From an observational perspective then, key issues are the tropical storm formation regions, the frequency, intensity, duration and tracks of tropical storms, and associated precipitation. (ipcc.ch)
Figure 7u - 11 describes the month frequency of storm formation in the three ocean basins found in the Northern Hemisphere for the period 1951 to 2002. (physicalgeography.net)
But California droughts are also fundamentally linked to the quantities and timing of precipitation, the dynamics of storm formation in the Pacific Ocean, the impacts of climate change on the frequency and intensity of El Niño and La Niña events and the Pacific Decadal Oscillation, and the behavior of the jet stream as conditions in the Arctic change. (californiadrought.org)