Weather Alert - Yellowstone National Park|
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FGUS75 KRIW 221607
National Weather Service Riverton WY
1006 AM MDT Tue May 22 2018
...Accelerated snowmelt at the 9,000 to 10,000 foot elevation
Friday through Sunday...
...Significant rises in creeks and streams during the
Memorial Day Weekend...
The snowpack at the 9,000 to 10,000 foot elevation has ripened
considerably in the last week to 10 days due to mild temperatures
and recent rainfall. Rainfall today and Wednesday will only
further ripen or increase the water content of the current snowpack.
Afternoon mountain temperatures at the 9,000 foot elevation are
expected to warm to near 60 for Thursday--and into the lower to
middle 60s Friday through Sunday. Morning low temperatures are
forecasted to be at or above the frost temperature of 37 degrees
Thursday through Sunday.
Increased snowmelt at the 9,000 to 10,000 foot elevation Friday
through Sunday will cause significant rises in creeks and streams
during the Memorial Day Weekend.
Rain showers are in the forecast for Sunday afternoon through and Memorial
Day. The combination of rain and snowmelt runoff will greatly increase
The Wind River and the South Fork of the Shoshone River should see flows
high enough to cause flooding by Monday and Tuesday of next week.
Tributary streams that feed into the Big Horn and Snake Rivers may
see the highest flows of the season early next week.
During active snowmelt runoff, mountain creeks and streams are
at their highest levels during the late afternoon/early evening
hours. Crossing creeks and streams during that time is highly
Graphical forecasts are available at:
Visit weather.gov/riverton and select the rivers & lakes tab for
graphical forecasts and additional information.