"Warmer winters make for less snow in the Sierra Nevada Mountains. When the snow melts into the state's rivers, it provides water throughout the summer, when the state typically experiences little rain."

"SAN FRANCISCO -- California is coming off of its warmest winter on record, aggravating an enduring drought in the most populous US state, federal weather scientists said Monday.

The state had a average temperature of 48 Fahrenheit (9 Celsius) for December, January and February, an increase from 47.2 F in 1980-81, the last hottest winter, and more than 4 degrees hotter than the 20th-century average in California, the National Oceanic and Atmospheric Administration (NOAA) said in a statement.

Warmer winters could make the already parched state even drier by making it less likely for snow to accumulate in the Sierra Nevada Mountains, NOAA spokesman Brady Phillips said. That snow, melting in the spring and summer and running down through the state's rivers, is vital for providing water in the summer, when the state typically experiences little rain."

Laila Kearney reports for Reuters March 17, 2014. [2]