Flood Potential Outlook
Issued by NWS Hastings, NE
Issued by NWS Hastings, NE
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PROBABILISTIC HYDROLOGIC OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE Hastings NE
817 AM CST Tue Feb 18 2025
...2025 Spring Flood and Water Resources Outlook Number 1...
This outlook is for the Hastings Hydrologic Service Area (HSA). In
central and 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 shorter term potential for early-spring flooding from ice
jams/snow melt is near-to-below normal, with any potential ice jam
risk focused along the Platte and Loup Rivers...
...The longer term potential for spring flooding (not related to ice
jams/snow melt) is currently considered below normal across our
area...
...Shorter Term Hydrologic Outlook...February 13th - 28th...
With overall-solidly-below normal temperatures dominating the next 7
to 10 days (see forecast section below), followed by the expectation
of a late-February warming trend, there is some concern that the
risk for ice jam flooding could increase somewhat over the next few
weeks as ice formation increases and then starts to break up. Ice is
currently not overly-thick (owing to overall-near-normal
temperatures so far this winter). However, steady ice growth is
likely given the increasingly-colder signal in the short-term.
Fortunately, there are no signficant liquid precipitation events
evident over the next few weeks to perhaps exacerbate the situation
(mainly some lighter snow chances over the next week). In addition,
streamflow levels are currently near-normal to slightly below normal
across much of our area. Overall, the risk for flooding for our
forecast area as a whole through late February into the first part
of March is below normal...but is perhaps near-normal for those ice
jam-prone areas along the Platte and Loup River systems.
...Longer Term Hydrologic Outlook...March 1st Through May 16th...
The overall potential for broader-scale spring flooding is below
normal across our 30-county forecast area.
Spring flood outlooks are routinely issued from February into March
to give advanced notice of any signals that might favor an increased
risk of mainly broader-scale flooding (beyond localized ice jam
issues). These outlooks incorporate various factors including: soil
moisture, snowpack magnitude, stream flow conditions, and the longer
range forecast of future precipitation.
There are several primary factors leading to our below average
threat for spring flooding.
- The local snowpack is currently not overly-deep (most areas have
no more than 2-5" on the ground).
- The mountain snowpack in the Platte River Basin is near to below
normal.
- Lake McConaughy (upstream of our forecast area along the North
Platte River) is at only 58 percent capacity and has plenty of
storage space available.
- Soil moisture is drier than normal across our area (as evidenced
by most of our area being in Moderate Drought/D1). As a result, once
the ground thaws our soils will be capable of efficiently absorbing
most normally occurring spring rainfall.
- Current streamflow on our primary river systems is mainly near
normal to below normal for this time of year, especially along the
Platte basin southward into northern Kansas. However, parts of our
Loup River system are indicated to have slightly above normal flow.
- The latest Climate Prediction Center (CPC) three-month
precipitation outlook for March-May does not favored above normal
precipitation for our area (only a mix of equal chances and a slight
lean toward below normal).
It is important to note that isolated/localized spring flooding is
always possible from occasional bouts of heavy rain/thunderstorms,
even in dry years, when the overall, larger-scale risk for
widespread flooding is considered low.
For a graphical PDF presentation with information closely tied to
this traditional written Flood Outlook assessment, please visit:
https://www.weather.gov/media/gid/hydro/SpringFloodOutlook1_2025.pdf
...Current and Recent Hydrologic and Climatological Conditions...
For an overview of annual precipitation totals/departures from
normal along with drought conditions/trends across our 30-county
forecast area during calendar-year 2024, please check out our web
story at: https://www.weather.gov/gid/2024precip_recap
Now we`ll take a look at more recent precipitation totals/departures
and drought conditions since the start of "meteorological winter"
back on Dec. 1, 2024 (meteorological winter is defined as the three
full months of Dec-Jan-Feb). NOTE: Unfortunately, precipitation data
from the very recent Feb. 11-12 snowfall was not able to be included
in time for this analysis (this event brought a much-needed 0.15-
0.40" liquid equivalent to most of our forecast area). As a result,
the following information discusses precipitation totals/departures
from Dec. 1, 2024 - Feb. 10, 2025.
As evidenced in the data presented in the table below (and supported
by NWPS precipitation analysis), up through Feb. 10th this
meteorological winter had been notably dry. Not only had roughly 94
percent of our forecast area received below normal precipitation,
but around 84% had measured LESS THAN HALF NORMAL (meaning less than
around 0.84"). Going hand in hand with this, seasonal snowfall was
also far-below normal in most areas. Through Feb. 10th, Grand Island
airport had measured merely 2.9" of snow, which was not only 15"
below normal but also marked the 2nd-least on record out of 124
years! Of the less than 10% of our area that had collected above
normal winter precipitation through Feb. 10th, the vast majority of
it included portions of Mitchell, Jewell and Osborne counties in
north central Kansas, where a significant early-January snowfall
occurred.
Turning to current drought conditions and recent trends (per weekly
updates by the U.S. Drought Monitor/USDM), and despite the
aforementioned prevailing dryness, drought categories have actually
remained largely unchanged across our 30-county area so far this
winter. This is due to a combination of coming into the winter
months right on the heels of a notably-wet November, along with the
fact that winter is the climatologically-driest time of the year. As
of the Feb. 4th USDM issuance, around 84% of our area was under
Moderate Drought (D1), with only small slivers of Dawson, Valley,
and Sherman counties assigned Severe Drought (D2). Meanwhile, the
remaining 14% of our area was assigned less-serious Abnormally Dry
(D0), mainly centered over some Nebraska counties west of Highway
281 and along/south of Interstate 80.
The table below highlights precipitation totals and departures
from normal/percent of normal for this meteorological winter,
covering Dec. 1st - Feb. 10th. Data is shown for just a small
sampling of official NWS cooperative observers representing various
parts of our area, along with a few primary airport sites.
* NOTE: This table does not include the very recent Feb. 11-12th
snowfall, which brought a much-needed 0.15-0.40" liquid
equivalent to most of our forecast area.
Location *Precip Departure Percent of
North Central KS Dec 1-Feb 10 from Normal Normal
--------------- -------- ------ ---------
Beloit 2.30 +0.29 114
Phillipsburg 0.34 -1.39 20
Plainville 4WNW 0.71 -1.18 38
Smith Center 0.57 -1.06 35
Location *Precip Departure Percent of
South Central NE Dec 1-Feb 10 from Normal Normal
--------------- -------- ------ ---------
Cambridge 0.10 -1.21 8
Elwood 8S 0.16 -1.11 13
Grand Island Arpt 0.54 -1.17 32
Hastings Airport 0.75 -0.94 44
Hebron 1.40 -0.74 65
Holdrege 0.32 -1.20 21
Kearney Airport 0.33 -1.07 24
Lexington 6SSE 0.22 -0.99 18
Ord 0.63 -0.90 41
Osceola 0.40 -1.63 20
Superior 1.01 -1.00 50
St. Paul 0.55 -1.11 33
York 3N 0.98 -1.20 45
...Climatological Outlook and Shorter-Term Forecast Conditions...
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:
The next week (through Feb. 19):
According to our latest official 7-day forecast, this next week
looks overall-cold and at-times snowy, with various/intermittent
chances for wintry precipitation especially Friday night into
Saturday and then again between Monday morning and Tuesday night.
While widespread heavy snow is not currently anticipated, at least
modest snow accumulation is quite possible...adding to the existing
fresh snowpack. Temperature-wise, this next week will average well
below normal for mid-February, with daytime highs mostly in the
teens or 20s, and overnight lows mostly in the single digits above
or below zero. The primary warmer exception will be right away
Friday (Feb. 14), as highs briefly rebound into the 30s-40s in
between cold fronts.
Two weeks out (Feb. 20-26):
Looking out just a bit farther in time, the latest 8-14 day outlook
from the Climate Prediction Center (CPC) calls for a gradual warm-up
and return toward at least near-normal temperatures with a slight
lean toward below normal precipitation. Ensemble model data supports
these forecast trends, suggesting that high temperatures should
rebound more so into the 30s-50s range (albeit the degree of warming
could be modulated by the extent of snow cover).
Meteorological Spring (March-May):
Turning to the upcoming meteorological spring months of March-April-
May as a whole, the latest Climate Prediction Center (CPC) three-
month outlook (issued Jan. 16th) indicates "equal chances" across
our area for temperatures to average above normal, below normal, or
near normal. Precipitation in/near our forecast area is a mix of
equal chances and a slight lean toward below normal. Equal chances
means that there are no clear signals in current longer-range
forecast data to lean toward one of the possible outcomes over
another. Based on 30-year normals, total March-May precipitation
across the NWS Hastings coverage area typically ranges from 7-10",
with the lowest amounts generally west of Highway 183 and highest
amounts near the Highway 81 corridor.
U.S. Seasonal Drought Outlook (issued by CPC on Jan. 31st and valid
through April 30th):
Going hand in hand with the aforementioned slight lean toward below
normal precipitation this spring, this outlook indicates that
drought of at least Moderate (D1) intensity is likely to persist
across most of our area.
(The 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: https://www.cpc.ncep.noaa.gov)
...Long Range Probabilistic Outlooks...
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: 02/15/2025 - 05/16/2025
: 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
-------- ----- ----- ----- : --- --- --- --- --- ---
:Little Blue River
Deweese 10.0 16.0 17.0 : 14 15 <5 <5 <5 <5
:North Fork Solomon
Glade 11.0 16.0 18.0 : <5 12 <5 <5 <5 <5
:Bow Creek
Stockton 9.0 12.0 13.6 : <5 17 <5 <5 <5 <5
:Platte River
Darr 11.5 12.5 13.0 : 9 17 7 12 6 9
Overton 7.5 12.0 14.0 : 8 14 <5 <5 <5 <5
Kearney 7.0 8.0 9.0 : 5 8 <5 <5 <5 <5
:Wood River
Gibbon 15.0 16.0 16.5 : 10 20 8 15 7 14
Alda 10.0 11.0 12.2 : 14 36 11 20 8 15
Wood River Divers 19.5 20.5 21.5 : 7 14 5 13 <5 9
:Platte River
Grand Island 6.5 7.0 7.5 : 11 17 10 16 7 11
:South Loup River
Ravenna 5.5 7.5 9.5 : 8 16 <5 8 <5 6
:Mud Creek
Sweetwater 16.5 18.0 21.0 : 5 14 <5 6 <5 <5
:South Loup River
Saint Michael 9.5 14.0 17.0 : 8 14 <5 5 <5 <5
:Middle Loup River
Saint Paul 8.0 10.0 12.0 : <5 6 <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 15.0 18.0 : 5 6 <5 <5 <5 <5
:Loup River
Genoa 10.5 12.0 13.0 : 5 6 <5 5 <5 <5
:Beaver Creek
Genoa 15.0 17.0 19.0 : 5 18 <5 7 <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: 02/15/2025 - 05/16/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Little Blue River
Deweese 2.4 3.2 4.8 6.4 8.6 11.1 12.6
:North Fork Solomon
Glade 2.5 2.5 2.6 4.1 7.3 9.6 9.9
:Bow Creek
Stockton 4.3 4.3 4.3 4.6 6.1 7.7 8.0
:Platte River
Darr 6.5 6.5 6.5 7.6 9.9 11.1 13.8
Overton 3.8 3.8 3.8 3.8 4.9 6.5 9.2
Kearney 3.1 3.1 3.1 3.2 4.2 5.4 6.9
:Wood River
Gibbon 4.0 4.0 4.1 5.4 9.1 15.2 16.9
Alda 3.8 3.8 4.6 5.7 7.3 11.5 13.0
Wood River Divers 8.9 8.9 12.2 13.2 15.0 17.7 20.4
:Platte River
Grand Island 3.8 3.8 3.9 4.0 4.8 6.9 7.7
:South Loup River
Ravenna 2.6 2.6 3.2 3.9 4.5 5.0 7.0
:Mud Creek
Sweetwater 5.7 5.7 7.3 10.2 11.7 15.3 16.6
:South Loup River
Saint Michael 2.0 2.0 2.8 4.4 5.7 7.4 11.9
:Middle Loup River
Saint Paul 1.2 1.2 1.7 2.5 3.2 4.5 6.7
:North Loup River
Saint Paul 2.6 2.8 3.0 3.7 4.2 4.9 6.0
:Cedar River
Fullerton 1.8 2.1 2.7 3.4 5.1 6.4 9.5
:Loup River
Genoa 3.0 3.0 3.6 5.0 6.0 7.7 10.1
:Beaver Creek
Genoa 3.1 3.3 3.9 4.9 8.5 10.6 15.7
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: 02/15/2025 - 05/16/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Little Blue River
Deweese 2.3 2.3 2.2 2.2 2.1 2.1 2.1
:North Fork Solomon
Glade 2.4 2.4 2.3 2.2 2.2 2.1 2.1
:Bow Creek
Stockton 4.2 4.2 4.2 4.2 4.1 4.1 3.9
:Platte River
Darr 6.4 6.0 4.7 4.4 4.3 4.2 4.2
Overton 2.6 2.6 2.5 2.5 2.5 2.5 2.5
Kearney 2.5 2.5 2.4 2.2 2.1 2.1 2.1
:Wood River
Gibbon 4.0 4.0 4.0 4.0 4.0 4.0 4.0
Alda 3.8 3.8 3.8 3.8 3.8 3.8 3.8
Wood River Divers 8.9 8.9 8.9 8.9 8.9 8.8 8.8
:Platte River
Grand Island 3.6 3.6 3.5 3.2 3.2 3.2 3.2
:South Loup River
Ravenna 2.6 2.6 2.5 2.5 2.5 2.5 2.5
:Mud Creek
Sweetwater 5.7 5.7 5.5 5.4 5.3 5.2 5.2
:South Loup River
Saint Michael 2.0 2.0 1.6 1.5 1.3 1.2 1.2
:Middle Loup River
Saint Paul 1.0 0.9 0.7 0.5 0.4 0.3 0.3
:North Loup River
Saint Paul 2.5 2.5 2.5 2.3 2.2 2.2 2.1
:Cedar River
Fullerton 1.7 1.7 1.6 1.6 1.5 1.4 1.3
:Loup River
Genoa 3.0 3.0 3.0 3.0 3.0 3.0 3.0
:Beaver Creek
Genoa 3.0 3.0 3.0 2.9 2.9 2.8 2.8
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 National Wather Prediction Service
(NWPS).
...Future Outlooks...
The next/updated spring flood outlook will be issued in two weeks on
Thursday, Feb. 27th.
&&
Visit our local NWS Hastings website for current
weather/hydrological and climate information across our forecast
area at: https://www.weather.gov/hastings
NWS National Water Prediction Service (NWPS) river stage and
precipitation analysis data can be found at: https://water.noaa.gov
NOAA Climate Prediction Center (CPC) climate outlooks and soil
moisture monitoring can be found at:
https://www.cpc.ncep.noaa.gov
https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring
NOAA snowpack analysis from National Operational Hydrologic Remote
Sensing Center can be found at: https://www.nohrsc.noaa.gov
Additional climate information for the region can be obtained
from the High Plains Regional Climate Center: https://hprcc.unl.edu
Further information on drought conditions can be obtained at:
https://droughtmonitor.unl.edu
https://www.drought.gov
https://drought.unl.edu
USDA information on mountain snowpack/precipitation that feeds
rivers that flow into our region can be found at:
https://www.nrcs.usda.gov/resources/data-and-reports/snow-and-water-
interactive-map
NOAA snowpack analysis from National Operational Hydrologic Remote
Sensing Center can be found at: https://www.nohrsc.noaa.gov
Burea of Reclamation (USBR) information for various regional
reservoirs can be found at:
www.usbr.gov/gp/hydromet/curres_google.htm
$$
Pfannkuch