Ocean currents off eastern Japan could hold the key to the spread of major leak of radioactive water or airborne fallout.
Reports have told of greatly elevated levels of radiation in sea water at the stricken Fukushima Daiichi nuclear power plant. Others have spoken of detectable traces of radioactive isotopes near the plant, but also as far south as greater Tokyo, home to about 35 million residents.
While the exact nature of the cause of the radioactive releases, as discussed in the international news media, seems unclear, it has raised fears of a breach in containment at one or more of the six Fukushima reactors.
Any radioactive matter finding its way into waters off northeastern Honshu would be subject to local sea currents.
The most important current off Fukushima is known as the Oyashio, a chilly current that drifts southward from the Sea of Okhotsk to waters east of Hokkaido and northern Honshu, two of the main land masses of Japan. This current ends its southward journey off Cape Inubo, east of Tokyo, whereupon it veers sharply eastward--out to sea.
Nuclear contamination released at the power plant would tend to be diluted by the vast volume of the ocean. Greatest impact from such contamination would most likely be felt near the site. However, measurable contamination, depending upon the amount released, could ride the Oyashio southward off the shore of Fukushima, Ibaraki and northern Chiba prefectures.
A pattern favoring waves of progressively cooler air will set up across much of the Midwest and Northeast during next week and could continue into early May.
Round after round of drenching rain will continue to cause flooding in the South, while another dose of rain may renew flooding in the Ohio Valley this weekend.
Ahead of the monsoon season in India, temperatures will swell well above normal in parts of India and Pakistan.
The 119th Boston Marathon will take place on Monday, April 20, and runners set to take on the historic course will face cool and rainy conditions.
The southern Plains will once again become the target of severe thunderstorms into Saturday evening.
The southern Plains will finally catch a break from severe weather to end the weekend as the danger shifts to the lower Mississippi Valley.
San Francisco, CA (1906)
Earthquake and fire. Infrequent easterly wind drove flames westward through the city rather than confining them to the downtown harbor area.
Wyoming, South Dakota (1966)
24" of snow and blizzard conditions in South Dakota. 20" of snow at Lander, Wyoming.
Rapid City, SD (1970)
22" of snow (17th-18th) -- 24-hour record.