Flood Potential Outlook
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
441
FGUS73 KDVN 131724 CCA
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
1224 PM CDT Thu Mar 13 2025
...2025 Spring Flood and Water Resources Outlook 3...
.Introduction:
... Below Normal Flood Risk This Spring...
This is the third and final Spring Flood and Water
Resource Outlooks for 2025 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 just north of Dubuque, Iowa to south of 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, Green, and the La Moine Rivers in Illinois. This
outlook is for the time period from mid-March through mid-June.
.Flood Outlook Overview...
The spring flood risk remains below normal for the Mississippi River,
and near to below normal for local tributary rivers across the NWS
Quad Cities HSA.
Some factors contributing to the current risk levels include:
1. No snow on the ground and below normal precipitation throughout
the local area and across the Mississippi River headwaters in
Minnesota and Wisconsin.
2. Below normal soil moisture levels in the local area and across
much of Minnesota and Wisconsin.
3. Deep frozen soils remain upstream, especially near the headwaters
of the Mississippi River. Little to no frost remains locally
across the Quad Cities HSA.
4. Near to below normal streamflows throughout the local forecast
area.
Through the Spring, impacts from these factors are expected to
change. One of the biggest factors that will drive any flood
threat will be any precipitation that we receive in the coming
months, whether it be from rain or snow.
.Key Takeaways...
1. Even though the overall risk of Spring flooding is near to below
normal 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.
2. Throughout the winter, precipitation both locally and regionally
remained below normal. This is especially true when it comes to
snowpack, or the lack thereof. The only snow remaining resides in
two areas; along and north of a line from Fargo, ND to Duluth, MN
and in northern WI north of Wausau, WI.
3. An active weather pattern in the coming weeks will introduce more
precipitation to the region, especially the Upper Mississippi
River Basin. Although, given the ongoing drought and near normal
streamflows, there remains plenty of room in local streams before
flooding occurs. Current outlooks show the likelihood of Major
Flooding on the Mississippi River being very low (<5-10% chance).
4. Widespread below normal soil moisture in the local area will
increase the capacity of the soils to soak in precipitation
and will 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 a
decreased contributor to potential spring flooding.
.Seasonal Precipitation:
Tributary Rivers - Neutral to Decreased Threat
Mississippi River - Neutral to Decreased Threat
Precipitation in eastern Iowa, northwest Illinois, and northeast
Missouri has been below normal this winter. With that, 73% of the
HSA remains Abnormally Dry or in a Severe Drought due to below normal
precipitation observed since the fall months in 2024. Most of the
precipitation in the upper Mississippi River Basin, has averaged
below normal.
Latest monthly outlooks from the Climate Prediction Center (CPC)
favor near to above normal precipitation through the rest of March
for all of the Upper and Mid-Mississippi River Basin. Thus, guidance
is highlighting the potential for an active period of weather for the
rest of March. This currently seems to favor within bank rises on
local streams, rather than having much of an impact of the flood
threat. Although, we will continue to monitor for any further changes
over the coming weeks.
.Snow Cover and Liquid Water Content:
Local Rivers - Decreased Threat
Mississippi River - Decreased Threat
Recent above normal temperatures in the 1st half of March has melted
all of the snow locally and most in the upper Mississippi River
basin. This has resulted in decreased threat to Spring flooding. Any
additional snow locally or upstream in the coming weeks, will have a
minimal impact on Spring flooding for the remainder of the cold
season.
.Soil Conditions:
Local Rivers - Neutral to Decreased Threat
Mississippi River - Neutral to Decreased Threat
Below normal precipitation since Fall 2024 has kept soil moisture
levels below normal. Latest analysis from the Climate Prediction
Center shows soil moisture ranking percentiles around 10-30% along
and east of the Mississippi River in IL, with near normal soil
conditions as we head towards the Mississippi River headwaters. We
continue to see widespread Abnormally Dry to Severe Drought
conditions through the Upper Mississippi River Valley. Considering
these factors, they favor a neutral to decreased threat for Spring
flooding, as drier soils will be better suited to soak in heavier
rains.
.Frost Depth:
Local Rivers - Decreased Threat
Mississippi River - Neutral Threat
Recent above normal temperatures has resulted in losing most if not
all of frost in the ground across Iowa, Illinois, and Missouri.
Upstream across Minnesota and Wisconsin, deep frost depths over 20
inches remain. Any precipitation that falls upstream on top of this
frozen ground will increase runoff into the mainstem Mississippi
resulting in a neutral threat to Spring flooding.
.River Conditions:
Local Rivers - Neutral Threat
Mississippi River - Neutral to Decreased Threat
Streamflow analysis from the United States Geological Survey (USGS)
indicates the majority of the Upper Mississippi River watershed and
tributary streamflows are near to below normal. Locally, the
precipitation in the past week has resulted in higher streamflows in
the Iowa tributary rivers and in the Rock River in Illinois. The
smaller streams and creeks, especially in Illinois are showing below
normal streamflows.
.Ice Jam Flooding:
Local Rivers - Neutral Threat for Breakup Jams
Mississippi River - Decreased Threat for Breakup Jams
Temperatures have been quite variable this winter, with stretches of
cold resulting in plenty of river ice. The recent stretch of warm
weather has allowed for most of this ice to melt and/or breakup.
Current observations are indicating a low-medium threat for break
up ice jams, but fortunately we are lacking any heavy rain at the
moment. This should mean that the ice can gradually melt/break up
without many impacts. Will continue to message a Neutral to Decreased
Threat for ice jam flooding this Spring.
.Weather/Climate Outlooks:
Local Rivers - Neutral to Decreased Threat
Mississippi River - Neutral to Decreased 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 snow to
parts of the region.
According to the latest outlooks from the Climate Prediction Center,
probabilities are leaning toward above normal temperatures and near
to above normal precipitation for the last 2 weeks of March.
The outlook for March through May is showing no signal favoring
above, near, or below normal temperatures locally and for the
upper Mississippi River basin and leaning towards above normal
precipitation for the eastern third of the upper Mississippi
River basin.
.Summary:
The Spring flood risk is below normal for the Mississippi River, and
near to below normal for local tributary rivers across the NWS Quad
Cities Hydrologic Service Area. Recent above normal temperatures have
melted all the remaining snow locally and most of the snow upstream.
Frost depths have decreased substantially locally, but remain deep
across Minnesota and Wisconsin. In addition, ice in area rivers has
begun to melt and/or breakup and float downstream resulting in
within bank rises.
Any spring flooding that occurs will be largely dependent on any
precipitation that we receive in the coming months. Some factors
contributing to the current risk levels include: 1) The general
lack of precipitation this winter, keeping us below normal, 2) Deep,
frozen grounds across the upper Mississippi River Basin will prevent
much infiltration until thawed, 3) Streamflows trending near to below
normal, and 4) below normal soil moisture levels.
.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: 03/17/2025 - 06/15/2025
: 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 : 13 48 8 38 <5 12
Dubuque 17.0 18.0 21.5 : 14 55 12 47 <5 15
Bellevue LD12 17.0 18.0 20.0 : 7 36 <5 31 <5 12
Fulton LD13 16.0 18.0 20.0 : 12 53 5 33 <5 14
Camanche 17.0 18.5 20.5 : 11 47 5 33 <5 14
Le Claire LD14 11.0 12.0 13.5 : 12 53 7 36 <5 20
Rock Island LD15 15.0 16.0 18.0 : 23 61 12 53 6 26
Ill. City LD16 15.0 16.0 18.0 : 19 60 11 48 6 26
Muscatine 16.0 18.0 20.0 : 28 62 11 48 6 26
New Boston LD17 15.0 16.5 18.5 : 33 65 14 54 8 31
Keithsburg 14.0 15.5 17.0 : 36 64 14 51 9 27
Gladstone LD18 10.0 12.0 14.0 : 36 65 13 47 <5 23
Burlington 15.0 16.5 18.0 : 32 64 14 48 8 28
Keokuk LD19 16.0 17.5 19.0 : 11 33 7 24 <5 12
Gregory Landing 15.0 18.0 25.0 : 34 65 13 42 <5 <5
:Maquoketa River
Manchester Hwy 20 14.0 17.0 20.0 : 18 25 13 18 <5 9
Maquoketa 24.0 26.0 28.5 : 5 11 <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 : 17 28 6 12 <5 <5
De Witt 4S 11.0 11.5 12.5 : 66 72 55 65 33 45
:North Skunk River
Sigourney 16.0 18.0 21.0 : 47 56 27 41 7 11
:Skunk River
Augusta 15.0 17.0 20.0 : 32 45 20 33 10 17
:Cedar River
Vinton 15.0 18.0 19.0 : 7 17 <5 8 <5 5
Palo Blairs Ferry 12.5 15.5 17.0 : 8 25 <5 8 <5 <5
Cedar Rapids 12.0 14.0 16.0 : 10 33 6 16 5 10
Cedar Bluff 16.0 20.0 26.0 : 9 32 <5 9 <5 <5
Conesville 13.0 15.0 16.5 : 28 52 5 15 <5 8
:Iowa River
Marengo 15.0 17.0 19.0 : 57 70 26 48 <5 7
Iowa City 23.5 24.5 26.0 : <5 <5 <5 <5 <5 <5
Lone Tree 16.0 18.5 22.0 : 23 32 6 8 <5 <5
Columbus Jct 23.0 25.0 26.5 : 6 18 <5 7 <5 <5
Wapello 21.0 25.0 27.5 : 28 54 <5 8 <5 <5
Oakville 11.0 15.0 20.0 : 21 43 <5 7 <5 <5
:English River
Kalona 14.0 16.0 18.0 : 38 49 22 32 8 13
:Des Moines River
Keosauqua 22.0 25.0 27.0 : 10 13 <5 <5 <5 <5
St Francisville 18.0 22.0 25.0 : 33 43 9 10 <5 <5
:Fox River
Wayland 15.0 18.0 20.0 : 26 28 11 14 <5 <5
:Pecatonica River
Freeport 13.0 14.0 16.0 : 19 40 7 24 <5 <5
:Rock River
Como 12.5 15.5 18.0 : 13 23 <5 8 <5 <5
Joslin 12.0 14.0 16.5 : 36 57 16 31 10 19
Moline 12.0 13.0 14.0 : 28 55 19 31 12 23
:Green River
Geneseo 15.0 16.5 18.0 : 13 24 8 11 <5 <5
:La Moine River
Colmar 20.0 22.0 24.0 : 52 65 37 43 15 20
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: 03/17/2025 - 06/15/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11 9.2 9.4 10.0 11.8 14.2 16.4 18.0
Dubuque 11.2 11.4 11.8 13.7 16.2 18.2 19.8
Bellevue LD12 10.0 10.2 10.7 12.5 14.5 16.3 17.6
Fulton LD13 9.6 9.7 10.3 12.6 14.7 16.5 18.6
Camanche 11.7 11.7 12.1 13.6 15.3 17.0 19.1
Le Claire LD14 7.3 7.4 7.8 9.0 10.2 11.4 12.9
Rock Island LD15 10.0 10.3 10.9 12.5 14.7 16.6 18.6
Ill. City LD16 8.7 8.9 10.0 12.2 14.5 16.2 18.6
Muscatine 10.5 10.7 11.7 13.7 16.2 18.2 20.5
New Boston LD17 10.4 10.6 11.7 13.5 15.6 17.3 19.8
Keithsburg 10.5 10.8 11.6 12.8 14.5 16.7 17.5
Gladstone LD18 5.9 6.4 7.4 8.9 10.7 13.1 14.0
Burlington 11.4 11.9 12.7 13.8 15.4 17.7 18.5
Keokuk LD19 7.5 8.3 9.2 11.2 13.1 16.5 18.2
Gregory Landing 9.1 10.4 12.0 14.2 16.2 19.6 21.0
:Maquoketa River
Manchester Hwy 20 5.7 6.5 7.4 8.7 11.0 17.7 19.4
Maquoketa 12.5 12.7 13.9 15.7 17.6 21.0 25.9
:Wapsipinicon River
Independence 6.0 6.2 6.8 7.6 8.6 11.0 14.0
Anamosa Shaw Rd 7.3 8.2 9.4 10.8 13.2 16.6 19.1
De Witt 4S 9.2 9.5 10.5 11.9 12.7 13.4 13.8
:North Skunk River
Sigourney 6.3 9.0 12.5 15.6 18.4 19.9 21.8
:Skunk River
Augusta 5.7 6.5 9.0 13.4 16.2 19.9 24.1
:Cedar River
Vinton 5.5 6.4 8.3 10.1 11.7 13.5 16.8
Palo Blairs Ferry 5.2 6.0 7.4 8.8 10.3 11.7 14.4
Cedar Rapids 5.1 5.6 6.7 7.9 9.8 11.9 16.1
Cedar Bluff 7.3 8.6 10.0 11.6 13.4 15.7 19.5
Conesville 8.2 9.1 10.5 11.6 13.2 14.0 15.4
:Iowa River
Marengo 9.4 10.5 13.0 16.0 17.3 18.3 18.6
Iowa City 12.6 13.3 15.9 17.3 19.1 19.8 21.1
Lone Tree 8.6 9.2 11.7 13.7 15.5 17.8 19.1
Columbus Jct 12.9 13.5 16.3 17.1 19.4 22.1 23.8
Wapello 15.9 16.5 18.7 19.5 21.3 23.0 24.3
Oakville 4.9 5.3 7.6 8.5 10.4 12.2 13.7
:English River
Kalona 6.3 7.8 11.1 13.3 15.6 17.5 19.3
:Des Moines River
Keosauqua 13.1 13.9 17.1 18.6 19.9 22.0 24.0
St Francisville 10.6 12.4 15.3 17.1 19.0 21.3 24.1
:Fox River
Wayland 3.9 5.3 7.8 11.4 15.2 18.4 19.8
:Pecatonica River
Freeport 7.0 7.3 8.2 10.1 12.1 13.7 14.6
:Rock River
Como 5.1 5.3 6.2 7.6 9.4 13.7 14.7
Joslin 7.2 7.5 8.9 10.6 12.9 16.4 19.5
Moline 9.0 9.2 9.9 11.2 12.4 14.5 17.3
:Green River
Geneseo 4.2 5.4 8.2 10.6 13.5 15.6 16.9
:La Moine River
Colmar 9.3 10.6 15.1 20.4 23.4 24.5 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--Nonexceedance Probabilities...
Chance of Falling Below Stages
at Specific Locations
Valid Period: 03/17/2025 - 06/15/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Mississippi River
Dubuque LD11 61.5 54.3 47.1 36.3 28.5 23.8 21.4
Dubuque 61.5 54.3 47.1 36.3 28.5 23.8 21.4
Bellevue LD12 61.7 55.8 47.7 36.9 28.7 24.1 21.7
Fulton LD13 61.6 59.2 50.0 38.3 30.1 25.1 22.8
Camanche 61.6 59.2 50.0 38.3 30.1 25.1 22.8
Le Claire LD14 62.0 61.7 53.2 40.7 32.0 26.1 23.9
Rock Island LD15 66.6 66.5 58.0 44.9 37.5 29.2 26.4
Ill. City LD16 67.3 67.2 59.9 47.4 39.0 30.3 27.3
Muscatine 67.3 67.2 59.9 47.4 39.0 30.3 27.3
New Boston LD17 66.4 66.3 60.2 47.6 39.2 30.3 27.4
Keithsburg 77.3 77.1 68.0 52.4 42.2 33.7 29.8
Gladstone LD18 74.8 74.7 68.4 52.5 42.2 33.8 29.8
Burlington 75.2 75.0 68.6 52.6 42.3 34.1 29.9
Keokuk LD19 77.8 77.6 72.3 55.0 42.7 30.9 26.7
Gregory Landing 86.8 86.5 76.5 61.3 44.4 35.1 29.0
:Maquoketa River
Manchester Hwy 20 0.2 0.2 0.1 0.1 0.1 0.1 0.1
Maquoketa 1.0 0.9 0.7 0.7 0.5 0.5 0.4
:Wapsipinicon River
Independence 0.7 0.6 0.5 0.4 0.3 0.3 0.2
Anamosa Shaw Rd 1.1 1.0 0.8 0.7 0.6 0.4 0.4
De Witt 4S 1.7 1.5 1.3 1.1 0.9 0.7 0.6
:North Skunk River
Sigourney 0.3 0.2 0.2 0.1 0.1 0.0 0.0
:Skunk River
Augusta 2.2 2.1 1.5 1.1 0.8 0.5 0.4
:Cedar River
Vinton 3.4 2.9 2.4 1.8 1.4 1.1 1.0
Palo Blairs Ferry 3.6 3.1 2.5 1.9 1.5 1.1 1.0
Cedar Rapids 3.7 3.1 2.6 2.0 1.6 1.2 1.1
Cedar Bluff 4.0 3.5 2.7 2.2 1.7 1.3 1.2
Conesville 4.6 4.1 3.0 2.4 1.9 1.4 1.3
:Iowa River
Marengo 1.8 1.3 1.1 0.8 0.6 0.5 0.4
Iowa City 1.9 1.4 0.9 0.3 0.2 0.2 0.2
Lone Tree 2.6 1.9 1.3 0.9 0.5 0.3 0.3
Columbus Jct 7.8 6.5 5.0 3.7 2.7 1.9 1.6
Wapello 8.5 6.6 5.1 3.8 2.9 1.9 1.7
Oakville 8.7 6.7 5.1 3.9 2.9 2.0 1.7
:English River
Kalona 0.2 0.2 0.1 0.1 0.1 0.0 0.0
:Des Moines River
Keosauqua 5.9 5.1 3.1 2.1 1.3 0.8 0.6
St Francisville 6.1 5.2 3.2 2.2 1.3 0.8 0.7
:Fox River
Wayland 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:Pecatonica River
Freeport 1.1 1.0 0.9 0.8 0.7 0.6 0.6
:Rock River
Como 6.0 5.6 4.4 3.9 3.1 2.6 2.4
Joslin 6.8 6.1 4.8 4.3 3.4 2.8 2.6
Moline 7.6 6.7 5.5 4.7 3.8 3.0 2.8
:Green River
Geneseo 0.4 0.3 0.3 0.2 0.1 0.1 0.1
:La Moine River
Colmar 0.0 0.0 0.0 0.0 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.
$$
Gross