Flood Potential Outlook
Issued by NWS Hastings, NE

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000
FGUS73 KGID 052121
ESFGID
NEC129-NEC175-NEC077-NEC125-NEC163-NEC093-NEC019-NEC079-NEC019-
KSC147-KSC163-071800-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE HASTINGS NE
321 PM CST THU MAR 5 2015

...Spring Flood and Water Resources Outlook Number 2...

This outlook is for the Hastings Hydrologic Service Area (HSA). In
South Central Nebraska this outlook includes the
Platte...Loup...Little Blue...and Republican Rivers and their
tributaries. In North Central Kansas...the Solomon River and its
tributaries are included.

...The Potential For Spring Flooding Is Near Average to Slightly
Below Average Across The Hydrologic Service Area...

...Short Term Hydrologic Outlook...March 5th - March 18th...

There is little to no snow cover across the outlook area. The 8 to
14 day forecast taking us into the middle of March is calling for
above normal temperatures and near normal precipitation. Most of the
ice already melted off of the rivers in late January due to the
abnormal warmth back then. Temperatures then cooled in February
averaging below normal, resulting in some new ice development.
Overall current river ice is not very thick and will likely melt off
in the next two weeks with only a very minimal threat of ice jams.

...Long Term Hydrologic Outlook...March 18th Through June 5th...

The potential for spring flooding is near average to slightly below
average across a majority of the area.

Spring flood outlooks are routinely issued from February through
March to give advanced notice of possible flooding. They are based
on soil moisture, snowpack magnitude, streamflow conditions and
the long range forecast of future temperatures and precipitation
patterns.

The long range three month precipitation outlook indicates fairly
equal chances of seeing above normal or below normal precipitation
across our HSA. Current soil moisture conditions are running near
normal across the HSA. Current stream flow conditions are generally
running from near normal to below normal for most stream gauging
sites across our HSA.

The only river within the Hastings HSA that originates deep in the
Rockies and is fed by spring snow melt is the Platte River. The
current snow water equivalent within the Platte River Basin of the
Rocky Mountains is running near average. It generally takes an
exceptionally above normal mountain snow pack for our area to see
flooding or even high water related to mountain snow melt. Therefore,
high water or flooding from mountain snow melt run off as far east as
our HSA this spring is very unlikely.

After considering all of the above mentioned factors, the overall
forecast for a majority of our HSA is to expect a near normal to
slightly below normal chance of seeing spring flooding. However, it
is also important to remember that even in dry periods, localized
flooding and especially flash flooding are still possible from
locally heavy rainfall generated by strong thunderstorms.


...Climatological Review (mainly winter precipitation trends)...

In the previous issuance of this ESF product back on Feb. 19, this
section contained a detailed narrative and table outlining
precipitation totals and departures from normal for the entire year
of 2014 across the 30-county NWS Hastings 30-county coverage area
(24 counties in Nebraska and 6 in Kansas). Please refer to this
previous product for the "full details" regarding 2014
precipitation, but here is a brief summary: 2014 precipitation could
best be described as "fairly normal but somewhat variable". On a
positive note, most places were not "overly dry" or "overly wet", as
the majority of the area registered totals somewhere between 80-110
percent of the 30-year normal.

From this point forward, the focus will be on more recent
precipitation trends over the past few months, specifically what
transpired during "meteorological winter" of 2014-15, which just
ended on Feb. 28 (meteorological winter consists of the three full
calendar months of Dec-Jan-Feb):

As evidenced in the table below, along with NWS AHPS precipitation
analysis data found online, the majority of the 30-county area
measured between 70-125 percent of normal winter precipitation,
meaning that most areas were generally "near normal" with only few
exceptions of well-below or well-above normal values. Although most
places did not observe any "major" snow storms of 8+ inches, there
were enough "minor" snow events along with a few rounds of liquid
rain to give most areas near normal winter totals. On a resounding
positive note, this winter was considerably better-off in the
moisture department than last winter was, as winter 2013-14 only
featured 25-65% of normal precipitation across most of the local
area. Using Grand Island airport as a specific example, last winter
featured only 0.76" of precipitation while this winter tallied a
notably-higher 1.93" (see table below). However, one site/area that
did stand out as being a bit on the drier side this winter was
Hebron, where the winter total of 1.13" was only 46% of normal.
Keeping things in perspective though, one must always keep in mind
that no matter how much or how little precipitation falls during the
winter it usually only accounts for a small percentage of total
annual precipitation, the vast majority of which falls during the
spring and summer.

Winter drought trends: As a result of the generally near normal
precipitation observed within the area during winter 2014-2015,
there was essentially no change whatsoever in drought conditions,
according to drought classification updated issued weekly by the
U.S. Drought Monitor. As a result, North Central Kansas portions of
the local area along with most counties in South Central Nebraska
west of the Highway 281 corridor remained in Category D0 Abnormally
Dry throughout the winter (considered to be one category better than
"true" drought). Meanwhile, most counties east of the Highway 281
corridor in Nebraska remained void of all drought categories
whatsoever.

The table below features precipitation totals and departures from
normal/percent of normal for meteorological winter 2014-15
(Dec-Feb), and includes data for 32 chosen locations scattered
throughout the local area. Most of these stations are NWS
Cooperative Observers, along with a few primary airport sites:


 Location           Precip
North Central KS   Dec-Feb        Normal   Departure  % Normal
--------           --------       ------   ---------  --------
Alton 2SW            1.50          2.16      -0.66       69
Beloit               1.87          2.28      -0.41       82
Burr Oak             1.68          2.11      -0.43       80
Logan                1.35          1.71      -0.36       80
Natoma               1.62          2.41      -0.79       67
Phillipsburg         1.35          1.88      -0.53       72
Plainville 4WNW      1.75          2.10      -0.35       83
Smith Center         1.54          1.73      -0.19       89


  Location          Precip
South Central NE   Dec-Feb        Normal   Departure  % Normal
--------           --------       ------   ---------  --------
Aurora 4N            2.06          2.22      -0.16       93
Belgrade             2.21          1.91      +0.30       116
Cambridge            1.82          1.59      +0.23       114
Central City         1.73          2.26      -0.53       77
Clay Center 6ESE     1.84          1.91      -0.07       96
Elwood 8S            1.14          1.69      -0.55       67
Franklin             1.24          1.89      -0.65       66
Geneva               1.52          1.92      -0.40       79
Gothenburg           1.97          1.36      +0.61       145
Grand Island Arpt    1.93          1.84      +0.09       105
Greeley              1.41          1.88      -0.47       75
Hastings Airport     1.65          1.51      +0.14       109
Hebron               1.13          2.44      -1.31       46
Holdrege             2.24          1.65      +0.59       136
Kearney Airport      1.23          1.61      -0.38       76
Lexington 6SSE       1.62          1.33      +0.29       122
Minden               1.39          1.48      -0.09       94
Nelson               1.73          2.14      -0.41       81
Ord Airport          2.30          1.40      +0.90       164
Osceola              2.40          2.25      +0.15       107
Ravenna              2.09          1.66      +0.43       126
St. Paul             2.82          1.60      +1.22       176
Superior             1.87          2.32      -0.45       81
York 3N              2.58          2.91      -0.33       89


Concluding this climatological review section with a brief look at
average soil temperatures during the past week at a 4-inch depth:
Values across most of the 30-county area have generally averaged
28-32 degrees, which is roughly 4-6 degrees below normal. These cold
soil temperatures are a direct reflection of the colder-than-average
temperature pattern of late.


...Weather/Climatological Outlook...

It`s now time to switch gears and look ahead to expected weather
conditions over the next several days and expected climate trends
over the next several months:

Starting with the most immediate local weather expectations over the
next week (through March 12) as forecasted by NWS Hastings, by far
the biggest story involves a notable switch to prevailing
milder, above normal temperatures. In fact, most of the area will
observe high temperatures well into the 50s and 60s, with especially
southwestern counties possibly seeing some 70s as well. Putting
these expected readings during the next week in perspective, 30-year
normal highs for this portion of March typically average in the
mid-40s to low-50s. Precipitation-wise during the next week,
confidence is high in prevailing dry weather with little if any
chance for measurable precipitation.

Looking out a bit farther, the latest 8-14 day outlook from the
Climate Prediction Center (valid March 13-20) calls for a continued,
decent chance of above normal temperatures, along with an
expectation of near normal precipitation. As a point of reference,
30-year normals indicate that March high temperatures across South
Central Nebraska and North Central Kansas gradually climb to the
upper 50s/low 60s by month`s end, while average daily
low temperatures increase to around 30 degrees. Precipitation-wise,
normal March precipitation across the local area ranges from around
1.40" in the western-most counties, up to around 2.10" in far eastern
counties along and near Highway 81.

Turning next to the "bigger picture" expectations for the
meteorological spring months of March-April-May as a whole, the
latest Climate Prediction Center (CPC) three-month seasonal
outlook calls for "equal chances" of observing above normal, near
normal or below normal values in both the temperature and
precipitation departments. In other words, long range forecast tools
just do not present enough of a signal to support one of these
possible outcomes over another. Despite the current lack of
predictability regarding how this spring might turn out, one
can keep in mind that 30-year normal precipitation from March-May
across the NWS Hastings coverage area typically ranges from 7-10
inches, with the lowest amounts generally west of Highway 183 and the
highest amounts near Highway 81.

Finally turning to the latest U.S. Seasonal Drought Outlook issued
by CPC and valid through the end of May, there are currently no
expectations of drought conditions (Category D1 Moderate-or-worse)
returning to the local area this spring.

(Longer range forecasts issued by CPC and referenced in the
preceding paragraphs are based on output from various forecast
models, as well as forecaster expertise, and take into consideration
ongoing global/tropical atmospheric and oceanic states, recent
trends in observed data, soil moisture conditions, etc. More
information about these longer-range forecasts can be obtained from
the CPC web site at: http://www.cpc.ncep.noaa.gov)


...Advanced Hydrologic Prediction Service Probabilistic Outlook...

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:  3/7/2015 - 6/5/2015

                                       :    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
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:Little Blue River
Deweese             10.0   16.0   17.0 :  14   16   <5   <5   <5   <5
:North Fork Solomon
Glade               11.0   16.0   18.0 :  <5   <5   <5   <5   <5   <5
:Bow Creek
Stockton             9.0   12.0   13.6 :  <5    6   <5   <5   <5   <5
:Platte River
Cozad                6.5    8.0   10.0 :  20   37    9   20   <5   <5
Overton              8.0   12.0   14.0 :  10   16   <5   <5   <5   <5
Kearney              6.0    8.0    9.0 :  18   29    8   11    6   <5
Grand Island         6.5    7.0    7.5 :  13   20    9   18    8   12
:Wood River
Riverdale           11.0   15.0   20.0 :   7   17   <5   <5   <5   <5
Gibbon              15.0   16.0   16.5 :   9   20    6   14   <5   12
Alda                10.0   11.0   12.2 :  13   25   10   22   <5   14
:South Loup River
Ravenna              5.0    8.0   10.0 :  24   32   <5   <5   <5   <5
:Mud Creek
Sweetwater          15.0   18.0   20.0 :  11   14   <5   <5   <5   <5
:South Loup River
Saint Michael        6.5    9.0   12.0 :  15   28   <5    5   <5   <5
:Middle Loup River
Saint Paul           8.0   10.0   12.0 :  <5   <5   <5   <5   <5   <5
:North Loup River
Saint Paul           7.0   10.0   12.0 :  <5   <5   <5   <5   <5   <5
:Cedar River
Fullerton            9.0   17.0   18.0 :  <5   <5   <5   <5   <5   <5
:Loup River
Genoa               10.5   12.0   13.0 :  <5   <5   <5   <5   <5   <5
:Beaver Creek
Genoa               15.0   17.0   19.0 :   7    9    6   <5   <5   <5
:Republican River
Riverton             9.0   10.5   13.5 :   5    5    5   <5   <5   <5
Guide Rock          11.0   14.0   16.0 :   9   15   <5   <5   <5   <5
Hardy               11.0   11.5   12.0 :   6    8   <5    5   <5   <5
:South Fork Solomon River
Woodston            12.0   16.0   27.0 :  14   20    8   14   <5   <5
:South Fork Solomon
Osborne             14.0   20.0   27.0 :  17   31   10   13   <5   <5
:North Fork Solomon
Portis              15.0   20.0   25.0 :  10   24    8   13   <5   <5
:Solomon River
Beloit              20.0   25.0   30.0 :  23   29   10   11   <5   <5
:Republican River
Cambridge            9.0   10.0   16.0 :  <5   <5   <5   <5   <5   <5
Orleans              9.0   11.0   13.0 :  <5   10   <5   <5   <5   <5
:Beaver Creek
Beaver City         11.0   13.0   15.0 :   7    7    5    5   <5   <5
:Sappa Creek
Beaver City         16.0   18.0   20.0 :  <5   <5   <5   <5   <5   <5
Stamford            19.0   22.0   26.0 :  <5   <5   <5   <5   <5   <5
:Prairie Dog Creek
Woodruff            21.0   24.0   30.0 :  <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: 3/7/2015 - 6/5/2015
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Little Blue River
Deweese               2.5    3.3    4.5    7.2    8.9   11.0   13.7
:North Fork Solomon
Glade                 2.0    2.0    2.0    4.3    6.7    8.7    9.6
:Bow Creek
Stockton              3.6    3.6    3.6    3.7    5.8    6.8    8.1
:Platte River
Cozad                 3.9    4.0    4.5    5.4    6.1    7.7    8.7
Overton               4.3    4.3    4.4    4.9    5.5    8.1   10.4
Kearney               4.2    4.3    4.4    4.7    5.2    7.2    9.1
Grand Island          4.5    4.5    4.6    4.9    5.4    6.8    8.0
:Wood River
Riverdale             2.1    2.1    2.1    3.0    5.2   10.2   11.5
Gibbon                4.1    4.1    4.1    5.6    8.1   14.2   16.1
Alda                  4.4    4.4    4.4    5.2    7.0   11.0   12.2
:South Loup River
Ravenna               2.6    2.9    3.3    4.0    5.0    5.5    5.7
:Mud Creek
Sweetwater            5.4    5.4    7.3   10.0   12.6   15.4   16.3
:South Loup River
Saint Michael         2.5    2.8    3.1    4.1    5.5    6.9    7.4
:Middle Loup River
Saint Paul            2.3    2.4    2.6    3.2    3.9    4.8    5.5
:North Loup River
Saint Paul            3.1    3.1    3.5    3.8    4.3    4.7    5.0
:Cedar River
Fullerton             3.2    3.5    4.3    5.0    5.9    6.7    7.3
:Loup River
Genoa                 4.5    4.5    5.4    6.9    8.1    9.3   10.1
:Beaver Creek
Genoa                 4.0    4.4    6.0    7.5   10.3   11.3   17.3
:Republican River
Riverton              1.6    1.7    2.3    3.9    5.1    7.1    9.7
Guide Rock            4.0    4.0    4.6    6.9    8.8   10.7   13.3
Hardy                 2.3    3.1    4.0    5.6    6.8    9.0   11.2
:South Fork Solomon River
Woodston              3.0    3.0    3.9    5.0    6.4   15.0   18.6
:South Fork Solomon
Osborne               3.5    3.5    5.2    6.3   10.5   20.2   21.3
:North Fork Solomon
Portis                3.5    3.5    4.1    5.6    9.3   15.7   21.7
:Solomon River
Beloit                3.1    4.0    4.9   11.8   19.6   25.0   29.4
:Republican River
Cambridge             4.1    4.1    4.1    4.1    4.3    6.2    6.5
Orleans               3.1    3.1    3.2    3.6    5.2    7.4    8.4
:Beaver Creek
Beaver City           3.0    3.0    3.0    4.1    7.5    9.9   13.2
:Sappa Creek
Beaver City           2.8    2.8    2.8    3.5    7.9   10.8   12.1
Stamford              6.5    6.5    6.6    7.8   11.0   13.0   16.1
:Prairie Dog Creek
Woodruff              1.2    1.2    2.4    4.7    7.8    9.0   11.5

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: 3/7/2015 - 6/5/2015
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Little Blue River
Deweese               2.5    2.5    2.5    2.3    2.1    1.9    1.8
:North Fork Solomon
Glade                 2.0    2.0    2.0    2.0    2.0    2.0    2.0
:Bow Creek
Stockton              3.6    3.4    2.0    2.0    2.0    2.0    2.0
:Platte River
Cozad                 1.7    1.5    1.3    1.2    1.2    1.2    1.2
Overton               2.1    2.1    2.1    1.9    1.9    1.9    1.9
Kearney               3.2    2.9    2.3    2.1    2.0    2.0    2.0
Grand Island          3.8    3.4    3.1    3.0    3.0    2.9    2.9
:Wood River
Riverdale             2.1    2.1    2.1    2.1    2.1    2.1    2.1
Gibbon                4.1    4.1    4.1    4.1    4.1    4.1    4.1
Alda                  4.4    4.4    4.4    4.4    4.4    4.4    4.4
:South Loup River
Ravenna               2.6    2.6    2.5    2.5    2.4    2.4    2.4
:Mud Creek
Sweetwater            5.4    5.4    5.3    4.0    4.0    4.0    4.0
:South Loup River
Saint Michael         2.4    2.4    2.3    2.3    2.3    2.3    2.3
:Middle Loup River
Saint Paul            2.2    2.2    2.1    2.0    2.0    1.8    1.7
:North Loup River
Saint Paul            3.0    3.0    2.8    2.7    2.6    2.5    2.5
:Cedar River
Fullerton             3.0    3.0    2.9    2.8    2.7    2.6    2.6
:Loup River
Genoa                 4.5    4.5    4.5    4.5    4.5    4.5    4.5
:Beaver Creek
Genoa                 3.4    3.4    3.4    3.2    3.1    2.9    2.9
:Republican River
Riverton              1.6    1.6    1.6    1.6    1.6    1.6    1.6
Guide Rock            2.3    2.3    2.3    2.3    2.3    2.3    2.3
Hardy                 1.9    1.5    1.3    1.2    1.2    1.2    1.2
:South Fork Solomon River
Woodston              3.0    3.0    3.0    3.0    3.0    3.0    3.0
:South Fork Solomon
Osborne               3.5    3.5    3.5    3.5    3.5    3.4    3.4
:North Fork Solomon
Portis                3.5    3.5    3.5    3.5    3.5    3.5    3.5
:Solomon River
Beloit                3.0    3.0    3.0    2.9    2.9    2.9    2.9
:Republican River
Cambridge             2.3    2.2    2.0    1.8    1.6    1.6    1.5
:Beaver Creek
Beaver City           3.0    3.0    3.0    3.0    3.0    3.0    3.0
:Sappa Creek
Beaver City           2.8    2.8    2.8    2.8    2.8    2.8    2.8
Stamford              6.5    6.5    5.5    5.5    5.5    5.5    5.5
:Prairie Dog Creek
Woodruff              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.


...Future Outlooks...

The next routine probabilistic outlook is currently scheduled to be
issued Wednesday April 22nd.

&&

Visit our local NWS office website for current weather/hydrological
and climate information for South Central Nebraska and North Central
Kansas at:
www.weather.gov/hastings

Additional climate information for the region can be obtained at:
www.hprcc.unl.edu

Additional information on climatological outlooks can be found at:
www.cpc.ncep.noaa.gov

Further information on drought conditions can be obtained at:
www.drought.gov
www.drought.unl.edu
www.droughtmonitor.unl.edu

Information on mountain snowpack can be found at:
www.wcc.nrcs.usda.gov/ftpref/downloads/wsf/201502wsfwww.pdf

NWS AHPS precipitation analysis maps can be found at:
http://water.weather.gov

National snow analysis page can be found at:
www.nohrsc.noaa.gov/nsa

For training on NWS probabilistic graphics:
www.youtube.com/watch?v=pSoEgvsnpv4

For training on NWS river forecast graphics:
www.youtube.com/watch?v=psIByj8EZY0

$$




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