Western Pacific sees rare trio of storms

Three storms are churning simultaneously across the western Pacific, an unusual October clustering that’s generating high waves around parts of Japan.

Typhoon Choi-wan, Typhoon Nolo and Tropical Storm Koguma were all active on Tuesday, marking the first time in five years that three systems have existed at the same time in the month of October, according to the Japan Weather Association (JWA).

The three storms are at different stages of development and are spread across a wide swath of the Pacific.

On Tuesday, Choi-wan was moving north, away from the Ogasawara Islands, at a speed of 30 kilometers per hour. At 3:45 p.m., it had a central pressure of 960 hectopascals and maximum sustained winds of 144 kph and gusts of up to 198 kph, according to the Japan Meteorological Agency (JMA).

The typhoon is expected to move rapidly northeast and transition into an extratropical cyclone by Wednesday. Even as it retreats, swells associated with Choi-wan are expected to produce rough seas around the Ogasawara and Izu islands and along parts of the Pacific coast of eastern Japan.

Farther east, Nolo remained a very strong typhoon as of Tuesday afternoon. At 4:05 p.m., it was moving west at 30 kph by the Wake Islands with a central pressure of 965 hectopascals. Maximum sustained winds near its center were 162 kph, with gusts of up to 216 kph.

Nolo is unusual in that it originated east of the International Date Line before crossing into the western part of the North Pacific and entering the area monitored by the JMA, making it a transboundary typhoon, the last of which occurred in August 2023, according to JWA. It’s forecast to continue westward before gradually turning northeast of Japan around Saturday.

Koguma is the newest of the three systems. It formed Monday over the Marshall Islands and was moving northwest on Tuesday. At 4:05 p.m., the storm had a central pressure of 1,000 hectopascals, with maximum sustained winds of around 65 kph and gusts of 90 kph.

The storm is forecast to strengthen steadily, reaching typhoon intensity later this week as it tracks toward waters near Minamitorishima. By Saturday, the JMA forecasts Koguma could have a central pressure of about 950 hectopascals and maximum winds of 144 kph, and gusts of up to 216 kph.

The JWA said the storm could affect the Ogasawara Islands during the three-day holiday weekend beginning Saturday, while swells may also bring high waves to the Pacific coast of Honshu.

Despite the unusual concentration of tropical systems, widespread disruption across Japan’s main islands is not currently expected. Clear autumn weather is forecast across much of the country from Wednesday, including during the three-day holiday.

This year has seen an unusually high number of typhoons, reaching over 28 for the year so far, the first time in seven years.