1. El Nino and California Winter Weather

2. Talk Overview Antecedent Conditions Current El Nino Status Expectations for next 4 months

3. Source: Western Region Climate Center’s California Climate Tracker California Climate Tracker Central Coast Water Year 1896-2015 2015 2014 2013

4. Atmospheric Rivers and Precipitation Accumulation 12/2012 – 2/2014 16.8” 404 Days 8.4“ in 14 days 16.4” in 24 days 44% of WY total 6.84” in 5 days 18% of WY total WY2015: 121 days 37.2” 1” in 45 days

5. All major reservoirs below their daily average storage Most Reservoirs started gaining storage this month

6. Talk Overview Antecedent Conditions Current El Nino Status Expectations for next 4 months

7. Latest Sea Surface Temperature Anomalies (Departure from Average)

8. Niño Region SST Departures ( o C) Recent Evolution The latest weekly SST departures are: Niño 41.7ºC Niño 3.42.8ºC Niño 32.9ºC Niño 1+2 2.3ºC

9. Nino 3.4 ONI Data YearDJFJFMFMA MAM AMJMJJJJAJASASOSONONDNDJ 1997-0.5-0.4-0.20.10.611.41.722.22.3 2015 0.50.40.50.70.911.21.51.72 This year second only to 1998/1998 Event

10. Talk Overview Antecedent Conditions Current El Nino Status Expectations for next 4 months

12. Water Year 1998 Precipitation Outcome by Month Nov9.45” (150%) Dec4.79” (57%) Jan18.82” (209%) Feb21.22” (265%) Mar8.63” (125%) Apr7.47” (192%) Northern Sierra 8 Station Index California Statewide Average Snowpack % of avg Water Year1-Feb1-Mar1-Apr1-May 199872159158154 Nov4.35” (92%) Dec4.17” (67%) Jan13.56” (180%) Feb18.68” (270%) Mar7.29” (120%) Apr5.00” (139%) Central Sierra 5 Station Index

13. Storm Track changes Flooding & water supply MJO/Tropical Convection ENSO Polar Processes Key Phenomena Affecting California Water Supply/Flooding: Atmospheric River Easterly Wave Cyclogensis L The size, number, and characteristics of atmospheric river events (ARs) result from the alignment of key processes

14. San Francisco Tide Gauge – December 2015 Dates for Extreme Tides Assuming 1 ft Anomaly due to El Nino, Warm Ocean or consecutive coastal storms MonTuesWedsThursFriSatSun 123456 78910111213 14151617181920 21222324252627 28293031 December 12/7 0 ft 12/8 0.1 ft 12/9 0.2 12/10 0.3 12/11 0.4 12/12 0.3 12/13 0.2 12/14 0.0 12/15 12/16 12/17 12/18 12/19 0.1 12/20 0.4 12/21 0.7 12/22 0.9 12/23 1.0 12/24 1.0 12/25 0.9 12/26 0.7 12/27 0.4 12/28 0 12/29 12/30 12/31 Below Predicted King Tide Equivalent relative to MHHW (<0.9) King Tide Equivalent (0.9 to1.0 ft above MHHW) Tall King (1.1 to1.5 ft above MHHW) Emperor Tide (1.6 to 2.0 ft above MHHW) Predicted<-0.1-0.1 to 0.00.1 to 0.50.6 to1.0 Plus estimated 1 ft anomaly <0.90.9 to 1.01.1 to 1.51.6 to2.0

15. CNAP RISA El Nino Tools (http://cnap.ucsd.edu/)

16. Final Thoughts Current El Nino conditions among strongest on record for this time of year Above average precipitation expected for most of the State after the New Year with continued above normal temperatures. Snowpack is expected to be better than any of the past 4 years. Moisture, freezing elevation, and duration of individual storms important to water year evolution. Sea level readings near record levels with new highs possible with storm surge and spring/neap cycles.

17. Questions? Email: Michael.L.Anderson@water.ca.gov