Flood Potential Outlook
Issued by NWS Green Bay, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3

000
FGUS73 KGRB 142028
ESFGRB
WIC125-085-041-037-075-069-067-083-073-115-125-078-029-141-097-
135-087-061-009-137-139-015-071-182000-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE GREEN BAY WI
308 PM CST THU MAR 14 2024

...BELOW AVERAGE RISK OF FLOODING THIS SPRING...

This outlook references information from the following partners
including: the United States Geological Survey (USGS), the U.S.
Army Corps of Engineers, Regional Climate Centers, U.S. Drought
Monitor, the Climate Prediction Center and NOAA Office of Water
Prediction.

This is the third and last of the three spring flood outlooks. The
next outlook will be provided next February 2025.

Flood outlook factors...

Soil moisture values across all of northeast Wisconsin remains well-
below normal. The lack of snowfall this winter will allow for more
moisture to be absorbed into the soils and play a large role in the
decreased flood risk.

Streamflows are generally considered near normal over most of
northeast Wisconsin with the exception of below normal streamflow
along the Fox Valley.

Snow water equivalent indicated that much of northeast Wisconsin was
well-below normal, primarily due to warmer than normal temperatures
and below normal snowfall. This will also lead to a decreased flood
risk.

Frost depth this season is considered shallow, even more shallow
than last year. This was due again to the above normal temperatures
seen so far this winter. Frost depths ranged from zero to around 17
inches, which for the most part is less than the same time in 2023.
The more shallow frost depThese 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.th may lead to decreased runoff as the
less frozen ground will allow water to readily pass through the
surface.

Lake Michigan water levels continue to run slightly above normal
which has been the case the past two years. This level will allow
for decreased flooding impacts this season. For a comparison of
impacts, there were very few impacts in 2022 and 2023, and Lake
Michigan levels are slightly lower this year.

The warm conditions for most of January and February 2024 has led to
thinner ice or no ice on area rivers this season. Therefore, there
is a very low risk of break up ice jamming on area rivers this
season. The potential for ice jams generally increases with heavy
rainfall events before the ice is out of the river system.

...Weather/climate outlook...

Temperatures are expected to trend below normal through the last
week of March. Precipitation during this same time frame has an
enhanced odds of being above normal. There is a signal for these
conditions to remain above normal for the March-April-May time frame
and equal chances of above, near or below average precipitation.

In Table 1 below, the current (CS) and historical (HS) or normal
probabilities of exceeding Minor...Moderate...And Major flood stage
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
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:WISCONSIN RIVER
MERRILL             11.0   13.5   15.0 :  <5   22   <5   <5   <5   <5
ROTHSCHILD          25.0   27.0   28.0 :  <5   21   <5    8   <5    6
:YELLOW RIVER
BABCOCK             12.0   15.5   17.0 :  26   69    6   19   <5   <5
:WISCONSIN RIVER
WISCONSIN RAPIDS    12.0   13.5   14.5 :  <5   11   <5   <5   <5   <5
:OCONTO RIVER
OCONTO               9.0   12.0   14.0 :   5   26   <5   <5   <5   <5
:UPPER WOLF RIVER
LANGLADE            11.5   12.5   14.0 :  <5   <5   <5   <5   <5   <5
:WOLF RIVER
SHIOCTON            11.0   13.5   15.0 :  15   46   <5    5   <5   <5
NEW LONDON           9.0   10.5   11.1 :  15   50   <5    5   <5   <5
:LITTLE WOLF RIVER
ROYALTON             5.0    8.0   10.0 :  14   40   <5   <5   <5   <5
:WAUPACA RIVER
WAUPACA              6.0    7.5    9.0 :  <5    7   <5   <5   <5   <5
:FOX RIVER
APPLETON             8.4    9.0   10.5 :  <5   <5   <5   <5   <5   <5
:MENOMINEE RIVER
FLORENCE             9.0   11.0   13.0 :  <5   37   <5   14   <5   <5
NIAGARA             13.0   15.0   16.0 :  <5   34   <5   14   <5    5
VULCAN              15.0   17.0   19.0 :  <5   25   <5    6   <5   <5
MCALLISTER          15.0   18.0   19.0 :   6   53   <5   14   <5   <5

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%
--------            ------ ------ ------ ------ ------ ------ ------
:WISCONSIN RIVER
MERRILL               5.4    5.8    6.1    6.9    7.6    8.8   10.0
ROTHSCHILD           15.7   16.3   16.9   18.4   19.5   22.5   23.5
:YELLOW RIVER
BABCOCK               5.2    6.2    7.4    9.6   12.3   15.1   15.7
:WISCONSIN RIVER
WISCONSIN RAPIDS      3.9    4.2    4.7    5.8    6.8    8.5    9.4
:OCONTO RIVER
OCONTO                5.3    5.7    6.1    6.8    7.5    8.6    9.2
:UPPER WOLF RIVER
LANGLADE              8.1    8.3    8.5    8.7    9.0    9.3    9.4
:WOLF RIVER
SHIOCTON              6.8    7.1    8.4    9.4   10.3   11.3   11.6
NEW LONDON            6.2    6.2    7.3    8.1    8.8    9.3    9.3
:LITTLE WOLF RIVER
ROYALTON              2.5    2.8    3.2    3.7    4.4    5.1    5.6
:WAUPACA RIVER
WAUPACA               2.2    2.3    2.6    3.3    4.2    4.9    5.0
:FOX RIVER
APPLETON              6.0    6.1    6.3    6.7    7.1    7.5    7.8
:MENOMINEE RIVER
FLORENCE              4.4    4.6    5.0    5.7    6.7    7.9    8.3
NIAGARA               6.5    6.9    7.5    8.3    9.8   10.8   11.7
VULCAN                6.6    6.9    7.6    8.6   10.4   11.5   12.6
MCALLISTER           10.3   10.5   11.3   12.1   13.4   14.4   15.1

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%
--------            ------ ------ ------ ------ ------ ------ ------
:WISCONSIN RIVER
MERRILL               4.7    4.6    4.5    4.3    4.1    3.9    3.8
ROTHSCHILD           13.5   13.4   13.2   12.9   12.6   12.3   12.1
:YELLOW RIVER
BABCOCK               2.2    2.1    2.0    2.0    1.9    1.9    1.9
:WISCONSIN RIVER
WISCONSIN RAPIDS      3.0    1.6    1.5    1.4    1.4    1.4    1.3
:OCONTO RIVER
OCONTO                4.8    4.7    4.5    4.5    4.3    4.3    4.3
:UPPER WOLF RIVER
LANGLADE              7.9    7.8    7.8    7.7    7.7    7.6    7.6
:WOLF RIVER
SHIOCTON              5.1    4.8    3.9    3.6    3.1    2.8    2.6
NEW LONDON            3.3    3.2    2.6    2.3    2.1    1.8    1.7
:LITTLE WOLF RIVER
ROYALTON              1.4    1.4    1.3    1.2    1.2    1.2    1.2
:WAUPACA RIVER
WAUPACA               1.6    1.6    1.6    1.5    1.5    1.4    1.4
:FOX RIVER
APPLETON              5.5    5.3    5.1    4.9    4.9    4.9    4.9
:MENOMINEE RIVER
FLORENCE              2.7    2.6    2.6    2.5    2.5    2.5    2.5
NIAGARA               4.8    4.6    4.5    4.4    4.3    4.2    4.2
VULCAN                5.1    5.0    4.9    4.9    4.8    4.8    4.7
MCALLISTER            9.1    9.0    8.9    8.8    8.7    8.6    8.6

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 weather.gov/grb for more weather and water
information.

The next outlook will be issued on February 2025.

$$

Kallas


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