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Heavy Rain and Flash Flooding Concerns in California; Heavy Snow in the Sierra

An atmospheric river will bring heavy rainfall to lower elevations of California this week, and heavy snow to the Sierra Nevada mountains. Flash flooding, some of which may be locally considerable, will be a concern on the western foothills of the Sierra Nevada mountains through Tuesday. Landslides, rockfalls and mudslides are possible in the Southern California mountains. 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: