When National Weather Service hydrologist Jim Fahey made his first “flood outlook” graphic of 2019 last month, the watersheds near Laramie and Saratoga were the only ones in Wyoming identified as having “moderate” flood potential this year.
At the time, the snowpack levels across the state were fairly mild.
The Laramie Basin, the Upper North Platte River Basin and the South Platte River Basin were no different.
All three basins fuel Albany County’s spring runoff, and Fahey noted the three basins’ snowpack was “not extraordinary at all” when he predicted “moderate” flood potential in late February.
However, Fahey also took into account the precipitation forecasts of the National Weather Service, which indicated then — and still do — that the area of Colorado that feeds Albany County’s water supply is one of the few areas of the country expected to have above-average precipitation in March, April and May.
March’s snowpack figures have only solidified Fahey’s flood forecast for Laramie.
In the last month, the Laramie Basin’s snowpack has jumped from 102 percent of median to 117 percent.
Colorado’s South Platte River Basin’s snowpack has now jumped to 127 percent. The total snow-water equivalent in that basin is now at the level it’s normally at during its late-April peak.
While Fahey said there’s still “a lot of uncertainty, of course,” he expects to keep Laramie’s flood potential as “moderate” when he puts out the March flood potential graphic in the next week.
At 131 percent of median, the Madison-Gallatin Basin in Yellowstone National Park currently has the state’s highest snowpack deviation.
Compared to its norm, Sheridan has the lowest. The Tongue Basin, which feeds the Sheridan area, had 82 percent of its median snowpack as of Monday. Only four of the state’s 19 basins have below-median snowpack.