Flood Potential Outlook
Issued by NWS Grand Forks, ND

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MNC005-007-027-029-051-057-069-077-087-089-107-111-113-119-125-
135-159-167-NDC003-005-017-019-027-035-039-063-067-071-073-077-
081-091-095-097-099-311200-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS ND
925 AM CST Thu March 2 2017

...SPRING FLOOD AND WATER RESOURCES OUTLOOK...

...RED RIVER BASIN OUTLOOK FOR RIVER FLOOD POTENTIAL...

         This Outlook covers the Red River of the North
         and its Minnesota and North Dakota tributaries,
               from March 5th to June 3rd 2017.

...RISK OF SNOW MELT FLOODING MOSTLY NORTH OF HILLSBORO/HALSTAD...

.OUTLOOK SUMMARY...

 * Probabilities for exceeding Major, Moderate, Minor Flood Stage...

Major Flooding...

   A high risk (greater than 65%) of Major Flooding is expected at
Pembina ND on the Red River, Grafton ND on the Park River, Neche
ND on the Pembina River, and at High Landing MN on the Red Lake
River.

 Moderate Flooding...

  A high risk (greater than 65%) of Moderate Flooding is expected at
Oslo, Drayton, and Pembina on the Red River. Additionally, at High
Landing MN on the Red Lake River, Hallock MN on the Two Rivers River,
Grafton ND on the Park River, and Neche ND on the Pembina River.

  A medium risk (35 to 65%) of Moderate Flooding is expected at
Fargo/Moorhead and Grand Forks on the Red River. Additionally, at
Alvarado on the Snake River, Abercrombie on the Wild Rice River,
and on the West Fargo Diversion on the Sheyenne River.

 Minor Flooding...

  A low risk (less than 35%) of Minor Flooding is expected at
Hickson on the Red River. On the Minnesota tributaries, at Twin
Valley on the Wild Rice River, Shelly on the Marsh River, Climax on
the Sandhill River, and Warren on the Snake River. On the North
Dakota tributaries, at Valley City and Lisbon on the Sheyenne River.

  Otherwise there is a high to medium risk of Minor Flooding for the
rest of the forecast locations in the Red River of the North basin.

 * This 90-day Outlook covers the period from March 5th to June 3rd
2017.

.OUTLOOK DISCUSSION...

  Hydrologic and climate conditions which affect each of the several
factors that significantly determine the timing and magnitude of
spring snowmelt flooding within the Red River of the North are
discussed below:

 * SNOWPACK CONDITIONS...

  Since the last outlook, there has been a period of above normal
temperatures, resulting in a reduction in the areal coverage and
volume of the snowpack. However, some 10 to 20 inches of snow is
still on the ground in the extreme northern part of the Red River
Basin and northwest Minnesota. Specifically, in the Grafton, Pembina
to Hallock regions of the valley proper and portions of Kittson,
Marshall, and Roseau counties in northwest Minnesota. Additionally,
10 to 20 inches of snow extend across most of the Devils Lake basin.

  Elsewhere, the snow depth tapers off rapidly south of a
Cooperstown to Oslo to Thief River Falls line. Further south from
Valley City to Grand Forks to Fosston, only trace residual snow
patches remain, including roughly the southern half of the Red River
Basin.

  Snow Water Equivalents range from 3 to 5 inches of water in the
deepest snowpack northeast of Devils Lake towards Pembina, then
quickly decrease south of a Grafton to Warren to Warroad line.

  For the most current snowpack information, refer to the National
Operational Hydrologic Remote Sensing Center (NOHRSC) snow
interactive snow information web site at:

   www.nohrsc.noaa.gov/interactive/html/map.html

 * SOIL MOISTURE AND FROST DEPTHS...

  The warm and moist fall weather extending into the early winter
months have kept the soil moistures high going into freeze-up. As
of February 28th, the soil moistures in eastern North Dakota and
far northwestern Minnesota range from the 90th to 99th percentile.

  Due to the warm autumn and deep snowpack on the ground before the
very cold temperatures, frost depths are less than normal for this
time of year across northern portions of the Red River Valley,
generally around 12 inches or less. On the other hand, the recent
cool down, coupled with generally snow-free ground, has allowed
frost depths to increase across southern parts of the valley,
ranging from 12-24 inches, with 19 inches measured at Grand Forks and
near 30 inches at Fargo.

 * RIVER FLOWS...

  The USGS indicates that rivers and streams in the basin are running
two to six times their normal flow for this time of the year. High
flows are attributed to excessive late summer and fall rainfalls,
very moist soils, and recent thaw conditions.

 * RIVER ICE...

  There is little to no solid ice cover on the rivers and streams
in the southern Red River Basin, with more normal ice thickness of
12 to 18 inches evident across the northern basin. Be aware that
there will be thinner ice in more turbulent water, and especially
near rock-riffle dams.

 * FACTORS YET TO BE DETERMINED...
    - Further snowpack growth,
    - Rate of snowmelt/thaw,
    - Heavy rain or snow on frozen ground during thaw or peak flood,
    - Heavy rain on ice-covered rivers causing short-term ice jams.

 * SPRING SEASON CLIMATE OUTLOOK...

  The NWS Climate Prediction Center is forecasting a March through
May period with equal chances for below normal or above normal
temperatures, combined with an above normal precipitation regime.

Details can be found at: www.cpc.noaa.gov

.NEXT HYDROLOGIC OUTLOOK...

  The next monthly hydrologic outlook will be issued on, or around,
Thursday, March 24th, should conditions warrant.

.FLOOD OUTLOOK PROBABILITIES TABLES...

  The following is broken into two sections...the first gives the
current and normal/historical chances of river locations reaching
their Minor, Moderate, and Major Flood Categories. The second gives
the current chances of river locations rising above the river
stages listed.


...RED RIVER LONG-RANGE PROBABILISTIC OUTLOOK BY FLOOD CATEGORY...

            Valid from March 5, 2017 to June 3, 2017

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:   03/05/2017 - 06/03/2017

                                         : 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
--------            ------ ------ ------ : --- ---  --- ---  --- ---
Red River of the North.....
  Wahpeton            11.0   13.0   15.0 :  69  53   28  26   12  14
  Hickson             30.0   34.0   38.0 :  20  23    5  12   <5  <5
  Fargo               18.0   25.0   30.0 :  94  80   42  39   17  23
  Halstad             26.0   32.0   37.5 :  40  35   13  18   <5   9
  Grand Forks         28.0   40.0   46.0 : >95  59   49  34    6  10
  Oslo                26.0   30.0   36.0 : >95  63  >95  56   26  20
  Drayton             32.0   38.0   42.0 : >95  51   89  35   13  11
  Pembina             39.0   44.0   49.0 : >95  56  >95  43   78  23
Minnesota Tributaries.....
  Sabin               13.0   15.0   19.0 :  72  50   13  15   <5  <5
  Hawley               8.0    9.0   11.0 :  52  38   22  26   <5  <5
  Dilworth            13.0   20.0   26.0 :  87  67   18  21   <5  <5
  Twin Valley         10.0   12.0   14.0 :  11  18   <5   6   <5  <5
  Hendrum             20.0   28.0   32.0 :  69  55   16  23   <5   6
  Shelly              14.0   20.0   23.0 :  17  31   <5  11   <5   6
  Climax              20.0   25.0   30.0 :  21  24    6  11   <5   7
  High Landing        12.0   12.5   13.0 : >95  46  >95  43   86  33
  Crookston           15.0   23.0   25.0 : >95  53   18  13    6   8
  Above Warren        67.0   71.0   75.0 :  22  14   <5  <5   <5  <5
  Alvarado           106.0  108.0  110.0 :  77  21   43  16    7  <5
  Hallock            802.0  806.0  810.0 : >95  63  >95  45   30  15
  Roseau              16.0   18.0   19.0 :  35  19   <5   5   <5  <5
   Note: The Roseau numbers consider the flow through its diversion
North Dakota Tributaries.....
  Abercrombie         10.0   12.0   18.0 :  55  37   40  34    8  20
  Valley City         15.0   16.0   17.0 :  30   8   28   7   21  <5
  Lisbon              15.0   17.0   19.0 :  28   9   19   8   12   6
  Kindred             16.0   19.0   20.5 :  59  18   28  10   17   9
  West Fargo Dvrsn    18.0   20.0   21.0 :  65  21   35  16   31  11
  Harwood            884.0  886.0  891.0 :  43  23   30  21   11  10
  Enderlin             9.5   12.0   14.0 :  46  21   14  10   <5  <5
  Mapleton           905.0  908.0  910.0 :  56  33   16  14   <5  <5
  Hillsboro           10.0   13.0   16.0 :  76  17   33  10   <5  <5
  Minto                6.0    8.0   11.0 : >95  26   23   8   <5  <5
  Grafton             12.0   13.5   14.5 : >95  19  >95   6   94  <5
  Walhalla            11.0   16.0   18.0 : >95  19    8  <5   <5  <5
  Neche               18.0   19.0   20.5 : >95  28  >95  26   93  19

LEGEND:
    CS  =  Conditional Simulation (Outlook for current conditions)
    HS  =  Historical  Simulation ( "       "  normal  conditions)
    FT  =  Feet                   (above gage zero datum)


...RED RIVER LONG-RANGE PROBABILISTIC OUTLOOK BY RIVER STAGE...
            Valid from March 5, 2017 to June 3, 2017

In Table 2 below, the 95 through 5 percent columns indicate the
 current probability of exceeding the listed stage levels (ft)
  for the valid time period.

               ...TABLE 2--EXCEEDANCE PROBABILITIES...
               Valid Period:   03/05/2017 - 06/03/2017

LOCATION              95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Red River of the North.....
  Wahpeton             8.7    9.5   10.8   11.6   13.3   15.2   15.6
  Hickson             17.7   18.4   22.2   24.5   28.0   32.9   34.0
  Fargo               17.9   19.1   20.9   24.1   28.5   32.5   35.0
  Halstad             15.6   17.2   19.7   24.6   29.9   33.6   35.6
  Grand Forks         29.5   31.0   35.5   40.0   43.3   45.0   47.7
  Oslo                30.7   31.7   33.8   34.8   36.0   36.7   37.9
  Drayton             35.8   37.9   39.6   40.8   41.3   42.2   43.4
  Pembina             46.9   47.6   49.5   50.8   51.6   52.7   53.5

Minnesota Tribs:      95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
South Fork Buffalo River.....
  Sabin               11.5   11.9   12.8   13.6   14.5   15.2   15.9
Buffalo River.....
  Hawley               5.8    6.1    6.9    8.1    8.8    9.5   10.2
  Dilworth            11.5   12.8   14.7   17.8   19.6   20.9   22.0
Wild Rice River.....
  Twin Valley          5.3    5.8    6.6    7.6    8.8   10.4   11.5
  Hendrum             14.6   16.2   19.1   22.3   26.2   29.1   30.4
Marsh River.....
  Shelly               6.5    7.2    9.1   10.8   12.9   16.1   18.0
Sand Hill River.....
  Climax               8.9   10.1   11.6   13.2   17.2   22.2   27.4
Red Lake river.....
  High Landing        12.9   13.0   13.1   13.2   13.3   13.4   13.6
  Crookston           15.8   17.3   19.1   20.8   22.5   24.4   25.5
Snake River.....
  Above Warren        64.4   64.6   65.0   65.6   66.8   68.1   69.7
  Alvarado           105.1  105.3  106.3  107.8  109.0  109.8  110.3
Two Rivers River.....
  Hallock            807.6  808.1  808.7  809.5  810.2  810.7  811.1
Roseau River..... considering the flow through the Roseau diversion.
  Roseau              12.8   13.0   14.2   15.4   16.4   17.3   17.4

North Dakota Tribs:   95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Wild Rice River.....
  Abercrombie          3.7    5.4    7.4   11.2   15.0   17.5   19.8
Sheyenne River.....
  Valley City         11.5   11.7   12.3   13.1   16.5   20.0   23.4
  Lisbon              11.2   11.4   11.9   13.0   15.8   19.5   24.5
  Kindred             13.8   14.0   14.8   16.5   20.0   21.1   21.1
  West Fargo Dvrsn    16.4   16.5   17.3   18.5   22.3   23.1   23.2
  Harwood            878.3  879.1  880.1  883.0  887.0  891.2  892.0
Maple River.....
  Enderlin             7.3    7.6    8.4    9.1   10.6   12.3   13.4
  Mapleton           899.1  899.7  902.1  905.8  907.6  908.7  909.4
Goose River.....
  Hillsboro            7.8    8.5   10.2   12.3   13.6   14.5   15.9
Forest River.....
  Minto                6.5    6.7    7.1    7.5    7.9    8.7    8.8
Park River.....
  Grafton             14.5   14.8   16.1   17.2   18.1   19.4   20.0
Pembina River.....
  Walhalla            11.6   12.0   12.7   13.9   14.8   15.8   16.4
  Neche               20.3   20.7   21.2   21.4   21.5   21.6   21.6

.THE OUTLOOK PRODUCTION PROCESS...

  This long range probabilistic outlook is based on a series of peak
river levels or crests taken from the forecast hydrograph results
of the NWS Community Hydrologic Prediction System (CHPS). The model
is run for multiple scenarios starting at current river levels and
soil conditions using over 60 years of past precipitation and
temperature conditions that were experienced for those past years
during the time-frame of the outlook period. These crests can then
be ranked from lowest to highest, and then be assigned an
exceedance probability. For example, for a series of 50 years, the
lowest ranked crest has 49 crests above it and since 95 percent
of the crests are above it, it is assigned a 95 percent probability
of exceedance (POE).

A YouTube video on "How to Interpret River Outlook Products" is at:

         www.youtube.com/watch?v=pSoEgvsnpv4

  The probabilities can be used for risk management by using them as
an indication of the range of crests that may be expected during
the valid period of the outlook.

  By providing a range of peak river level probabilities, the NWS is
contributing to the area`s Decision Support Services that help
with long-range flood planning and response readiness. This outlook
is a part of NOAA`s National Weather Service`s AHPS (Advanced
Hydrologic Prediction Services).

  This outlook was produced using precipitation and temperatures
for the years 1949 through 2012.

.ADDITIONAL INFORMATION SOURCES...

  The AHPS Long-Range Probabilistic Hydrologic Outlooks are issued
each month typically between the first and second Friday after
mid-month. However, Spring Flood and Water Resources Outlooks are
issued several times during the critical spring melt period,
usually on Thursdays beginning in late February or early March and
ending in early April, depending on the spring flooding conditions.

  This outlook is also presented as graphs of the probability of
stage exceedance for the full period and for weekly intervals during
the period. These graphs, together with explanations that help in
interpreting them, are available from the NWS Grand Forks AHPS web
page:

        www.weather.gov/grandforks or weather.gov/fgf

  Then click on "Rivers and Lakes" on the tab above the map.

  Current river conditions for all river forecast points in the Red
River of the North and Devils/Stump Lake basins are also available
on our web site, as well as 7-day forecasts when river levels at
the forecast point is in or near flood.

  Additional Probabilistic Hydrologic Outlooks will be issued
monthly throughout  the rest of the year during the later part of the
month or as conditions warrant.

If you have any questions, contact the NWS at 701-772-0720.

  Refer to the separate Devils Lake Probabilistic Hydrologic Outlook
for Devils and Stump Lakes Probability of Exceedance levels and
low-water non-exceedance levels.

You can follow us on Facebook at: www.facebook.com/NWSGrandForks
 and on Twitter at: @NWSGrandForks.

$$

www.weather.gov/fgf

NNNN



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