Typhoon Gaemi unleashed torrential rainfall and powerful winds across the island of Taiwan on Thursday, July 25. As of 2 a.m. in Taiwan, Typhoon Gaemi has maximum sustained winds of 110 miles per hour with a central pressure of 945 millibars. It's not necessarily the intensity of Gaemi that makes this storm interesting. Instead, the "wobbly" motion of this typhoon is some of the most erratic motion you may ever see in a landfalling tropical cyclone. Let's dive into what makes this storm so interesting.
Imagery Courtesy NOAA/CSU/CIRA
In short, Typhoon Gaemi did a massive "loop-the-loop" as it approached the eastern coastline of Taiwan. Meteorologists pointed to recent studies, in the mid 2010's, describing some of the factors leading to this meteorological phenomenon. It is believed that the mountainous terrain of Taiwan can severely interrupt, even "deflect", the forward motion of an incoming typhoon.
Courtesy Brian McNoldy/X
Courtesy Jeff Berardelli/X
In this case of Taiwan, it is believed the mountainous terrain redirects the bands of storms to the south, instead of moving over the mountains to the west. This in turn causes the center of the circulation to dip south. Then, bands of thunderstorms move parallel to the mountains and the storm's circulation returns to its previous course, due to larger steering patterns in the atmosphere. The fact that this has happened in previous typhoons showcases the unique nature of tropical cyclones approaching the island of Taiwan.
It's unclear if the wild forward motion of Gaemi was solely from interaction with Taiwan's terrain, or if there was an upcoming eye wall replacement cycle. Another fascinating phenomenon with these tropical cyclones is referred to as an eye wall replacement cycle, where the inner core of the cyclone dissipates and then reforms with a center of circulation. Sometimes, this can result in massive "wobbles" or "turns" in the forward path of a tropical cyclone. This is referred to as a "trochoidal loop." It's just another spectacular attribute to these amazing storms.
Because of how large Typhoon Gaemi was, torrential rains associated with the storm lashed the nearby islands of the Philippines to the south. This resulted in flooding, especially across the northern islands.