← Previous May 25, 2023 12:34 PM

FGUS73 KFGF 251734


Probabilistic Hydrologic Outlook
National Weather Service Grand Forks ND
1234 PM CDT Thu May 25 2023


                          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.


Note: This outlook incorporates a daily average of 350 cfs worth of
pumping operations on Devils Lake from June 1st through November

Fall 2022 brought below normal precipitation to much of the basin.
The lack of fall precipitation allowed soil moisture to drop below
normal conditions before freeze up with abnormally dry to moderate
drought conditions persisting. However, winter began on a very active
note with several storm systems affecting the basin. Plenty of
snowfall (and associated water content) early in the winter season
quickly brought snow and precipitation totals well above normal
values. The new year began very dry with a return to a more active
pattern by mid-February which persisted through March before quieting
down again a bit in April. Overall, snow and precipitation through
the winter and into spring has been above normal across the southern
basin, transitioning to slightly below normal across the far northern

Temperatures throughout the majority of the spring (generally the
months of March and April) were well below normal. However,
temperatures quickly warmed throughout the month of May with many
days of well above normal temperatures. As for precipitation, the far
southern portion of the basin continued to see the majority of
precipitation throughout the spring well northern portions remained
quite dry.

Above normal temperatures will continue through the Memorial Day
weekend with sporadic chances for showers and thunderstorms. The
above normal temperatures look to continue well into June with below
normal precipitation expected. Further out, climate outlooks indicate
equal chances for above, below, or near normal precipitation and
temperatures through the remainder of the summer season.

.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 that were run through the model using the precipitation
     and temperatures for those years during the valid period of the

  Interpretation Aid: There is a 50 percent chance that Devils
   Lake will rise above 50.8 feet during the valid period and
    only a 5 percent chance that it will rise above 51.4 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 MAY 22, 2023 TO SEPTEMBER 30, 2023

LOCATION              95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Devils Lake.....
  CREEL BAY           50.7   50.7   50.8   50.8   50.9   51.0   51.4
Stump Lake.....
  EAST STUMP LAKE     50.7   50.7   50.8   50.8   50.9   51.0   51.4

.Current and Previous Record High Lake Levels...

 *  The current height of Devils Lake is 1450.70 feet NGVD29.
 *  The current height of  Stump Lake is 1450.51 feet NGVD29.

 *  The most recent USGS provisional record daily average height
    for Devils Lake at the Creel Bay gage:
                ...1454.30 feet on   June 27 of 2011
 *  Previous records:
                ...1452.05 feet on   June 27 of 2010
                ...1450.93 feet on   June 27 of 2009
                ...1449.20 feet on    May  9 of 2006
                ...1449.18 feet on   June 17 of 2004
                ...1449.17 feet on August  2 of 2005
    Note: All previous records are recorded in NGVD29.


 - 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 Management Outlooks will be issued
    in late February and early 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 of exceedance/non-exceedance information will be
    given from October through December, since lake freeze-up
     levels will be given in the fall outlooks previously issued.


The long-range probabilistic outlook is based on high and low lake
  levels that were calculated for the valid period using multiple
  scenarios of temperature and precipitation from 1949 to 2018 and
  current conditions of the lake, snowcover (in winter), and soil

By providing the complete range of lake level probabilities, the
  amount of risk associated with long-range planning decisions can
  be determined. These probabilistic outlooks are part of NOAA's
  National Weather Service's Advanced Hydrologic Prediction
  Services (AHPS).

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


This outlook is also presented as probability graphs of lake height
  for the full period as well as weekly probabilities. The outlook
  graphics and explanations that help in interpreting these outlooks
  are available on the NWS Grand Forks AHPS web page at:


Wind and wave forecasts for Devils and Stump lakes are available for
a 7-day period when the lakes are sufficiently ice-free at:


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.