Hurricanes?

[Stu in USA]

Why do hurricanes rarely affect the west coast of the USA. I noticed that another Pacific hurricane is expected in Baja California, one of a few this season. California is immediately north and I cannot ever remember a hurrican in that area. Why?

[BabsG]

Winds in the Tropics generally blow fron east to west. So hurricanes which develop over warm seas in the Atlantic will be blown on to the East coast of the US by the prevailing winds. Storms which develop in the Pacific tend to head for Japan etc. Occasionally hurricanes do affect California but it is rare.

[reinganum]

For hurricanes to form and be sustained the sea surface temperature needs to be at or above 26�C, which is why hurricanes weaken and die either when (a) they hit land (no continuous supply of moisture to sustain the clouds) or (b) they move into an area of cooler seas.

The Humboldt Current (which is cool) reaches as far south as California, and thus when Pacific hurricanes move any further north than Baja California the storm weakens (and also tends to move away from the coast as Babs has already said).