Two typhoons are chugging toward Southeast Asia, and though their final course isn’t set, one could skim Taiwan or the northern Philippines with super typhoon force by the end of the week.

Typhoon Goni is leading the way, as the pair moves northwest across the central Pacific. Goni skated between Saipan and Guam last weekend, dumping 10 inches on the latter and leading to flash flood warnings. At that point, Goni’s gales clocked at 58 mph — just shy of what would be considered a Category 1 hurricane in the Atlantic ocean. Then within a matter of six hours, Goni’s strength boomed — with Category 4 winds topping 135 mph — as the storm crept steadily toward Taiwan.

As of yesterday, the second storm — Typhoon Atsani — was 1,000 miles east of Goni, but turning toward Japan. NASA Goddard reported that as of this morning, Typhoon Atsani had winds near the Category 4 range.

Both storms are gaining strength, and the Joint Typhoon Warning Center predicts that the twins will reach super typhoon status — with winds in excess of 150 mph — by Thursday.

“The last time there were two super typhoons in the Pacific at the same time was in October 1997, when Super Typhoons Ivan and Joan overlapped. Not coincidentally, 1997 was also the strongest El Niño on record…,” wrote Angela Fritz for the Washington Post. Warmer waters mean bigger storms.

At this stage, it’s uncertain when, where and if the storms will hit land. AccuWeather meteorologist Anthony Sagliani expects Goni to swing through the corridor between Taiwan and Japan this weekend and into next week, potentially hitting Japan’s Ryukyu Islands and the Korean Peninsula. Less than two weeks ago, Taiwan was battered by the strongest storm that our planet has experienced this year, Super Typhoon Soudelor.

Atsani might strike mainland Japan within the same timeframe, which could be life-threatening, or it could pass through the open waters to the east, dousing the island nation with heavy rain and strong waves.