1. Climate Literacy Session: Climate, Climatology of California Elissa Lynn August 5, 2015

2. Climate, Climatology of California California Climate Climate Signals Atmospheric Rivers

3. California Geography (Major Climate Factor) 1340 miles of coastline (~75% coast of lower US) 800 miles long 250 miles wide LA is east of Reno Land area of 163,696 sq. miles 3.79 million sq. miles – 3 rd biggest after AK and TX

4. California Geography (Major Climate Factor) 1340 miles of coastline (~75% coast of lower US) 800 miles long 250 miles wide LA is east of Reno Land area of 163,696 sq. miles 3.79 million sq. miles – 3 rd biggest after AK and TX Mediterranean Climate - warm dry summer, cool wet winter

5. California Topography (Major Climate Factor)

6. Greatest Precipitation falls in northern mountains in CA Biggest Population centers are along coasts and southern part of CA Precipitation: Limited Locations Dettinger et al, 2011

7. Just a few storms each year provide California’s water supply 5-10 stormy days or storm events each winter December, January, February responsible for 50% of precipitation Precipitation: Limited Opportunity Dettinger et al, 2011

8. Measuring CA Precipitation Northern Sierra 8 Station Index Annual Average: 50 inches Maximum Year (1983): 88.5 inches Minimum Year (1924): 17.1 inches Period of Record 1921- Present Average of: Mt. Shasta CityQuincy Shasta Dam Sierraville RS MineralPacific House Brush Creek RS Blue Canyon

9. Annual Average: 40 inches Maximum Year (1983) 77.4 inches Minimum Year (1924) 14.8 inches Period of Record 1949 - Present Average of: Calaveras Big Trees Hetch Hetchy Yosemite HQ North Fork Ranger Station Huntington Lake Measuring CA Precipitation Southern Sierra 5 Station Index

10. Snowpack

11. Drought Worst Years for Snowpack April 1 Percent of Average 2015 5 2014 25 1977 25 1988 29 1976 37 2007 39 2013 42 1963 45 1990 45 1994 52 2012 52

12. Each of last 4 years are in the top-10 lowest snowpacks 5 of 10 driest years in last hundred have been this decade 1977 used to be worst; 2014 tied at 25% of average 2015 was 20% of EITHER of those; only 5% of average System managed better than in 1977; but worse hydrology In recent years, it’s WARMER Drought

13. Runoff Observations: Timing Shift Brochure Page 3

14. California 1895-Present Courtesy: Western Region Climate Center Observed Maximums Observed Minimums Temperatures

15. Climate Signal; El Nino

16. El Niño conditions are present Warm Sea Surface Temperatures over Eastern Pacific (us!) Greater than 90% chance that El Niño will continue through winter, and around an 80% chance it will last into early spring 2016. Climate Signal; El Nino

17. Climate Signal; Pacific Decadal Oscillation

18. Storm Track changes Flooding & water supply MJO/Tropical Convection ENSO Polar Processes Atmospheric River Easterly Wave Cyclogensis L Different Hydrologic Outcomes Result from the Combination of Key Processes Evolving at Different Space/Time Scales Climate Signal; Atmospheric Rivers -> KEY for Water Supply/Flooding

19. https://www.youtube.com/watch?v=MgKT__9ThSs& feature=youtu.be https://www.youtube.com/watch?v=MgKT__9ThSs& feature=youtu.be Atmospheric Rivers (CalWater Research) DWR YouTube

20. Take Home Points California has a Mediterranean Climate Topography/Geography very important for CA precipitation Lots of variability in space and time Many processes in play to create events in historic record Atmospheric Rivers important for floods and water supply Climate Change will impact these relationships; drought, etc.