It's not that California never gets these high-pressure zones blocking its rain, but usually they only last a short time. This current one has lasted 13 straight months! Scientists aren't sure why the ridge is lasting so long, but it is causing some drastic effects. Last year was the driest year in California's recorded history (160 years), and the Sierra Nevada snowpack is 20% of what it normally is. (I'm sure the ski resorts are hurting bad). Reservoirs across the state are only 30-36% full, which means water rationing may occur soon unless they get several big storms.