National Climate Report - January 2014
February 4 U.S. Drought Monitor — California
Source: U.S. Drought Monitor
California has been dealing with abnormally dry conditions since January 2013, with 2013 ranking as the driest year in the 119-year period of record for the state. The below-average precipitation continued into January 2014, with the month ranking as the third driest January on record. In fact, all timescales back to 48 months have been drier than average. For the first time in the 15-year period of record for the U.S. Drought Monitor, California experienced the worst classification of drought, known as D4 or "exceptional". As of the February 4, 2014 U.S. Drought Monitor Report, 94.2 percent of the state was experiencing drought conditions. The statewide Palmer Z Index has indicated severe short-term drought for eleven of the last 13 months, with the persistent and extreme dryness causing the California statewide PDSI to reach values rivalling the most severe droughts of the 20th century (1990-91, 1976-77, and 1924).
Western U.S. Snowpack
The winter season is important for California's water resources. December, January, and February are climatologically the three wettest months of the year in California. During the winter of 2013/14, California had its driest December-January on record with 0.94 inch of precipitation, 7.35 inches below average. The previous record dry December-January occurred in 1975/76, when the two-month precipitation total was 1.32 inches. Winter precipitation is vital to replenish reservoirs and builds mountain snowpack that melts during the spring and summer. As of February 1, most mountain locations in California had less than 50 percent of normal snowpack and reservoirs across northern and central regions of the state had storage levels between 37 percent and 75 percent of historical averages for the date. Many stream gauges in the state were also at record-low levels during January with reports of non-irrigated crops suffering and lack of forage causing ranchers to cull their herds. More information on the California drought, as well as drought nationwide, can be found in the January 2014 U.S. Drought Report,a>.