Flood Potential Outlook
Issued by NWS Quad Cities, IA IL

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FGUS73 KDVN 040124
ESFDVN
IAC011-019-031-045-055-057-061-087-095-097-101-103-105-107-111-113-
115-139-163-177-183-ILC011-015-067-071-073-085-109-131-155-161-177-
187-195-MOC045-199-151800-

Probabilistic Hydrologic Outlook
National Weather Service Quad Cities IA IL
810 PM CDT Thu Apr 03 2025

...Advanced Hydrologic Prediction Service Probabilistic Outlook...

This outlook provides long-range probabilistic river outlooks for
river basins in the NWS Quad Cities service area. This outlook is
divided into three parts, the first part for the probabilities of
minor, moderate and major flooding, the second part for high water
and the final part for low water.

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 greater 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
Dubuque LD11        16.0   17.0   20.5 :  15   47   10   36   <5   12
Dubuque             17.0   18.0   21.5 :  20   53   14   45   <5   15
Bellevue LD12       17.0   18.0   20.0 :   8   35    7   28   <5   12
Fulton LD13         16.0   18.0   20.0 :  16   53    9   32   <5   13
Camanche            17.0   18.5   20.5 :  15   47    9   32   <5   13
Le Claire LD14      11.0   12.0   13.5 :  16   53   12   36    6   18
Rock Island LD15    15.0   16.0   18.0 :  28   61   21   53    8   25
Ill. City LD16      15.0   16.0   18.0 :  24   60   19   48    8   26
Muscatine           16.0   18.0   20.0 :  32   62   19   48    8   26
New Boston LD17     15.0   16.5   18.5 :  42   66   22   54   11   31
Keithsburg          14.0   15.5   17.0 :  45   66   22   52   14   26
Gladstone LD18      10.0   12.0   14.0 :  47   67   18   49    7   23
Burlington          15.0   16.5   18.0 :  37   65   19   49   12   27
Keokuk LD19         16.0   17.5   19.0 :  16   33   11   22    5   12
Gregory Landing     15.0   18.0   25.0 :  49   66   18   43   <5    5

:Maquoketa River
Manchester Hwy 20   14.0   17.0   20.0 :  19   23   14   18   <5    7
Maquoketa           24.0   26.0   28.5 :   7   12    6    9   <5    5

:Wapsipinicon River
Independence        12.0   13.0   15.0 :   8    9    6    7   <5   <5
Anamosa Shaw Rd     14.5   18.0   21.5 :  17   26    7   12   <5   <5
De Witt 4S          11.0   11.5   12.5 :  72   75   65   65   39   46

:North Skunk River
Sigourney           16.0   18.0   21.0 :  47   54   28   37    9   11

:Skunk River
Augusta             15.0   17.0   20.0 :  42   46   25   33   17   18

:Cedar River
Vinton              15.0   18.0   19.0 :  10   17   <5    8   <5    5
Palo Blairs Ferry   12.5   15.5   17.0 :  11   21   <5    8   <5   <5
Cedar Rapids        12.0   14.0   16.0 :  13   31   10   16    5    9
Cedar Bluff         16.0   20.0   26.0 :  13   30    5    9   <5   <5
Conesville          13.0   15.0   16.5 :  34   56    9   14   <5    8

:Iowa River
Marengo             15.0   17.0   19.0 :  65   74   45   53    7   11
Iowa City           23.5   24.5   26.0 :  <5   <5   <5   <5   <5   <5
Lone Tree           16.0   18.5   22.0 :  31   36   10   11   <5   <5
Columbus Jct        23.0   25.0   26.5 :  10   17    5    8   <5   <5
Wapello             21.0   25.0   27.5 :  34   52    6    9   <5   <5
Oakville            11.0   15.0   20.0 :  24   41    6    9   <5   <5

:English River
Kalona              14.0   16.0   18.0 :  46   53   25   32    9   13

:Des Moines River
Keosauqua           22.0   25.0   27.0 :  14   17   <5    5   <5   <5
St Francisville     18.0   22.0   25.0 :  47   45   11   12   <5   <5

:Fox River
Wayland             15.0   18.0   20.0 :  32   31   15   14   <5   <5

:Pecatonica River
Freeport            13.0   14.0   16.0 :   6   16   <5    6   <5   <5

:Rock River
Como                12.5   15.5   18.0 :  17   23    6    8   <5   <5
Joslin              12.0   14.0   16.5 :  49   55   23   32   12   19
Moline              12.0   13.0   14.0 :  43   47   28   31   18   25

:Green River
Geneseo             15.0   16.5   18.0 :  19   24    9   10   <5   <5

:La Moine River
Colmar              20.0   22.0   24.0 :  64   67   47   50   27   26

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
Dubuque LD11         11.2   11.3   11.6   12.9   14.8   17.0   19.5
Dubuque              13.0   13.1   13.4   14.8   16.7   18.7   21.3
Bellevue LD12        11.8   11.8   12.2   13.4   15.0   16.7   18.7
Fulton LD13          11.4   11.5   11.8   13.8   15.3   17.5   19.5
Camanche             12.8   12.9   13.1   14.5   15.8   18.0   20.0
Le Claire LD14        8.3    8.4    8.7    9.6   10.4   12.1   14.0
Rock Island LD15     11.4   11.5   11.9   13.5   15.2   17.5   19.2
Ill. City LD16       10.8   10.9   11.6   13.3   14.8   17.5   19.3
Muscatine            12.3   12.4   13.1   14.8   16.5   19.5   21.1
New Boston LD17      12.3   12.4   13.0   14.5   15.9   18.7   20.3
Keithsburg           11.6   11.7   12.3   13.7   15.2   17.1   18.5
Gladstone LD18        7.5    7.6    8.3    9.8   11.4   13.6   15.2
Burlington           12.7   12.7   13.4   14.6   16.2   18.2   19.5
Keokuk LD19           9.1    9.2   10.1   11.9   14.1   17.6   19.4
Gregory Landing      10.9   11.4   12.9   14.9   17.1   20.2   22.2

:Maquoketa River
Manchester Hwy 20     6.3    6.5    8.0    9.2   12.6   18.0   19.1
Maquoketa            13.1   13.1   14.2   16.4   18.7   22.8   28.0

:Wapsipinicon River
Independence          6.3    6.5    7.1    8.0    8.9   11.3   13.7
Anamosa Shaw Rd       7.9    8.5    9.5   11.3   13.8   16.9   19.8
De Witt 4S            9.3    9.8   10.8   12.2   12.9   13.6   14.0

:North Skunk River
Sigourney             7.5    8.8   12.5   15.9   18.3   20.3   22.4

:Skunk River
Augusta               6.9    7.4   10.1   13.7   16.8   21.7   24.1

:Cedar River
Vinton                8.1    8.2    8.6   11.1   12.6   15.2   17.2
Palo Blairs Ferry     7.2    7.3    7.9    9.6   10.9   13.0   14.8
Cedar Rapids          6.4    6.5    7.1    8.8   10.4   13.7   16.8
Cedar Bluff           9.3    9.5   10.5   12.2   13.8   17.8   20.3
Conesville            9.9   10.0   11.1   12.3   13.7   14.7   16.2

:Iowa River
Marengo              11.1   11.5   14.0   16.6   17.6   18.7   19.3
Iowa City            13.0   13.4   15.6   18.1   19.2   20.4   22.9
Lone Tree             9.9   10.1   11.6   14.2   16.6   18.7   19.4
Columbus Jct         14.6   15.0   16.4   18.1   19.9   22.8   25.2
Wapello              17.4   17.7   18.7   20.3   21.5   23.5   26.0
Oakville              6.3    6.5    7.8    9.4   10.7   12.7   15.7

:English River
Kalona                8.7    8.8   10.4   13.7   16.0   17.6   20.1

:Des Moines River
Keosauqua            14.7   15.4   17.6   19.0   20.7   22.9   23.9
St Francisville      12.8   13.3   15.9   17.7   19.7   22.3   24.0

:Fox River
Wayland               6.5    6.6    8.2   12.0   15.8   19.0   19.8

:Pecatonica River
Freeport              8.7    8.8    9.1    9.9   11.8   12.8   13.3

:Rock River
Como                  6.8    6.8    7.5    8.9   10.7   14.2   15.9
Joslin                9.4    9.5   10.3   11.7   13.8   17.2   20.3
Moline               10.2   10.3   10.6   11.5   13.1   15.0   18.3

:Green River
Geneseo               7.6    7.7    8.8   11.3   14.1   15.8   17.0

:La Moine River
Colmar               11.6   12.5   16.6   21.9   24.2   25.6   26.5

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
Dubuque LD11         63.4   58.0   45.4   34.7   27.9   23.8   22.5
Dubuque              63.4   58.0   45.4   34.7   27.9   23.8   22.5
Bellevue LD12        62.1   59.4   46.1   35.5   28.2   24.1   22.9
Fulton LD13          63.5   62.2   48.2   37.3   29.4   25.4   24.6
Camanche             63.5   62.2   48.2   37.3   29.4   25.4   24.6
Le Claire LD14       65.9   65.9   51.0   39.3   30.7   27.1   25.6
Rock Island LD15     72.0   71.9   57.3   46.5   35.9   30.4   28.5
Ill. City LD16       73.9   73.8   59.5   48.6   37.1   31.6   29.5
Muscatine            73.9   73.8   59.5   48.6   37.1   31.6   29.5
New Boston LD17      74.1   74.1   60.6   48.8   37.2   31.7   29.6
Keithsburg           83.2   83.1   66.4   54.2   42.4   34.2   33.2
Gladstone LD18       79.2   79.1   67.0   54.6   42.4   34.2   33.2
Burlington           80.3   80.3   67.3   55.3   42.5   34.5   33.3
Keokuk LD19          82.0   81.9   72.2   58.2   40.6   32.2   30.4
Gregory Landing      94.3   94.2   88.8   67.8   45.7   36.3   34.1

:Maquoketa River
Manchester Hwy 20     0.2    0.2    0.1    0.1    0.1    0.1    0.1
Maquoketa             1.1    1.0    0.8    0.7    0.6    0.4    0.4

:Wapsipinicon River
Independence          0.8    0.7    0.6    0.4    0.3    0.2    0.2
Anamosa Shaw Rd       1.2    1.1    0.9    0.7    0.6    0.4    0.3
De Witt 4S            2.0    1.7    1.5    1.1    0.8    0.6    0.6

:North Skunk River
Sigourney             0.3    0.2    0.1    0.1    0.1    0.0    0.0

:Skunk River
Augusta               2.8    2.5    2.0    1.3    0.9    0.6    0.4

:Cedar River
Vinton                3.8    3.4    2.6    2.0    1.4    1.2    1.0
Palo Blairs Ferry     3.9    3.6    2.7    2.1    1.5    1.3    1.1
Cedar Rapids          4.0    3.7    2.8    2.2    1.6    1.3    1.1
Cedar Bluff           4.3    3.9    3.0    2.4    1.8    1.4    1.2
Conesville            4.8    4.3    3.4    2.5    2.0    1.6    1.3

:Iowa River
Marengo               1.9    1.7    1.2    0.8    0.6    0.5    0.4
Iowa City             1.9    1.5    1.1    0.6    0.2    0.2    0.2
Lone Tree             2.7    2.1    1.6    0.9    0.6    0.4    0.4
Columbus Jct          7.9    7.0    5.4    3.8    2.8    2.1    1.9
Wapello               8.0    7.4    5.5    4.1    3.0    2.2    1.9
Oakville              8.2    7.8    5.6    4.1    3.0    2.2    1.9

:English River
Kalona                0.2    0.2    0.2    0.1    0.1    0.0    0.0

:Des Moines River
Keosauqua             9.6    7.2    5.4    2.7    1.8    1.2    1.1
St Francisville      10.3    7.3    5.5    2.8    1.8    1.3    1.1

:Fox River
Wayland               0.0    0.0    0.0    0.0    0.0    0.0    0.0

:Pecatonica River
Freeport              1.2    1.1    0.9    0.8    0.7    0.6    0.6

:Rock River
Como                  7.9    7.0    5.8    4.1    3.3    2.8    2.6
Joslin                8.2    7.5    6.2    4.5    3.6    2.9    2.8
Moline                9.1    8.4    6.7    4.9    4.0    3.1    3.0

:Green River
Geneseo               0.5    0.4    0.4    0.3    0.2    0.1    0.1

:La Moine River
Colmar                0.2    0.2    0.1    0.1    0.0    0.0    0.0

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 at http://www.weather.gov/dvn for more weather and
water information.

The next outlook will be issued near the end of next month.

$$