National Weather Service United States Department of Commerce

 

Figure 1: Snow Water Equivalent Image. (Courtesy of NOHRSC)
Figure 2: USGS Current Streamflow Analysis
Figure 3: 180 Day Percentage of Mean Precipitation Analysis (Courtesy of Midwest Climate Center)
Figure 4: Palmer Drought Severity Index
Figure 5: Soil Moisture (mm)
Figure 6: Three Month Temperature Outlook
Figure 7: Three Month Precipitation Outlook

NWS
St. Louis, Missouri

Spring Flood Outlook
Issued: March 27, 2019

Snow Water EquivalentCurrent Snow Water Equivalent

Streamflow AnalysisUSGS Stream Analysis

  30 Day Rainfall DeparturePrecipitation 30 Day Percentage of Mean

Soil Moisture PercentileCurrent Soil Moisture

1-Month Precip Outlook3 Month Precipitation Outlook

1-Month Temp Outlook3 Month Temperature Outlook

3-Month Precip Outlook3 Month Precipitation Outlook

3-Month Temp Outlook3 Month Temperature Outlook

Probabilistic Hydrologic Outlook
National Weather Service ST. LOUIS MO
455 PM CDT WED MAR 27 2019

...Spring flood probabilities remain very high along major rivers...

Despite the loss of significant snow cover in the basins of both the
Mississippi and Missouri rivers, the probabilities of reaching
significant flood levels remains quite high for this spring season.
Along the Missouri River, minor to moderate flooding is likely, with
moderate flooding expected at Jefferson City, Hermann, and St.
Charles.  Along the Mississippi River, moderate to major flooding
remains likely.

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:  04/01/2019 - 06/30/2019

                                       :    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 LD20         14.0   20.0   25.0 : >95   69  >95   15   11   <5
LaGrange            18.0   23.0   25.0 : >95   42   50    9   14   <5
Quincy              17.0   22.0   26.0 : >95   68  >95   28   54    9
Quincy LD21         17.0   21.0   25.0 : >95   62  >95   26   54    9
Hannibal            16.0   22.0   24.0 : >95   69  >95   15   60    9
Saverton LD22       16.0   20.0   22.0 : >95   65  >95   38  >95   18
Louisiana           15.0   20.0   25.0 : >95   73  >95   35   25    6
Clarksville LD24    25.0   31.0   33.0 : >95   73  >95   28  >95   12
Winfield LD25       26.0   30.0   34.0 : >95   68  >95   41   92    9
Grafton             18.0   24.0   29.0 : >95   82  >95   30   50   12
Mel Price LD        21.0   29.0   34.0 : >95   74  >95   40   46   12
St. Louis           30.0   35.0   40.0 : >95   60  >95   46   65   19
Chester             27.0   35.0   40.0 : >95   81  >95   57   82   25
:North Fabius River
Ewing               11.0   14.0   18.0 :  60   50   28   26   11   11
:Middle Fabius River
Ewing               12.0   17.0   19.5 :  52   44   18   14   11   10
:South Fabius River
Taylor               9.5   14.0   19.0 :  50   45   14   12    5    5
:North River
Palmyra             13.0   16.0   22.0 :  51   45   36   31   <5   <5
:Mid Fork Salt River
Holliday            17.0   22.0   26.0 :  54   43    7   <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 :  56   53   25   25    9    9
Old Monroe          24.0   27.0   30.0 : >95   57  >95   26   52   12
:Dardenne Creek
St. Peters          18.0   20.0   23.0 :  28   28   19   19   <5   <5
:Bourbeuse River
Union               15.0   22.0   26.0 :  50   46    9    9   <5   <5
:Big River
Byrnesville         16.0   20.0   28.0 :  54   49   21   19   <5   <5
:Meramec River
Steelville          12.0   20.0   25.0 :  42   34   <5   <5   <5   <5
Sullivan            11.0   20.0   29.0 :  64   57   15   13   <5   <5
Pacific             15.0   23.0   27.0 :  46   39   10    8   <5   <5
Eureka              19.0   26.0   31.0 :  44   33   17   16    9    7
Valley Park         16.0   19.0   25.0 :  51   66   42   46   18   27
:Meramec
Fenton              25.0   29.0   32.0 :  32   44    8   21   <5   11
:Meramec River
Arnold              24.0   35.0   38.0 :  39   79   <5   30   <5   22
:Kaskaskia River
Vandalia            18.0   24.0   26.0 : >95   70   22   22   15   13
Carlyle TW         423.5  431.0  435.0 :  27   34   <5   <5   <5   <5
:La Moine River
Ripley              22.0   23.0   27.0 : >95   48  >95   39   18   13
:Moreau River
Jefferson City      17.0   25.0   29.0 :  83   83   44   42   20   18
:Maries River
Westphalia          10.0   15.0   20.0 :  50   53   19   23   <5   <5
:Gasconade River
Rich Fountain       20.0   25.0   30.0 :  26   29   18   21   <5   <5
:Missouri River
Jefferson City      23.0   25.0   30.0 : >98   61  >98   52   32   15
:Osage River
St. Thomas          23.0   30.0   35.0 :  12   16   <5   <5   <5   <5
Mari-Osa Campgrou   19.0   22.0   25.0 : >98   63   49   25   14   13
:Missouri River
Chamois             17.0   28.0   31.0 : >98   72   15   10    9    5
Gasconade           22.0   34.0   37.0 : >98   79   22   13    8   <5
Hermann             21.0   26.0   33.0 : >98   73   77   41   15   11
Washington          20.0   28.0   31.0 : >98   64   24   13   12    9
St. Charles         25.0   30.0   36.0 : >98   68   64   28   13    8

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: 04/01/2019 - 06/30/2019
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Canton LD20          20.7   20.8   21.0   22.1   23.3   25.2   26.6
LaGrange             21.6   21.6   21.9   23.0   24.2   26.1   27.5
Quincy               25.0   25.0   25.0   26.2   27.6   30.0   31.7
Quincy LD21          23.8   23.8   23.9   25.2   26.9   29.3   30.9
Hannibal             23.6   23.6   23.6   24.6   25.9   29.1   30.7
Saverton LD22        24.1   24.1   24.1   25.0   26.1   28.5   29.4
Louisiana            23.5   23.5   23.5   24.0   25.0   27.2   28.6
Clarksville LD24     34.1   34.1   34.1   34.5   35.3   37.1   38.2
Winfield LD25        34.0   34.0   34.1   34.5   35.4   37.4   38.6
Grafton              27.9   27.9   28.0   29.0   31.4   36.0   36.1
Mel Price LD         31.2   31.2   31.7   33.6   35.2   40.1   42.4
St. Louis            38.6   38.6   39.2   41.1   42.8   48.0   49.9
Chester              39.9   39.9   40.5   42.4   44.8   48.8   50.5
:North Fabius River
Ewing                 5.8    6.7    8.9   12.0   15.2   19.0   21.3
:Middle Fabius River
Ewing                 5.2    6.2    8.7   12.1   16.0   20.0   21.5
:South Fabius River
Taylor                4.1    5.6    6.9    9.5   12.1   15.1   19.1
:North River
Palmyra               6.3    7.4    9.1   13.1   18.2   19.8   21.2
:Mid Fork Salt River
Holliday              9.0   10.5   14.2   17.2   19.1   20.9   22.3
:Salt River
New London            9.1    9.1    9.5   10.7   12.5   15.8   17.9
:Cuivre River
Troy                 11.3   12.6   16.4   22.3   25.0   28.7   29.7
Old Monroe           27.4   28.4   29.2   30.0   31.3   34.1   35.1
:Dardenne Creek
St. Peters            3.7    6.2   10.1   12.6   19.2   21.3   22.4
:Bourbeuse River
Union                 6.8    9.0   11.6   15.0   18.6   21.4   24.9
:Big River
Byrnesville           7.9    8.6   12.8   16.2   19.2   22.0   23.2
:Meramec River
Steelville            4.0    5.4    7.4   11.4   14.5   16.5   19.5
Sullivan              6.3    7.1    9.5   14.0   18.2   21.1   23.5
Pacific               3.9    6.0   10.3   14.7   18.0   22.9   24.3
Eureka                8.0   10.0   12.7   17.4   23.5   30.8   31.8
Valley Park           6.8    8.4   12.8   16.5   22.4   27.3   31.2
:Meramec
Fenton               11.2   12.8   17.3   20.9   25.4   28.7   31.7
:Meramec River
Arnold               11.4   12.2   15.6   19.3   26.5   30.8   33.7
:Kaskaskia River
Vandalia             19.6   19.6   20.0   21.6   23.2   26.5   27.7
Carlyle TW          420.7  420.7  421.1  422.5  423.6  424.7  425.9
:La Moine River
Ripley               25.0   25.0   25.1   25.3   26.1   28.0   28.9
:Moreau River
Jefferson City        9.4   12.8   18.5   22.3   28.3   33.5   40.1
:Maries River
Westphalia            2.5    3.0    4.0    9.8   13.5   16.2   18.4
:Gasconade River
Rich Fountain         6.2    7.0   10.5   15.9   20.7   27.3   28.9
:Missouri River
Jefferson City       25.3   25.3   25.5   28.2   30.7   33.3   36.2
:Osage River
St. Thomas           12.7   12.8   13.1   14.9   18.3   23.4   26.4
Mari-Osa Campgrou    20.2   20.2   20.9   21.9   23.5   27.1   32.0
:Missouri River
Chamois              22.4   22.4   22.8   24.6   27.1   30.7   31.8
Gasconade            30.0   30.0   30.6   32.0   33.9   36.5   37.3
Hermann              25.8   25.8   26.5   28.8   31.4   35.8   36.2
Washington           22.5   22.5   23.2   25.4   27.8   32.4   33.1
St. Charles          28.2   28.2   28.9   31.2   33.5   37.4   38.2

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: 04/01/2019 - 06/30/2019
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Canton LD20          11.7   11.0    8.8    7.8    5.4    4.4    4.1
LaGrange             12.6   11.9    9.7    8.7    6.3    5.3    5.0
Quincy               14.9   14.6   12.8   12.6   12.0   11.7   11.6
Quincy LD21          13.1   12.8    9.6    8.3    5.8    5.0    4.7
Hannibal             14.4   14.3   12.3   11.7   10.7   10.2   10.0
Saverton LD22        12.8   12.7    9.7    8.5    6.7    5.8    5.5
Louisiana            13.7   13.2   12.1   12.0   12.0   11.9   11.9
Clarksville LD24     23.5   22.8   20.2   18.8   16.9   15.8   15.3
Winfield LD25        23.8   22.9   20.2   18.7   16.7   15.6   15.1
Grafton              16.1   16.0   15.8   15.3   15.1   14.9   14.7
Mel Price LD         17.2   16.3   13.8   10.0    6.9    4.7    3.8
Chester              24.4   22.3   20.3   14.1    9.0    4.7    3.0
:North Fabius River
Ewing                 3.9    3.8    3.5    3.4    3.3    3.2    3.2
:Middle Fabius River
Ewing                 3.3    3.2    3.1    3.0    3.0    2.9    2.9
:South Fabius River
Taylor                2.2    2.1    2.0    1.8    1.7    1.6    1.6
:North River
Palmyra               4.1    4.0    3.9    3.8    3.8    3.7    3.7
:Mid Fork Salt River
Holliday              4.5    4.4    4.4    4.3    4.2    4.2    4.1
:Salt River
New London            5.4    5.2    5.2    5.1    3.6    2.2    2.1
:Cuivre River
Troy                  6.0    5.8    5.5    5.3    5.1    5.1    5.0
Old Monroe           19.0   17.8   15.5   14.6   12.7   11.5   10.9
:Dardenne Creek
St. Peters            1.7    1.7    1.6    1.4    1.4    1.4    1.4
:Bourbeuse River
Union                 2.4    2.3    2.2    2.0    1.9    1.8    1.7
:Big River
Byrnesville           3.2    2.8    2.4    2.2    1.9    1.8    1.7
:Meramec River
Steelville            2.2    2.0    1.8    1.7    1.5    1.4    1.4
Sullivan              3.1    2.9    2.7    2.5    2.3    2.2    2.2
Eureka                4.3    4.2    3.8    3.5    3.4    3.3    3.2
:Meramec
Fenton                3.9    3.4    2.6    2.0    1.8    1.4    1.2
:Meramec River
Arnold                7.8    7.7    7.2    6.9    6.7    6.5    6.4
:Kaskaskia River
Vandalia              9.5    8.6    3.9    3.3    3.0    2.8    2.8
Carlyle TW          419.4  419.4  417.1  411.2  411.2  411.2  411.2
:La Moine River
Ripley                7.0    6.7    6.0    5.3    5.1    4.9    4.9
:Moreau River
Jefferson City        1.9    1.7    1.4    1.1    1.0    0.7    0.7
:Maries River
Westphalia            1.3    1.2    0.5    0.3    0.3    0.3    0.3
:Gasconade River
Rich Fountain         4.4    4.3    3.8    3.5    3.1    3.0    3.0
:Missouri River
Jefferson City       17.0   14.7   10.1    6.7    4.2    3.1    2.1
:Osage River
St. Thomas            3.7    3.5    2.7    2.5    1.8    1.2    1.2
:Missouri River
Gasconade            19.6   13.5    9.1    3.7    3.0    3.0    3.0
St. Charles          20.8   17.1   14.3    9.5    5.9    3.8    2.4

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 2019.

Fuchs
$$