Flood Potential Outlook
Issued by NWS St. Louis, MO
Issued by NWS St. Louis, MO
600
FGUS73 KLSX 011301
ESFLSX
ILC001-009-013-027-051-149-MOC051-053-071-073-099-111-113-127-
137-151-163-173-183-189-221-DDHHMM-
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE ST. LOUIS MO
755 AM CDT Tue Apr 01 2025
In Table 1 below...the current (CS) and historical (HS) or normal
probabilities of exceeding minor...moderate...and major flood stages
are listed for the valid time period.
CS values indicate the probability of reaching a flood category
based on current conditions.
HS values indicate the probability of reaching a flood category
based on historical or normal conditions.
When the value of CS is more than HS...the probability of
exceeding that level is higher than normal. When the value of CS is
less than HS...the probability of exceeding that level is lower
than normal.
...Table 1--Probabilities for minor...moderate and major flooding...
Valid Period: 03/31/2025 - 06/29/2025
: Current and Historical
: Chances of Exceeding
: Flood Categories
: as a Percentage (%)
Categorical :
Flood Stages (FT) : Minor Moderate Major
Location Minor Mod Major : CS HS CS HS CS HS
-------- ----- ----- ----- : --- --- --- --- --- ---
:Mississippi River
Canton 15.0 20.0 25.0 : 37 64 7 15 <5 <5
LaGrange 17.0 23.0 25.0 : 30 54 <5 10 <5 <5
Quincy 19.0 22.0 26.0 : 32 56 13 30 <5 10
Lock & Dam 21 18.0 21.0 25.0 : 31 56 13 26 <5 10
Hannibal 17.0 22.0 24.0 : 47 64 8 14 7 10
Saverton 16.0 20.0 24.0 : 50 67 14 40 7 11
Louisiana 15.0 20.0 25.0 : 69 76 13 35 <5 8
Clarksville 25.0 31.0 33.0 : 70 76 13 28 8 13
Winfield 26.0 30.0 34.0 : 56 71 15 43 6 10
Grafton 20.0 24.0 29.0 : 41 67 12 19 7 10
Mel Price LD 21.0 29.0 34.0 : 50 80 20 25 <5 11
St. Louis 30.0 35.0 40.0 : 39 60 22 34 7 17
Herculaneum 26.0 32.0 37.0 : 48 63 22 36 10 18
Chester 27.0 35.0 40.0 : 59 81 26 43 16 25
:North Fabius River
Ewing 11.0 17.0 20.0 : 59 56 17 15 11 11
:Middle Fabius River
Ewing 12.0 17.0 20.0 : 46 50 16 17 10 12
:South Fabius River
Taylor 10.0 14.0 19.0 : 33 48 14 17 7 7
:North River
Palmyra 13.0 16.0 22.0 : 25 28 10 12 <5 <5
:Mid Fork Salt River
Holliday 17.0 22.0 26.0 : 53 51 <5 <5 <5 <5
:Salt River
New London 19.0 25.0 27.0 : <5 <5 <5 <5 <5 <5
:Cuivre River
Troy 21.0 25.0 29.0 : 55 53 21 18 8 8
Old Monroe 24.0 27.0 30.0 : 44 62 24 27 8 14
:Dardenne Creek
St. Peters 18.0 20.0 23.0 : 34 33 26 25 7 7
:Meramec River
Steelville 12.0 20.0 25.0 : 41 35 <5 <5 <5 <5
Sullivan 11.0 20.0 29.0 : 62 59 13 13 <5 <5
:Bourbeuse River
Union 15.0 22.0 26.0 : 51 47 9 9 <5 <5
:Meramec River
Pacific 15.0 23.0 27.0 : 42 38 6 5 <5 <5
:Big River
Byrnesville 16.0 20.0 28.0 : 46 44 21 20 <5 <5
:Meramec River
Eureka 19.0 26.0 31.0 : 40 38 14 17 5 5
Valley Park 18.0 21.0 27.0 : 46 48 33 34 13 22
Fenton 23.0 29.0 32.0 : 44 50 14 22 9 11
Arnold 24.0 35.0 38.0 : 59 81 19 28 15 20
:Kaskaskia River
Vandalia 18.0 24.0 26.0 : 72 75 28 31 18 19
Carlyle 16.5 23.0 27.0 : 53 72 <5 <5 <5 <5
New Athens 79.0 82.0 85.0 : 39 43 36 40 27 25
:La Moine River
Ripley 22.0 23.0 27.0 : 41 50 33 40 13 14
:Moreau River
Jefferson City 17.0 25.0 29.0 : 70 75 46 53 19 28
:Hinkson Creek
Columbia 15.0 18.0 20.0 : 55 56 25 27 9 9
:Maries River
Westphalia 10.0 15.0 20.0 : 49 50 21 26 <5 <5
:Gasconade River
Rich Fountain 20.0 25.0 30.0 : 22 35 10 22 5 6
:Missouri River
Jefferson City 23.0 25.0 30.0 : 43 68 26 54 16 28
:Osage River
St. Thomas 23.0 30.0 35.0 : <5 17 <5 <5 <5 <5
Mari-Osa Campgrou 19.0 22.0 25.0 : 41 60 18 31 14 22
:Missouri River
Chamois 17.0 28.0 31.0 : 64 80 12 18 <5 10
Hermann 21.0 26.0 33.0 : 56 78 25 46 14 21
Washington 20.0 28.0 31.0 : 49 70 19 21 6 19
St. Charles 25.0 30.0 36.0 : 48 72 22 27 <5 15
Legend
CS = Conditional Simulation (Current Outlook)
HS = Historical Simulation
FT = Feet
In Table 2 below...the 95 through 5 percent columns indicate the
probability of exceeding the listed stage levels (FT) for the valid
time period.
...Table 2--Exceedance Probabilities...
Chance of Exceeding Stages
at Specific Locations
Valid Period: 03/31/2025 - 06/29/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Canton 10.1 10.6 12.2 14.3 16.4 19.3 21.2
LaGrange 11.0 11.5 13.1 15.2 17.2 20.2 22.1
Quincy 13.5 14.0 15.2 17.2 19.8 23.1 25.5
Lock & Dam 21 11.3 12.0 13.6 16.1 18.5 21.9 24.5
Hannibal 13.3 13.7 14.8 16.5 18.6 21.5 24.3
Saverton 11.1 11.8 13.5 16.1 18.6 22.1 24.8
Louisiana 12.3 12.7 14.1 16.2 18.8 21.6 23.8
Clarksville 21.4 22.1 23.9 26.4 29.4 32.2 34.3
Winfield 21.6 22.3 24.1 26.4 29.5 32.2 34.2
Grafton 15.9 16.0 16.7 19.4 21.0 24.1 30.2
Mel Price LD 13.6 14.7 17.4 21.0 25.6 31.5 32.9
St. Louis 16.6 17.4 22.1 26.7 32.9 39.5 41.0
Herculaneum 14.7 15.5 20.1 24.6 30.6 37.2 38.7
Chester 17.9 19.6 24.3 28.4 36.0 43.1 43.4
:North Fabius River
Ewing 7.5 7.6 8.7 11.8 15.4 20.5 24.2
:Middle Fabius River
Ewing 5.7 6.2 7.8 11.2 16.0 20.2 22.9
:South Fabius River
Taylor 4.0 5.0 6.1 8.6 12.1 17.0 19.8
:North River
Palmyra 5.8 6.2 7.3 9.4 13.0 16.0 18.1
:Mid Fork Salt River
Holliday 11.0 11.3 14.2 17.2 19.2 20.7 21.6
:Salt River
New London 8.3 8.7 9.3 9.9 11.5 13.1 13.8
:Cuivre River
Troy 12.7 13.1 16.4 21.7 24.8 28.6 29.5
Old Monroe 17.9 18.4 20.0 23.4 26.6 29.1 30.6
:Dardenne Creek
St. Peters 7.1 7.8 9.8 13.4 20.4 22.4 23.8
:Meramec River
Steelville 3.8 5.1 7.0 10.1 14.3 16.5 19.4
Sullivan 6.8 7.5 9.2 12.9 17.4 20.7 23.7
:Bourbeuse River
Union 7.1 8.8 11.6 15.1 19.5 21.5 24.9
:Meramec River
Pacific 3.9 5.7 9.8 14.1 17.3 21.8 23.7
:Big River
Byrnesville 6.4 7.2 11.6 15.7 19.5 22.3 23.4
:Meramec River
Eureka 7.7 9.7 13.3 16.8 22.4 28.8 31.2
Valley Park 12.0 13.0 13.6 16.4 23.7 29.2 39.4
Fenton 16.5 17.9 18.7 20.8 27.1 29.9 38.7
Arnold 16.3 16.4 22.2 27.1 31.9 39.3 41.4
:Kaskaskia River
Vandalia 16.9 17.0 17.9 22.4 25.2 27.8 29.2
Carlyle 13.6 13.7 14.7 16.7 19.4 21.7 22.1
New Athens 72.2 72.2 73.0 76.4 85.6 90.2 92.7
:La Moine River
Ripley 11.5 12.4 15.9 20.2 25.2 27.8 28.5
:Missouri River
Jefferson City 11.4 12.9 17.1 21.0 25.3 35.0 35.5
:Osage River
St. Thomas 6.7 8.5 10.4 12.2 15.3 21.3 22.7
Mari-Osa Campgrou 8.3 10.9 13.4 17.4 20.5 25.7 28.9
:Missouri River
Chamois 8.8 10.3 13.8 19.1 22.4 29.0 29.8
Hermann 10.9 13.1 16.4 22.6 26.3 34.2 34.7
Washington 8.2 11.3 14.0 19.8 23.1 30.5 31.6
St. Charles 14.4 18.1 20.1 24.5 27.5 34.8 35.5
In Table 3 below...the 95 through 5 percent columns indicate the
probability of falling below the listed stage levels (FT) for the
valid time period.
...Table 3--Nonexceedance Probabilities...
Chance of Falling Below Stages
at Specific Locations
Valid Period: 03/31/2025 - 06/29/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Canton 91.9 91.4 89.2 68.1 49.3 39.6 36.6
Quincy 93.6 93.2 89.9 68.3 49.7 39.8 36.7
Lock & Dam 21 93.6 93.2 89.9 68.3 49.7 39.8 36.7
Hannibal 95.5 95.1 90.2 68.5 49.9 39.9 36.8
Saverton 94.4 94.1 90.2 68.8 50.0 40.0 36.8
Louisiana 103.4 103.2 93.1 70.2 51.7 40.5 38.3
Clarksville 103.6 103.4 93.3 70.5 51.8 40.5 38.3
Winfield 105.5 105.3 93.4 71.0 51.9 40.6 38.4
St. Louis 172.9 170.7 169.7 154.1 123.9 102.0 92.2
Chester 179.2 178.0 176.5 165.5 128.6 104.2 94.9
:North Fabius River
Ewing 0.1 0.0 0.0 0.0 0.0 0.0 0.0
:Middle Fabius River
Ewing 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:South Fabius River
Taylor 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:North River
Palmyra 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Mid Fork Salt River
Holliday 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Salt River
New London 1.8 1.8 1.3 0.8 0.1 0.1 0.1
:Cuivre River
Troy 0.2 0.1 0.1 0.0 0.0 0.0 0.0
Old Monroe 0.3 0.2 0.1 0.1 0.0 0.0 0.0
:Dardenne Creek
St. Peters 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Meramec River
Steelville 0.4 0.4 0.3 0.2 0.2 0.1 0.1
Sullivan 0.8 0.7 0.6 0.5 0.4 0.3 0.3
:Bourbeuse River
Union 0.2 0.2 0.2 0.1 0.1 0.1 0.1
:Meramec River
Pacific 1.4 1.2 0.9 0.7 0.6 0.5 0.4
:Big River
Byrnesville 0.5 0.4 0.3 0.2 0.2 0.1 0.1
:Meramec River
Eureka 2.0 1.7 1.3 1.0 0.8 0.7 0.6
:Kaskaskia River
Vandalia 1.2 1.1 0.2 0.1 0.1 0.1 0.0
Carlyle 2.5 2.5 2.1 0.1 0.1 0.1 0.1
:La Moine River
Ripley 0.3 0.2 0.2 0.1 0.0 0.0 0.0
:Missouri River
Jefferson City 3.8 3.8 3.8 3.8 3.8 3.6 3.2
:Osage River
St. Thomas 3.8 3.6 2.8 2.6 2.4 2.4 2.0
:Missouri River
Chamois 1.0 1.0 1.0 1.0 1.0 0.6 0.1
Hermann 3.8 3.8 3.8 3.8 3.8 3.4 2.9
Washington 1.9 1.9 1.9 1.9 1.9 1.6 1.1
St. Charles 8.5 8.5 8.5 8.5 8.5 8.5 7.9
These long-range probabilistic outlooks contain forecast values that
are calculated using multiple season scenarios from 30 or more years
of climatological data...including current conditions of the
river...soil moisture...snow cover...and 30 to 90 day long-range
outlooks of temperature and precipitation. By providing a range of
probabilities...the level of risk associated with long-range planning
decisions can be determined. These probabilistic forecasts are part
of the National Weather Service`s advanced hydrologic prediction
service.
Visit our web site weather.gov/lsx for more weather and water
information.
The next outlook will be issued the last week of April.
$$
Fuchs