R E G I O N A L C L I M A T E : P A S T A N D

P R E S E N T

Climate vs. Weather

Climate:

Long term average conditions

Weather:

The conditions day to day

Climate vs. Weather

Climate:

Weather:

Climate vs. Weather

Weather Forecasting• What will the weather be on a specific day in a specific place

• Short term (7-10 days)

Future Climate Simulations• What will the climate trends

be in a region in the future

• Long term (50-100 years)

Climate vs. Weather

Water Year

Hydrologic Water YearCalifornia:

October 1 – September 30

Orographic Precipitation

Orographic Precipitation

Bucks Lake

50 Year Mean Annual Precipitation 1951-2000

Lake Almanor

Eagle Lake

93” per Year

7” per Year

33” per Year

16” per Year

50 Miles!

http://www.wrcc.dri.edu/monitor/cal-mon/

http://www.wrcc.dri.edu/monitor/cal-mon/

Recent Observations

Warming Trend

Less Snowpack

Less snow/more rain; changing

snow thresholds

Earlier greenup dates; more tree mortalities;

enhanced wildfires

Animals moving north

Earlier snowfed streamflowMike Dettinger, USGS and SIO/UCSD

Recent Local Groundwater Elevation Observations

http://www.water.ca.gov/waterdatalibrary/index.cfm

Recent Local Groundwater Elevation Observations

Example of Groundwater Overdraft(Well in Sacramento Valley)

Recent Local Groundwater Elevation Observations

El Nino?

NCEP Coupled Forecast System (CFS) Model Version 2

El Nino?

Mike Dettinger, USGS/SIO

Collecting and Understanding Data to

Adapt