Flood Potential Outlook
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
790
FGUS73 KFGF 232119
ESFFGF
NDC005-027-071-281200-
Probabilistic Hydrologic Outlook
National Weather Service Grand Forks ND
419 PM CDT Thu Jul 23 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.
June 2026 was extremely wet with precipitation totals for the month
coming in 2-5 inches above normal basin-wide. On the other hand, the
first three weeks of July have been extremely hot and dry with
precipitation totals thus far for the month roughly 1-3 inches below
normal.
While the exceedance probabilities with this outlook have generally
remained the same, the wet conditions throughout June (especially
towards the end of the month) have increased lake levels associated
with the non-exceedance probabilities. In other words, with lake
levels rising mid-summer rather than beginning to fall as in most
years, evaporation and pumping operations will not allow as much of a
decrease as indicated in the previous outlook.
Climate outlooks indicate warmer and drier than normal conditions to
persist through the end of July. Thereafter, trends do point towards
the potential for a cooler and more active end to 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 (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 50.6 feet during the valid period and
a 5 percent chance that it will rise above 50.8 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 JULY 20, 2026 TO SEPTEMBER 30, 2026
LOCATION 95% 90% 75% 50% 25% 10% 05%
-------- ------ ------ ------ ------ ------ ------ ------
Devils Lake.....
CREEL BAY 50.5 50.5 50.6 50.6 50.7 50.8 50.8
Stump Lake.....
EAST STUMP LAKE 50.5 50.5 50.6 50.6 50.7 50.8 50.8
.Current and Previous Record High Lake Levels...
* The current height of Devils Lake is 1450.4 feet NGVD29.
* The current height of Stump Lake is 1450.1 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 50.0 feet during the valid period and
a 5 percent chance that it will fall below 49.7 feet.
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 50.4 50.2 50.1 50.0 49.8 49.7 49.7
Stump Lake.....
EAST STUMP LAKE 50.4 50.2 50.1 50.0 49.8 49.7 49.7
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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