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.  
 

 
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