American Airlines Flight 280: Multiple injuries as massive turbulence forces emergency landing in Japan

An American Airlines flight from Seoul to Dallas has been diverted, after 15 passengers were reportedly injured due to turbulence.

Flight 280 is set to make an emergency landing in Narita Airport, Japan. The plane is carrying 240 passengers plus crew. It has been forced to make the landing five hours after leaving Incheon Airport, just outside Seoul, according to Flight Radar 24.

UPDATE: the plane has landed in Narita
From Weather.com:

A U.S.-bound passenger jet was forced to make an emergency landing near Tokyo Tuesday night after encountering severe turbulence while flying through a rapidly intensifying winter storm. At least 14 people on the flight have been injured, according to Japan's public broadcaster, NHK.

American Airlines Flight 280, which originated at Incheon International Airport near Seoul, South Korea, was flying east when it hit severe turbulence over the Pacific Ocean just east of Japan. NHK said 10 passengers and four crew members were injured on the plane, which was en route to Dallas-Fort Worth International Airport.

A powerful winter storm is developing over Japan, associated with a powerful ribbon of 150- to 200-mph winds in the jet stream, about 38,000 feet above sea level. The center of low pressure is moving north near the Pacific coast of northern Japan. It is expected to become a meteorological "bomb" as its central pressure plummets to 948 millibars near Hokkaido, Japan's northernmost major island, by Wednesday morning Japanese time (Tuesday evening U.S. time).