Why do the Hawaiian islands have intense but short rain storms?

Question

It is well-known that the sides facing the wind in the Hawaiian islands are

characterized by frequent rains that are heavy (intense), but brief in duration. At the

same time, it is also known that the Southern California skies sometimes experience a

heavy overcast for weeks at a time. Based on what you know on nucleation, provide a

thermodynamic argument for this difference in climate.

Answer 1

To at least get you started, you can talk about the tradewinds (east flow) across the hawaiian islands. The orographic lift caused by the elevated islands volcanic structure... which leads to windward showers because the airmass is cooled and volume expanded...This reduces the ability of the airmass to hold water as cooler air holds less moisture than warmer air.  The islands are small, and create this local effect, but they are brief as the airmass quickly reaches the peak of elevation, then descends on the leeward side of the island... drying out and contracting as it warms.  

As for Cali, I'm not sure how to answer completely.  But it has to do with the cold water on the west coast, the higher elevation...  and obviously there is no easterly tradewind in the mid-latitudes.