Flood Potential Outlook
Issued by NWS Quad Cities, IA IL

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FGUS73 KDVN 021912
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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
112 PM CST Thu Mar 02 2017

...2017 Spring Flood and Water Resources Summary and Outlook #2...

This is the second and final Spring Flood and Water Resources
Outlook for the Quad Cities Hydrologic Service Area (HSA) for 2017.
The area covered is portions of eastern Iowa, northwest and west
central Illinois, and extreme northeast Missouri. Rivers included
are the Mississippi River and its tributaries from above Dubuque,
Iowa to below Gregory Landing, Missouri. The primary tributaries
include the Maquoketa, Wapsipinicon, Cedar, Iowa, Skunk, and Des
Moines Rivers in Iowa; the Fox River in Missouri; and the
Pecatonica, Rock, Green, and La Moine Rivers in Illinois. The
outlook is for the time period from March through May.

...The risk for flooding this spring is elevated for minor flooding
on portions of the Mississippi River, with near to below normal risk
for flooding on the tributary river systems...

...Main Points...

* Spring conditions are 2-3 weeks ahead of normal
* The Mississippi River is currently experiencing spring snowmelt
  high water flows
* Minor flooding is expected for portions of the Mississippi River
  through the first half of March
* Local tributaries have already observed spring snowmelt high water
  flows
* Heavy rainfall is needed for moderate to major flooding to occur
* Little or no snowpack remains across the region
* A warm forecast will cause the remainder of snow across the
  region to melt in the coming weeks
* The local area has fully thawed ground
* Wet ground conditions continue for the northern part of the
  region, with drought persisting and extending northward from
  Missouri and Illinois.

Detailed information on these points can be found below.

...River Flood Potential Overview...

Mississippi River:
    Dubuque to Le Claire: Near to Below Normal
    Quad Cities and downstream: Above Normal for Minor Flooding

Mississippi River Tributaries across Iowa:
    Near to Below Normal

Mississippi River Tributaries across Illinois:
    Near to Slightly Below Normal

Mississippi River Tributaries across Missouri:
    Below Normal

*** Spring Flood Outlook Information and Details ***

There are above normal chances for minor river flooding along the
Mississippi River from the Quad Cities downstream through Gregory
Landing. Locations upstream of the Quad Cities have near to below
normal chances for flooding this Spring.

Where rivers remain high in Iowa and Illinois, chances are slightly
above normal for minor flooding, while other areas will have near to
below normal chances for flooding. Locations across southern and
southeast Iowa into northeast Missouri and west central Illinois have
observed continued dry conditions and lowering river levels over the
past few weeks. These areas will have a below normal chance for
flooding this Spring.

The weather pattern through the late winter months has been warm and
wet in some areas and warm and dry in others. These conditions have
brought on an early spring with conditions being 2 to 3 weeks ahead
of normal. This has caused snowpack and frost to diminish earlier
than would be normally expected across the entire Upper Mississippi
River Basin. Also, all local rivers are free of ice. With the loss of
snow and frost, the tributaries have already seen their peak spring
flood scenarios play out, and the Mississippi River is now observing
the peak spring snowmelt runoff moving through the system. Again,
this is weeks ahead of normal.

Minor flooding is currently being forecast for portions of the
mainstem Mississippi River through the first half of March. In order
for higher flood concerns with the water currently moving through
the system, significant rainfall would need to occur.

NOTE: A heightened risk for flooding is not an indicator of severity.

Many factors are considered when determining the overall flood risk
for the season, with the combination of these influences factoring
into the final determination. These factors are discussed in detail
below.

.Seasonal Precipitation: Above Normal - northern HSA
                         Below Normal - southern HSA

Locally, precipitation for the winter season has ranged from 150 to
175 percent of normal in the northwest part of the HSA to under 50
percent of normal in the far southern part of the HSA.

Warm temperatures this winter season allowed for much of the
precipitation to fall in the form of rain rather than snow.

Snowfall was well below normal for the local area with amounts
observed being 25 to 75 percent of normal snowfall. Looking to the
northern part of the Upper Mississippi River Basin, snowfall was
closer to normal with a swath of above normal snows from northwest
Iowa into central Wisconsin.

.River Conditions: High flows in the north, Low flows in the South

Streamflows range from above normal in the northern part of the area
and along the Mississippi River to below normal across southeast
Iowa, northeast Missouri and west central Illinois. Levels are high
on particular rivers largely due to the snowmelt runoff already
having occurred or being in progress, as well as from recent
rainfall. Where rivers are low, drought conditions are persisting,
and with little snow this season levels remain low.

.Soil Conditions: Wet across the North, Dry across the South

There is a significant gradient in the moisture content of soils
across the HSA. The Interstate 80 corridor has soil moisture levels
near normal, while areas to the north are well above normal and
areas to the south are well below normal. The nearly saturated soils
across the northern areas will not be able to hold much additional
water, which will lead to excessive runoff if heavy rains occur. The
likelihood for extreme runoff will lessen going southward. This being
said, many rivers in the HSA originate across northern Iowa, southern
Wisconsin, or northern Illinois so despite the lack of snow cover and
dry soils, flood potential remains near normal even in the dry areas.

.Snow Cover and Liquid Water Content: Below Normal

Snow pack across the Upper Mississippi River Basin is well below
normal for this time of year. There is a narrow swath of snow from
northwest Iowa into central Wisconsin that holds 1 to 2 inches of
liquid water. These are areas where soils are wet, but the
ground is thawed so the soils may be able to absorb some of the
water content before becoming purely runoff. Additionally, these
flows will be delayed from the ongoing high flows so additional
significant flooding is not expected from the current snowpack
unless the melt occurs along with heavy rains.

.Frost Depth: Below Normal

The ground has thawed across the entire local area. There does
remain some frost in the ground in the upper parts of the
Mississippi River Basin, but it is less than normal for early March.
Warm temperatures are expected over the next few weeks so further
thawing of the ground is anticipated. Frozen ground will be a small
contributor to any spring flooding across the northern parts of the
Mississippi River basin and will not contribute to any local
tributary flooding potential.

.Ice Jam Flooding...

Above normal temperatures late this winter have allowed for all
river channels to be free of ice as of early March. No additional
extreme cold is forecast in the coming weeks, so the potential for
ice jam flooding is little to none this spring.

.Drought...

Abnormally Dry (D0) drought conditions continue to slowly expand
northeast as precipitation amounts have been well below normal for
the season. D0 drought is being identified across northeast Missouri,
southeast Iowa, and into west central Illinois. Elsewhere, occasional
widespread precipitation has kept any other areas from developing
drought conditions.

.Weather Outlooks...

For the month of March, temperatures have a high chance of averaging
above normal, while there are equal chances for above, near or below
normal precipitation.

The long-range outlook for the period of March through May indicates
a high chance for above normal temperatures. For precipitation,
chances are above normal north of Interstate 80 with equal chances
for above, near, or below normal south of Interstate 80.

.Numerical Long-Range Probabilistic River Outlooks...

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:  03/05/2017 - 06/03/2017

                                       :    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 :  47   46   31   35    9   10
Dubuque             17.0   18.0   21.5 :  56   52   41   42   12   11
Bellevue LD12       17.0   18.0   20.0 :  23   32   16   20    9   10
Fulton LD13         16.0   18.0   20.0 :  54   51   18   26   11   11
Camanche            17.0   18.5   20.5 :  46   42   23   31   14   12
Le Claire LD14      11.0   12.0   13.5 :  47   49   31   32   16   14
Rock Island LD15    15.0   16.0   18.0 : >95   56   55   48   24   20
Ill. City LD16      15.0   16.0   18.0 : >95   56   47   46   24   20
Muscatine           16.0   18.0   20.0 : >95   61   47   46   22   19
New Boston LD17     15.0   16.5   18.5 : >95   62   57   51   28   25
Keithsburg          14.0   15.5   17.0 : >95   62   55   51   28   25
Gladstone LD18      10.0   12.0   14.0 : >95   63   49   46   26   23
Burlington          15.0   16.5   18.0 : >95   62   48   47   27   26
Keokuk LD19         16.0   17.5   19.0 :  31   34   25   24   14   11
Gregory Landing     15.0   18.0   25.0 : >95   65   39   40   <5   <5
:Maquoketa River
Manchester Hwy 20   14.0   17.0   20.0 :  16   19   12   13    6    5
Maquoketa           24.0   26.0   28.5 :  10   17   <5   13   <5    6
:Wapsipinicon River
Independence        12.0   13.0   15.0 :  13   13    8    8    7    7
Anamosa Shaw Rd     14.5   18.0   21.5 :  22   26   14   16    6    7
De Witt 4S          11.0   11.5   12.5 :  75   67   61   64   22   30
:North Skunk River
Sigourney           16.0   18.0   21.0 :  47   55   25   40    5   11
:Skunk River
Augusta             15.0   17.0   20.0 :  22   47   12   32    6   13
:Cedar River
Vinton              15.0   18.0   19.0 :  11   21    5    8   <5    6
Cedar Rapids        12.0   14.0   16.0 :  19   30   10   17    6    9
Conesville          13.0   15.0   16.5 :  71   56   16   26    6    8
:Iowa River
Marengo             14.0   15.5   18.5 :  81   75   65   63   <5    5
Iowa City           22.0   23.0   25.0 :  <5    8   <5    7   <5   <5
:English River
Kalona              14.0   16.0   18.0 :  48   49   25   33    8   15
:Iowa River
Lone Tree           15.0   16.5   18.0 :  10   24    7   15   <5   11
Columbus Jct        19.0   22.0   23.0 :  57   54   13   23   11   14
Wapello             20.0   22.0   25.0 :  69   61   36   47   10   12
Oakville            10.0   12.0   19.0 :  65   59   25   34   <5   <5
:Des Moines River
Keosauqua           22.0   25.0   27.0 :  <5   10   <5   <5   <5   <5
St Francisville     18.0   22.0   25.0 :  34   44   <5    6   <5   <5
:Fox River
Wayland             15.0   18.0   20.0 :  21   24    7   12   <5   <5
:Pecatonica River
Freeport            13.0   14.0   16.0 :  28   31   13   12   <5   <5
:Rock River
Como                10.0   11.0   12.0 :  42   44   27   26   18   17
Joslin              12.0   14.0   16.5 :  55   53   25   25   10   14
:Green River
Geneseo             15.0   16.5   18.0 :  17   23   10   16    7    9
:Rock River
Moline              12.0   13.0   14.0 :  50   54   30   28   20   18
:La Moine River
Colmar              20.0   22.0   24.0 :  61   63   47   46   22   21

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: 03/05/2017 - 06/03/2017
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11         15.1   15.1   15.1   15.9   17.4   20.3   21.8
Dubuque              16.7   16.8   16.8   17.5   19.0   21.8   23.3
Bellevue LD12        14.8   14.8   14.9   15.5   16.9   19.7   21.0
Fulton LD13          15.6   15.6   15.6   16.1   17.5   20.3   21.5
Camanche             16.1   16.1   16.1   16.6   18.2   21.4   22.6
Le Claire LD14       10.6   10.6   10.6   11.0   12.4   14.9   16.1
Rock Island LD15     15.4   15.4   15.4   16.2   17.9   20.5   21.3
Ill. City LD16       15.0   15.0   15.1   15.8   17.9   21.2   22.0
Muscatine            16.7   16.7   16.8   17.8   19.8   22.3   22.9
New Boston LD17      16.0   16.0   16.1   16.9   19.1   21.9   22.5
Keithsburg           14.8   14.8   14.9   15.7   17.7   19.3   20.5
Gladstone LD18       11.1   11.1   11.2   12.0   14.2   16.1   17.7
Burlington           15.6   15.6   15.7   16.5   18.6   20.2   21.9
Keokuk LD19          12.9   12.9   13.0   14.2   17.7   19.7   21.1
Gregory Landing      15.2   15.3   15.5   16.9   19.9   22.2   23.4
:Maquoketa River
Manchester Hwy 20     6.6    7.5    8.5    9.7   11.8   18.6   20.2
Maquoketa            12.4   13.4   15.1   16.8   19.6   24.0   25.4
:Wapsipinicon River
Independence          6.7    6.8    7.1    8.0    8.8   12.2   16.6
Anamosa Shaw Rd       9.3    9.6   10.1   11.9   13.2   18.9   22.3
De Witt 4S           10.0   10.0   11.0   11.9   12.4   13.1   13.3
:North Skunk River
Sigourney             5.5    8.0   13.4   15.5   18.0   19.5   21.2
:Skunk River
Augusta               3.5    3.8    7.9   11.5   14.4   17.3   21.5
:Cedar River
Vinton               10.2   10.3   10.6   12.2   14.1   15.3   19.0
Cedar Rapids          8.1    8.2    8.4    9.9   11.8   13.6   18.6
Conesville           11.8   11.9   12.4   13.8   14.7   15.5   17.1
:Iowa River
Marengo              13.3   13.3   14.5   16.1   16.9   17.9   18.4
Iowa City            15.8   15.8   16.6   18.7   19.6   19.7   20.0
:English River
Kalona                5.1    7.4   12.1   13.9   16.0   17.6   19.0
:Iowa River
Lone Tree            10.2   10.6   12.1   13.7   14.3   14.9   17.7
Columbus Jct         16.3   16.4   17.5   19.2   20.9   23.5   25.2
Wapello              18.1   18.2   19.5   21.3   22.7   25.2   26.6
Oakville              8.1    8.1    9.2   10.8   12.0   14.6   15.9
:Des Moines River
Keosauqua            14.3   14.4   17.3   18.3   19.7   21.0   21.5
St Francisville      12.5   12.7   15.9   16.9   18.6   19.9   21.5
:Fox River
Wayland               2.8    4.0    7.7   10.3   14.2   17.2   19.2
:Pecatonica River
Freeport              9.7    9.7   10.4   11.9   13.3   14.4   15.1
:Rock River
Como                  7.7    7.7    7.8    9.3   11.2   12.8   13.9
Joslin               10.1   10.1   10.5   12.3   13.9   16.3   18.5
:Green River
Geneseo               5.7    6.3    9.1   12.1   14.3   16.5   20.0
:Rock River
Moline               10.5   10.5   11.0   11.9   13.7   14.8   16.7
:La Moine River
Colmar                8.4   12.8   16.7   21.8   23.4   25.1   25.9


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--Non-Exceedance Probabilities...

                            Chance of Falling Below Stages
                                 at Specific Locations
                          Valid Period: 03/05/2017 - 06/03/2017
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11          9.6    8.7    8.1    6.8    6.0    5.0    4.7
Dubuque              11.5   10.8   10.3    9.2    8.4    7.9    7.7
Bellevue LD12        10.3    9.5    9.0    7.7    6.1    4.9    4.4
Fulton LD13          10.2    9.2    8.7    7.5    5.8    4.9    4.6
Camanche             12.1   11.5   11.2   10.2    9.5    9.1    8.9
Le Claire LD14        7.7    7.2    6.8    6.1    5.3    4.8    4.7
Rock Island LD15     10.4   10.1    9.3    8.0    6.2    5.3    4.9
Ill. City LD16        9.5    8.9    7.9    6.3    5.0    4.3    3.9
Muscatine            11.2   10.7    9.7    7.9    7.0    6.5    6.3
New Boston LD17      11.4   10.6    9.5    7.6    5.8    4.4    4.0
Keithsburg           11.4   10.7    9.9    8.8    7.1    6.2    5.8
Gladstone LD18        7.4    6.5    5.4    4.0    2.8    1.9    1.5
Burlington           12.8   11.9   11.1   10.1    8.8    8.2    8.0
Keokuk LD19           9.6    8.6    7.3    6.2    5.1    3.9    3.0
Gregory Landing      12.2   10.7    9.4    8.0    6.8    6.6    6.3
:Maquoketa River
Manchester Hwy 20     4.7    4.7    4.5    4.3    4.2    4.2    4.1
Maquoketa            11.5   11.2   11.1   10.8   10.5   10.2   10.1
:Wapsipinicon River
Independence          5.3    5.2    5.2    5.0    5.0    4.9    4.8
Anamosa Shaw Rd       6.7    6.3    5.9    5.7    5.5    5.3    5.1
De Witt 4S            7.7    7.2    6.9    6.5    6.1    5.7    5.5
:North Skunk River
Sigourney             5.1    5.0    4.8    4.5    4.1    3.7    3.6
:Skunk River
Augusta               3.3    3.1    2.6    2.2    1.8    1.4    1.2
:Cedar River
Vinton                4.7    4.7    4.2    3.5    2.9    2.5    2.4
Cedar Rapids          5.3    5.2    5.1    4.7    4.4    4.2    4.1
Conesville            8.2    7.9    7.7    7.0    6.5    6.1    6.0
:Iowa River
Marengo               9.0    8.5    7.9    7.4    7.0    6.5    6.3
Iowa City            11.5   11.1   10.9   10.7    9.6    9.1    9.1
:English River
Kalona                4.4    4.3    4.0    3.8    3.5    3.2    3.1
:Iowa River
Lone Tree             6.9    6.7    6.1    5.6    4.4    3.8    3.6
Columbus Jct         13.5   12.4   11.6   10.9   10.2    9.5    9.2
Wapello              15.4   14.3   13.7   12.9   12.2   11.5   11.2
Oakville              5.4    4.3    3.7    3.1    2.4    1.7    1.5
:Des Moines River
Keosauqua            13.6   13.1   12.0   11.5   11.0   10.6   10.5
St Francisville      11.6   10.9    9.1    8.3    7.2    6.4    6.0
:Fox River
Wayland               1.7    1.6    1.5    1.5    1.4    1.3    1.3
:Pecatonica River
Freeport              6.7    6.3    5.6    4.8    4.3    4.0    3.8
:Rock River
Como                  6.0    5.2    4.8    4.1    3.5    3.3    3.1
Joslin                8.4    7.6    7.1    6.1    5.4    4.9    4.6
:Green River
Geneseo               4.8    4.6    4.4    4.1    3.8    3.4    3.1
:Rock River
Moline                9.6    9.2    8.9    8.6    8.2    8.1    7.9
:La Moine River
Colmar                2.9    2.7    2.6    2.5    2.5    2.3    2.1

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 (AHPS).

Information in this outlook has been collected from numerous sources,
including the United States Geological Survey (USGS), the US Army
Corps of Engineers (USACE), the Midwest Regional Climate Center
(MRCC), the National Drought Monitor, NOAA`s Climate Prediction
Center (CPC), and the National Operational Remote Sensing Center
(NOHRSC).

Weather and water information for the local area, including the
statistical data available in graphical format can be found at the
following location: weather.gov/dvn. Additional information can be
found at the North Central River Forecast Center`s website at:
weather.gov/ncrfc.

The next long-range probabilistic outlook will be issued near the end
of March.

Any questions concerning this outlook can be directed to:

Jessica Brooks
Service Hydrologist
National Weather Service Quad Cities
9050 Harrison St
Davenport, IA 52806
563-391-7094 ext 493
jessica.brooks@noaa.gov

$$



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