Typhoon Kilo, already the longest-lived tropical cyclone on on Earth so far this year, is well on its way to ending among the longest-lived on record at the end of this week.
Kilo formed from a cluster of thunderstorms way back on Aug. 20, as a tropical depression south of Hawaii. Since then the storm strengthened to a very strong hurricane, the westernmost in a trio of Category 4s, marking the first time three storms of that intensity spun simultaneously in the northeast Pacific Ocean since satellite records began in the 1960s.
Then on Sept. 1, Hurricane Kilo crossed west over the international dateline and became a typhoon. East of the international dateline, Pacific Ocean cyclones are managed by NOAA’s Central Pacific Hurricane Center, which calls tropical cyclones “hurricanes.” The western side is monitored by the Joint Typhoon Warning Center, where tropical cyclones are called “typhoons.”
Amazingly, Kilo has tracked nearly 4,000 miles over its 21-day existence. On average, storms that develop in the eastern Pacific Ocean have a life of about six days.
If Kilo can maintain its tropical characteristics through Saturday, as the Joint Typhoon Warning Center forecasts, it will have lasted 24 days as a tropical cyclone — far from the longest on record, but solidly in the top five longest-lived tropical cyclones that formed in the eastern Pacific Ocean, and the top 10 longest-lived cyclones in any basin.
The record-longest tropical cyclone on Earth was Hurricane (Typhoon) John in 1994, which lasted an incredible 31 days on its westward journey across the Pacific — similar to Kilo’s track. Typhoon Kilo will end about a week short of John’s impressive record, but will likely snag the title of third-longest Eastern Pacific tropical cyclone on record.
Longest-lived East Pacific hurricanes, according to the NOAA Hurricane Research Division:
1. John, 1994 — 30 days
2. Tina, 1992 — 24.5 days
3. Paka, 1997 — 24 days
4. Ioke, 2006 — 21.5 days
5. Tied between Keoni, 1993, and Boris, 1984 — 20.5 days
As of Wednesday morning, Typhoon Kilo was the equivalent of a Category 1 hurricane, spinning west toward Japan. The Joint Typhoon Warning Center estimates that Kilo is packing sustained winds of 75 mph, though it’s expected to weaken over the next few days as it turns north.
As the typhoon encounters cooler water, Kilo is forecast to weaken to a tropical storm and possibly come ashore in Japan’s far northern prefecture of Hokkaido, though it seems more likely that Kilo will continue to turn north and wash over the southern Kuril Islands, which extend from northern Japan to northeast Russia, with heavy rain and high surf.
Jasper and Sardine 
