Flood Potential Outlook
Issued by NWS Grand Forks, ND

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
000
FGUS73 KFGF 221556
ESFFGF

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-
067-071-073-077-081-091-095-097-099-281200-

Probabilistic Hydrologic Outlook
National Weather Service Eastern North Dakota/Grand Forks ND
1055 AM CDT Thu Mar 22 2018

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

         This outlook covers the Red River of the North
         and its Minnesota and North Dakota tributaries.

.OUTLOOK SUMMARY...

  The threat for significant (moderate to major) snowmelt flooding
remains low across the main-stem Red River and its tributaries.
Current conditions and expectations into late April now indicate
minor to low moderate flooding (generally near long term averages) as
the predominant risk.

Major Flooding...

  There is a low risk (less than 35 percent chance) of major flooding
at all forecast points across the Red River basin.

Moderate Flooding...

  There is a high risk (greater than 65 percent chance) of moderate
flooding at Oslo MN on the Red River and Hallock MN on the Two Rivers
River. There is a medium risk (35 to 65 percent chance) of moderate
flooding at Abercrombie ND on the Wild Rice River and at Fargo,
Drayton, and Pembina on the Red River. Elsewhere, there is a low risk
(less than 35 percent chance) of moderate flooding.

Minor Flooding...

  There is a high risk (greater than 65 percent chance) of minor
flooding at Fargo, Grand Forks, Oslo, Drayton, and Pembina on the Red
River, along with Abercrombie ND on the Wild Rice River, Sabin MN on
the South Branch Buffalo River, Dilworth MN on the Buffalo River,
Crookston MN on the Red Lake River, Hallock MN on the Two Rivers
River, and Minto ND on the Park River. There is a medium risk (35 to
65 percent chance) of minor flooding at Wahpeton and Halstad on the
Red River, along with Hendrum MN on the Wild Rice River, Enderlin ND
on the Maple River, and Hillsboro ND on the Goose River. Elsewhere,
this is a low risk (less than 35 percent chance) of minor flooding.


.OUTLOOK DISCUSSION...

  Abnormally dry conditions have steadily diminished across most of
the area and should continue to improve. The early spring period
should start with temperatures continuing to be below normal but
trend to near normal by late April, in addition to somewhat above
normal moisture.

  Snowpack and snow water content is now near normal in most areas
thanks to recent precipitation. Snowpack and associated snow water
content remains least across the far southern Red River Valley and
far northeastern ND with the highest across east central ND and into
far northwestern MN (6 to 22 inches of snowpack holding two to five
inches of water).

  Base streamflow remains near normal while soil moisture remains
near to well below normal due to dry conditions last summer and fall
(prior to freeze-up). Frost depths are slightly lower than normal and
range from 40 to 50 inches across the area.


.CHANGES FROM PREVIOUS OUTLOOK...

  Changes from the previous outlook include moderate increases at
points along the Red River with slight increases at some points along
the tributaries. While minor to low moderate flooding is possible,
the main message is that the threat for significant (moderate to
major) snowmelt flooding remains low across the main-stem Red River
and its tributaries.


.NEXT OUTLOOK...

  The next monthly hydrologic outlook will be issued by Thursday,
April 26th.


  The following message has three river data sections:

    - The first (Table 1) gives the current and normal/historical
       chances of river locations reaching their minor, moderate,
        and major flood categories.

    - The second (Table 2) gives the current chances of river
       locations rising above the river stages listed.

    - The third (Table 3) gives the current chances of river
       locations falling below the river stages listed.

.Red River Long-Range Probabilistic Outlook by Flood Category...
             Valid from March 25, 2018 to June 23, 2018.


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 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:   03/25/2018 - 06/23/2018

                                         : 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 :  60  61   30  35    6  15
  HICKSON             30.0   34.0   38.0 :  20  30    5  14   <5  <5
  FARGO               18.0   25.0   30.0 :  92  82   45  42   17  27
  HALSTAD             26.0   32.0   37.5 :  35  37   11  20   <5  11
  GRAND FORKS         28.0   40.0   46.0 :  93  57   34  34    6  11
  OSLO                26.0   30.0   36.0 : >95  65   92  56   17  21
  DRAYTON             32.0   38.0   42.0 :  82  50   44  35    6  12
  PEMBINA             39.0   44.0   49.0 :  87  56   54  43   21  23

                                         : 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
--------            ------ ------ ------ : --- ---  --- ---  --- ---
Minnesota Tributaries.....
  SABIN               13.0   15.0   19.0 :  70  51   11  17   <5  <5
  HAWLEY               8.0    9.0   11.0 :  28  36   12  23   <5  <5
  DILWORTH            13.0   20.0   26.0 :  82  69   16  20   <5  <5
  TWIN VALLEY         10.0   12.0   14.0 :   5  17   <5   6   <5  <5
  HENDRUM             20.0   28.0   32.0 :  57  56   16  24   <5   6
  SHELLY              14.0   20.0   23.0 :  28  28   <5  11   <5  <5
  CLIMAX              20.0   25.0   30.0 :  14  26   <5  12   <5   7
  HIGH LANDING        12.0   12.5   13.0 :   9  18    6  17   <5  13
  CROOKSTON           15.0   23.0   25.0 :  77  51   13  11   <5   8
  ABOVE WARREN        67.0   71.0   75.0 :  14  13   <5  <5   <5  <5
  ALVARADO           106.0  108.0  110.0 :  25  21   11  15   <5  <5
  HALLOCK            802.0  806.0  810.0 : >95  60   85  43    7  11
  ROSEAU              16.0   18.0   19.0 :  14  20   <5   8   <5  <5
   Note: The Roseau numbers consider the flow thru its diversion

                                         : 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
--------            ------ ------ ------ : --- ---  --- ---  --- ---
North Dakota Tributaries.....
  ABERCROMBIE         10.0   12.0   18.0 :  77  42   60  38   19  20
  VALLEY CITY         15.0   16.0   17.0 :   6  10    5   9   <5  <5
  LISBON              15.0   17.0   19.0 :  16  10   10   8    6   6
  KINDRED             16.0   19.0   20.5 :  26  19   15  10    7   9
  WEST FARGO DVRSN    18.0   20.0   21.0 :  34  23   21  18   15  12
  HARWOOD            884.0  886.0  891.0 :  25  24   22  22    8  10
  ENDERLIN             9.5   12.0   14.0 :  52  21    9  10   <5  <5
  MAPLETON           905.0  908.0  910.0 :  34  37   10  14   <5  <5
  HILLSBORO           10.0   13.0   16.0 :  45  15   17   9   <5  <5
  MINTO                6.0    8.0   11.0 :  77  31   26  11   <5  <5
  GRAFTON             12.0   13.5   14.5 :  14  22    6   8   <5   6
  WALHALLA            11.0   16.0   18.0 :  <5  19   <5  <5   <5  <5
  NECHE               18.0   19.0   20.5 :  <5  30   <5  28   <5  19

LEGEND:
    CS  =  Conditional Simulation (outlook for current conditions)
    HS  =  Historical  Simulation ( "       "  normal  conditions)
    ft  =  feet                   (above gage zero datum)


...Table 2--Exceedance Probabilities...

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 at the locations listed.

  Interpretation Aid: The flood stage for Wahpeton on the Red
   River of the North is 11 feet. There is a 50 percent chance
    that it will rise above 11.6 feet and only a 10 percent chance
     that it will rise above 14.4 feet.

                                 Chance of Exceeding Stages
at Specific Locations                                        Valid
Period:   03/25/2018 - 06/23/2018

LOCATION              95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Red River of the North.....
  WAHPETON             8.6    8.9   10.3   11.6   13.4   14.4   15.2
  HICKSON             17.7   18.1   19.3   23.9   29.0   32.3   34.0
  FARGO               17.7   18.4   19.8   24.5   27.8   33.1   34.8
  HALSTAD             16.2   17.6   18.8   22.7   28.9   32.8   36.3
  GRAND FORKS         27.1   30.0   32.8   36.2   42.2   44.6   47.1
  OSLO                27.6   30.6   32.6   33.9   35.5   36.5   37.6
  DRAYTON             28.3   30.2   32.9   36.7   40.2   41.0   42.4
  PEMBINA             37.9   38.7   41.4   45.7   47.8   50.1   51.8


Minnesota Tribs:      95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
South Fork Buffalo River.....
  SABIN               12.1   12.3   12.8   13.4   14.4   15.1   15.7
Buffalo River.....
  HAWLEY               4.8    5.2    6.1    7.2    8.3    9.2    9.4
  DILWORTH            11.7   12.4   14.2   16.8   19.4   20.3   21.6
Wild Rice River.....
  TWIN VALLEY          4.4    4.6    5.0    6.1    7.3    9.5   10.0
  HENDRUM             16.6   17.5   18.5   21.2   26.3   29.1   29.8
Marsh River.....
  SHELLY               9.0    9.8   10.5   12.2   14.3   18.6   19.6
Sand Hill River.....
  CLIMAX              11.1   11.4   11.7   12.0   18.1   20.8   25.0
Red Lake River.....
  HIGH LANDING         6.3    6.6    7.3    8.4   10.0   11.9   12.6
  CROOKSTON           13.0   14.1   15.3   17.1   20.5   23.6   24.6
Snake River.....
  ABOVE WARREN        63.6   64.0   64.5   65.0   65.8   67.4   68.2
  ALVARADO           100.6  101.7  102.7  104.1  106.1  108.3  109.1
Two Rivers River.....
  HALLOCK            805.0  805.4  806.2  807.4  808.8  809.6  810.1
Roseau River..... considering the flow thru the Roseau diversion
  ROSEAU              10.7   10.9   11.5   12.7   15.1   16.3   16.6


North Dakota Tribs:   95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Wild Rice River.....
  ABERCROMBIE          6.7    7.5   10.0   13.0   17.1   19.8   20.8
Sheyenne River.....
  VALLEY CITY          7.7    8.2   10.1   12.1   12.6   13.8   16.0
  LISBON               7.5    8.2   10.2   12.1   13.0   17.0   20.1
  KINDRED              9.2   10.6   11.9   14.5   16.1   20.1   20.7
  WEST FARGO DVRSN    14.2   14.4   15.5   17.0   18.9   22.4   23.1
  HARWOOD            877.0  878.2  878.9  880.4  883.8  889.9  891.9
Maple River.....
  ENDERLIN             8.4    8.7    9.0    9.5   10.5   11.9   12.7
  MAPLETON           900.4  900.8  901.9  903.1  905.8  907.7  909.2
Goose River.....
  HILLSBORO            5.7    6.5    8.6    9.7   12.1   14.0   14.5
Forest River.....
  MINTO                4.5    5.4    6.2    7.2    8.1    8.7    9.6
Park River.....
  GRAFTON              9.1    9.2    9.4    9.7   10.3   12.9   13.8
Pembina River.....
  WALHALLA             3.3    3.5    3.8    4.7    6.7    8.5    9.1
  NECHE                5.4    5.7    6.4    7.8   11.3   15.5   17.5


...Table 3--Non-Exceedance Probabilities...

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 at the locations listed.

  Interpretation Aid: The flood stage for Wahpeton on the Red
   River of the North is 11 feet. There is a 50 percent chance
    that it will fall below 5.4 feet and only a 10 percent chance
     that it will fall below 4.2 feet.


                               Chance of Not Exceeding Stages
at Specific Locations                                        Valid
Period:   03/25/2018 - 06/23/2018

LOCATION              95%    50%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Red River of the North.....
  WAHPETON             8.2    7.9    6.5    5.4    4.8    4.2    3.8
  HICKSON             14.0   13.2   12.4   11.3   10.8   10.3   10.1
  FARGO               15.9   15.8   15.6   14.9   14.6   14.3   14.1
  HALSTAD              7.6    7.4    7.2    5.9    4.9    4.0    3.6
  GRAND FORKS         16.1   16.0   16.0   15.9   15.9   15.7   15.5
  OSLO                 7.1    7.0    7.0    7.0    6.9    6.7    6.4
  DRAYTON             11.7   11.7   11.6   11.6   11.6   11.6   11.4
  PEMBINA              9.0    9.0    8.9    8.9    8.9    8.8    8.5


Minnesota Tribs:      95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
South Fork Buffalo River.....
  SABIN                6.6    6.3    5.9    5.6    5.4    5.1    5.0
Buffalo River.....
  HAWLEY               3.9    3.9    3.7    3.6    3.5    3.4    3.3
  DILWORTH             5.2    5.0    4.5    4.1    3.8    3.5    3.4
Wild Rice River.....
  TWIN VALLEY          2.8    2.7    2.7    2.4    2.2    1.9    1.8
  HENDRUM              4.2    3.8    3.4    2.8    2.4    2.0    2.0
Marsh River.....
  SHELLY               4.4    4.2    4.1    4.0    4.0    3.9    3.9
Sand Hill River.....
  CLIMAX               5.1    4.9    4.8    4.6    4.5    4.3    4.2
Red Lake River.....
  HIGH LANDING         1.6    1.5    1.1    0.9    0.8    0.7    0.7
  CROOKSTON            3.6    3.0    2.8    2.7    2.7    2.7    2.7
Snake River.....
  ABOVE WARREN        60.8   60.8   60.7   60.7   60.7   60.7   60.7
  ALVARADO            96.0   96.0   95.9   95.8   95.8   95.8   95.8
Two Rivers River.....
  HALLOCK            794.3  794.1  794.0  793.9  793.7  793.6  793.4
Roseau River..... considering the flow thru the Roseau diversion
  ROSEAU               5.7    5.7    5.3    4.8    4.6    4.5    4.5


North Dakota Tribs:   95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Wild Rice River.....
  ABERCROMBIE          1.0    0.9    0.8    0.6    0.5    0.2    0.1
Sheyenne River.....
  VALLEY CITY          4.1    3.7    3.6    3.5    3.5    3.5    3.5
  LISBON               3.3    3.0    2.6    2.4    2.4    2.3    2.3
  KINDRED              3.9    3.5    2.9    2.5    2.4    2.3    2.3
  WEST FARGO DVRSN    10.4   10.2   10.0    9.7    9.5    9.4    9.3
  HARWOOD            871.1  869.8  868.8  867.8  867.0  866.6  866.4
Maple River.....
  ENDERLIN             2.0    1.9    1.7    1.7    1.7    1.7    1.7
  MAPLETON           895.4  895.1  895.0  894.9  894.8  894.7  894.6
Goose River.....
  HILLSBORO            1.7    1.7    1.7    1.7    1.7    1.6    1.6
Forest River.....
  MINTO                1.5    1.4    1.3    1.3    1.3    1.2    1.2
Park River.....
  GRAFTON              7.2    7.2    7.2    7.1    7.1    7.1    7.1
Pembina River.....
  WALHALLA             1.8    1.7    1.6    1.5    1.4    1.2    1.1
  NECHE                2.8    2.7    2.4    2.3    2.1    1.7    1.7


  Probabilistic Hydrologic Outlooks now use 64 years (1949-2012)
    of past weather, temperature, and precipitation for the
    ensemble predictive hydrographs used in calculating the
    probabilities of exceeding a river level for the valid period
    of the outlook.

  Outlook Schedule - The National Weather Service in Grand Forks,
    North Dakota will be providing the Advanced Hydrologic
    Prediction Services (AHPS) Long-Range Probabilistic Hydrologic
    Outlooks for the Red River of the North and its Minnesota and
    North Dakota tributaries according to the following schedule:

    - Near the end of the month throughout the year, except for...

    - The Spring Flood and Water Resources Outlooks that will be
       issued at least twice a month during the spring snowmelt
        season beginning in mid-to-late February or early March.


.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, snow, and
 soil conditions using over 60 years of past precipitation and
 temperature conditions that were experienced for those past years
 during the timeframe of the outlook period. These crests can then
 be ranked from lowest to highest and assigned an exceedance
 probability. For example, for a series of 50 years, the lowest
 ranked crest has 49 crests above it. 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 Impacted-Based 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
 Advanced Hydrologic Prediction Services (AHPS).

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


.ADDITIONAL INFORMATION SOURCES...

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 at:

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

 then click on "Rivers and Lakes" above the map.

Current river conditions for all river forecast points in the Red
 River of the North and Devils/Stump Lake basins are available on
 our web site. Also, 7-day deterministic forecasts will be issued
 at least once a day when river forecast locations will be at or
 above flood during that period.

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

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

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

$$
     weather.gov/fgf
NNNN





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