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NDC005-027-071-281200-

Probabilistic Hydrologic Outlook
National Weather Service Grand Forks ND
157 PM CDT Thu Aug 27 2026

...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.

As of this issuance, summer (June, July, August) precipitation thus
far has generally been below normal across the majority of the basin
(with the exception of a few small areas). Although the month of June
was very wet, conditions were much drier throughout July and August.
With that said, chances for showers and thunderstorms through the
last week of August may bring summer precipitation totals closer to
normal values.

After a warm and potentially more active last week of August, climate
outlooks indicate near to above normal temperatures for the fall
(September, October, November) season. Outlooks also indicate near to
potentially drier than normal conditions throughout the fall.

No exceedance numbers are issued with this outlook but will resume in
January 2027. The next (and final) set of non-exceedance numbers of
the season will be issued on Thursday, September 24, 2026.


.Current and Previous Record High Lake Levels...

 *  The current height of Devils Lake is 1450.0 feet NGVD29.
 *  The current height of  Stump Lake is 1449.9 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 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 fall below 50.2 feet during the valid period and
    a 5 percent chance that it will fall below 50.0 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 Falling Below Listed Lake Levels

             FROM SEPTEMBER 01, 2026 TO NOVEMBER 30, 2026

LOCATION              95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Devils Lake.....
  CREEL BAY           50.3   50.3   50.3   50.2   50.1   50.0   50.0
Stump Lake.....
  EAST STUMP LAKE     50.3   50.3   50.3   50.2   50.1   50.0   50.0

  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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