Wyoming Spring 2019 Snowmelt Flood Potential---issued March 18th

Storm Impacting the Northwest U.S.; Fire Weather Conditions in Southern California; Severe Weather in the South

A Pacific storm is bringing areas of low elevation rain, moderate to heavy mountain snow, and high winds to the Northwest. Strong Santa Ana winds and very dry conditions are producing elevated to critical fire weather conditions in southern California. Isolated strong to severe thunderstorms are possible through early Wednesday morning across parts of northeast Texas into western Tennessee. Read More >

QUICK SYNOPSIS:

Mountain snowpack and associated snow water equivalents (SWEs) across most of Wyoming were generally above average by the middle of March. SWEs at the peak snowmelt runoff elevations (8,500’ – 10,000’) were the highest across the Little Snake, Upper North Platte, and Laramie Basins at 120 to 130 percent of median. The Tongue Watershed had SWEs at 80 to near 90 percent of median at the peak snowmelt runoff elevations.

This outlook is based on various diverse hydrological factors such as snow water equivalents (SWEs) in the mountain snowpack, basin morphology (i.e. how basins respond to snowmelt runoff), antecedent soil moisture, biological/physical factors (bark beetle kill/spruce blight///fire burn scars), low elevation snow depths, and likely temperature and precipitation trends during late spring/early summer.

HIGHLIGHTS:

…Moderate potential for snowmelt runoff flooding is forecasted along the lower portions of the Upper North Platte River Basin (near Saratoga) and along the lower portions of the Laramie Watershed (near Laramie)…

… Moderate potential for flooding due to snowmelt is also expected over a few tributary basins along the Snake River Drainage…

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

The current Wyoming Spring 2019 Snowmelt Runoff Flood Potential Outlook graphic: