California-Nevada Adaptation Program (A NOAA CAP/RISA Team)

Although numerous studies have previously explored streamflow responses to annual climate warming, less attention has been given to the differing effects of seasonal (winter vs. summer) warming. It is well-known, for instance, that the seasonal timing of streamflow in snow-affected river basins is strongly affected by warmer winters, which lead to less snow, more rain, and earlier runoff. What

In the western U.S., the impacts of drought conditions in the 21st century are increasingly evident as extended fire seasons, dwindling water supplies, and widespread tree mortality are becoming more common occurrences. Fundamentally, drought is a shortage of water that is driven by an imbalance between supply and demand. From a meteorological perspective, periods of low precipitation (i.e., the

Since the start of the 21st century, California and Nevada have suffered extreme wildland fires and droughts that have caused devastating impacts to ecosystems and society. A common feature of these events has been very high evaporative demand—the “thirst” of the atmosphere—which has largely been driven by increased air temperatures caused by anthropogenic climate change. According to new

A Red Flag Warning (RFW) is a term that has been used since the 1960s by the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) fire weather forecasters to alert forecast users to an ongoing or imminent critical fire weather pattern. Through time, however, several issues with this system have evolved and created concerns about effectiveness of messaging,

The 2018-2019 water year is now underway, and with all eyes on the developing El Niño, there are many people wondering whether this winter will be any better than last year - particularly for snowpack in the West.  Last winter was marked by below-average precipitation and above-average temperatures through the first several months in many places across the country - with relief not

Visit the new snow drought page The beginning of the 2017/2018 winter season brought little rain and snow, giving rise to concerns about snow drought across the Western United States. Snow drought is defined as a period of abnormally low snowpack for the time of year, reflecting either below-normal cold-season precipitation (dry snow drought) or a lack of snow accumulation, despite near-