This swirling mass of terror above is Super Typhoon Soudelor in the western Pacific, which is the strongest tropical cyclone we’ve seen in 2015, packing winds of 180 MPH (and gusts to 220 MPH) as it makes its way toward East Asia later this week. Meanwhile, a much weaker tropical storm is heading toward Hawaii.


Beginning here in the United States, all eyes in Hawaii are on Tropical Storm Guillermo this afternoon as the system makes its way toward the island chain. The seventh named storm of the eastern Pacific hurricane season began life nearly 2,500 miles to the east of its current position, still in the area covered by the National Hurricane Center in Miami. Since it developed last week, Guillermo has since crossed 140°W—the line of longitude that separates the eastern and central Pacific basins—and swirled into Hawaii’s area of concern.

Now a tropical storm with 70 MPH winds, Guillermo is still on track to come very close to Hawaii, as forecasters have expected for several days now. Satellite imagery shows that Guillermo isn’t the healthiest system, with the southern half of the tropical storm lacking in thunderstorm activity as wind shear in the upper levels of the atmosphere shred away it.

The lopsided nature of Guillermo makes the exact track of the center of the storm key to who gets inclement weather, if any at all. Assuming the storm holds together long enough to make it to Hawaii, the latest forecast from the Central Pacific Hurricane Center shows the storm’s center skirting north of the islands, which would dramatically lessen the impact it has on the state. If the tropical storm were to track along the southern edge of the cone of uncertainty—or if the thunderstorms reform south of the center of circulation—most of the islands would experience a period of gusty winds and heavy rain between Wednesday afternoon and Thursday night.

For what it’s worth, the latest model guidance are in pretty good agreement that the center of the storm will track a few dozen miles north of the islands, but it’s going to be close enough that residents and visitors alike will have to watch how Guillermo develops over the coming days. Regardless of its track, high surf and rip currents are likely as the storm approaches and moves through the area. Stay out of the water if you’re not a confident swimmer, and heed the advice of lifeguards and local officials if they tell you not to go in the water.

Super Typhoon Soudelor

A few thousand miles to Guillermo’s northwest is a powerful super typhoon that has its sights set on an East Asia landfall late this week. The term “super typhoon” is a designation based on wind speeds much the same way we use “major hurricane” in the Atlantic and eastern Pacific basins. A super typhoon is similar to a category five hurricane in our part of the world—a typhoon has to reach winds of 150 MPH or greater to achieve the designation. (A category five has winds of 156 MPH or stronger.)

The term “super typhoon” doesn’t do this storm justice. Soudelor has 180 MPH winds according to the latest advisory from the Joint Typhoon Warning Center , and the U.S. military’s tropical forecasting branch predicts that Soudelor will strengthen even further over the coming hours, possibly reaching a mind-blowing maximum wind speed of 185 MPH before it gets too strong for its own good and starts a slow but steady weakening trend. Weakening is relative when it comes to a storm this strong, and the JTWC expects the storm to maintain winds of 135 MPH (equivalent of a category four) when it reaches the smaller islands of Japan’s Okinawa Prefecture on Friday. Soudelor will continue toward Taiwan and mainland China on Saturday as a formidable typhoon with wind of more than 100 MPH, which will likely cause significant damage, flooding and mudslides from heavy rain, and storm surge as a result.

Soudelor’s cone of uncertainty is quite large, and the storm could move anywhere within (or even outside of) that cone over the next couple of days. If you’re in Asia or plan to visit soon, don’t pay attention to just the path of the center of the storm—destructive winds and flooding rains extend far away from the eye, and the storm could always change track with little or no notice.

If you were wondering, the name “Soudelor” is one of 140 typhoon names used for storms in the western Pacific basin. The name was contributed by the Federated States of Micronesia, and it means “chief” or “ruler” in the Pohnpeian language, according to Guam’s Pacific Daily News.

Typhoon vs. Hurricane

One of the most common questions asked after a story like this is “I thought they were called typhoons in the Pacific?” We only call strong tropical cyclones “typhoons” in the western Pacific Ocean near Asia. Strong tropical cyclones that form in the central and eastern Pacific—think near Hawaii or the west coast of Mexico—are called “hurricanes” like they are over in the Atlantic Ocean.

There’s not much of a difference between a hurricane and a typhoon except that the two terms each require storms to reach slightly different wind speeds before being called one. It’s all just a name.

[Images: NOAA, author, JMA, JTWC]

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