Flood Potential Outlook
Issued by NWS Grand Forks, ND
FGUS73 KFGF 191928
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS ND
130 PM CST THU FEB 19 2015
...Devils Lake Outlook for Spring Flood Potential...
Devils and Stump Lakes
Long-Range Probabilistic Outlook
The National Weather Service is providing long-range probabilistic
hydrologic outlooks for Devils and Stump lakes between January
and September. They will not be provided between October and
The AHPS graphics associated with this outlook will be on the web
no later than 10:30 AM this Friday under the experimental
long-range flood risk tab at...
Depending on the season, the high or low water probabilities may
be omitted due to their applicability to the hydrologic situation.
Refer to the scheduling section farther on in this message.
. Outlook Discussion...
There has been little change since the last outlook at the end
of January...with below normal lake rises expected due to
below normal springtime inflows.
Fall and winter precipitation has been within the 20 to 50% of
normal across the Devils Lake basin ranging from a bit above on
the northwestern side and below normal on the eastern side.
Snow water equivalents (SWEs) in the snowpack are modeled at
0.85 inches compared to a typical 1.25 to 2.75 inches.
The model was run with normal climatological precipitation and
slightly above normal temperatures...and with the maximum 600
cfs pumping capacity of the Devils Lake outlets from the 1st
of June through the 10th of November. This produced the
highest rising hydrograph member derived from the 60+ years
of temperature and precipitation used in the model to peak
at 1453.13 feet.
. 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 1452.0 feet during the valid period and
only a 5 percent chance that it will rise above 1452.3 feet.
Probabilities for exceeding listed lake levels
FROM FEBRUARY 16, 2015 TO SEPTEMBER 30, 2015
LOCATION 95% 90% 75% 50% 25% 10% 05%
-------- ------ ------ ------ ------ ------ ------ ------
CREEL BAY 1451.8 1451.8 1451.9 1452.0 1452.1 1452.3 1452.6
EAST STUMP LAKE 1451.8 1451.8 1451.9 1452.0 1452.1 1452.3 1452.6
. Current and previous record high lake levels...
* The current height of Devils Lake at Creel Bay is 1451.6 feet
* The current height of Stump Lake near Lakota is 1451.5 feet
* 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
* For more high water marks...see the USGS flood tracking charts at:
. Outlook Schedule...
- Between January and May, only the high water exceedances will be
provided with valid periods ending at the end of September.
- 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...
Snowpack information provided by NWS National Operational Hydrologic
Remote Sensing Center (NOHRSC) is on the web at:
Wind and Wave forecasts for Devils and Stump lakes are available for
a seven day period when the lakes are sufficiently ice-free at:
Additionally, 7 day lake evaporation forecasts are available
during the growing season at:
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 2012 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 Noah`s
National Weather Service`s Advanced Hydrologic Prediction
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 from the NWS Grand Forks AHPS web page
on the internet at:
Outlook graphics of the probabilities of exceeding various lake
levels for Devils and Stump lakes are also on out web site. They
should be available by 10:30 AM Friday. Monthly probabilistic
outlooks are usually issued on the Thursday or Friday of the week
following the first Thursday after the 15Th of the month,
the third or fourth week of the month.
If you have any questions, contact the NWS at 701-772-0720