California Applications Program / California Climate Change Center

Drought grips California

Last update: 15 April 2009
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California sites show large precipitation deficits



Many sites around the state show extreme deficits in precipitation. Click here to examine the 365-day time series for other locations.
Percent of Normal Precipitation
Most of California is at half the normal amount of precipitation for the last 12 months (Apr 2008 - Apr 2009), as shown in the image below from the Western Regional Climate Center.

The image for the 2007 water year (Oct 2006 - Sep 2007) also shows most of California well below 50% of normal precipitation.
Dry conditions in the news ....
Low snowpack may mean a third dry year for California

Brian Heiland, left, and Frank Gehrke, scientists in the California Department of Water Resources, measure the snowpack south of Lake Tahoe. Photo by: Jonah M. Kessel / Associated Press

from: Los Angeles Times
30 January 2009
(summary; please click above for full article)

The all-important Sierra Nevada snowpack remains well below normal, signaling that California may be headed for a third consecutive dry year.

When state workers took the second snow measurement of the winter Thursday, they found that statewide, the snow's water content was 61% of the average, over many years, for this point in the season. The figure was even lower in the northern Sierra, which feeds the state's biggest reservoirs.

SNOTEL - Basin Average Snow Water Content - January 30, 2009


The SNOTEL river basin average snow water content and precipitation data are updated daily by the Western Regional Climate Center.

Click here for most recent SNOTEL River Basin Precipitation

SNOTEL (SNOw TELemetry) data are from remote sites that use pressure pillows for measuring snowfall.

Click here to learn more about SNOTEL

Climate Tracker: South Coast region water year (Oct-Sep) precipitation


(Click here for full size image)

Plot of the climate tracker south coast region shows 7 of the last 10 years significantly below normal water year precipitation. Find more plots on the Western Regional Climate Center's Climate Tracker web page.

Divisional Precipitation Time Series

The California south coast division water year precipitation time series shows 7 of the last 10 water years have had below normal precipitation (normal shown by the solid green line). Using the tools at the been made using the Western Regional Climate Center time series can be made for other divisions.
Tropical Pacific SST Anomalies and OLR

High pressure dominates California region

The 700mb geopotential height anomaly plots to the right show a persistent pattern of increased height over the western Pacific, especially off the coast of California. The Oct-Mar 700mb height anomalies shown are: upper left 1999-2008, upper right 2005-2008, lower left 2008 and lower right 1 Oct 2008 through 25 Jan 2009. Note particular dominance of high pressure during the current water year.