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https://www.cnn.com/2022/06/15/us/what-caused-yellowstone-flooding-climate/index.html
What caused Yellowstone's 'unprecedented' flooding? Scientists saw it coming
The North Entrance Road of Yellowstone was severely damaged by flooding June 13.
(CNN)Extreme rainfall rates and rapid snowmelt prompted the flash flooding in Yellowstone National Park early this week, washing out roads and bridges in the park and causing "significant" damage to the town of Gardiner, Montana, at the park's entrance.
Abnormally
warm temperatures and torrential rain triggered a wave of snowmelt over
the weekend which produced nearly a foot of water runoff by Monday.
The
Beartooth and Absaroka mountain ranges "received anywhere from 0.8
inches to over 5 inches of rainfall" from June 10 to June 13, the
National Weather Service in Billings revealed Tuesday.
The
extreme rainfall combined with snowmelt led to a massive deluge of
water equivalent to the area receiving two to three months worth of
summer precipitation in just three days, according to CNN Weather
calculations.
The
enormous volume of water then flowed into the rivers and valleys in
lower elevations, where it quickly rose to record depths and led to
"flooding rarely or never seen before," forecasters at the National
Weather Service said.
The
Yellowstone River, which runs through the park and several Park County
cities, reached 13.88 feet at Corwin Springs Monday afternoon,
surpassing the historical high crest of 11.5 feet from 1918, according
to NOAA.
Scientists
predicted events like this week's flash flooding would happen more
often in the Yellowstone area as global temperatures climb. A report published just last year on the future of Yellowstone concluded the climate crisis would lead to more rainfall and rapid snowmelt due to extreme spring and summer warmth.
In
the report published last year, scientists with the US Geological
Survey, Montana State University and the University of Wyoming examined
how the climate has changed from 1950 to 2018, and how it would continue
until the end of the century based on projected greenhouse gas
scenarios from the UN Intergovernmental Panel on Climate Change.
The
report showed average temperatures in the Greater Yellowstone Area rose
by 2.3 degrees Fahrenheit since 1950, and could increase another five
to 10 degrees in the coming decades.
Under
the climate scenario where significant reductions to greenhouse gas
emissions are made in the next few years, scientists found annual
precipitation in the region could still increase by 9% to 15%, though
high temperatures and evaporation rates would still likely worsen the
region's drought conditions.
It
suggests the Yellowstone region will experience what the rest of the
West is already experiencing: long periods of dry conditions punctuated
by brief moments of torrential rainfall, which leads to dangerous flash
flooding.
Studies
have shown how climate change could produce larger and more intense
rain events, leading to more flash floods like the Montana and Wyoming
are facing right now.
Though
cooler temperatures and drier weather have allowed for rivers and
streams in the Yellowstone region to drop back to normal levels, even
hotter temperatures are expected late this week and weekend, which could
lead to more melting, and bring additional flooding to the region.
"Plan
on highs in the 60 to 70s in the higher elevations [Friday and
Saturday], which should melt much of the remaining snowpack and lead to
additional river rises," the National Weather Service in Billings said
Tuesday.
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