Tropical Storm Erika may have fizzled out, leaving Florida’s 10-year hurricane-free streak still running, but there is plenty of other tropical cyclone activity afoot: Once again this year, there is a string of storms spanning the Pacific, while over in the Atlantic, a hurricane has formed further east in the tropics than any other on record.More
While the bulk of the hurricane action so far this year has been in the hopping Pacific, the more muted Atlantic Ocean season doesn’t seem to be quite done yet. Tropical Storm Kate formed near the Bahamas early Monday, a late-season storm that is in many ways emblematic of the overall El Niño-influenced season.
On Monday morning, hurricane hunters flew into what was then known as Tropical Depression Twelve and measured winds that were high enough to bump the storm up to tropical storm status, the point at which a storm gets an official name. Kate is the 11th named storm of the 2015 Atlantic hurricane season.
While Kate will spend the rest of the day in an environment favorable for some strengthening, forecasters think it won’t get above tropical storm strength, and it isn’t expected to be much of a threat to land areas. Some parts of the Bahamas have seen rains associated with the storm, but nothing severe.
#Kate is the 1st November tropical storm in the central or northwestern Bahamas since Noel of 2007 #climate #weather pic.twitter.com/j3BTLT1WEB
— Eric Blake (@EricBlake12) November 9, 2015
The chill that sets in come November may seem to be at odds with tropical weather, but the Atlantic hurricane season officially extends through the end of the month (and storms have even been known to form after that). Generally, 95 percent of Atlantic storm activity has happened by this point in the season, but it’s still possible for a storm like Kate to spin up if the right set of conditions comes together.
The same can be said more broadly of storm activity during an El Niño year, when the season tends to be less active than in average years. This is because the shifts El Niño causes in Pacific Ocean temperatures and winds have a knock-on effect on a prime area of storm formation in the Atlantic. In the deep tropics, winds become very unfavorable to burgeoning storms. But outside of that area, it’s possible to get small pockets that let storms like Kate flourish.
“It’s not as though the whole basin is wiped out in an El Niño year,” James Franklin, branch chief of the National Hurricane Center’s hurricane specialist unit, said.
The system that became Kate “happened to find a small area of supportive upper level winds,” Franklin said. That small area is reflected in the fact that “Kate’s a very, very small storm,” he added.
Tropical Storm #Kate to affect Bahamas before turning N-NE out to sea. HDOB from reconnaissance aircraft shown here. pic.twitter.com/pgu7ylLqj2
— UW-Madison CIMSS (@UWCIMSS) November 9, 2015
Similarly, other storms this season found pockets where they could develop, with a few more storms forming than was initially anticipated for a year when a strong El Niño was in place. Overall though, “we didn’t’ have a lot of strong storms,” Franklin said.
Many storms, like Tropical Storm Erika, stayed weak after forming because of unfavorable winds. And in the case of Hurricane Danny, which did strengthen, it soon hit those hostile winds “and weakened almost as quickly as it developed,” Franklin said.
And despite a scare from Hurricane Joaquin, which for a time looked like it could follow Hurricane Sandy’s example, the U.S. extended its streak of years without a major hurricane landfall, now at 10.
But the U.S., of course, isn’t the only area affected by Atlantic storms. This year, for example, “there were lots of impacts in the Bahamas from Joaquin,” Franklin said. “So for them it was a very busy season.” Those impacts outside the U.S. aren’t always appreciated by the American public.
“Impacts, I guess, like politics, are local,” Franklin said.