News•September 2, 2015

In Week of Cyclone Records, Kilo Could Break More

It’s been a banner week for tropical cyclones (the umbrella term for hurricanes and typhoons), with records set left and right thanks in part to a strong El Niño. And more potential records could be in store if Typhoon Kilo keeps on keeping on.

Hurricanes Kilo, Ignacio and Jimena (from west to east) seen at night and in daylight on Aug. 30 by the Suomi-NPP satellite.

Credit: NASA Earth Observatory

Prior to Sept. 1, Kilo was one of a trio of Category 4 hurricanes in the northeastern Pacific — a record clustering for any ocean basin. Kilo and one of the other storms, Ignacio, were both in a subregion known as the central north Pacific, sitting at opposite ends of the Hawaiian Islands. That pairing marked another first; never before had two Category 3 storms been in that area at the same time, according to hurricane researcher and forecaster Phil Klotzbach of Colorado State University.

(At the same time all of this activity was lighting up the Pacific, Hurricane Fred formed further east in the tropical Atlantic than any hurricane on record.)

Then Kilo crossed over the International Date Line, a rare, but not unprecedented, event that meant it was considered a typhoon and not a hurricane (the phenomena are the same, but are called different names in different ocean basins). What made the event particularly notable was that Kilo was the third such storm to make the crossing this season, the most storms of any season on record.

Now, as Kilo is expected to continue its westward journey, it could become one of the longest-lived storms on record. It has already been around for 14 days and is expected to carry on for another 7 to 10. It will have to last a few days longer than that to top the current title holder, Hurricane John, which spun across the Pacific for 30 days in 1994, beginning in the east Pacific off the coast of Mexico continuing on past the International Date Line before cutting back into the northeast Pacific.

The western half of #Kilo is a typhoon and it's Sept. 2, but the eastern half is a hurricane and it's Sept. 1! pic.twitter.com/iljoimCl1M

— Dan Lindsey (@DanLindsey77) September 1, 2015

All this record-breaking activity is linked to the strong El Niño that is making central Pacific waters warmer, and so increasing the storms’ fuel source, and cutting down on the wind shear that normally makes the area less friendly to hurricane formation. (Wind shear is when the direction of the wind changes at different heights in the atmosphere.)

The area around Hawaii, and the broader central Pacific, tends to see more storms in El Niño years. The previous record for named storms forming in there was in 1982, with four; 2015 has already seen five tropical cyclones.

Crossings of the International Date Line are also more common in El Niño years, Klotzbach said.

The central Pacific is also expected to see more tropical cyclones as the world warms, with the effects similar to an El Niño.