Flood Potential Outlook
Issued by NWS Grand Forks, ND

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FGUS73 KFGF 241646
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Probabilistic Hydrologic Outlook
National Weather Service Grand Forks ND
1046 AM CST Fri Jan 24 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.

Precipitation last fall overall (September-November 2024) was above
normal across northern portions of the basin while slightly below
normal in the far south. However, the fall season did end with well
above normal precipitation throughout the month of November. This
allowed soils to be fairly saturated moving into the winter freeze-
up period.

Thus far this winter, slightly above normal precipitation and
snowfall has occurred across much of the basin. This is especially
true across the northern half of the basin with snow depth values
(and snow water equivalent) dropping off rapidly as you move
southward.

Climate outlooks continue to indicate a strong signal for below
normal temperatures through the remainder of the winter and into the
spring (with a brief warm up expected late this weekend and into
early next week). There is no strong signal either way for above,
below, or near normal precipitation into the spring.

The next lake exceedance numbers will be issued on Thursday, February
13, 2025.


.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
      outlook.

  Interpretation Aid: There is a 50 percent chance that Devils
   Lake will rise above 51.2 feet during the valid period and
    only a 5 percent chance that it will rise above 52.8 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 JANUARY 20, 2025 TO SEPTEMBER 30, 2025

LOCATION              95%    90%    75%    50%    25%    10%    05%
--------            ------ ------ ------ ------ ------ ------ ------
Devils Lake.....
  CREEL BAY           50.6   50.6   50.9   51.2   51.8   52.4   52.8
Stump Lake.....
  EAST STUMP LAKE     50.6   50.6   50.9   51.2   51.8   52.4   52.8


.Current and Previous Record High Lake Levels...

 *  The current height of Devils Lake is 1449.4 feet NGVD29.
 *  The current height of  Stump Lake is 1449.4 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.


.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 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.

.ADDITIONAL INFORMATION...

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
  moisture.

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 National Water Prediction Service
 (NWPS).

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

         www.youtube.com/watch?v=pSoEgvsnpv4

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 NWPS web page at:

              www.water.noaa.gov/wfo/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, contact the NWS at 701-772-0720.

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

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      weather.gov/fgf
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