Flood Potential Outlook
Issued by NWS Omaha/Valley, NE

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FGUS73 KOAX 022204
ESFOAX
NEC003-023-025-039-053-055-067-095-107-109-119-127-139-141-147-151-
153-155-159-167-IAC071-085-133-137-145-155-DDHHMM-

Probabilistic Hydrologic Outlook
National Weather Service Omaha NE
405 PM CST Thu Mar 02 2017

...Near normal risk for flooding this spring...

...Spring Flood and Water Resources Outlook...

This flood outlook is for the National Weather Service (NWS)
Omaha/Valley Hydrologic Services Area. This area includes eastern
Nebraska and portions of southwest Iowa including the following
rivers and their tributaries.

Missouri River from Decatur to Rulo
Niobrara River from Verdel to the Missouri River
Big Blue River from Surprise to the Kansas border
Elkhorn River from Neligh to the Platte River confluence
Platte River from Duncan to the Missouri River confluence
Other tributaries to the Missouri River in Iowa and Nebraska

                 ** Current Flood Outlook Highlights **

*The risk of flooding through the end of this outlook period, May
19th, is near normal. For this runoff season, there is little to no
contribution from snowmelt, also frost depths are near zero. Past
precipitation, since December 1, 2016 is above normal and this is the
main reason the flood risk is near normal and not below normal. This
past precipitation has created a fairly wet soil profile, which could
lead to increased runoff as we go through the spring. The information
to follow provides more details regarding the flood threat for the
spring months.

                  ***********************************
                  ** Summary of Current Conditions **
                  ***********************************

.Mountain Snowpack: For the headwaters of the Missouri River, the
snowpack is at 97% of average above the Fort Peck reservoir. Between
Garrison and Fort Peck reservoirs, the snowpack is 132% of average.
Normally by this time of year about 79% of the mountain snowpack has
accumulated. Though not substantial, the mountain snowpack runoff
will play a role in the flooding threat for the Missouri River. Given
that the snowpack is above normal below the Fort Peck reservoir this
lends to an increased flood threat for portions of the Missouri River
below Nebraska City.

The Platte River mountain snowpack looks to play a significant role
in this years spring runoff. As of 3/2 the Platte River mountain
snowpack is around 125% of normal. This will lead to increased flows
along the Platte River, mainly across western and central Nebraska.
By the time this water reaches eastern Nebraska enough attenuation
of the water will have occurred that flood stage will not be reached
on the Platte River from Duncan to the Missouri River confluence.

.Plains Snowpack: Across portions of the Dakotas, some snowpack
remains, though a significant amount has melted.

.Ice Jam Threat: No ice remains on area rivers.

.Frost Depths: Area reports of frost depths are zero or near zero.

.Current River Conditions: The USGS reports that area rivers are
running above normal for this time of year.

.Climate Outlook for the next two weeks (through March 15th):
Above-normal temperatures are expected with near-normal
precipitation.

.Climate Outlook for March through May:
There is a slightly higher than usual chance for conditions in March
through May to be like the warmest third of years compared to climate
records. The Climate Prediction Center also indicates equal chances
of above-, near-, and below-normal precipitation in March through
May.

Below is some river specific information related to this years
outlook.

                ***************************************
                * Missouri River from Decatur to Rulo *
                ***************************************

Overview: There is a greater than 50% chance for minor flooding along
the Missouri River below Nebraska City. Areas upstream of Nebraska
City are less likely to reach flood stage, especially above the
Platte River confluence.


                    ********************************
                    * Other rivers across the area *
                    ********************************

Most rivers across the area have a near or slightly below-normal
threat of flooding over the next 90 days. Due to favorable antecedent
conditions, the following rivers have an above-normal threat for
reaching or exceeding minor flood stage.

Ponca Creek
Wahoo Creek
Salt Creek (downstream of Lincoln)
Platte River (downstream of Ashland)
West Nishnabotna River
Nishnabotna River

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 more 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:  03/04/2017  - 06/02/2017

                                       :    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
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:Niobrara River
Verdel               7.0    9.0   10.0 :  <5   <5   <5   <5   <5   <5
:Ponca Creek
Verdel              12.0   15.0   17.0 :  15   15   <5    6   <5   <5
:Elkhorn River
Neligh              11.0   12.0   14.0 :  <5   <5   <5   <5   <5   <5
Norfolk             12.0   13.0   17.0 :  <5   <5   <5   <5   <5   <5
:North Fork Elkhorn River
Pierce              12.0   14.0   16.0 :  <5   10   <5    8   <5   <5
:Elkhorn River
Pilger              12.0   14.0   15.0 :  <5   <5   <5   <5   <5   <5
West Point          12.0   16.0   18.7 :  <5    5   <5   <5   <5   <5
Winslow             18.0   20.0   24.0 :  <5   <5   <5   <5   <5   <5
:Logan Creek
Uehling             18.0   19.0   21.0 :  <5   <5   <5   <5   <5   <5
:Maple Creek
Nickerson           11.5   13.0   17.0 :  <5   10   <5   <5   <5   <5
:Elkhorn River
Waterloo            17.0   18.0   21.0 :  <5   <5   <5   <5   <5   <5
:Platte River
Duncan               8.0    9.0   10.0 :  <5    6   <5   <5   <5   <5
:Shell Creek
Columbus            20.0   21.0   22.0 :   5    5   <5   <5   <5   <5
:Platte River
North Bend           8.0   12.0   15.0 :   8   18   <5   <5   <5   <5
Leshara              8.0   10.0   12.0 :  13   27   <5   <5   <5   <5
Ashland             20.0   22.0   26.0 :  <5    7   <5   <5   <5   <5
:Salt Creek
Roca                19.0   21.5   23.0 :   7   12   <5   <5   <5   <5
Lincoln             20.5   26.5   29.0 :   8    9   <5   <5   <5   <5
Greenwood           20.0   24.0   31.0 :  24   24    7    7   <5   <5
:Wahoo Creek
Ithaca              19.0   22.0   23.0 :  40   38   16   13   <5   <5
:Salt Creek
Ashland             16.0   20.0   23.0 :  38   36   15   11    6   <5
:Platte River
Louisville           9.0   11.0   12.0 :   8    8   <5   <5   <5   <5
:Big Blue River
Surprise             7.0   10.0   12.0 :  12   16   <5   <5   <5   <5
:Lincoln Creek
Seward              15.0   17.0   20.0 :  19   28    7    8   <5   <5
:Big Blue River
Seward              18.0   22.0   27.0 :   9   14   <5   <5   <5   <5
:West Fork Big Blue River
Dorchester          15.0   22.0   24.4 :  13   30   <5   <5   <5   <5
:Big Blue River
Crete               21.0   25.0   29.0 :  26   36    5   10   <5   <5
:Turkey Creek
Wilber              12.5   16.0   21.0 :  40   40   <5   <5   <5   <5
:Big Blue River
Beatrice            18.0   26.0   32.0 :   7   22   <5   <5   <5   <5
Barneston           20.0   27.0   33.0 :  <5   13   <5    6   <5   <5
:Little Blue River
Fairbury            18.5   20.0   23.0 :   7   <5    6   <5   <5   <5
:Maple River
Mapleton            21.0   24.0   27.0 :  <5   <5   <5   <5   <5   <5
:Little Sioux River
Turin               25.0   28.0   34.5 :   9    7   <5   <5   <5   <5
:Soldier River
Pisgah              28.0   29.0   30.0 :  <5   <5   <5   <5   <5   <5
:Boyer River
Logan               21.0   22.0   25.0 :  13    6   11    5   <5   <5
:Weeping Water Creek
Union               25.0   28.0   30.0 :  19   17   <5   <5   <5   <5
:East Nishnabotna River
Red Oak             18.0   22.0   27.0 :  33   36    9   13   <5   <5
:West Nishnabotna River
Hancock             14.0   19.0   23.0 :  29   30   12   13   <5    6
Randolph            19.0   22.0   24.0 :  32   36   15   14   <5    6
:Nishnabotna River
Hamburg             25.0   27.0   33.0 :  31   36   20   24   <5   <5
:Little Nemaha River
Auburn              22.0   23.0   27.0 :  13   16    6   14   <5   <5
:North Fork Big Nemaha River
Humboldt            28.0   29.5   31.0 :  <5   <5   <5   <5   <5   <5
:Big Nemaha River
Falls City          27.0   30.0   36.0 :  <5   15   <5   <5   <5   <5
:Nodaway River
Clarinda            23.0   26.0   29.0 :  <5   <5   <5   <5   <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: 03/04/2017  - 06/02/2017
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Niobrara River
Verdel                3.9    3.9    4.0    4.2    4.5    5.1    5.6
:Ponca Creek
Verdel                7.7    7.7    8.3    9.4   10.9   13.8   14.5
:Elkhorn River
Neligh                4.1    4.1    4.8    5.9    6.6    7.7    8.9
Norfolk               3.1    3.1    3.7    4.6    5.3    6.5    8.4
:North Fork Elkhorn River
Pierce                3.5    3.5    3.9    5.5    8.3   10.1   11.3
:Elkhorn River
Pilger                7.5    7.5    8.0    8.7    9.3   10.0   10.8
West Point            7.1    7.2    7.9    8.7   10.0   10.9   11.4
Winslow               8.9    9.1   10.3   11.6   14.2   16.0   16.5
:Logan Creek
Uehling               4.8    5.0    6.5    8.9   12.7   14.9   15.6
:Maple Creek
Nickerson             1.0    3.5    5.9    7.2    8.5   10.3   10.4
:Elkhorn River
Waterloo              3.5    4.3    6.0    8.0   10.6   12.7   14.7
:Platte River
Duncan                4.5    4.5    4.6    4.8    5.8    7.1    7.8
:Shell Creek
Columbus              1.5    1.5    4.4   10.0   16.2   19.2   19.9
:Platte River
North Bend            4.7    4.7    5.0    6.0    7.1    7.8    8.2
Leshara               4.9    4.9    5.2    6.3    7.5    8.2    8.7
Ashland              16.1   16.2   16.7   17.8   18.9   19.7   19.9
:Salt Creek
Roca                  1.7    2.1    3.5    5.6    9.8   18.6   19.5
Lincoln               2.4    3.1    5.0    9.3   14.8   18.8   24.2
Greenwood             3.1    3.9    6.7   11.4   19.9   23.1   26.2
:Wahoo Creek
Ithaca                4.2    4.8    9.2   14.6   21.6   22.1   22.6
:Salt Creek
Ashland               7.3    8.5    9.8   13.4   18.8   20.8   23.7
:Platte River
Louisville            4.0    4.1    4.8    6.4    7.7    8.7    9.2
:Big Blue River
Surprise              1.4    1.9    2.8    3.5    4.8    7.9    9.7
:Lincoln Creek
Seward                4.0    4.3    8.3   11.9   14.6   16.6   17.3
:Big Blue River
Seward                1.6    2.3    5.2    9.9   15.5   17.7   19.9
:West Fork Big Blue River
Dorchester            2.7    3.3    5.1    8.4   12.1   15.9   19.5
:Big Blue River
Crete                 8.0    8.6   11.8   17.4   21.2   23.4   25.3
:Turkey Creek
Wilber                1.2    4.2    7.9   10.9   13.8   15.1   16.0
:Big Blue River
Beatrice              3.4    4.5    6.8   10.9   14.3   16.5   18.5
Barneston             3.7    4.8    7.5   11.1   14.2   16.5   19.0
:Little Blue River
Fairbury              6.4    7.6    9.4   12.3   15.6   16.4   20.3
:Maple River
Mapleton              7.0    7.7    8.6   10.8   11.9   16.8   19.5
:Little Sioux River
Turin                11.1   11.3   12.9   16.1   19.6   23.6   26.8
:Soldier River
Pisgah                4.3    5.3    6.4    8.2    9.9   11.4   12.1
:Boyer River
Logan                 6.6    7.8    9.0   12.5   16.7   22.2   22.7
:Weeping Water Creek
Union                 2.8    4.2    7.6   13.3   20.8   26.9   27.6
:East Nishnabotna River
Red Oak               7.1    7.5   10.7   15.4   19.6   21.8   24.7
:West Nishnabotna River
Hancock               3.2    5.3    7.1    8.5   15.1   20.5   21.7
Randolph              8.6   10.4   13.1   15.8   20.1   22.3   23.2
:Nishnabotna River
Hamburg               8.5   10.5   15.9   21.7   25.7   28.4   29.0
:Little Nemaha River
Auburn                2.8    5.1    9.6   12.6   20.1   22.8   23.0
:North Fork Big Nemaha River
Humboldt              2.0    2.6    5.4    7.0   12.1   16.2   18.2
:Big Nemaha River
Falls City            3.8    5.0    9.3   12.6   18.3   23.1   25.9
:Nodaway River
Clarinda             10.6   11.1   12.3   13.6   18.6   21.0   21.9

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--Nonexceedance Probabilities...

                            Chance of Falling Below Stages
                                 at Specific Locations
                          Valid Period: 03/04/2017  - 06/02/2017
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Niobrara River
Verdel                3.4    3.4    3.3    3.2    3.2    3.2    3.2
:Ponca Creek
Verdel                5.1    5.0    4.8    4.7    4.4    4.1    3.9
:Elkhorn River
Neligh                2.2    2.0    1.7    0.9    0.7    0.5    0.5
Norfolk               2.7    2.6    2.5    2.4    2.3    2.2    2.2
:North Fork Elkhorn River
Pierce                3.1    3.0    2.9    2.6    2.4    2.3    2.2
:Elkhorn River
Pilger                7.0    7.0    6.8    6.3    6.1    6.0    6.0
West Point            6.4    6.3    6.0    5.5    5.2    5.2    5.2
Winslow               8.4    8.3    8.0    7.7    7.3    6.9    6.8
:Logan Creek
Uehling               3.7    3.6    3.4    3.1    3.0    2.9    2.9
:Maple Creek
Nickerson             1.0    1.0    1.0    1.0    1.0    1.0    1.0
:Elkhorn River
Waterloo              3.0    2.9    2.5    2.2    1.9    1.6    1.5
:Platte River
Duncan                4.0    3.7    3.5    3.3    3.1    3.1    3.1
:Shell Creek
Columbus              0.2    0.1    0.1    0.1    0.1    0.1    0.1
:Platte River
North Bend            3.9    3.7    3.3    3.1    2.9    2.7    2.7
Leshara               4.4    4.3    4.0    3.9    3.6    3.4    3.4
Ashland              15.7   15.6   15.2   15.0   14.8   14.6   14.6
:Salt Creek
Roca                  1.6    1.6    1.6    1.5    1.5    1.5    1.5
Lincoln               2.4    2.4    2.4    2.3    2.3    2.3    2.3
Greenwood             2.6    2.5    2.4    2.3    2.3    2.3    2.3
:Wahoo Creek
Ithaca                4.2    4.2    4.1    3.9    3.8    3.7    3.7
:Salt Creek
Ashland               7.1    7.1    7.0    6.8    6.7    6.6    6.6
:Platte River
Louisville            3.6    3.5    3.1    2.7    2.3    2.0    2.0
:Big Blue River
Surprise              1.2    1.2    1.2    1.2    1.2    1.1    1.1
:Lincoln Creek
Seward                4.0    4.0    3.9    3.9    3.8    3.7    3.7
:Big Blue River
Seward                1.5    1.5    1.4    1.3    1.2    1.2    1.1
:West Fork Big Blue River
Dorchester            2.7    2.6    2.6    2.6    2.5    2.4    2.4
:Big Blue River
Crete                 7.9    7.8    7.8    7.7    7.7    7.6    7.6
:Turkey Creek
Wilber                1.2    1.1    0.9    0.8    0.5    0.3    0.2
:Big Blue River
Beatrice              3.2    3.2    3.2    3.0    3.0    2.9    2.9
Barneston             3.6    3.6    3.5    3.4    3.3    3.2    3.2
:Little Blue River
Fairbury              6.4    6.3    6.3    6.2    6.1    6.1    6.1
:Maple River
Mapleton              6.3    6.2    5.9    5.6    5.3    5.2    5.2
:Little Sioux River
Turin                10.3    9.7    9.2    8.7    8.2    8.1    7.8
:Soldier River
Pisgah                3.6    3.6    3.5    3.4    3.3    3.2    3.2
:Boyer River
Logan                 3.9    3.8    3.7    3.6    3.5    3.5    3.5
:Weeping Water Creek
Union                 2.8    2.8    2.8    2.8    2.8    2.8    2.8
:East Nishnabotna River
Red Oak               6.2    6.1    6.0    5.9    5.7    5.6    5.5
:West Nishnabotna River
Hancock               1.9    1.7    1.7    1.5    1.4    1.4    1.3
Randolph              8.3    8.2    8.1    8.0    7.7    7.5    7.4
:Nishnabotna River
Hamburg               7.9    7.8    7.5    7.1    6.7    5.8    4.5
:Little Nemaha River
Auburn                2.8    2.8    2.8    2.8    2.7    2.7    2.7
:North Fork Big Nemaha River
Humboldt              2.0    2.0    2.0    2.0    2.0    1.9    1.9
:Big Nemaha River
Falls City            3.8    3.8    3.8    3.7    3.6    3.6    3.5
:Nodaway River
Clarinda             10.6   10.6   10.6   10.5   10.5   10.5   10.5

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


$$






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