Flood Potential Outlook
Issued by NWS Quad Cities, IA IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4
000
FGUS73 KDVN 141659
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
1159 AM CDT Thu Mar 14 2024

.2024 Spring Flood and Water Resources Outlook 3...

...Well Below Normal Flood Risk This Spring...

This is the third and final update of the three planned Spring Flood
and Water Resource Outlooks for 2024 for the Quad Cities Hydrologic
Service Area (HSA), which covers portions of eastern Iowa, northwest
and west central Illinois, and extreme northeast Missouri. Rivers
included in this outlook are the Mississippi River and its
tributaries from above Dubuque, Iowa to below Gregory Landing,
Missouri. The primary tributary systems include the Maquoketa,
Wapsipinicon, Cedar, English, Iowa, Skunk, North Skunk, and Des
Moines Rivers in Iowa; the Fox River in Missouri; and the Pecatonica,
Rock, and Green Rivers in Illinois, as well as the La Moine River in
Illinois. This outlook is for the time period from mid March through
mid June.

.Flood Outlook Overview...
The spring flood risk is well below normal for the Mississippi River,
and below normal for local tributary rivers across the NWS Quad
Cities Hydrologic Service Area.
Some factors contributing to the current risk levels include:
1) Lack of a snowpack in the local area or in the headwater areas in
Minnesota and Wisconsin.
2) Below normal soil moisture levels in the local area that will
provide more potential storage for spring rains.
3) Lack of frozen soils in the local area or in the headwater areas
to the north.
4) Local streams are currently flowing at, to below the normal level.

.Key Takeaways…

* Even though the overall risk of spring flooding is below average in
the NWS Quad Cities HSA, this does not guarantee that high impact
flooding will not occur. The severity of any flooding will be
determined primarily by changes in the key factors mentioned above.
In addition, we will be monitoring the outlooks for spring
precipitation to see if that could become a contributing factor this
year.
* Current lack of snow cover and well below normal snowfall this
winter has greatly reduced the overall flood threat. In addition, the
snow water equivalent in the headwaters of the upper Mississippi
River basin are well below normal, which will further decrease our
likelihood of major impacts on the Mississippi River.
 * Widespread below normal soil moisture levels in the local area
increases the capacity of the soils to soak in spring precipitation
and which will significantly mitigate the near term flood risk as
well as decrease the risk for prolonged flooding.

Many factors are considered when determining the overall flood risk
for the upcoming spring season. A combination of these are factored
into the final threat categorization. These factors are discussed in
detail below, and are categorized as an increased, neutral, or
decreased contributor to potential spring flooding.

.Seasonal Precipitation:
     Local Rivers - Neutral to Decreased Threat
     Mississippi River - Neutral to Decreased Threat

Precipitation in eastern Iowa, northwest Illinois, and northeast
Missouri has been near to slightly above average so far this winter.
However, much of the Hydrologic Service Area (HSA), especially
eastern Iowa, remains in some level of drought due to well below
normal precipitation observed from the fall months in 2023. This is
also reflected well in soil moisture levels (see below). North of the
area, precipitation in the upper Mississippi River Basin so far this
winter has averaged below normal, aside from parts of northern
Minnesota.

Latest outlooks from the Climate Prediction Center favor above normal
precipitation through the second half of March for much, if not all,
of the Mississippi River Basin. With dry soils and ongoing drought,
much of the precipitation should be allowed to infiltrate into the
ground.

With all of this in mind, any contributions from seasonal
precipitation to spring flood threat will be minimal.

.Snow Cover and Liquid Water Content:
     Local Rivers - Decreased Threat
     Mississippi River - Decreased Threat

The Mississippi River Basin and the area tributaries are completely
free of snow cover per the latest analysis from the National
Operational Hydrologic Remote Sensing Center (NOHRSC).
Although additional snowfall is possible early in the spring, the
likelihood of developing a deep snowpack is low.



.Soil Conditions:
     Local Rivers - Decreased Threat
     Mississippi River - Decreased Threat

Despite near to above normal precipitation values so far this winter,
soil moisture levels remain below normal due to an extremely dry
Fall. Latest analysis from the Climate Prediction Center shows soil
moisture ranking profiles around 10-40% for the majority of the HSA,
and also includes much of the upper Mississippi River Basin. This
favors a decreased to neutral threat from this category for spring
flooding, as drier soils will be better suited to soak in heavier
rains.


.Frost Depth:
     Local Rivers - Decreased Threat
     Mississippi River - Decreased Threat

The ground remains thawed across the entire local area, and much of
the Mississippi River basin.  Some frost is in the ground in the
headwaters of the Mississippi River in Minnesota, but it is less than
normal and not deep. While colder air is still possible in early
spring, it is unlikely that deeper frost depths will occur.

.River Conditions:
     Local Rivers - Decreased Threat
     Mississippi River - Decreased Threat

Streamflow analysis from the United States Geological Survey (USGS)
indicates the majority of the Upper Mississippi River watershed and
tributary streamflows are below to near normal. Streamflows that are
below normal levels would have more capacity to hold runoff from
heavy rains.

.Ice Jam Flooding:
      Local Rivers - Decreased Threat for Breakup Jams
      Mississippi River - Decreased Threat for Breakup Jams

The warmer weather this winter has largely limited the development of
river ice. Bouts of colder air are possible through early spring,
however, without a long period of extreme cold the development of
river ice and ice jam flooding is unlikely.

.Weather/Climate Outlooks:
     Local Rivers - Below normal Threat
     Mississippi River - Well below normal Threat

While active weather patterns are typical of the spring months, this
could lead to variations of warmer and colder temperatures, where the
risk for flooding will be determined by the tracks of individual and
multiple storm systems that could bring heavy rain or heavy snow to
parts of the region.

According to the latest climate outlooks from the Climate Prediction
Center, probabilities are leaning toward near normal temperatures for
much of the region for the remainder of March, with a signal for
somewhat above normal precipitation during the same timeframe.

The three month outlook for April through June is leaning toward a
continuation of above normal temperatures for much of the region,
with slightly above normal precipitation.


.Summary:
The spring flood risk is well below normal for the Mississippi River,
and below normal for local tributary rivers across the NWS Quad
Cities Hydrologic Service Area.
With the lack of snow cover and persistent cold weather, current
conditions are unfavorable for snowmelt or ice jam flooding on local
tributaries.
Some factors contributing to the current risk levels include: 1) Lack
of deep and widespread snowpack in the local area and the headwater
areas of the Mississippi River basin. 2) A general lack of deep, hard
frozen ground across the upper Mississippi River Basin. 3) Near to
below average stream flows and below average soil moisture levels.

.Numerical Probabilistic River Outlooks...

...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:  03/18/2024 - 06/16/2024

                                       :    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 :   6   48   <5   37   <5   12
Dubuque             17.0   18.0   21.5 :   7   54    5   45   <5   15
Bellevue LD12       17.0   18.0   20.0 :  <5   36   <5   30   <5   12
Fulton LD13         16.0   18.0   20.0 :   5   53   <5   33   <5   14
Camanche            17.0   18.5   20.5 :   5   46   <5   33   <5   14
Le Claire LD14      11.0   12.0   13.5 :   6   52   <5   36   <5   17
Rock Island LD15    15.0   16.0   18.0 :  12   61    8   51   <5   25
Ill. City LD16      15.0   16.0   18.0 :  11   60    8   47   <5   24
Muscatine           16.0   18.0   20.0 :  18   62    8   47   <5   24
New Boston LD17     15.0   16.5   18.5 :  20   66   10   51    5   30
Keithsburg          14.0   15.5   17.0 :  20   64   10   50   <5   26
Gladstone LD18      10.0   12.0   14.0 :  22   65   10   47   <5   23
Burlington          15.0   16.5   18.0 :  18   64   11   48   <5   28
Keokuk LD19         16.0   17.5   19.0 :   8   33   <5   24   <5   12
Gregory Landing     15.0   18.0   25.0 :  25   65    9   42   <5    5

:Maquoketa River
Manchester Hwy 20   14.0   17.0   20.0 :  17   25   11   18   <5    9
Maquoketa           24.0   26.0   28.5 :   5   12   <5   10   <5    6

:Wapsipinicon River
Independence        12.0   13.0   15.0 :   7   10    6    7   <5   <5
Anamosa Shaw Rd     14.5   18.0   21.5 :  14   28    6   12   <5   <5
De Witt 4S          11.0   11.5   12.5 :  60   72   49   65   31   46

:North Skunk River
Sigourney           16.0   18.0   21.0 :  45   56   26   41    7   11

:Skunk River
Augusta             15.0   17.0   20.0 :  32   44   20   32   10   17

:Cedar River
Vinton              15.0   18.0   19.0 :   5   17   <5    8   <5    5
Palo Blairs Ferry   12.5   15.5   17.0 :   6   27   <5    8   <5   <5
Cedar Rapids        12.0   14.0   16.0 :   7   33    5   16   <5   10
Cedar Bluff         16.0   20.0   26.0 :   6   32   <5    9   <5   <5
Conesville          13.0   15.0   16.5 :  15   55   <5   17   <5    8

:Iowa River
Marengo             15.0   17.0   19.0 :  44   71   18   51   <5    6
Iowa City           23.5   24.5   26.0 :  <5   <5   <5   <5   <5   <5
Lone Tree           16.0   18.5   22.0 :  18   28    6    8   <5   <5
Columbus Jct        23.0   25.0   26.5 :  <5   18   <5    7   <5   <5
Wapello             21.0   25.0   27.5 :  15   46   <5    8   <5   <5
Oakville            11.0   15.0   20.0 :   9   36   <5   <5   <5   <5

:English River
Kalona              14.0   16.0   18.0 :  40   49   22   32    8   13

:Des Moines River
Keosauqua           22.0   25.0   27.0 :   8   13   <5   <5   <5   <5
St Francisville     18.0   22.0   25.0 :  23   40    9   10   <5   <5

:Fox River
Wayland             15.0   18.0   20.0 :  26   27   13   14   <5   <5

:Pecatonica River
Freeport            13.0   14.0   16.0 :   7   23   <5    9   <5   <5

:Rock River
Como                12.5   15.5   18.0 :  17   23    7    8   <5   <5
Joslin              12.0   14.0   16.5 :  53   57   28   31   13   18
Moline              12.0   13.0   14.0 :  51   55   28   31   20   23

:Green River
Geneseo             15.0   16.5   18.0 :  20   24    9   11   <5   <5

:La Moine River
Colmar              20.0   22.0   24.0 :  68   65   43   43   23   22

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: 03/18/2024 - 06/16/2024
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11          6.3    6.7    7.9   10.0   12.6   14.8   16.7
Dubuque               8.7    9.0   10.2   11.8   14.4   16.7   18.5
Bellevue LD12         6.9    7.4    8.8   10.7   13.2   14.9   16.3
Fulton LD13           6.9    7.4    8.3   10.6   13.2   15.2   16.7
Camanche              9.8   10.1   10.8   12.3   14.1   15.8   17.2
Le Claire LD14        5.7    6.0    6.6    8.0    9.5   10.4   11.8
Rock Island LD15      7.4    8.4    9.5   11.2   13.4   15.7   17.6
Ill. City LD16        5.9    6.7    8.3   10.8   13.1   15.4   17.4
Muscatine             7.6    8.4   10.1   12.2   14.7   17.3   19.4
New Boston LD17       7.0    8.2    9.9   12.3   14.4   16.5   18.6
Keithsburg            8.4    8.8   10.4   11.7   13.8   15.6   16.6
Gladstone LD18        3.7    4.0    5.8    7.4    9.8   11.8   13.0
Burlington            9.8   10.0   11.4   12.7   14.6   16.9   17.6
Keokuk LD19           5.6    6.0    7.8    9.6   11.9   14.8   17.0
Gregory Landing       7.0    7.6    9.6   12.4   15.1   17.2   19.8

:Maquoketa River
Manchester Hwy 20     5.8    6.2    7.2    8.5   10.6   17.1   19.1
Maquoketa            11.9   12.3   13.4   15.2   17.4   21.8   25.3

:Wapsipinicon River
Independence          5.7    5.9    6.6    7.3    8.2   10.6   13.6
Anamosa Shaw Rd       6.6    7.7    8.5   10.3   12.4   16.3   18.6
De Witt 4S            8.9    9.3   10.2   11.4   12.7   13.3   13.8

:North Skunk River
Sigourney             5.9    8.6   12.2   15.4   18.1   19.9   21.5

:Skunk River
Augusta               4.9    6.2    8.5   12.8   15.9   20.1   23.8

:Cedar River
Vinton                3.3    3.9    5.7    8.2    9.9   11.5   15.6
Palo Blairs Ferry     3.2    3.6    5.3    7.3    8.7   10.3   13.6
Cedar Rapids          3.6    3.9    4.7    6.0    7.3    9.5   14.4
Cedar Bluff           5.5    6.3    7.9    9.7   11.0   13.8   18.0
Conesville            6.6    6.9    8.7   10.1   11.9   13.3   14.9

:Iowa River
Marengo               7.8    8.6   10.1   14.0   16.4   17.4   18.2
Iowa City            10.4   11.0   13.0   15.4   18.3   19.7   21.4
Lone Tree             6.0    7.4    9.9   12.4   14.4   17.3   18.7
Columbus Jct         10.7   11.2   14.2   15.3   17.5   20.7   22.8
Wapello              13.0   13.3   16.3   17.5   19.3   21.7   23.5
Oakville              2.3    2.7    5.1    6.4    8.5   10.6   12.5

:English River
Kalona                6.1    7.6   11.2   13.5   15.6   17.5   19.3

:Des Moines River
Keosauqua            11.7   13.3   16.0   17.0   19.3   21.6   23.5
St Francisville       9.0   10.5   13.8   15.2   17.7   21.0   23.7

:Fox River
Wayland               4.5    6.1    8.0   11.5   15.2   18.6   19.7

:Pecatonica River
Freeport              7.9    8.0    8.7   10.4   12.1   12.9   13.6

:Rock River
Como                  6.8    6.9    8.0    9.3   11.6   14.6   16.1
Joslin                9.3    9.6   10.6   12.6   14.4   17.5   20.5
Moline               10.1   10.2   10.7   12.2   13.4   15.4   18.4

:Green River
Geneseo               6.0    6.4    9.3   12.0   14.7   16.0   17.5

:La Moine River
Colmar               12.0   14.6   17.9   21.7   23.9   25.3   26.0

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: 03/18/2024 - 06/16/2024
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11          5.2    5.1    5.0    4.5    4.2    3.9    3.7
Dubuque               8.0    7.9    7.9    7.5    7.3    7.1    7.0
Bellevue LD12         4.9    4.8    4.8    4.1    3.7    3.3    3.1
Fulton LD13           4.9    4.9    4.8    4.5    4.3    4.1    4.1
Camanche              9.0    9.0    9.0    8.8    8.7    8.7    8.6
Le Claire LD14        4.8    4.8    4.8    4.6    4.4    4.3    4.3
Rock Island LD15      5.8    5.7    5.6    4.9    4.5    4.0    3.8
Ill. City LD16        4.8    4.7    4.5    4.0    3.6    3.3    3.2
Muscatine             6.8    6.7    6.6    6.3    6.1    5.8    5.7
New Boston LD17       5.3    5.2    4.8    4.0    3.6    3.2    3.0
Keithsburg            6.7    6.7    6.5    5.8    5.6    5.3    5.2
Gladstone LD18        2.4    2.3    2.2    1.5    1.2    0.9    0.7
Burlington            8.5    8.5    8.4    8.0    7.8    7.5    7.3
Keokuk LD19           4.7    4.6    4.5    3.4    2.5    2.3    2.1
Gregory Landing       6.7    6.7    6.6    6.4    6.3    6.2    6.1

:Maquoketa River
Manchester Hwy 20     4.3    4.2    4.1    4.0    4.0    3.9    3.8
Maquoketa            11.0   10.8   10.6   10.4   10.2   10.0   10.0

:Wapsipinicon River
Independence          5.2    5.1    5.0    5.0    4.9    4.8    4.7
Anamosa Shaw Rd       5.6    5.4    5.2    5.0    4.8    4.6    4.5
De Witt 4S            7.0    6.9    6.7    6.3    6.1    5.6    5.4

:North Skunk River
Sigourney             5.1    4.3    3.9    3.5    3.4    3.0    2.8

:Skunk River
Augusta               2.6    2.3    1.9    1.6    1.4    1.1    1.0

:Cedar River
Vinton                2.0    1.8    1.7    1.6    1.4    1.2    1.1
Palo Blairs Ferry     2.1    1.9    1.8    1.6    1.5    1.3    1.2
Cedar Rapids          3.1    3.0    2.9    2.8    2.7    2.7    2.6
Cedar Bluff           4.6    4.4    4.1    4.0    3.8    3.6    3.5
Conesville            5.8    5.6    5.3    5.1    4.8    4.4    4.3

:Iowa River
Marengo               6.6    6.5    6.3    6.0    5.8    5.6    5.4
Iowa City            10.0    9.8    9.4    9.2    9.2    9.1    9.1
Lone Tree             5.2    4.8    4.4    4.0    3.7    3.5    3.5
Columbus Jct          9.9    9.6    9.2    8.8    8.5    8.2    8.0
Wapello              12.2   11.9   11.3   10.8   10.3    9.7    9.5

:English River
Kalona                4.9    4.7    4.5    4.1    4.0    3.6    3.5

:Des Moines River
Keosauqua            10.7   10.5   10.2    9.9    9.7    9.6    9.5
St Francisville       6.9    6.6    6.1    5.7    5.4    5.2    5.1

:Fox River
Wayland               2.1    2.0    1.9    1.7    1.5    1.4    1.3

:Pecatonica River
Freeport              6.4    5.7    5.1    4.7    4.3    4.0    3.9

:Rock River
Como                  5.1    4.9    4.4    3.9    3.5    3.2    3.1
Joslin                7.2    6.9    6.2    5.5    5.0    4.5    4.4
Moline                9.1    9.0    8.7    8.3    8.1    7.9    7.9

:Green River
Geneseo               3.5    3.2    3.1    2.7    2.5    2.1    2.0

:La Moine River
Colmar                5.0    4.4    4.0    3.7    3.4    3.3    3.2

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.

$$






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.