Flood Potential Outlook
Issued by NWS Grand Forks, ND

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FGUS73 KFGF 191932
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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-
081-091-095-097-099-301200-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS ND
135 PM CST THU FEB 19 2015

...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.

...MEDIUM RISK FOR MINOR SPRING SNOWMELT FLOODING...

...LOW RISK FOR MODERATE OR MAJOR SPRING SNOWMELT FLOODING

. OUTLOOK SUMMARY...

 * There is a MEDIUM risk (greater than 33%) for minor flooding
   at Fargo/Moorhead on the mainstem Red...and for Sabin and
   Dilworth, MN on the Buffalo river. (Please note that the flood
   stages for Sabin...Dilworth and Hawley, MN will be raised by
   a foot by the time of the next spring flood outlook scheduled
   to be released on Thursday, March 5th, 2015. Risk corresponding
   to those new flood stages are included in Table 1 below.)

 * There is a low risk (between 33% and 5%) for minor flooding at
   Wahpeton/Breckenridge...Halstad...Grand Forks...Oslo and Pembina
   on the mainstem Red...Hendrum, MN on the eastern Wild Rice...
   Hallock, MN on the Two Rivers river...Abercrombie, ND on the
   western Wild Rice...Kindred and Harwood, ND on the Sheyenne...
   the West Fargo on the Diversion...Enderlin and Mapleton, ND on
   the Maple and lastly...Minto, ND on the Forest.

 * There is a low risk for moderate flooding at Wahpeton...Fargo
   and Oslo on the Red...as well as at Abercrombie...Kindred...
   Harwood...West Fargo Diversion and Mapleton. Otherwise...there
   is a less than 5% risk for moderate flooding at all our other
   river forecast locations on the mainstem Red and its Minnesota
   and North Dakota tributaries.

 * This 90-day Outlook covers the period from Monday, February 23rd
    through Sunday, May 24th, 2015.

. 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...
   Snowdepths ranged from 1 to 15 inches with lesser amounts in the
    middle Sheyenne Basin and far southern Red River Basin. Highest
      amounts ranged across northern tier counties and include
       portions of the Pembina...Two Rivers...Tamarac...and Roseau
        River Basins. Overall snowpack moisture is less than an inch
         across the southern two-thirds of the Red River Basin and
          from one to two inches across the northern third.

 * SOIL MOISTURE AND FROST DEPTHS...
   Soil moisture reports across most of the Red River Basin lay near
    long term normal /25th to 75th percentile/ ranges with somewhat
     above normal soil moisture evident across the Devils Lake Basin
      and northeast North Dakota. Frost depths are estimated to be
       between three and four feet across the basin.

 * RIVER FLOWS...
   All rivers are frozen solid with base flows and river levels
    are mainly within long term normal /25th to 75th percentile/
ranges.

 * RIVER ICE...
   Ice depths on the rivers and streams in the basin are within the
    normal range...from one and a half to two and a half feet thick.

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

* SHORT TERM WEATHER FORECAST...look for mainly dry and colder
  than normal conditions through late February into early March with
  no major preciptation events expected.

* SPRING FLOOD SEASON CLIMATE OUTLOOK...near normal temperature and
  precipitation is expected through March and April.

. NEXT SPRING FLOOD OUTLOOK is scheduled to be issued on...
                                Thursday, March 5th, 2015.

. FLOOD OUTLOOK PROBABILITIES TABLES...

The following message has two sectitons...the first gives the
 current and normal/historical chances of river locations reaching
  their Minor...Modrate...and Major Flood Category...the second
   gives the current chances of river locations rising above river
    stages listed.


...Red River Long-Range Probabilistic Outlook by Flood Category...

            Valid from February 23, 2015  to May 24, 2015

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:   2/23/2015 - 5/24/2015

                                         : Current and Historical
                                         :  Chances of Exceeding
                                         :    Flood Categories
                                         :   as s 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 :  20  49    6  23   <5  10
  HICKSON             30.0   34.0   38.0 :  <5  18   <5   9   <5  <5
  FARGO               18.0   25.0   30.0 :  43  75   12  36   <5  21
  HALSTAD             26.0   32.0   37.5 :   6  32   <5  16   <5   7
  GRAND FORKS         28.0   40.0   46.0 :  16  56   <5  30   <5   9
  OSLO                26.0   30.0   36.0 :  16  61   12  53   <5  18
  DRAYTON             32.0   38.0   42.0 :  <5  40   <5  30   <5   9
  PEMBINA             39.0   44.0   49.0 :   7  55   <5  41   <5  21
MINNESOTA TRIBUTARIES.....
  SABIN               12.0   15.0   19.0 :  44  64   <5  13   <5  <5
  SABIN (new)         13.0   15.0   19.0 :  25  64   <5  13   <5  <5
  HAWLEY               7.0    9.0   11.0 :  <5  47   <5  24   <5  <5
  HAWLEY (new)         8.0    9.0   11.0 :  <5  47   <5  24   <5  <5
  DILWORTH            12.0   20.0   26.0 :  44  67   <5  18   <5  <5
  DILWORTH (new)      13.0   20.0   26.0 :  27  67   <5  18   <5  <5
  TWIN VALLEY         10.0   12.0   14.0 :  <5  16   <5  <5   <5  <5
  HENDRUM             20.0   28.0   32.0 :  10  50   <5  20   <5  <5
  SHELLY              14.0   20.0   23.0 :  <5  30   <5  10   <5   6
  CLIMAX              20.0   25.0   30.0 :  <5  21   <5   9   <5   6
  HIGH LANDING        12.0   12.5   13.0 :  <5  30   <5  26   <5  24
  CROOKSTON           15.0   23.0   25.0 :  <5  50   <5  12   <5   7
  ABOVE WARREN        67.0   71.0   75.0 :  <5  12   <5  <5   <5  <5
  ALVARADO           106.0  108.0  110.0 :  <5  18   <5  13   <5  <5
  HALLOCK            802.0  806.0  810.0 :  21  60    6  40   <5   9
  ROSEAU              16.0   18.0   19.0 :  <5  21   <5  12   <5   9
NORTH DAKOTA TRIBUTARIES.....
  ABERCROMBIE         10.0   12.0   18.0 :  12  35    9  32   <5  16
  VALLEY CITY         15.0   16.0   17.0 :  <5  10   <5   9   <5   6
  LISBON              15.0   17.0   19.0 :  <5  10   <5   7   <5  <5
  KINDRED             16.0   19.0   20.5 :   6  21    6  12   <5   9
  WEST FARGO DVRSN    18.0   20.0   21.0 :   9  23    6  18    6  12
  HARWOOD            884.0  886.0  891.0 :   7  23    7  20   <5  10
  ENDERLIN             9.5   12.0   14.0 :   7  20   <5   9   <5  <5
  MAPLETON           905.0  908.0  910.0 :  12  29    6  13   <5  <5
  HILLSBORO           10.0   13.0   16.0 :  <5  15   <5   9   <5  <5
  MINTO                6.0    8.0   11.0 :   9  24   <5   6   <5  <5
  GRAFTON             12.0   13.5   14.5 :  <5  16   <5  <5   <5  <5
  WALHALLA            11.0   16.0   18.0 :  <5  18   <5  <5   <5  <5
  NECHE               18.0   19.0   20.5 :  <5  27   <5  24   <5  16

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 February 23, 2015  to May 24, 2015

LOCATION              95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Red River of the North.....
  WAHPETON             5.6    6.3    7.9    9.0   10.5   12.6   13.7
  HICKSON             11.8   12.5   14.4   16.9   22.2   27.7   29.7
  FARGO               15.4   15.7   16.5   17.3   20.6   26.3   29.6
  HALSTAD              7.0    8.3   10.3   13.3   17.9   24.0   28.6
  GRAND FORKS         17.5   17.7   18.5   20.1   23.2   31.0   37.4
  OSLO                10.5   11.2   13.2   17.3   22.9   31.4   33.9
  DRAYTON             13.3   13.6   15.4   17.9   22.8   28.8   34.9
  PEMBINA             16.0   16.9   20.0   25.3   32.2   37.9   43.8


MINNESOTA TRIBS:      95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
South Fork Buffalo River.....
  SABIN                8.7    9.6   10.3   11.9   12.9   14.2   14.5
Buffalo River.....
  HAWLEY               3.9    4.1    4.3    4.6    5.3    6.6    7.3
  DILWORTH             6.5    7.6    8.8   11.1   13.7   17.8   18.2
Wild Rice River.....
  TWIN VALLEY          3.0    3.1    3.6    4.2    5.1    6.4    6.8
  HENDRUM              4.5    4.9    7.6   10.6   15.9   21.2   24.5
Marsh River.....
  SHELLY               4.0    4.3    4.8    5.9    7.7    9.3   11.7
Sand Hill River.....
  CLIMAX               5.0    5.3    5.9    6.7    8.3   11.8   19.1
Red Lake river.....
  HIGH LANDING         9.2    9.2    9.4    9.6   10.1   10.6   11.8
  CROOKSTON            7.8    8.0    8.5    9.8   11.6   13.7   15.1
Snake River.....
  ABOVE WARREN        61.5   61.6   61.8   62.3   62.8   64.2   66.2
  ALVARADO            97.1   97.2   98.0   98.8  100.2  101.9  107.1
Two Rivers River.....
  HALLOCK            796.5  796.8  797.3  798.4  801.6  804.7  806.9
Roseau River.....
  ROSEAU               6.8    6.9    7.2    8.2   10.0   11.4   14.9


NORTH DAKOTA TRIBS:   95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Wild Rice River.....
  ABERCROMBIE          1.5    2.0    2.9    3.9    5.8   12.2   15.0
Sheyenne River.....
  VALLEY CITY          3.5    3.7    4.4    6.0    7.5    9.4   11.5
  LISBON               2.7    2.7    3.3    5.1    8.4   12.0   14.8
  KINDRED              2.7    3.0    4.1    6.5   10.2   15.3   19.7
  WEST FARGO DVRSN     9.7   10.0   10.5   12.3   14.4   17.6   21.8
  HARWOOD            867.6  869.9  872.1  874.2  877.9  881.6  889.9
Maple River.....
  ENDERLIN             2.1    3.4    4.6    5.7    7.0    8.5   10.9
  MAPLETON           894.7  896.0  897.8  900.0  902.7  906.6  908.3
Goose River.....
  HILLSBORO            1.7    1.7    2.3    3.1    3.5    5.2    8.5
Forest River.....
  MINTO                1.5    1.6    1.9    2.8    4.5    5.9    7.4
Park River.....
  GRAFTON              7.5    7.5    7.7    8.1    8.6   10.1   11.5
Pembina River.....
  WALHALLA             2.6    2.7    3.3    4.2    5.7    8.3    9.2
  NECHE                4.1    4.2    5.5    7.1    9.9   14.8   17.1


.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, low and
 soil conditions and 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).

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 seveal 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 on the Internet at:

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

  Then click on the "Rivers and Lakes AHPS" on the tab above the map
  ...or on the same link in the blue, left-hand banner.

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

Snowpack information is available from the NWS National Operational
 Hydrologic Remote Sensing Center...NOHRSC...on the web at:

            www.nohrsc.noaa.gov

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

A new...point specific flood briefing page is available at:

       www.crh.noaa.gov/fgf/briefing/floodbriefing.php

Also...7-day deterministic forecasts will be issued at least once a
 day when the river forecast locations will be in flood during that
  period.

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

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

$$

www.weather.gov/fgf







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