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

Tracking Severe Thunderstorms and Excessive Rainfall in the Southern U.S.; Winter Storm to Impact the Northern U.S.

A storm system will shift from eastern Texas into the lower Mississippi Valley Monday with additional threats of severe thunderstorms and heavy to excessive rainfall which may bring flooding. A Flood Watch remains in effect. In the northern U.S., a storm will bring heavy snow and gusty winds over parts of the northern Rockies, northern Plains, and Upper Midwest Monday into Wednesday. 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: