The Pacific’s Busy Storm Season in 2026

Since April 2026, the Northwest Pacific has experienced an extraordinary surge in tropical cyclone activity. The season began when Sinlaku intensified into a super typhoon, battering Micronesia, Guam, and the Northern Mariana Islands. By late October, 25 named storms had formed, and the basin remained active, with Super Typhoon In‑fa churning near the Mariana Islands while the remnants of Typhoon Champi headed toward Alaska.

In‑fa displayed traits that meteorologists classify as “annular” – a rare subset of tropical cyclones. The storm possessed a nearly circular shape and a large, clear eye, characteristics that set it apart from typical spiraling systems. “Annular storms are rare, accounting for just 4 percent of tropical cyclones in the western North Pacific, according to one analysis,” researchers note. Their eyes average about 45 kilometers (30 miles) in diameter, compared with roughly 25 kilometers for standard tropical cyclones, and they tend to maintain intensity longer when environmental conditions become unfavorable.

Later in the season, Champi underwent extratropical transition as it moved into the Bering Sea. Gary Partyka, a meteorologist at NASA’s Goddard Space Flight Center, explained the process: “One of the calling cards of extratropical transitions is the expansion of a storm’s wind field,” he said. “It’s not that the winds necessarily grow stronger, but they cover a much larger area.” This expansion can affect regions far from the original storm track, as seen when Champi’s remnants interacted with an existing midlatitude system over the Bering Sea.

The broader context includes a strong El Niño underway in the Pacific. El Niño, which recurs every two to seven years, is marked by warmer‑than‑normal sea‑surface temperatures in the equatorial Pacific. In the Northwest Pacific, this pattern tends to steer storms northward, increasing the likelihood that they will affect Guam, the Northern Mariana Islands, Japan, and even Alaska. Rick Thoman, a climatologist at the University of Alaska Fairbanks, reported that Champi was the fourth ex‑typhoon to enter Alaskan waters that year, following earlier systems Bang‑Lang, Dujuan, and Choi‑wan. Since 1970, roughly 60 ex‑typhoons have impacted Alaska, he noted.

For educators and students, this active season offers a concrete case study in climate dynamics, satellite observation, and hazard preparedness. Project ideas might include using publicly available EPIC and MODIS imagery to track storm evolution, or mapping the northward shift of cyclone tracks during El Niño years. On the operational side, agencies such as NASA and the National Weather Service rely on real‑time data from instruments like EPIC on DSCOVR and MODIS on Terra to forecast intensity and transition behavior. Understanding the differences between annular storms, extratropical transitions, and the influence of El Niño helps build a more nuanced picture of how ocean‑atmosphere interactions shape weather far from the tropics.

Source

NASA Science