At a Glance

Sebastien moved through the central Atlantic Ocean.Development this late in the season isn't unusual.

Tropical Storm Sebastien roamed through the central Atlantic, but it was no threat to any land areas.

Sebastien formed on the morning of Nov. 19, 2019, about 275 miles northeast of the Leeward Islands. Some strengthening was observed but it did not become a hurricane.

The Atlantic has now had 18 named storms in the 2019 hurricane season. The last time 18 or more named storms formed in a season was 2012.

It's Not Too Late

With Thanksgiving next week, it may sound weird to be discussing tropical development this late in the season, especially given the and snow this fall in parts of the nation.

(MORE: Seven Crazy Things We've Seen This Hurricane Season)

But this isn't unusual, and it's happened a number of times this century.

Roughly 3% of an occurs after Nov. 18, according to Dr. Phil Klotzbach, tropical scientist at Colorado State University.

Since 1950, have developed in the Atlantic Basin from Nov. 19 through New Year's Eve, according to NOAA's best track database. That's an average of one such late-developing storm roughly every three years.

The map of those storms shows a common corridor through the central Atlantic Ocean north of Puerto Rico and the Leeward Islands, similar to the location of Sebastien.

Tracks of all Atlantic storms since 1950 that formed from Nov. 19 through Dec. 31.

Eight of those post-Nov. 18 storms formed this century. The most recent was Olga in mid-December 2007.

The record-smashing 2005 hurricane season's three final named storms – Delta, Epsilon and Zeta – each formed after Nov. 18. Tropical storms Odette and Peter ended the 2003 season in early December.

Not every storm this late in the season stays out to sea.

On Thanksgiving Day 2016, made landfall near the Nicaragua-Costa Rica border at Category 3 intensity. Otto was the latest-in-season Atlantic Basin hurricane landfall on record and the first known hurricane to track over Costa Rica.

In 1985, Hurricane Kate became the latest-in-season U.S. hurricane landfall on record. It plowed ashore at Mexico Beach, Florida, on Nov. 21.

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