Hydrologic Outlook
National Weather Service Grand Forks ND
117 PM CDT Thu Mar 28 2019
…FAVORABLE THAW/MELT CONDITIONS TO CONTINUE THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK…MONITORING POTENTIAL WEATHER SYSTEM MIDWEEK NEXT WEEK…
A slow and gentle melt continues across the Red River basin due to
favorable temperatures and dry weather conditions.
Overall flood risk update…
Near perfect thaw/melt conditions thus far this spring have
potentially allowed for a reduced flood threat. If conditions in the
next several weeks continue to follow this pattern (slow melting
during the day with some refreezing at night and dry weather
conditions), most locations can expect to see river levels peak
from snowmelt in the 75% to 95% range of the probabilistic
guidance issued March 15th.
However, peak river levels will still be contingent upon future
precipitation. If significant precipitation happens to occur
(especially concurrent with peak snowmelt rises), river levels
will be prone to reaching higher levels, likely above the 50%
stage levels of the March 15th guidance.
The James River at LaMoure is currently at 7.5 feet and has risen around six inches in the past week, with a 50 percent chance the river will reach minor flood stage of 14 feet at LaMoure and a 5 percent chance it will reach major flood stage of 18 feet.
North of Jamestown the James River basin Jamestown and Pipestem dams shows a normal to slightly above normal chance of overland and small stream flooding.
South of the dams includes a well above normal chance of overland flooding.
The U.S. Army Corps of Engineers still forecasts a combined release from Jamestown and Pipestem dams of 750 cfs, below levels that would action for flood protection in Jamestown.
James River level through Jamestown.
Sheyenne River Level Though Valley City
Current conditions…
Temperatures warmed into the mid to upper 40s across the far
southern Red River Valley and into west central Minnesota on
Wednesday. This warmup allowed for more rapid snowmelt and
associated runoff across this area, resulting in the
Wahpeton/Breckenridge area rising above flood stage and numerous
road closures due to overland flooding across portions of west
central Minnesota.
Across the remainder of the southern basin, river conditions remain
mostly ice covered with some ponding of water on streams and rivers
and in fields and ditches. Snow cover across this area is rapidly
decreasing while the top layer of the ground is slowly warming and
may now be capable of soaking up some of this moisture.
For the northern half of the basin where it hasn`t been as warm, the
snow cover is gradually decreasing but rivers remain largely ice
covered.
Future conditions…
A roller coaster of temperatures is expected to continue through the
end of this week and into the first half of next week. Temperatures
on Friday are expected to once again warm into the 40s for much of
the basin. These temperatures will continue to decrease any
remaining snowpack across the far southern basin. However, the Corps
of Engineers has temporarily reduced outflows from area reservoirs
to slow down/reduce rises at Wahpeton/Breckenridge and locations
further downstream.
Runoff will be slowed even further on Saturday as colder air pushes
into the region and temperatures top out only around the freezing
mark. The roller coaster will continue heading into next week as
Monday and Tuesday look to bring a brief warm up before once again
dipping back down by midweek.
Overall quiet weather conditions will persist into early next week.
A weak disturbance looks to bring minor precipitation chances to the
northern basin on Friday but amounts will be minimal. Thereafter,
dry conditions will prevail through the weekend heading into early
next week.
Lastly, computer models do depict a system potentially targeting the
Plains around midweek next week. However, it is much too far into
the future for any specific locations or precipitation amounts. Our
area has the potential to experience this system with a mix of
weather types (rain, snow, etc.). On the other hand, this system
may miss our area completely with little to no precipitation. Stay
tuned to future weather forecasts regarding this system and its
impact on this year`s flood potential.
Next outlook…
There will be no additional probabilistic outlooks issued this
spring as we are now experiencing more widespread melting and the
issuance of deterministic forecasts. However, an updated thaw
progress statement will be issued on Monday, April 1st regarding the
status of the snowmelt, forecast weather conditions and the impacts
on future flood potential.
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