If the Meltdown of One or More of Japan's Nuclear Reactors Happens, is the United States in Danger of Radiation Fallout?

With the very real threat on the horizon of a meltdown being actually in process right now at not one, not two, but possibly three or more nuclear reactors are you, and the rest of the United States in imminent danger of contamination to dangerous radiation from nuclear fallout?

There is a map pretty much accepted to be a hoax that is widely circulating. This map predicts deadly doses coming across on the jetstream. I would like to point out that map is innaccurate in a number of ways.

First off the dose would not be calculated in rads. Secondly the chances of a dose coming across that is immediately deadly stands at pretty close to -0- %. This is not to say though that there are no fears. Radiation damage affects the most rapidly growing cells first, because of this children and infants are much more susceptable. Symptoms and health problems in adults may not be appearant for years and years.

A better information source can be found here, where according to the article titled West Coast USA Danger IF Japan Nuclear Reactor Meltdown, aside from the "immediately deadly doses", the other thing innaccurate about the map is that the fallout could arrive sooner.

Why would the west coast USA be in danger?
This article states, similar to other opinions, that "The prevailing jet stream winds are blowing from Japan directly across the Pacific ocean to the west coast of the United States. Any airborne radiation would make its way across with the jet stream, reaching the U.S. in approximately 36 hours, depending on the actual speed of the jet".

Link also provides detailed Images of the Jet Stream from Japan to the U.S., as well as detailed reactor information.

The author explains a number of things to know about Cesium-137, "IF" there is a complete meltdown and release into the environment. Information from the U.S. EPA states that "Radioactive cesium-137 is produced when uranium and plutonium absorb neutrons and undergo fission, and has a half-life of 30 years. Cesium moves easily through the environment".

Most fallout prediction maps show central California (San Francisco) to north to the Oregon border to be in the bulls-eye for the most part, although most show that it is likely none of the west really will escape with the wind current pattern in effect as forecasted.

If you doubt that the jet stream would carry the particles this far consider this tidbit from history...The Japanese sent balloon bombs to CONUS during WWII. A few of them made it to locations in the western US. They used the Jet Stream, something our scientists didn't even know about. It is detailed in this article, titled How Geologists Unraveled the Mystery of Japanese Vengeance Balloon Bombs in World War II, by author David Rogers, who states "The balloons were crafted from mulberry paper, glued together with potato flour and filled with expansive hydrogen. They were 33 feet in diameter and could lift approximately 1,000 pounds, but the deadly portion of their cargo was a 33-lb anti-personnel fragmentation bomb, attached to a 64-foot long fuse that was intended to burn for 82 minutes before detonating".
Only time will tell, and there may not be very long to wait until we have the answers.
You can access live radiation monitering systems from this link, it may prove a good link to have, although the California and Oregon links are often off line lately.