Extended Drought Scenarios
California has a highly variable climate and is susceptible to dry spells. Recent research suggests that extended drought occurrence (“mega-drought”) could become more pervasive in future decades. This tool explores data for two long 20-year drought scenarios derived from the LOCA downscaled HadGEM2-ES RCP 8.5 simulation.
This scenario represents a late century dry spell from 2051–2070 identified from the HadGEM2-ES RCP 8.5 simulation. The extended drought scenario is based on the average annual precipitation over 20 years. This average value equates to 78% of historical median annual precipitation averaged over the North Coast and Sierra California Climate Tracker regions.
LOCA Downscaled Climate Projections for Temperature & Precipitation
Projected daily minimum and maximum temperature and daily precipitation data. These data were statistically downscaled from 32 global climate models from the CMIP5 archive at a 1/16º (approximately 6 km) spatial resolution on a daily timescale using the LOCA technique. The historical period is 1950–2005, and there are two future scenarios available: RCP 4.5 and RCP 8.5 over the period 2006–2100 (although some models stop in 2099). Details are described in Pierce et al., 2014.
Gridded Historical Observed Meteorological and Hydrological Data
Historical observed daily temperature and precipitation data from approximately 20,000 NOAA Cooperative Observer (COOP) stations form the basis of this gridded dataset from 1950–2013 at a spatial resolution of 1/16º (approximately 6 km). Observation-based meteorological data sets offer insights into changes to the hydro-climatic system by diagnosing spatio-temporal characteristics and providing a historical baseline for future projections. Details are described in Livneh et al., 2015.