A lot of the western U.S. has began 2026 in the course of a snow drought. That would possibly sound unexpected, given the report precipitation from atmospheric rivers hitting the area in contemporary weeks, however the ones storms had been in fact a part of the issue.
To know this yr’s snow drought – and why stipulations like this are a rising fear for western water provides – let’s take a look at what a snow drought is and what came about when atmospheric river storms arrived in December.
Chart supply: Rittiger, Ok., et al., 2026, Nationwide Snow and Ice Information Middle
What’s a snow drought?
Most often, hydrologists like me measure the snowpack via the quantity of water it accommodates. When the snowpack’s water content material is low when put next with ancient stipulations, you’re having a look at a snow drought.
A snow drought can behind schedule ski slope opening dates and reason deficient early wintry weather game stipulations.
It may possibly additionally create water provide issues the next summer season. The West’s mountain snowpack has traditionally been a loyal herbal reservoir of water, offering recent water to downstream farms, orchards and towns because it slowly melts. The U.S. Geological Survey estimates that as much as 75% of the area’s annual water provide is determined by snowmelt.
Snowpack is usually measured via the quantity of water it accommodates, or snow water identical. The numbers display each and every location’s snowpack in comparison to its reasonable for the date. Whilst nonetheless early, a lot of the West was once in snow drought as 2026 started.
Herbal Sources Conservation Carrier
Snow drought isn’t the same as different varieties of drought as a result of its defining feature is loss of water in a selected shape – snow – however now not essentially the loss of water, according to se. A area can also be in a snow drought all over occasions of ordinary and even above-normal precipitation if temperatures are heat sufficient that precipitation falls as rain when snow would in most cases be anticipated.
This type of snow drought – referred to as a heat snow drought – is changing into extra prevalent because the local weather warms, and it’s what portions of the West were seeing thus far this wintry weather.
How an atmospheric river worsened the snow drought
Washington state noticed the hazards in early December 2025 when a significant atmospheric river hurricane dumped report precipitation in portions of the Pacific Northwest. As much as 24 inches fell within the Cascade Mountains between Dec. 1 and Dec. 15. The Middle for Western Climate and Water Extremes at Scripps Oceanographic Institute documented studies of flooding, landslides and harm to a number of highways that might take months to fix. 5 circulation gauges within the area reached report flood ranges, and 16 others exceeded “major flood” standing.
But, the hurricane mockingly left the area’s water provides worse off in its wake.
The explanation was once the double-whammy nature of the development: a big, most commonly rainstorm going on in opposition to the backdrop of an uncharacteristically heat autumn around the western U.S.
Cars had been stranded as floodwater in a swollen river broke a levee in Pacific, Wash., in December 2025.
Brandon Bell/Getty Pictures
Atmospheric rivers act like a conveyor belt, sporting water from heat, tropical areas. The December hurricane and the area’s heat temperatures conspired to provide a big rainfall tournament, with snow most commonly restricted to spaces above 9,000 toes in elevation, in keeping with information from the Middle for Western Climate and Water Extremes.
The rainfall melted a vital quantity of snow in mountain watersheds, which contributed to the flooding in Washington state. The melting additionally diminished the quantity of water saved within the snowpack via about 50% within the Yakima River Basin over the process that tournament.
As international temperatures upward push, forecasters be expecting to peer extra precipitation falling as rain within the overdue fall and early spring slightly than snow when put next with the previous. This rain can soften current snow, contributing to snow drought in addition to flooding and landslides.
What’s forward
Thankfully, it’s nonetheless early within the 2026 wintry weather season. The West’s primary snow accumulation months are in most cases from now till March, and the western snowpack may recuperate.
Extra snow has since fallen within the Yakima River Basin, which has made up the snow water garage it misplaced all over the December hurricane, even supposing it was once nonetheless neatly under ancient norms in early January 2026.
Scientists and water useful resource managers are operating on techniques to raised expect snow drought and its results a number of weeks to months forward. Researchers also are in the hunt for to raised know how particular person storms produce rain and snow in order that we will be able to reinforce snowpack forecasting – a theme of new paintings via my analysis team.
As temperatures heat and snow droughts grow to be extra commonplace, this analysis shall be crucial to lend a hand water assets managers, wintry weather sports activities industries and everybody else who depends upon snow to organize for the longer term.
