Super Typhoon In-fa and Extratropical Remnants of Champi Highlight an Active Pacific Storm Season

Tropical cyclone activity in the Northwest Pacific Basin has been elevated since April 2026, when Sinlaku surged to super typhoon strength and battered Micronesia, Guam, and the Northern Mariana Islands. Twenty-five named storms later, the basin remained active in late October. Super Typhoon In-fa was churning near the Mariana Islands on October 29, 2026, when the EPIC (Earth Polychromatic Imaging Camera) on the DSCOVR (Deep Space Climate Observatory) satellite captured an image of the storm. At the same time, the remnants of Typhoon Champi were approaching Alaska amid a parade of storms moving across the Bering Sea. In-fa is the fifth typhoon to affect the Mariana Islands this year. The MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA's Terra satellite imaged In-fa again on October 30, when the storm was just west of the island chain. Meteorologists noted that In-fa was unusually intense at the time, with a nearly circular shape and a large eye, characteristics that identify it as an annular storm. These storms typically lack the prominent outer spiral rainbands common to standard tropical cyclones, which is why forecasters sometimes call them "doughnuts" or "truck tires." Annular storms are rare, accounting for just 4 percent of tropical cyclones in the western North Pacific according to one analysis. Their eyes average about 45 kilometers (30 miles) in diameter, compared with about 25 kilometers for standard tropical cyclones, and the storms typically maintain their strength longer in unfavorable conditions. While In-fa was still a tropical cyclone, the remnants of Champi had completed extratropical transition and become a different type of storm as they entered the Bering Sea's busy storm track. Tropical cyclones are warm-core storms fueled by heat and moisture from warm ocean water, whereas extratropical cyclones typically have cold cores and draw energy from temperature contrasts between warm and cold air masses. Unlike tropical cyclones, extratropical cyclones typically develop fronts and large, spiraling comma-shaped cloud bands. "One of the calling cards of extratropical transitions is the expansion of a storm's wind field," said Gary Partyka, a meteorologist at NASA's Goddard Space Flight Center. "It's not that the winds necessarily grow stronger, but they cover a much larger area," he said. Partyka added that a midlatitude storm over the Bering Sea would likely have formed on October 30 even without Champi's remnants, but that Champi appears to have become intertwined with and helped intensify that system. Champi's transformation followed a long and destructive tour of the West Pacific, during which the typhoon reached maximum sustained winds of nearly 300 kilometers (185 miles) per hour, prompting some observers to call it one of the strongest storms of the season. Champi narrowly skirted Taiwan and Guam but still brought damaging winds and intense rain to both, as well as to parts of China and Japan. When the remnants reached Alaska, the state avoided damage on the scale of ex-typhoon Halong in October 2025, but news reports indicated some areas saw high winds and heavy rain and snowfall. University of Alaska Fairbanks meteorologist and climatologist Rick Thoman noted that Champi is the fourth ex-typhoon to enter Alaskan waters this year, following Bang-Lang in August, Dujuan in September, and Choi-wan in early October. The autumns of 1997 and 2015, both very strong El Niño years, each had three. Roughly 60 ex-typhoons have impacted the state since 1970, according to Thoman. Partyka described 2026 as a "particularly active year" for Pacific tropical cyclones, increasing the odds that Alaska would be affected by storms undergoing extratropical transition. The strong El Niño underway in the Pacific is a "likely contributor" to the increased activity, he said. El Niño is a climate pattern that emerges roughly every two to seven years and is marked by warmer-than-normal water temperatures in parts of the equatorial Pacific. In the Northwest Pacific, it tends to cause storms to curve more readily northward rather than continuing westward toward East and Southeast Asia, some experts say, bringing more storms toward Guam, the Northern Mariana Islands, Japan, and the Korean Peninsula.