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Atmospheric River in the Pacific Northwest and Northern Rockies this Weekend

A Pacific storm and atmospheric river will impact the Pacific Northwest states and northern Rockies this weekend, bringing locally heavy low elevations rain and heavy high elevation snow in the mountains. By Sunday over the Interior Northwest, rain combined with snowmelt will increase the risk of flood hazards. Flood Watches are in effect. Read More >

Quick Synopsis:

--Late February snowpack and/or SWEs were above average (105 to 115% of median) across almost all major basins in Wyoming.  The highest SWEs were over the Big Horn Mountains and the Sierra Madre Mountains (southern Wyoming).​

--Above average snow depths across western Wyoming.

--Above average soil moisture percentages across basins in northeastern Wyoming and potions of the Wind River Basin; below average soil moisture percentages across southern Wyoming.

--Widespread pine bark beetle damage (2010-2018) across the Upper North Platte, Little Snake, Laramie, and Wind River Basins.

--No significant precipitation trends during the spring runoff season (May – July).  Above average temperatures are expected across central to western Wyoming during the runoff season.

Highlights:

Low to Moderate potential for snowmelt runoff flooding is forecasted along the portions of the Laramie and the Salt River Basins (far western Wyoming)…

…All other of headwater basins across Wyoming can expect a generally Low potential for flooding due to springtime snowmelt runoff...

The current Wyoming Spring 2020 Snowmelt Runoff Flood Potential Outlook graphic:

 

Wyoming Spring Runoff 2020 Flood Potential Briefing: