1. Chris Funk, USGS/UCSB Climate Hazards Group
El Nino versus the Blob – is Spouthern California Facing more drought?
Chris Funk, Research Director, Climate Hazards Center
Chris Funk, USGS/UCSB Climate Hazards Group

2. Warming shifts the mean of distributions, causing more extreme events
Temperature
Probability
Probability=area under the curve
Threshold – crops, pregnant mothers, coral reef, snowpack, human body, …

3. Warming shifts the mean of distributions, causing more extreme events – example SoCal
--Past 5 years by FAR the warmest on record
--Every year since 2013 has been
exceptionally warm
annual T average (61.2F) is
way warmer than the
average (58.2F)
--New mean is higher than the old maximum

4. The old maximum is now the new normal
Mean=58.2F
Mean=61.2F
66%
old
max 60.8F
Warming shifts the mean of distributions, causing more extreme events

5. Warming contributes to higher sub-tropical highs – and associated droughts
Time series of global average
Upper-troposphere heights
Upper Height
∝ 0 𝑧 𝑇
i.e. proportional to the
temperature of the air
below it

6. Warming contributes to higher sub-tropical highs – and associated droughts
Map of changes in
Upper-troposphere heights
versus
Upper level ridging disrupts
Sub-tropical Westerly Jets
Perhaps also tilting us
Towards a La Nina like future

7. Global Land Temperatures Anomalies – Five Year Averages
-- Model predictions extremely accurate (R2=0.97)
-- +2F = +1.1C ~ +8% water vapor via Clausius-Claperyon
-- Intensification of precipitation extremes likely due to both thermodynamic and dynamic causes

8. Increasing air temperatures can dry soils, plants and increases the magnitude of fires
Saturation Vapor Pressure is a non-linear function of T
Increasing Vapor Pressure Deficits (VPD) dry plants and soils
Vapor Pressure Deficit = Saturation Vapor Pressure minus vapor pressure
Low frequency VPD/Temperature impacts can accumulate over time

9. June-July five-year average temperatures for Southern California
--Past 5 years by FAR the warmest
on record
--Every year since 2013 has been
exceptionally warm
-- Past 5 year average (62.7F) is
way warmer than the
average (58.2F)

10. US Wildfires getting bigger
A wildfire destroys homes in Goleta, California, on July 7, MARCUS YAM / LOS ANGELES TIMES VIA GETTY IMAGES

11. El Nino versus the Blob?
-- The ‘Blob’ is a region in the North Pacific linked to CA drought (~ W, 40-55N)
-- Often warm since 2013
-- Linked to Cod/Salmon disruptions, and other
marine impacts
The Blob was first detected in the autumn of 2013 and the early months of 2014 by Nicholas Bond of the Joint Institute for the Study of the Atmosphere and Ocean of the University of Washington
Very warm ocean temperatures can support droughts and floods

12. El Nino versus the Blob?
Analog blog years ? 1986/87, 1993/94, 2002/03, 2014/15, 2015/16
Very warm ocean temperatures can support droughts and floods

13. October-March Precipitation and Palmer Drought Severity Index blob analogs (1989,2014, 2015, 2016)
Standardized Precipitation Anomalies
Standardized Palmer Drought Severity Index
Water Supply
Water Supply -Demand

14. Upper level height composites
~8 meters per second

15. Annual November-October NE Pacific height anomalies

16. 10-year average rainfall, air temperatures and Palmer Drought Severity Index values

17. CPC/IRI Probabilistic ENSO Outlook
Updated: 11 October 2018
El Niño is favored to form in the next couple of months and continue through the Northern Hemisphere winter (70-75% chance).

18. SST Outlook: NCEP CFS.v2 Forecast (PDF corrected)
Issued: 4 November 2018
The CFS.v2 ensemble mean (black dashed line) predicts El Niño to form soon and to then continue through at least the Northern Hemisphere spring 2019.

19. U.S. Temperature and Precipitation Departures During the Last 30 Days
End Date: 4 November 2018
Percent of Average Precipitation
Temperature Departures (degree C)
1 of 2

20. U. S. Seasonal Outlooks November-January 2018
The seasonal outlooks combine the effects of long-term trends, soil moisture, and, when appropriate, ENSO.
Precipitation
Temperature

21. US Drought Outlook