Flood Potential Outlook
Issued by NWS Quad Cities, IA IL

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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
1151 AM CST THU FEB 16 2017

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

This is the first of two planned Spring Flood and Water Resources
Outlooks for the Quad Cities Hydrologic Service Area (HSA). 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 late February through May.

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

Mississippi River - Above Normal

Mississippi River Tributaries across Iowa - Near Normal

Mississippi River Tributaries across Illinois - Near to Below Normal

Mississippi River Tributaries across Missouri - Below Normal

*** Flood Outlook Summary ***

Above normal chances for river flooding exist along the main stem of
the Mississippi River. Tributaries across Iowa and Illinois have
chances near normal with some rivers towards west central Illinois
near to below normal. The Fox River in Missouri has a below normal
chance for flooding.

Above normal precipitation this past fall kept soils wet across
portions of the area. Meanwhile, winter rains and melting snow have
kept river levels above normal for this time of year. On the
tributaries, the main contributor for any flooding will come from
spring rains rather than snowmelt as there is no snowpack locally.
Along the main stem of the Mississippi River, there will be some
runoff from snowmelt from the upper parts of the basin, but snowpack
in those areas is below normal. While this snowmelt runoff will
contribute to rises on the river, significant flooding is not
expected from snowmelt alone.

Although dry conditions persist across the southeast part of Iowa,
many of the rivers in these areas originate in northern Iowa where
frost depths are slightly deeper and soils remain nearly saturated
from last fall. Any significant rainfalls over these areas early
this spring would cause heavy runoff into these river systems.

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

Snowfall has been well below normal for much of the region this
winter season. While parts of central Wisconsin did have slightly
above normal snow amounts, the majority of the Upper Mississippi
River Basin experienced amounts of 50 to 75 percent of normal.

Locally, precipitation for the winter season has ranged from about
an inch above normal in the northwest part of the HSA, to an excess
of three inches below normal in the far southern part of the HSA.
Near to above normal precipitation fell in January, in the forms of
both rain and snow. The heaviest of this precipitation fell over the
northern part of the HSA, which had wet antecedent soil conditions
going into the season. Aside from January, the remainder of the
season was generally below normal for precipitation.

.River Conditions/Current Streamflow: Near to Above Normal

Streamflows are running near to well above normal across the entire
area for this time of year. Streams went into the winter season at
above normal levels, and with additional rains in December and
January, along with intermittent snowmelts, the rivers have not
receded to normal baseflows. There has been a decline in flows over
the past month, yet levels remain above normal. With the high river
levels, it won`t take as much runoff to get a particular river to
flood stage as it typically would. This will promote near to above
normal chances for flooding.

.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

Normal snow depths for February range from 2 to 10 inches across the
HSA, and from 2 to 20 inches across the Upper Mississippi River
Basin. Locally, the entire area is snow free, so any impact from
snowmelt will only be in the main stem of the Mississippi River
unless additional snows occur.

The snowpack that does exist in the Upper Mississippi River Basin is
primarily across central and northern Wisconsin and has amounts as
of February 16 at approximately 50% of normal. Water equivalent in
this snowpack is on average two inches of water, with some locations
measuring up to four inches. These amounts are also below normal,
so while snowmelt will likely cause rises on the Mississippi River,
especially if the melt is quick, significant flooding is not
expected from snowmelt itself.

Warm temperatures are expected into March, which will likely cause a
good portion of the snowpack to melt. Therefore, impacts from
snowmelt will be observed earlier in the season than would typically
be expected.

.Frost Depth: Below Normal

Frost depths are less than would typically be expected for this time
of year. Lack of snow cover did promote frost development earlier in
the season which prompted significant runoff from heavy rains in
December and January. But, above normal temperatures the first few
weeks in February have allowed for thawing. Frost depths vary across
the local HSA from zero over northeast Missouri and west central
Illinois to around a foot in portions of northeast Iowa. Many areas
that continue to have frost have observed the top layer beginning to
thaw, where even a few inches of thawed soil could hold moisture if
rains would occur.

Looking at the upper parts of the Mississippi River basin, deeper
frost remains, but it is also less than normal. With the forecast
for warm weather over the next few weeks, 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 ice to melt
in the majority of the rivers as of mid-February. Additional ice
formation is possible on area rivers and streams if cold air returns.
However no significant cold air is anticipated to take residence
over the area so additional significant ice development does not
look likely at this time. This leads to little or no potential for
ice jam flooding this spring.

.Drought...

Abnormally Dry (D0) drought conditions have expanded into southeast
Iowa this winter as precipitation amounts have been well below
normal for the season. Elsewhere, occasional widespread
precipitation has kept any other areas from developing drought
conditions.

.Weather Outlooks...

Temperatures and precipitation are both expected to be above normal
going into March.

For the month of March, there is no strong pattern signal so there
are equal chances for above, near, and below normal temperatures and
precipitation.

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

.Numerical Long-Range Probabilisitic 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:  02/19/2017 - 05/20/2017

                                       :    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 :  55   46   39   35   16   10
Dubuque             17.0   18.0   21.5 :  65   52   51   42   17   11
Bellevue LD12       17.0   18.0   20.0 :  37   32   23   20   16   10
Fulton LD13         16.0   18.0   20.0 :  57   51   33   26   17   11
Camanche            17.0   18.5   20.5 :  52   40   36   31   17   12
Le Claire LD14      11.0   12.0   13.5 :  56   47   37   32   22   14
Rock Island LD15    15.0   16.0   18.0 :  65   56   55   47   28   19
Ill. City LD16      15.0   16.0   18.0 :  64   54   43   46   28   20
Muscatine           16.0   18.0   20.0 :  72   57   43   46   28   19
New Boston LD17     15.0   16.5   18.5 :  81   60   56   49   35   25
Keithsburg          14.0   15.5   17.0 :  79   59   50   49   33   25
Gladstone LD18      10.0   12.0   14.0 :  81   60   43   45   28   20
Burlington          15.0   16.5   18.0 :  77   59   44   45   30   24
Keokuk LD19         16.0   17.5   19.0 :  33   31   26   21   17   11
Gregory Landing     15.0   18.0   25.0 :  77   63   37   37   <5   <5

:Maquoketa River
Manchester Hwy 20   14.0   17.0   20.0 :  14   18   10   11    5   <5
Maquoketa           24.0   26.0   28.5 :  10   20   <5   16   <5    6

:Wapsipinicon River
Independence        12.0   13.0   15.0 :  12   12    8    7    6    6
Anamosa Shaw Rd     14.5   18.0   21.5 :  18   24   13   14    6    5
De Witt 4S          11.0   11.5   12.5 :  71   67   59   63   18   28

:North Skunk River
Sigourney           16.0   18.0   21.0 :  45   57   28   40   <5   10

:Skunk River
Augusta             15.0   17.0   20.0 :  23   43   11   31   <5   13

:Cedar River
Vinton              15.0   18.0   19.0 :  15   18   <5    6   <5   <5
Cedar Rapids        12.0   14.0   16.0 :  21   28   11   13    7    7
Conesville          13.0   15.0   16.5 :  69   54   18   21    6    7

:Iowa River
Marengo             14.0   15.5   18.5 :  77   74   63   63   <5    5
Iowa City           22.0   23.0   25.0 :  <5    8   <5    7   <5   <5
Lone Tree           15.0   16.5   18.0 :  15   26    8   15   <5   11
Columbus Jct        19.0   22.0   23.0 :  48   53   16   21   12   12
Wapello             20.0   22.0   25.0 :  70   61   35   44   12   11
Oakville            10.0   12.0   19.0 :  62   59   26   32   <5   <5

:English River
Kalona              14.0   16.0   18.0 :  48   54   25   33    9   15

:Des Moines River
Keosauqua           22.0   25.0   27.0 :   6   10   <5   <5   <5   <5
St Francisville     18.0   22.0   25.0 :  41   49    8   11   <5   <5

:Fox River
Wayland             15.0   18.0   20.0 :  18   23    7   10   <5   <5

:Pecatonica River
Freeport            13.0   14.0   16.0 :  22   28    8   11   <5   <5

:Rock River
Como                10.0   11.0   12.0 :  36   43   18   28   12   19
Joslin              12.0   14.0   16.5 :  55   49   20   26    6   16
Moline              12.0   13.0   14.0 :  51   51   27   31   14   22

:Green River
Geneseo             15.0   16.5   18.0 :  20   25   12   18    7    9

:La Moine River
Colmar              20.0   22.0   24.0 :  62   63   44   46   20   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: 02/19/2017 - 05/20/2017
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11         12.2   13.1   14.5   16.4   18.4   22.7   23.8
Dubuque              13.7   14.5   16.2   18.0   20.1   24.2   25.3
Bellevue LD12        12.3   12.9   14.2   15.9   17.9   21.5   22.5
Fulton LD13          12.2   13.5   14.6   16.4   18.6   22.4   23.3
Camanche             13.4   14.4   15.3   17.0   19.4   23.6   24.7
Le Claire LD14        8.7    9.4   10.1   11.1   13.2   16.5   17.5
Rock Island LD15     11.8   12.8   14.5   16.2   18.4   21.5   22.7
Ill. City LD16       11.4   12.4   14.1   15.7   18.4   22.2   24.0
Muscatine            12.8   13.9   15.8   17.6   20.2   23.1   24.6
New Boston LD17      12.8   13.7   15.3   16.7   19.6   22.7   24.1
Keithsburg           12.2   12.7   14.4   15.5   17.8   20.2   21.4
Gladstone LD18        8.2    8.8   10.4   11.8   14.5   17.2   18.8
Burlington           13.2   13.8   15.2   16.4   18.9   21.7   22.9
Keokuk LD19           9.8   10.5   12.5   14.0   18.1   21.0   22.1
Gregory Landing      11.9   12.6   15.2   16.7   20.6   23.6   24.3

:Maquoketa River
Manchester Hwy 20     6.6    7.0    8.2    9.4   11.4   17.2   20.1
Maquoketa            12.4   13.3   15.1   16.9   18.9   23.9   25.3

:Wapsipinicon River
Independence          6.5    6.6    7.1    8.0    8.9   12.2   16.6
Anamosa Shaw Rd       8.3    8.9   10.3   11.9   14.1   18.5   22.0
De Witt 4S            8.7    9.8   10.9   11.8   12.2   12.9   13.3

:North Skunk River
Sigourney             5.5   10.2   13.1   15.3   18.3   19.6   20.7

:Skunk River
Augusta               2.9    4.4    7.4   10.5   14.8   17.2   19.8

:Cedar River
Vinton                8.9    9.2   10.6   12.0   13.8   15.6   17.5
Cedar Rapids          7.3    7.4    8.6    9.6   11.7   14.1   16.6
Conesville           10.7   11.2   12.7   13.5   14.6   15.8   16.7

:Iowa River
Marengo              10.0   11.8   14.5   15.9   16.9   18.0   18.3
Iowa City            13.1   14.4   16.8   18.3   19.6   19.7   20.4
Lone Tree             8.2   10.5   12.0   13.6   14.4   15.8   17.9
Columbus Jct         14.7   15.6   17.8   18.9   21.0   24.1   24.6
Wapello              16.4   17.6   19.6   20.8   22.8   25.9   26.4
Oakville              6.3    7.4    9.2   10.4   12.0   15.3   15.7

:English River
Kalona                6.6    8.6   12.3   13.9   16.0   17.8   19.0

:Des Moines River
Keosauqua            13.2   15.4   17.3   18.3   19.5   21.2   22.5
St Francisville      10.6   13.8   16.2   17.5   19.2   21.3   23.0

:Fox River
Wayland               3.1    4.2    6.6   10.3   13.3   16.8   18.5

:Pecatonica River
Freeport              7.6    8.6    9.8   11.9   12.8   13.9   14.8

:Rock River
Como                  5.9    6.4    7.1    9.3   10.6   12.3   12.8
Joslin                8.3    9.2   10.1   12.2   13.5   15.8   16.6
Moline                9.5   10.1   11.1   12.1   13.0   14.4   15.1

:Green River
Geneseo               5.9    6.7    9.9   12.2   14.1   17.6   19.8

:La Moine River
Colmar                7.9   12.0   14.8   21.7   23.5   25.2   25.7


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: 02/19/2017 - 05/20/2017
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11          7.9    7.9    7.8    7.2    6.5    5.9    5.4
Dubuque              10.1   10.1   10.0    9.6    8.9    8.4    8.1
Bellevue LD12         8.7    8.7    8.6    8.1    7.3    6.0    5.3
Fulton LD13           8.3    8.3    8.2    7.8    7.1    5.7    5.2
Camanche             10.8   10.8   10.8   10.5   10.0    9.5    9.3
Le Claire LD14        6.5    6.5    6.5    6.2    5.8    5.2    5.0
Rock Island LD15      8.8    8.7    8.7    8.4    7.4    6.1    5.6
Ill. City LD16        7.1    7.1    7.1    6.8    5.9    4.9    4.5
Muscatine             8.8    8.8    8.8    8.5    7.7    6.9    6.6
New Boston LD17       8.6    8.6    8.5    8.3    7.1    5.6    4.8
Keithsburg            9.7    9.7    9.6    9.2    8.3    6.9    6.3
Gladstone LD18        4.8    4.8    4.8    4.5    3.8    2.6    2.0
Burlington           10.6   10.6   10.6   10.4    9.8    8.7    8.3
Keokuk LD19           6.4    6.4    6.4    6.4    5.8    4.8    3.8
Gregory Landing       8.2    8.2    8.2    8.1    7.4    6.7    6.5

:Maquoketa River
Manchester Hwy 20     4.6    4.5    4.5    4.3    4.2    4.2    4.1
Maquoketa            11.3   11.2   11.1   10.8   10.5   10.3   10.2

:Wapsipinicon River
Independence          5.4    5.3    5.2    5.1    5.0    4.9    4.8
Anamosa Shaw Rd       6.4    6.2    6.0    5.7    5.5    5.3    5.2
De Witt 4S            7.1    7.0    6.8    6.5    6.1    5.8    5.7

:North Skunk River
Sigourney             4.9    4.8    4.6    4.4    4.1    3.9    3.6

:Skunk River
Augusta               2.2    2.1    2.0    1.8    1.6    1.4    1.3

:Cedar River
Vinton                4.8    4.5    4.1    3.6    3.1    2.6    2.5
Cedar Rapids          5.3    5.2    5.0    4.8    4.5    4.2    4.2
Conesville            8.2    8.0    7.5    7.2    6.7    6.2    6.0

:Iowa River
Marengo               8.4    8.1    7.6    7.2    6.9    6.6    6.3
Iowa City            11.0   10.9   10.8   10.5    9.4    9.1    9.1
Lone Tree             7.0    6.4    6.0    5.5    4.3    3.8    3.7
Columbus Jct         12.6   12.3   11.4   10.8   10.2    9.4    9.2
Wapello              14.5   14.3   13.5   13.0   12.3   11.4   11.2
Oakville              4.5    4.3    3.6    3.1    2.4    1.7    1.5

:English River
Kalona                4.2    4.2    4.0    3.8    3.6    3.3    3.2

:Des Moines River
Keosauqua            12.7   12.2   11.8   11.4   10.9   10.7   10.6
St Francisville       9.8    9.2    8.6    8.1    7.4    7.1    7.0

:Fox River
Wayland               1.6    1.6    1.5    1.5    1.4    1.4    1.4

:Pecatonica River
Freeport              6.5    6.3    5.6    5.0    4.5    4.1    3.9

:Rock River
Como                  5.8    5.4    4.9    4.3    3.8    3.3    3.1
Joslin                8.2    7.8    7.2    6.3    5.6    5.0    4.7
Moline                9.4    9.2    9.0    8.6    8.4    8.1    8.0

:Green River
Geneseo               4.5    4.5    4.3    4.1    3.9    3.5    3.4

:La Moine River
Colmar                2.7    2.6    2.6    2.6    2.5    2.4    2.3

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.

There will be a second issuance of the 2017 Spring Flood and Water
Resources Outlook to update information. This outlook will be issued
March 2, 2017.

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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