Precipitation

Total Precipitation

Evaporation will intesify and total precipitation may increase 10% by end of the century, with most of the increase concentrated in the winter months and a higher proportion of winter precipitation falling as rain rather than snow.

Surface Runoff

Surface Runoff and Rainfall Intensity

Average precipitation on rainy days, the number of heavy events with more than 2 inches of rainfall in a single day, and the total rainfall in the biggest storms are projected to increase substantially by the end of the century. More rain on rainy days and more frequent large rainfall events will increase surface runoff, thereby influencing flooding risks and diminishing groundwater recharge.

Transpiration

Summer Drought

Increasing evaporative demand with rising summer temperatures coupled with stable summer rainfall, will increase the frequency of summer drought.

Freshwater Resources

Streamflow and Water Supplies

Reduced snowpack and an increase in winter rainfall, higher frequencies of summer drought, and a change in rainfall intensity will all impact streamflow, groundwater recharge, and the reliability of water supply systems. In coastal areas, rising sea level will exacerbate saltwater intrusion into groundwater.