California suffered its driest year on record in 2013, according to the National Overview – Annual 2013, a summary of the nation’s weather for the previous year published by the National Climatic Data Center each January. The Golden State received 7.38 inches of rain, less than 1/3 of its average amount. Oregon and Idaho were also very dry, respectively registering their 4th and 12th driest years on record.

The map at right shows 2013 precipitation by state for the Continental United States. Red, orange, and yellow states were drier than average, green states wetter.

(Click on map for larger view.)

Most of the country east of the Rocky Mountains was wetter than average, with North Dakota and Michigan recording their wettest years since record keeping began. Missouri was wetter than average, but not extremely wet.

California is in the grip of a long-term drought, as I noted in my recent post on Drought Trends in the Northern Plains and California. The new data updates that information for 2013, and the updated chart is at right.

(Click graph for larger view.)

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On the map at right, the current conditions at major California reservoirs are shown. The gold bars represent reservoir capacity, the red lines represent average reservoir levels on this date, and the blue bars represent current levels. The blue numbers represent current percent of capacity. The red numbers are the most important, showing current levels as a percentage of average levels on this date. Several reservoirs are at 1/2 of average levels or less.

(Click on map for larger view.)

The drought in California has been in the news recently, and the dry conditions are playing a role in the Colby Fire, currently burning in Los Angeles. This time of year is not usually wildfire season out there.

What’s going on? The answer is complex, and I’m not sure that it is fully understood. Some evidence suggests that California is naturally drier than we ever thought. In addition, however, the draft of the NCADAC Draft Climate Assessment Report makes it clear that climate change has already dried the climate in California, and is expected to dry it even more over the coming decades. The sort of drought they are experiencing may be their “new normal.”

California matters to us here in Missouri. Not only is it our nation’s most populous state, but it accounts for about 13% of the country’s entire gross domestic product. It produces more than half of the nation’s fruits and vegetables. Those people and those farms are very dependent on water from reservoirs which, as we saw, are beginning to look quite a bit low. Will they draw them down completely? If they did, what then?

In the following posts, I will update precipitation and temperature trends for Missouri and the United States.

Sources:

National Climatic Data Center. 2013. “National Overview – Annual 2013.” NCDC Home Page » Climate Information » Analyses – Monthly U.S. Climate Reports » U.S. Analysis. http://www.ncdc.noaa.gov/sotc/national. On this page, if the national overview is not showing, select “National Overview,” in the Report Field, “2013” in the Year Field, and “Annual” in the Month Field.

The California reservoir chart was from:
California Department of Water Resources. “Conditions for Major Reservoirs: 17-JAN-2014.” California Data Exchange Center-Reservoirs. Downloaded 1/18/2014 from http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action.

NCADAC Draft Climate Assessment Report, http://ncadac.globalchange.gov/.

The drought chart was created using:
National Climatic Data Center, “Climate at a Glance.” NCDC Home Page » Temperature, Precipitation, and Drought Rankings. http://www.ncdc.noaa.gov/cag.