AccuWeather.com - Weather News | Winds at Japan Power Plants Should Send Radiation out to Sea

"You can calculate how long the release of a radiation would take to cross the Pacific from Japan to the U.S. by choosing different speeds that the radioactive particles might be moving and using the direct distance between given locations- say Sendai, Japan, and Seattle, Wash.," Andrews added.

However, even that calculation may not reflect how long the particle would take to cross the Pacific, since it would not likely cross the ocean in a direct path. This is the case because the wind flow is often a complicated pattern.

A typical wind trajectory across the Pacific is westerly, since there is often a large dome of high pressure over the central Pacific and an area of low pressure in the Gulf of Alaska.

Any storm systems moving across the Pacific would add kinks in the westerly flow that would make the path of a particle crossing the Pacific longer.

"In other words, it would be a very intricate and difficult calculation," said Andrews.

via accuweather.com