EXT.KLSX.FL.W.0013.230325T0104Z-230328T0000Z/
/SEEM7.1.ER.230325T0104Z.230325T1800Z.230326T1800Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM FRIDAY EVENING TO MONDAY 
EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Meramec River near Steelville.

* WHEN...From Friday evening to Monday evening.

* IMPACTS...At 14.0 feet, Near this height, roads to the Lucky 
  Clover campgrounds begin to flood.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was 2.4 feet.
  - Forecast...The river is expected to rise above flood stage
    tomorrow evening to a crest of 15.5 feet early Saturday
    afternoon. It will then fall below flood stage early Sunday
    afternoon.
  - Flood stage is 12.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Steelville   12.0    2.4     15.2  13.3  7.9   5.3   4.2


&&

LAT...LON 3793 9152 3800 9152 3806 9125 3801 9121


$$

MOC099-251415-
/O.EXT.KLSX.FL.W.0020.230325T0404Z-230328T1727Z/
/BYRM7.2.ER.230325T0404Z.230326T1200Z.230327T1727Z.UU/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM FRIDAY EVENING TO EARLY TUESDAY 
AFTERNOON...

* WHAT...Moderate flooding is forecast.

* WHERE...Big River at Byrnesville.

* WHEN...From Friday evening to early Tuesday afternoon.

* IMPACTS...At 22.4 feet, At this level, Twin Rivers Bridge Road 
  must be closed.

* ADDITIONAL DETAILS...
  - At 8:45 PM CDT Thursday the stage was 4.1 feet.
  - Forecast...The river is expected to rise above flood stage
    late tomorrow evening to a crest of 22.5 feet Sunday morning.
    It will then fall below flood stage early Monday afternoon.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Big River
  Byrnesville  16.0    4.1     18.2  22.5  18.0  10.6  8.1


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

ILC051-251415-
/O.EXT.KLSX.FL.W.0022.230325T1009Z-230330T0313Z/
/VNDI2.1.ER.230325T1009Z.230327T0600Z.230328T2113Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM LATE FRIDAY NIGHT TO LATE 
WEDNESDAY EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Kaskaskia River at Vandalia.

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

* IMPACTS...At 19.2 feet, State Highway J just east of County Road 
  206 begins to flood near this height.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was 12.4 feet.
  - Forecast...The river is expected to rise above flood stage
    early Saturday morning to a crest of 22.0 feet early Monday
    morning. It will then fall below flood stage Tuesday
    afternoon.
  - Flood stage is 18.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Sat   Sun   Mon   Tue   Wed

Kaskaskia River
  Vandalia       18.0    12.4    18.4  21.4  22.0  19.9  15.0


&&

LAT...LON 3903 8910 3903 8906 3885 8909 3879 8919
      3882 8922


$$

MOC071-251415-
/O.EXT.KLSX.FL.W.0019.230326T0121Z-230329T0217Z/
/UNNM7.1.ER.230326T0121Z.230327T0000Z.230327T2017Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM SATURDAY EVENING TO LATE TUESDAY 
EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Bourbeuse River at Union.

* WHEN...From Saturday evening to late Tuesday evening.

* IMPACTS...At 19.8 feet, Near this height, Missouri State Route UU 
  is closed in both directions.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was 2.9 feet.
  - Forecast...The river is expected to rise above flood stage
    Saturday evening to a crest of 19.5 feet Sunday evening. It
    will then fall below flood stage Monday afternoon.
  - Flood stage is 15.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Sat   Sun   Mon   Tue   Wed

Bourbeuse River
  Union          15.0    2.9     10.4  18.2  17.7  9.4   5.4


&&

LAT...LON 3826 9123 3832 9133 3838 9137 3848 9094
      3842 9087


$$

MOC099-189-251415-
/O.EXT.KLSX.FL.W.0014.230326T0504Z-230330T1200Z/
/ERKM7.2.ER.230326T0504Z.230327T1800Z.230329T0600Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM LATE SATURDAY NIGHT TO THURSDAY 
MORNING...

* WHAT...Moderate flooding is forecast.

* WHERE...Meramec River near Eureka.

* WHEN...From late Saturday night to Thursday morning.

* IMPACTS...At 25.5 feet, Hornecker Road is closed near this height.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was 4.4 feet.
  - Forecast...The river is expected to rise above flood stage
    early Sunday morning to a crest of 26.3 feet early Monday
    afternoon. It will then fall below flood stage early
    Wednesday morning.
  - Flood stage is 19.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Eureka       19.0    4.4     15.2  20.9  26.1  23.8  16.7


&&

LAT...LON 3845 9065 3855 9063 3855 9056 3850 9056


$$

MOC071-099-251415-
/O.EXT.KLSX.FL.W.0015.230326T0912Z-230330T0352Z/
/PCFM7.1.ER.230326T0912Z.230327T1800Z.230328T2152Z.NO/
903 PM CDT Thu Mar 23 2023

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

* WHAT...Minor flooding is forecast.

* WHERE...Meramec River at Pacific.

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

* IMPACTS...At 19.4 feet, Private road under the Highway F bridge 
  becomes flooded at this height.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was 0.3 feet.
  - Forecast...The river is expected to rise above flood stage
    early Sunday morning to a crest of 20.0 feet early Monday
    afternoon. It will then fall below flood stage Tuesday
    afternoon.
  - Flood stage is 15.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Pacific      15.0    0.3     9.5   15.7  19.8  17.6  10.7


&&

LAT...LON 3838 9085 3840 9090 3848 9080 3849 9064
      3845 9065


$$

MOC099-189-251415-
/O.EXT.KLSX.FL.W.0016.230326T1446Z-230330T1407Z/
/VLLM7.2.ER.230326T1446Z.230328T0000Z.230329T0807Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM SUNDAY MORNING TO LATE THURSDAY 
MORNING...

* WHAT...Moderate flooding is forecast.

* WHERE...Meramec River at Valley Park.

* WHEN...From Sunday morning to late Thursday morning.

* IMPACTS...At 21.9 feet, Yarnell Road is closed at Riverside 
  Drive.  Larkin Williams is closed at Riverside Golf Club 
  entrance.  In Valley Park...Tree Court Industrial Road begins 
  flooding between Marshall Road and Scarlet Oak Boulevard.  Also...
  the golf course at Family Golf and Learning Center and the 
  Kirkwood Athletic Association ball fields begin flooding near this 
  height.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was -0.4 feet.
  - Forecast...The river is expected to rise above flood stage
    late Sunday morning to a crest of 22.5 feet Monday evening.
    It will then fall below flood stage early Wednesday morning.
  - Flood stage is 18.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Valley Park  18.0    -0.4    11.3  17.4  21.9  21.6  16.9


&&

LAT...LON 3853 9056 3855 9056 3857 9043 3854 9043


$$

MOC099-189-251415-
/O.EXT.KLSX.FL.W.0017.230327T0040Z-230330T1720Z/
/FNNM7.1.ER.230327T0040Z.230328T0600Z.230329T1120Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM SUNDAY EVENING TO EARLY THURSDAY 
AFTERNOON...

* WHAT...Minor flooding is forecast.

* WHERE...Meramec River at Fenton.

* WHEN...From Sunday evening to early Thursday afternoon.

* IMPACTS...At 25.4 feet, Water begins backing onto Water Street at 
  the riverside drain at the Ferry Street intersection.

* ADDITIONAL DETAILS...
  - At 8:15 PM CDT Thursday the stage was 3.8 feet.
  - Forecast...The river is expected to rise above flood stage
    Sunday evening to a crest of 25.5 feet early Tuesday morning.
    It will then fall below flood stage Wednesday morning.
  - Flood stage is 23.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Fenton       23.0    3.8     13.4  20.6  24.5  25.2  22.9


&&

LAT...LON 3854 9045 3854 9042 3848 9039 3848 9045


$$

MOC099-189-251415-
/O.EXT.KLSX.FL.W.0018.230327T1000Z-230330T2327Z/
/ARNM7.1.ER.230327T1000Z.230328T1200Z.230329T1727Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING NOW IN EFFECT FROM LATE SUNDAY NIGHT TO THURSDAY 
EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Meramec River near Arnold.

* WHEN...From late Sunday night to Thursday evening.

* IMPACTS...At 27.0 feet, Meramec Bottom Road between Wells Road and 
  Kerth Road begins flooding near this height.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Thursday the stage was 9.0 feet.
  - Forecast...The river is expected to rise above flood stage
    early Monday morning to a crest of 27.5 feet Tuesday morning.
    It will then fall below flood stage early Wednesday
    afternoon.
  - Flood stage is 24.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Arnold       24.0    9.0     12.7  18.6  24.5  27.5  25.0


&&

LAT...LON 3848 9043 3848 9039 3846 9032 3841 9034
      3845 9043


$$

MOC179-251415-
/O.CON.KLSX.FL.W.0021.230324T1227Z-230328T0600Z/
/ANNM7.2.ER.230324T1227Z.230325T0600Z.230327T0000Z.NO/
903 PM CDT Thu Mar 23 2023

...FLOOD WARNING REMAINS IN EFFECT FROM FRIDAY MORNING TO EARLY 
TUESDAY MORNING...

* WHAT...Moderate flooding is forecast.

* WHERE...Black River near Annapolis.

* WHEN...From Friday morning to early Tuesday morning.

* IMPACTS...At 14.0 feet, Flooding begins along County Road 146 
  Champion Springs Road... the road leading to the gage.

* ADDITIONAL DETAILS...
  - At 8:15 PM CDT Thursday the stage was 4.9 feet.
  - Forecast...The river is expected to rise above flood stage
    tomorrow morning to a crest of 16.5 feet early Saturday
    morning. It will then fall below flood stage Sunday evening.
  - Flood stage is 8.0 feet.


&&

             Fld   Observed  Forecasts (7:00 am)
Location     Stg    Stage    Sat   Sun   Mon   Tue   Wed

Black River
  Annapolis  8.0     4.9     16.0  9.0   7.4   6.6   MSG


&&

LAT...LON 3743 9087 3745 9078 3724 9074 3724 9079


$$

MRM

007 
WGUS83 KLSX 241007
FLSLSX

Flood Statement
National Weather Service St Louis MO
507 AM CDT Fri Mar 24 2023

...The Flood Warning is extended for the following rivers in 
Missouri...

  Maries River near Westphalia.

  Meramec River near Sullivan.

...The Flood Warning continues for the following rivers in 
Missouri...

  Big River at Byrnesville.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC151-252215-
/O.EXT.KLSX.FL.W.0024.230324T1007Z-230326T0615Z/
/WPHM7.1.ER.230324T0917Z.230324T1200Z.230325T0015Z.NO/
507 AM CDT Fri Mar 24 2023

...FLOOD WARNING NOW IN EFFECT FROM EARLY THIS MORNING TO EARLY 
SUNDAY MORNING...

* WHAT...Minor flooding is occurring and minor flooding is forecast.

* WHERE...Maries River near Westphalia.

* WHEN...From early this morning to early Sunday morning.

* IMPACTS...At 12.1 feet, The north end of County Road 521 begins 
  flooding adjacent to the river near this height.

* ADDITIONAL DETAILS...
  - At 4:32 AM CDT Friday the stage was 10.3 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 4:32 AM CDT Friday was 10.3 feet.
  - Forecast...The river is expected to rise to a crest of 12.5
    feet this morning. It will then fall below flood stage this
    evening.
  - Flood stage is 10.0 feet.


&&

              Fld   Observed  Forecasts (7:00 am)
Location      Stg    Stage    Sat   Sun   Mon   Tue   Wed

Maries River
  Westphalia  10.0    10.3    6.3   4.1   3.0   2.5   MSG


&&

LAT...LON 3840 9205 3850 9197 3846 9194 3827 9194
      3827 9202


$$

MOC055-221-252215-
/O.EXT.KLSX.FL.W.0012.230324T1654Z-230329T0036Z/
/SLLM7.1.ER.230324T1654Z.230326T0000Z.230327T1836Z.NO/
507 AM CDT Fri Mar 24 2023

...FLOOD WARNING NOW IN EFFECT FROM THIS MORNING TO TUESDAY 
EVENING...

* WHAT...Minor flooding is forecast.

* WHERE...Meramec River near Sullivan.

* WHEN...From this morning to Tuesday evening.

* IMPACTS...At 21.0 feet, Sappington Bridge Road just north of the 
  Meramec River bridge begins flooding near this height.

* ADDITIONAL DETAILS...
  - At 4:30 AM CDT Friday the stage was 8.7 feet.
  - Forecast...The river is expected to rise above flood stage
    late this morning to a crest of 19.8 feet tomorrow evening.
    It will then fall below flood stage early Monday afternoon.
  - Flood stage is 11.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Meramec River
  Sullivan     11.0    8.7     17.7  18.2  12.3  8.7   7.2


&&

LAT...LON 3800 9120 3806 9125 3829 9109 3840 9090
      3837 9082


$$

MOC099-252215-
/O.EXT.KLSX.FL.W.0020.230325T0152Z-230328T1434Z/
/BYRM7.2.ER.230325T0152Z.230326T1200Z.230327T1434Z.UU/
507 AM CDT Fri Mar 24 2023

...FLOOD WARNING NOW IN EFFECT FROM THIS EVENING TO LATE TUESDAY 
MORNING...

* WHAT...Moderate flooding is forecast.

* WHERE...Big River at Byrnesville.

* WHEN...From this evening to late Tuesday morning.

* IMPACTS...At 20.5 feet, Burgan Grove Road begins flooding near 
  Cottage Grove Road, cutting off access to Cottage Grove Road.  
  Highway W near Hoene Spring is closed as water crosses the 
  pavement.

* ADDITIONAL DETAILS...
  - At 4:45 AM CDT Friday the stage was 10.8 feet.
  - Forecast...The river is expected to rise above flood stage
    this evening to a crest of 21.3 feet Sunday morning. It will
    then fall below flood stage late Monday morning.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Big River
  Byrnesville  16.0    10.8    18.4  21.3  16.9  10.7  8.2


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

KD

378 
WGUS83 KLSX 241644
FLSLSX

Flood Statement
National Weather Service St Louis MO
1144 AM CDT Fri Mar 24 2023

...The Flood Warning is extended for the following rivers in 
Missouri...

               Big River at Byrnesville

               Bourbeuse River at Union.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC099-260445-
/O.EXT.KLSX.FL.W.0020.230324T2241Z-230328T1438Z/
/BYRM7.2.ER.230324T2241Z.230326T1200Z.230327T1438Z.UU/
1144 AM CDT Fri Mar 24 2023

...FLOOD WARNING NOW IN EFFECT FROM THIS AFTERNOON TO LATE TUESDAY 
MORNING...

* WHAT...Moderate flooding is forecast.

* WHERE...Big River at Byrnesville.

* WHEN...From this afternoon to late Tuesday morning.

* IMPACTS...At 22.4 feet, At this level, Twin Rivers Bridge Road 
  must be closed.

* ADDITIONAL DETAILS...
  - At 10:45 AM CDT Friday the stage was 12.9 feet.
  - Forecast...The river is expected to rise above flood stage
    late this afternoon to a crest of 22.9 feet Sunday morning.
    It will then fall below flood stage late Monday morning.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sat   Sun   Mon   Tue   Wed

Big River
  Byrnesville  16.0    12.9    20.1  22.9  17.1  10.5  8.1


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

MOC071-260445-
/O.EXT.KLSX.FL.W.0019.230325T2318Z-230329T0800Z/
/UNNM7.1.ER.230325T2318Z.230327T0000Z.230328T0200Z.NO/
1144 AM CDT Fri Mar 24 2023

...FLOOD WARNING NOW IN EFFECT FROM SATURDAY EVENING TO EARLY 
WEDNESDAY MORNING...

* WHAT...Minor flooding is forecast.

* WHERE...Bourbeuse River at Union.

* WHEN...From Saturday evening to early Wednesday morning.

* IMPACTS...At 21.0 feet, Near this height, water begins covering 
  Highway O between Highway AM and American Inn Road.

* ADDITIONAL DETAILS...
  - At 11:00 AM CDT Friday the stage was 7.8 feet.
  - Forecast...The river is expected to rise above flood stage
    tomorrow evening to a crest of 21.2 feet Sunday evening. It
    will then fall below flood stage late Monday evening.
  - Flood stage is 15.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Sat   Sun   Mon   Tue   Wed

Bourbeuse River
  Union          15.0    7.8     11.3  19.9  19.9  10.7  5.7


&&

LAT...LON 3826 9123 3832 9133 3838 9137 3848 9094
      3842 9087


$$

Fuchs

775 
WGUS83 KLSX 250231
FLSLSX

Flood Statement
National Weather Service St Louis MO
931 PM CDT Fri Mar 24 2023

...The Flood Warning is extended for the following rivers in 
Missouri...

  Big River at Byrnesville.

  Bourbeuse River at Union.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC099-261445-
/O.EXT.KLSX.FL.W.0020.000000T0000Z-230328T2040Z/
/BYRM7.2.ER.230325T0259Z.230326T1800Z.230327T2040Z.UU/
931 PM CDT Fri Mar 24 2023

...FLOOD WARNING NOW IN EFFECT UNTIL TUESDAY AFTERNOON...

* WHAT...Moderate flooding is forecast.

* WHERE...Big River at Byrnesville.

* WHEN...Until Tuesday afternoon.

* IMPACTS...At 22.4 feet, At this level, Twin Rivers Bridge Road 
  must be closed.

* ADDITIONAL DETAILS...
  - At 8:45 PM CDT Friday the stage was 15.3 feet.
  - Forecast...The river is expected to rise above flood stage
    late this evening to a crest of 22.6 feet early Sunday
    afternoon. It will then fall below flood stage Monday
    afternoon.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sun   Mon   Tue   Wed   Thu

Big River
  Byrnesville  16.0    15.3    22.4  19.5  11.3  8.5   7.2


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

MOC071-261445-
/O.EXT.KLSX.FL.W.0019.230325T1700Z-230329T1008Z/
/UNNM7.1.ER.230325T1700Z.230327T0600Z.230328T0408Z.NO/
931 PM CDT Fri Mar 24 2023

...FLOOD WARNING NOW IN EFFECT FROM SATURDAY AFTERNOON TO EARLY 
WEDNESDAY MORNING...

* WHAT...Minor flooding is forecast.

* WHERE...Bourbeuse River at Union.

* WHEN...From Saturday afternoon to early Wednesday morning.

* IMPACTS...At 19.8 feet, Near this height, Missouri State Route UU 
  is closed in both directions.

* ADDITIONAL DETAILS...
  - At 9:00 PM CDT Friday the stage was 12.0 feet.
  - Forecast...The river is expected to rise above flood stage
    early tomorrow afternoon to a crest of 20.2 feet early Monday
    morning. It will then fall below flood stage late Monday
    evening.
  - Flood stage is 15.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Sun   Mon   Tue   Wed   Thu

Bourbeuse River
  Union          15.0    12.0    18.3  20.2  11.0  5.3   4.1


&&

LAT...LON 3826 9123 3832 9133 3838 9137 3848 9094
      3842 9087


$$

Jaja

404 
WGUS83 KLSX 251524
FLSLSX

Flood Statement
National Weather Service St Louis MO
1024 AM CDT Sat Mar 25 2023

...The Flood Warning continues for the following rivers in 
Missouri...

  Big River at Byrnesville.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC099-270330-
/O.EXT.KLSX.FL.W.0020.000000T0000Z-230328T1513Z/
/BYRM7.2.ER.000000T0000Z.230326T1800Z.230327T1513Z.UU/
1024 AM CDT Sat Mar 25 2023

...FLOOD WARNING NOW IN EFFECT UNTIL LATE TUESDAY MORNING...

* WHAT...Minor flooding is occurring and moderate flooding is 
  forecast.

* WHERE...Big River at Byrnesville.

* WHEN...Until late Tuesday morning.

* IMPACTS...At 22.4 feet, At this level, Twin Rivers Bridge Road 
  must be closed.

* ADDITIONAL DETAILS...
  - At 9:45 AM CDT Saturday the stage was 18.6 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 9:45 AM CDT Saturday was 18.6 feet.
  - Forecast...The river is expected to rise to a crest of 21.5
    feet early tomorrow afternoon. It will then fall below flood
    stage late Monday morning.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Sun   Mon   Tue   Wed   Thu

Big River
  Byrnesville  16.0    18.6    21.2  17.4  10.7  8.3   7.1


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

Maples

996 
WGUS83 KLSX 260149
FLSLSX

Flood Statement
National Weather Service St Louis MO
849 PM CDT Sat Mar 25 2023

...The Flood Warning is extended for the following rivers in 
Missouri...

  Big River at Byrnesville.

...The Flood Warning continues for the following rivers in 
Missouri...

  Bourbeuse River at Union.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC099-271400-
/O.EXT.KLSX.FL.W.0020.000000T0000Z-230328T1906Z/
/BYRM7.2.ER.000000T0000Z.230326T1800Z.230327T1906Z.UU/
849 PM CDT Sat Mar 25 2023

...FLOOD WARNING NOW IN EFFECT UNTIL EARLY TUESDAY AFTERNOON...

* WHAT...Moderate flooding is occurring and moderate flooding is 
  forecast.

* WHERE...Big River at Byrnesville.

* WHEN...Until early Tuesday afternoon.

* IMPACTS...At 20.5 feet, Burgan Grove Road begins flooding near 
  Cottage Grove Road, cutting off access to Cottage Grove Road.  
  Highway W near Hoene Spring is closed as water crosses the 
  pavement.

* ADDITIONAL DETAILS...
  - At 7:45 PM CDT Saturday the stage was 20.0 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 7:45 PM CDT Saturday was 20.0 feet.
  - Forecast...The river is expected to rise to a crest of 21.6
    feet early tomorrow afternoon. It will then fall below flood
    stage early Monday afternoon.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Mon   Tue   Wed   Thu   Fri

Big River
  Byrnesville  16.0    20.0    19.2  10.8  8.3   7.0   6.4


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

MOC071-271400-
/O.EXT.KLSX.FL.W.0019.000000T0000Z-230329T0138Z/
/UNNM7.1.ER.230325T1934Z.230327T0600Z.230327T1938Z.NO/
849 PM CDT Sat Mar 25 2023

...FLOOD WARNING NOW IN EFFECT UNTIL TUESDAY EVENING...

* WHAT...Minor flooding is occurring and minor flooding is forecast.

* WHERE...Bourbeuse River at Union.

* WHEN...Until Tuesday evening.

* IMPACTS...At 17.0 feet, Flat Creek backs up to Smeltzer's Park.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Saturday the stage was 15.7 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 8:30 PM CDT Saturday was 15.7 feet.
  - Forecast...The river is expected to rise to a crest of 17.8
    feet early Monday morning. It will then fall below flood
    stage early Monday afternoon.
  - Flood stage is 15.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Mon   Tue   Wed   Thu   Fri

Bourbeuse River
  Union          15.0    15.7    17.0  8.6   4.6   4.0   3.6


&&

LAT...LON 3826 9123 3832 9133 3838 9137 3848 9094
      3842 9087


$$

Jaja

513 
WGUS83 KLSX 261553
FLSLSX

Flood Statement
National Weather Service St Louis MO
1053 AM CDT Sun Mar 26 2023

...The Flood Warning is extended for the following rivers in 
Missouri...

  Big River at Byrnesville.

...The Flood Warning continues for the following rivers in 
Missouri...

  Bourbeuse River at Union.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC099-280400-
/O.EXT.KLSX.FL.W.0020.000000T0000Z-230328T2041Z/
/BYRM7.2.ER.000000T0000Z.230326T1800Z.230327T2041Z.UU/
1053 AM CDT Sun Mar 26 2023

...FLOOD WARNING NOW IN EFFECT UNTIL TUESDAY AFTERNOON...

* WHAT...Moderate flooding is occurring and moderate flooding is 
  forecast.

* WHERE...Big River at Byrnesville.

* WHEN...Until Tuesday afternoon.

* IMPACTS...At 22.4 feet, At this level, Twin Rivers Bridge Road 
  must be closed.

* ADDITIONAL DETAILS...
  - At 9:45 AM CDT Sunday the stage was 21.6 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 9:45 AM CDT Sunday was 21.7 feet.
  - Forecast...The river is expected to rise to a crest of 21.8
    feet this afternoon. It will then fall below flood stage
    tomorrow afternoon.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Mon   Tue   Wed   Thu   Fri

Big River
  Byrnesville  16.0    21.6    19.8  11.2  9.2   7.7   6.9


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

MOC071-280400-
/O.EXT.KLSX.FL.W.0019.000000T0000Z-230328T2254Z/
/UNNM7.1.ER.230325T1934Z.230327T0600Z.230327T1654Z.NO/
1053 AM CDT Sun Mar 26 2023

...FLOOD WARNING NOW IN EFFECT UNTIL TUESDAY AFTERNOON...

* WHAT...Minor flooding is occurring and minor flooding is forecast.

* WHERE...Bourbeuse River at Union.

* WHEN...Until Tuesday afternoon.

* IMPACTS...At 17.0 feet, Flat Creek backs up to Smeltzer's Park.

* ADDITIONAL DETAILS...
  - At 10:30 AM CDT Sunday the stage was 17.4 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 10:30 AM CDT Sunday was 17.4 feet.
  - Forecast...The river is expected to rise to a crest of 17.8
    feet just after midnight tonight. It will then fall below
    flood stage late tomorrow morning.
  - Flood stage is 15.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Mon   Tue   Wed   Thu   Fri

Bourbeuse River
  Union          15.0    17.4    16.8  7.0   4.5   3.7   3.5


&&

LAT...LON 3826 9123 3832 9133 3838 9137 3848 9094
      3842 9087


$$

MRB

203 
WGUS83 KLSX 270209
FLSLSX

Flood Statement
National Weather Service St Louis MO
909 PM CDT Sun Mar 26 2023

...The Flood Warning continues for the following rivers in 
Missouri...

  Big River at Byrnesville.

  Bourbeuse River at Union.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 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.weather.gov/ahps2/index.php?wfo=lsx.

&&

MOC099-281415-
/O.EXT.KLSX.FL.W.0020.000000T0000Z-230328T1800Z/
/BYRM7.2.ER.000000T0000Z.230326T1700Z.230327T1800Z.UU/
909 PM CDT Sun Mar 26 2023

...FLOOD WARNING NOW IN EFFECT UNTIL EARLY TUESDAY AFTERNOON...

* WHAT...Moderate flooding is occurring and moderate flooding is 
  forecast.

* WHERE...Big River at Byrnesville.

* WHEN...Until early Tuesday afternoon.

* IMPACTS...At 20.5 feet, Burgan Grove Road begins flooding near 
  Cottage Grove Road, cutting off access to Cottage Grove Road.  
  Highway W near Hoene Spring is closed as water crosses the 
  pavement.

* ADDITIONAL DETAILS...
  - At 8:45 PM CDT Sunday the stage was 21.2 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 8:45 PM CDT Sunday was 21.8 feet.
  - Forecast...The river is expected to fall below flood stage
    early tomorrow afternoon and continue falling to 5.8 feet
    Sunday evening.
  - Flood stage is 16.0 feet.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Tue   Wed   Thu   Fri   Sat

Big River
  Byrnesville  16.0    21.2    9.6   7.8   7.1   6.6   6.2


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

MOC071-281415-
/O.EXT.KLSX.FL.W.0019.000000T0000Z-230329T0700Z/
/UNNM7.1.ER.230325T1934Z.230327T0600Z.230328T0100Z.NO/
909 PM CDT Sun Mar 26 2023

...FLOOD WARNING NOW IN EFFECT UNTIL EARLY WEDNESDAY MORNING...

* WHAT...Minor flooding is occurring and minor flooding is forecast.

* WHERE...Bourbeuse River at Union.

* WHEN...Until early Wednesday morning.

* IMPACTS...At 19.8 feet, Near this height, Missouri State Route UU 
  is closed in both directions.

* ADDITIONAL DETAILS...
  - At 8:30 PM CDT Sunday the stage was 18.3 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 8:30 PM CDT Sunday was 18.4 feet.
  - Forecast...The river is expected to rise to a crest of 18.5
    feet just after midnight tonight. It will then fall below
    flood stage tomorrow evening.
  - Flood stage is 15.0 feet.


&&

                 Fld   Observed  Forecasts (7:00 am)
Location         Stg    Stage    Tue   Wed   Thu   Fri   Sat

Bourbeuse River
  Union          15.0    18.3    10.2  4.9   3.9   3.5   3.3


&&

LAT...LON 3826 9123 3832 9133 3838 9137 3848 9094
      3842 9087


$$

MG/MRM

858 
WGUS83 KLSX 271712
FLSLSX

Flood Statement
National Weather Service St Louis MO
1212 PM CDT Mon Mar 27 2023

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

  Big River at Byrnesville.

River forecasts are based on observed precipitation and forecast 
precipitation for the next 48 hours.

MOC099-271815-
/O.CAN.KLSX.FL.W.0020.000000T0000Z-230327T1712Z/
/BYRM7.2.ER.000000T0000Z.230326T1700Z.230327T1534Z.UU/
1212 PM CDT Mon Mar 27 2023

...FLOOD WARNING IS CANCELLED...

The Flood Warning is cancelled for
  the Big River at Byrnesville.

* ADDITIONAL DETAILS...
  - At 11:45 AM CDT Monday the stage was 15.2 feet.
  - Forecast...The river is expected to fall to 5.4 feet Monday
    morning.


&&

               Fld   Observed  Forecasts (7:00 am)
Location       Stg    Stage    Tue   Wed   Thu   Fri   Sat

Big River
  Byrnesville  16.0    15.2    9.0   7.4   7.0   6.4   6.0


&&

LAT...LON 3834 9060 3833 9068 3846 9063 3849 9057


$$

Maples

Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
1052 AM CDT Thu Mar 23 2023

.UPDATE...
Issued at 1030 AM CDT Thu Mar 23 2023

Latest analysis shows the cold front is slightly quicker than
previously expected as it bisects the metro area. Winds have
turned out of the north-northwest generally along the I-70
corridor. Temperatures are in the upper 60s/low-70s just ahead of
the front and quickly drop to the upper 40s to mid-50s behind the
front. Adjustments have been made to account for the quicker
progress. In regards to rainfall potential, PoPs were limited to
slight chances in the immediate vicinity of the boundary. Latest
radar trends show isolated light rain showers along and just
behind the front. CAMs suggest this will be the theme through
mid- afternoon before another impulse moves up the boundary this
evening, when showers and thunderstorms develop out of the
southwest. The best potential currently looks to be around and
after 22z, developing out of the southwest and spreading to the
northeast into the CWA through tonight.

Maples

&&

.SHORT TERM... (Through Friday Night)
Issued at 328 AM CDT Thu Mar 23 2023

Key messages through Friday evening:

- All indications continue to point to two rounds of heavy rain
  to affect areas along and south of I-70 along a slow-moving cold
  front starting this evening. This will likely lead to flooding
  on several small streams and creeks including the Meramec, Big,
  Bourbeuse, and Black River basins (among others). An isolated
  threat for flash flooding also exists where several
  thunderstorms impact the same area.

- Rainfall totals have not changed dramatically from the last forecast,
  though the axis of heavy rain is trending very slightly further
  south. A wide swath of 2-3" of rain is forecast within the
  Flood Watch area by Friday night, with isolated instances of 4+"
  expected.

- An low threat for marginally-severe hail exists this afternoon
  and evening ahead of the cold front.

Regional surface analysis depicts a frontal boundary extending from
a surface low in south-central Kansas that stalled along an axis
from Columbia, Missouri to Springfield, Illinois. Aloft, an
amplified longwave trough is situated off the coast of Baja
California placing the south-central CONUS in southwest flow.
Isolated convection continues to percolate along the stalled
boundary, aided by a strengthening low-level jet. Forecast soundings
and SPC Mesoscale Analysis depict steep mid-level lapse rates above
8C/km amidst ~1000J/kg of MUCAPE just along and ahead of the
boundary. This environment will advect south along with the front
during the day today, as the trough out west begins to approach and
amplify flow aloft. Broad synoptic-scale lift and a strengthening
upper-level jet will promote a gradual uptick in precipitation
coverage through the day today along the front. While the
environment aloft will remain favorable for severe hail to develop,
the lower atmosphere is far less supportive of large hail reaching
the ground. While I cannot rule out an errant 1" hailstone,
primarily during the afternoon, the vast majority of any
thunderstorms that develop during the day will remain sub-severe.

This evening, a strengthening LLJ will draw an impulse of highly-
anomalous moisture into the region. Amidst strong, deep large-scale
lift, widespread showers and thunderstorms will develop along and
behind the front (coincident with stronger 850-700mb frontogenesis
and moisture convergence) around 00Z. The ingredients for efficient
heavy rain are still very evident in short-range ensembles, CAMs,
and deterministic guidance: warm cloud depths over 10,000ft, high RH
within the cloud depth, and steering flow parallel to the boundary
(introduces training thunderstorm potential). There appears to be a
weakening of MUCAPE in the most recent guidance during the evening
and overnight, which is one count against even more efficient heavy
rain, however the other factors still weigh heavily towards
impactful rainfall.

There remains some non-negligible uncertainty regarding the axis of
heavy rain, but overall the first round of thunderstorms looks to
orient itself along the I-44 corridor later this evening and
gradually drift southeast with time. HREF probability-matched mean
output, which tends to capture the high-end localized amounts fairly
well in these situations, shows a wide swath of 2-3" of rain by the
end of the initial wave overnight. Localized instances of 3+" are
depicted within that swath, which is completely plausible given the
combination of efficient rainfall and training convection. Global-
scale ensembles also feature high probabilities (~80%) for at least
2" of rain, and the NBM paints similar probabilities for this
threshold. In addition to flooding within several smaller river
basins (see the "Hydrology" section of the forecast discussion for
more information), these amounts are likely to cause impacts in low-
lying areas along with urbanized areas with poor runoff. Isolated
instances of flash flooding are also possible, particularly where
training convection can develop.

The LLJ weakens closer to sunrise on Friday, which will lead to a
lull (though likely not a complete end) to precipitation on Friday.
At the same time, the synoptic-scale system will begin to intensify
with the upper-level trough approaching the region. A surface low is
forecast to develop in the southern Great Plains and shunt northeast
into the Mid-Mississippi Valley during the afternoon on Friday. This
will draw another impulse of moisture north accordingly, and set the
stage for a second round of heavy rain Friday evening into very
early Saturday morning. The area of heavy rain will likely be
further south and east from the first round, and more progressive
given its association with a deepening cyclone. Regardless, given
a similar thermodynamic environment, impacts can be expected and
an additional 1-2" is forecast. There will likely be some overlap
from the two rounds, primarily in southeast Missouri and southwest
Illinois, where the highest forecast rainfall totals exist
(localized amounts up to 4").

MRB

.LONG TERM...  (Friday Night through Wednesday)
Issued at 328 AM CDT Thu Mar 23 2023

The surface low associated with the second round of heavy rain
Friday evening will deepen and exit the region to the northeast
overnight Friday. Deterministic global models and ensembles show a
deformation zone glancing the forecast area, though there is some
discrepancy as to how widespread any resultant precipitation it
will be. As evidenced in a close inspection of the clustered
ensemble members, some solutions develop the low slowly and cause
more widespread light precipitation. Others develop the low, and a
dry slot, more quickly and restrict precipitation to the northern
parts of the CWA. Regardless, precipitation should largely come
to an end by Saturday afternoon. The associated upper-level trough
will be east of the region by then, digging across the eastern
CONUS and allowing for longwave troughing to engulf most of the
CONUS.

While late Saturday into early Sunday looks dry, a weak shortwave in
the near-zonal flow is evident in a few deterministic models and
could spark light precipitation as early as Sunday evening. By
Monday, there is slightly more favorable jet-level dynamics for
precipitation to persist through Monday. Another very low potential
for rain exists on Tuesday associated with another shortwave, though
most ensemble members keep the region dry. Upper-level ridging
builds into the region by mid-week, bringing drier weather and
near-normal temperatures.

MRB

&&

.AVIATION...  (For the 12z TAFs through 12z Friday Morning)
Issued at 558 AM CDT Thu Mar 23 2023

A stalled front that hung between KCOU and KUIN overnight is
helping focus a round of showers with isolated thunderstorms
across northeast Missouri and west-central Illinois at this hour.
The front will slowly start to move south this morning, swinging
winds out of the north as it passes through the terminals. The
front will also draw lower CIGs (likely IFR) further south into
the St. Louis and mid-Missouri terminals. A strengthening low-
level jet will likely spawn showers and thunderstorms tonight
along and in the vicinity of the front. While the highest
rainfall totals will be south of the TAF sites, there will likely
be thunderstorms at the St. Louis terminals and in mid-Missouri
tonight. The thunderstorms may linger longer than the current
TAFs depict, but VCTS is used to indicate the most likely timing
for the thunderstorms.

SPECIFICS FOR KSTL: A stalled front that hung between KCOU and
KUIN overnight is helping focus a round of showers with isolated
thunderstorms across northeast Missouri and west-central Illinois
at this hour. The front will slowly start to move south this
morning, swinging winds out of the north as it passes through the
terminals. The front will also draw lower CIGs (likely IFR)
further south into KSTL. A strengthening low- level jet will
likely spawn showers and thunderstorms tonight along and in the
vicinity of the front. While the highest rainfall totals will be
south of KSTL, there will likely be thunderstorms tonight. The
thunderstorms may linger longer than the current TAFs depict, but
VCTS is used to indicate the most likely timing for the
thunderstorms.

MRB

&&

.HYDROLOGY...
Issued at 328 AM CDT Thu Mar 23 2023

The aforementioned heavy rain, discussed in greater detail in the
"Short Term" section of this discussion, will likely cause many
small streams and creeks to flood in east-central/southeast Missouri
and southwest Illinois. Additionally, areal flooding in low-lying
and urbanized places can be expected along with isolated instances
of flash flooding where training thunderstorms will develop.

Official river forecasts show notable rises within the Gasconade,
Maries, Meramec, Black, Big, and Bourbeuse River basins in Missouri
and the Kaskaskia River Basin in Illinois. Most forecast points
within these basins are expected to reach flood stage. The largest
source of uncertainty for these forecasts is where the heaviest rain
will set up, but with greater agreement among models in that detail,
confidence in flooding continues to increase and approach the
threshold for River Flood Warnings. Depending on the forecast point,
flooding from minor to near-major levels is forecast. Experimental
ensemble-based hydrographs suggest that there is some potential for
a few of these basins to exceed current forecasts, though that
depends entirely on where the band of heavy rain ultimately
develops. These ensembles also highlight rivers currently not
forecast to flood, such as the Cuivre River and Dardenne Creek, as
points to watch. As of now, the "worst-case" scenario brings these
gauges near or above minor flood stage, however they are not likely
to realize that solution unless a drastic shift in the heavy rain
axis occurs. As such, it is important to continue checking these
forecasts for updates during and after the rainfall.

MRB

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flood Watch from 7 PM CDT this evening through late Friday night
     for Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson
     MO-Madison MO-Osage 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 from 7 PM CDT this evening through late Friday night
     for Bond IL-Clinton IL-Fayette IL-Madison IL-Marion IL-
     Monroe IL-Randolph IL-Saint Clair IL-Washington IL.

&&

WFO LSX

Hazardous Weather Outlook
National Weather Service St Louis MO
336 AM CDT Thu Mar 23 2023

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-240845-
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-
336 AM CDT Thu Mar 23 2023

This Hazardous Weather Outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Today and tonight.

Thunderstorms are likely today and tonight across most of the area. A
few thunderstorms may have hail to the size of quarters.

Heavy rain and instances of flooding are expected late today through
tonight over parts of east central and southeast Missouri as well as
southwest Illinois where a Flood Watch is in effect.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Another round of thunderstorms with heavy rain is likely Friday
over parts of east central and southeast Missouri as well as
southwest Illinois where a Flood Watch is in effect.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report rainfall totals and instances of
flooding to the National Weather Service.

MRB