Wyoming Spring 2019 Snowmelt Flood Potential---issued April 17th

Areas of Extreme Heat and Fire Weather in the Pacific Northwest; Heavy Rain in the West and South-central US

Extreme heat will continue across the Pacific Northwest into midweek before finally waning. Hot temperatures, dry, gusty conditions, and isolated dry thunderstorms will bring critical fire weather. Heavy rain and thunderstorms are expected across portions of the Southwest, the Sierras, and the central/southern Plains. A series of storms will bring heavy rain and strong winds to southern Alaska. Read More >

HIGHLIGHTS:

…Moderate to High potential for snowmelt runoff flooding is forecasted along the lower portions of the Laramie Watershed (near Laramie)…

…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 Little Snake Watershed (near Dixon/Baggs)…

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

QUICK SYNOPSIS:

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

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