FGUS73 KFGF 261744

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NDC005-027-071-281200-



Probabilistic Hydrologic Outlook

National Weather Service Grand Forks ND

1243 PM CDT Thu Jun 26 2025



...DEVILS LAKE OUTLOOK FOR FLOOD POTENTIAL...



                          Devils and Stump Lakes

                    Long-Range Probabilistic Outlook



  The National Weather Service provides long-range probabilistic

   hydrologic outlooks for Devils and Stump lakes between January

    and September. They will not be provided between October and

     December. Depending on the season, the high or low water

      probabilities may be omitted due to their applicability to

       the hydrologic situation.



.OUTLOOK SUMMARY...



Note: This outlook incorporates a daily average of 350 cfs worth of

pumping operations on Devils Lake from May 15th through October 30th.



Spring precipitation (March, April, and May) ended slightly below

normal for much of the basin (up to 1 inch below normal) with the far

northeastern portion of the basin even a bit drier (up to 2 inches

below normal). Summer has started off very dry with precipitation

thus far (June 1-current) coming in well below normal for this time

period.



Climate outlooks continue to indicate above normal temperatures

through the summer season (June, July, and August). A more active

pattern looks to persist into the beginning of July with sporadic

rainfall chances across the basin. A drier trend is still anticipated

for the second half of the summer with below normal precipitation.



This month's outlook includes the first non-exceedance numbers of the

season. The next outlook scheduled for Thursday, July 24, 2025 will

include the last set of exceedance numbers for the year, along with

updated non-exceedance numbers.





.Chances of Devils and Stump Lakes Rising Above Given Lake Levels...



  The probability of exceeding a given lake level is the percentage

   of maximum lake level rises that are above that level for all the

    years (1949-2019) that were run through the model using the

     precipitation and temperatures for those years during the valid

      period of the outlook.



  Interpretation Aid: There is a 50 percent chance that Devils

   Lake will rise above 49.5 feet during the valid period and

    a 5 percent chance that it will rise above 49.6 feet.



  Note: The current gage zero datum of the Devils Lake at Creel Bay

gage is 1401.33 feet NAVD88 or 1400.00 feet NGVD29. The gage zero

datum of the Stump Lake at East Stump Lake gage is 1401.21 feet

NAVD88 or 1400.00 feet NGVD29.



           Probabilities for Exceeding Listed Lake Levels



               FROM JUNE 23, 2025 TO SEPTEMBER 30, 2025



LOCATION              95%    90%    75%    50%    25%    10%    05%

--------            ------ ------ ------ ------ ------ ------ ------

Devils Lake.....

  CREEL BAY           49.5   49.5   49.5   49.5   49.5   49.6   49.6

Stump Lake.....

  EAST STUMP LAKE     49.5   49.5   49.5   49.5   49.5   49.6   49.6





.Current and Previous Record High Lake Levels...



 *  The current height of Devils Lake is 1449.3 feet NGVD29.

 *  The current height of  Stump Lake is 1449.3 feet NGVD29.



 *  USGS daily average height records for Devils Lake at the Creel

    Bay gage:

                ...1454.30 feet on June 27, 2011

                ...1452.05 feet on June 27, 2010

                ...1450.93 feet on June 27, 2009

                ...1449.20 feet on May 9, 2006

                ...1449.18 feet on June 17, 2004

                ...1449.17 feet on August 2, 2005

    Note: All previous records are recorded in NGVD29.





.Chances of Devils and Stump Lakes Falling Below Given Lake Levels...



  The probability of not exceeding a given lake level is the

   percentage of lake level falls that are below that level for

    all the years (1949-2019) that were run through the modelusing

     the precipitation and temperatures for those years during the

      valid period of the outlook.



  Interpretation Aid: There is a 50 percent chance that Devils

   Lake will fall below 47.8 feet during the valid period and

    a 5 percent chance that it will fall below 47.4 feet.



           Probabilities for Falling Below Listed Lake Levels



             FROM SEPTEMBER 01, 2025 TO NOVEMBER 30, 2025



LOCATION              95%    90%    75%    50%    25%    10%    05%

--------            ------ ------ ------ ------ ------ ------ ------

Devils Lake.....

  CREEL BAY           48.4   48.3   47.9   47.8   47.6   47.5   47.4

Stump Lake.....

  EAST STUMP LAKE     48.4   48.3   47.9   47.8   47.6   47.5   47.4



  The non-exceedance value for a listed percentage is the value

    where that percentage of all model cases run were below that

      lake level for the specified valid period of the outlook.



.OUTLOOK SCHEDULE...



 - Between January and May, only the high water exceedances will be

    provided with valid periods ending at the end of September.



 - Special Spring Flood and Water Resources Outlooks will be issued

    from mid-February through mid-March.



 - For June and July, both high-water and low-water exceedances will

    be provided.



 - For August and September, only the low-water exceedances will be

    provided with valid periods ending at the end of November.



 - No probability information will be provided from October through

    December.



.ADDITIONAL INFORMATION...



These lake level probabilities can be used for risk management as an

 indication of the range of lake levels that may be possible during

 the valid period of the outlook. However, note that it is possible

 that lake levels may still reach above/fall below the 95th and 5th

 percentile values.



This outlook is also presented as graphs of the potential lake

 levels for the full outlook period as well as weekly probabilities.

 These graphics, and explanations that help in interpreting them,

 can be found on the NWS Grand Forks NWPS web page by clicking on

 "Rivers and Lakes" above the map at www.weather.gov/fgf.



Wind and wave forecasts for Devils and Stump Lakes are available for

a 7-day period when the lakes are sufficiently ice-free at

www.weather.gov/fgf/lake_info.



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



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

 and on X at @NWSGrandForks.



$$

      weather.gov/fgf

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