The New York Times notes:
A United Nations forecast of the possible movement of the radioactive plume coming from crippled Japanese reactors shows it churning across the Pacific and touching the Aleutian Islands on Thursday before hitting Southern California late Friday.
The projection, by the Comprehensive Test Ban Treaty Organization, an arm of the United Nations in Vienna, gives no information about actual radiation levels but only shows how a radioactive plume would probably move and disperse.
The forecast, calculated Tuesday, is based on patterns of Pacific winds at that time and the predicted path is likely to change as weather patterns shift.
The Japan forecast shows that the radioactive plume will probably miss the agency’s monitoring stations at Midway and in the Hawaiian Islands but is likely to be detected in the Aleutians and at a monitoring station in Sacramento. The forecast assumes that radioactivity in Japan is released continuously and forms a rising plume. It ends with the plume heading into Southern California and the American Southwest, including Nevada, Utah and Arizona. The plume would have continued eastward if the United Nations scientists had run the projection forward.
The Pacific jetstream is currently flowing due east directly toward the United States. In the event of a major meltdown and continuous large-volume radioactive release, airborne particles will be carried across the ocean in bands that will cross over the southern halves of Oregon, Montana and Idaho, all of California, Nevada, Utah, Colorado, Wyoming, the Dakotas, northern Nebraska and Iowa and ending in Wisconsin and Illinois, with possible further eastward drift depending on surface wind direction.
But it is vital to note that many experts are saying that only extremely low levels of radiation will hit Americans. As the New York Times reports:
Health and nuclear experts emphasize that radiation in the plume will be diluted as it travels and, at worst, would have extremely minor health consequences in the United States, even if hints of it are ultimately detectable. In a similar way, radiation from the Chernobyl disaster in 1986 spread around the globe and reached the West Coast of the United States in 10 days, its levels measurable but minuscule.
