The image above shows the strong La Nina event in the tropical Pacific. This follows a weaker El Nino event last winter. It is typical of La Nina to generate west ward winds over the Pacific coast of North America, as well as heavier precipitation. This is a particularly strong La Nina, and we have heard reports of hurricane force winds lashing the North West as well as up to a foot of flooding rain falling.
Australians are hoping that La Nina will break the drought, since it is also typical for Australia to receive heavier rainfall during a La Nina event, and drought during El Nino.