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Hydrologic Outlook

Hydrologic Outlook

Hydrologic Outlook
National Weather Service Riverton WY
234 PM MDT Mon Jun 1 2020

Unseasonably warm temperatures and gusty wind are allowing for an
active snow melt in the far western mountains where snow remains
above the 8,000 foot elevation. East of the Continental Divide,
the remaining snow is mainly confined to elevations above 9,000
feet. After a slight cool down Tuesday, temperatures will trend
upward all week with Friday looking very warm. These temperatures
will keep an active snow melt through the week.

Automated mountain stations indicate water equivalents of around one
inch to nearly two inches melting from the snowpack the past few
days. It appears the impact from rain falling on the melting
snowpack will not be significant through the week. The next chance
for widespread precipitation looks to be later Friday night into
Saturday. Cooler temperatures will then arrive for the weekend.

Minor flooding is most likely along the upper Wind River above
Diversion Dam, tributaries of the Snake River in Teton County, and
the creeks along the western slope of the Bighorn Mountains.
These waterways include Pacific Creek, the Gros Ventre River,
Medicine Lodge Creek, Paintrock Creek, and Tensleep Creek all of
which will generally remain bankfull.

Remember, during active snowmelt runoff, mountain and foothill
creeks flow highest from late evening through early morning.
Recreationists should stay away from these cold, fast-moving streams
and avoid camping near any waterway. Do not attempt to cross a creek
or stream on foot as the power of the water will easily carry you


Hydrologic Outlook

Hydrologic Outlook
National Weather Service Bismarck ND
114 PM CDT Mon Jun 1 2020


The Missouri River near Williston is expected to rise through the
week and eventually crest near, or just above, flood stage around
June 6th. The high water will remain in the area for a few days
before falling to near normal water levels by mid-June. Water on the
parking lot of the Lewis and Clark boat ramp along with inundation
of low-lying agricultural fields are the most likely impacts to be


Hydrologic Outlook

Hydrologic Outlook
National Weather Service Billings MT
1051 AM MDT Mon Jun 1 2020

...Rising river and stream levels will continue this week...

Recent warm temperatures will result in melting of the existing snow
pack (above 8000 feet) in the mountains this week. The snow melt
will cause increased flows along rivers and streams emerging from
the high country. This includes the Yellowstone, Clarks Fork of the
Yellowstone, Shields, Boulder, Stillwater, Little Bighorn and Tongue
Rivers, as well as numerous other smaller streams.

Afternoon temperatures at 8000 feet will reach the 60s to lower 70s,
and overnight temperatures should stay above freezing through much
of the week. Significant flooding is not expected at this time,
however, minor flooding is expected on many rivers and streams, as
flows reach the highest levels of the Spring.

Recreationists near the foothills should be prepared for changing
conditions and use extra caution when in and near the water, as
flows will be fast and the water cold. Many river banks will be
undergoing erosion due to high flows, which could make walking near
the water dangerous. Those with interests near waterways should move
equipment and livestock away from low lying areas.

The latest stages and forecasts for rivers and streams can be found
at our web page:


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