A super typhoon is heading north for Japan’s mainland, and it could cause damage to three of the country’s nuclear power plants.

Typhoon Neoguri was spotted about 370 miles south of the Okinawa island chain at 3 a.m. GMT on Monday (or 11 p.m. EDT on Sunday) and was expected to ravage the archipelago with damaging winds and torrential rains by early Tuesday, before spiraling toward mainland Japan on Wednesday, the Japan Meteorological Agency said.

“This is the most powerful typhoon to hit the island in 15 years,” Brigadier General James Hecker of the U.S. Air Force wrote on the Kadena Air Base’s Facebook page on Sunday. “I can’t stress enough how dangerous this typhoon may be when it hits Okinawa.”

Okinawa doesn’t have any nuclear plants, but Japan’s westernmost main island Kyushu has two, and the typhoon is likely to pass over them. A third nuclear plant on Shikoku island, which borders Kyushu, could also be affected by the storm, Reuters reported on Monday.

All of the plants have been halted as per the current national policy. A spokeswoman at Kyushu Electric Power Co. (TYO:9508) told Reuters that it didn’t have any specific plans related to Typhoon Neoguri but that the utility has a year-round strategy to protect the nuclear facilities from severe weather.

The Fukushima Daiichi nuclear plant is on the other side of Japan and will likely see only rain at the worst, Reuters noted. That facility was crippled after a 45-foot tsunami, triggered by a 9.0-magnitude earthquake, struck Japan on March 11, 2011. A day later, the plant's damaged reactors began releasing large amounts of radioactive material. Three years later, the plant's operator, Tokyo Electric Power Co. (TYO:9501), is still struggling to contain contaminated water leaking from the site.

Typhoon Neoguri was already gusting at more than 150 miles per hour on Monday and is moving north/northwest at 16 miles per hour, according to Japan’s weather agency. It is expected to dump as much as 3 inches of rain per hour on Okinawa when it hits.

Still, Neoguri is not expected to be as strong as Typhoon Haiyan, the storm that killed thousands in the Philippines in September 2013 and one of the strongest tropical cyclones ever recorded.

Photo: Japan Meteorological Agency