Colorado’s snowpack situation continues to worsen despite recent snowfall, with statewide levels dropping from 57% of average last week to 55% of average today. … A persistent ridge of high pressure over the western United States has dominated weather patterns this winter, keeping storm systems away while maintaining unusually warm temperatures across the region. La Niña conditions in the Pacific Ocean are partly responsible, but the upper ridge has been further east than usual as well. That’s partly been driven by a persistently “positive” PNA – the Pacific North American Oscillation. The combination of the northerly jet stream changes from La Niña plus the positive PNA – and a couple of other patterns – are why it has been so dry.

Other snowpack news around the West:

• NBC9 (Denver, Colo.): Colorado farmers worry low snowpack could wind up costing them their crops
• WeatherNation: Blog: California snowpack drops after dry January
• LAist: A dry January has created dire conditions for California’s snowpack
• Invisible Waters: Blog: The West faces a snow drought