The official end of the 2019 Atlantic hurricane season is only nine days away. It runs from June 1 through Nov. 30. But Mother Nature didn’t get the memo: A tropical storm that was named earlier this week may very well become the seventh hurricane of the season.
Tropical Storm Sebastien began on Nov. 16 as just a cluster of thunderstorms in the western Caribbean, just east of the Lesser Antilles. Within a few days, the storms joined hands (in a manner of speaking), smoothly swirling counterclockwise around a center of circulation, like a choreographed round dance. This further energized the storm’s rotation, like when a figure skater pulls his or her arms toward the body. This, in turn, increased the storm’s winds, which reached minimum tropical storm strength of 39 mph on Nov. 19. At that point, the National Hurricane Center (NHC) attached the name Sebastien.
Since that day, Sebastien has been spinning over open waters, slowly turning to the northeast and farther out to sea. As of 4 p.m. EST today, Nov. 21, its maximum sustained winds were up to 60 mph. However, the NHC is forecasting Sebastien to become a hurricane tonight. This would be official once its winds reach 74 mph.
Late-season hurricanes in or after November are rare in the Atlantic basin, which also includes the Caribbean Sea and Gulf of Mexico. This is because of cooling sea surface temperatures (SSTs) and changes in wind shear patterns in the Northern Hemisphere.
According to data compiled by NOAA’s Atlantic Oceanographic and Meteorological Laboratory for the years 1851–2018, there have been 47 total November hurricanes and only five that made landfall in the U.S. Now compare those numbers to the data for the month of September, which is the peak of hurricane season. During the same 164-year period, 406 September hurricanes formed and 108 made U.S. landfall. That is an 8.6-fold decrease in the number of hurricanes that developed between September and November and a 21.6-fold decrease in the number that made landfall. A few hurricanes over the decades that have developed in November lasted into December, and a few have even formed in December.
Philip Klotzbach, a meteorologist specializing in tropical systems, tweeted that if Sebastien becomes a hurricane, it would be only the eighth in the satellite era (since 1966) to form after Nov. 20.
The FreightWaves SONAR Critical Events platform houses up-to-date NHC information about worldwide tropical cyclones. It shows Sebastien reaching the Azores by early Sunday, Nov. 24, with gusts of 50 mph. This is shown on the right-hand side of the map above. However, this forecast may change a bit over the next couple of days.
For now, Sebastien is mainly a concern for container ship captains who will have to slow down or steer clear of the storm. This may lead to minor delays of freight movement in the coming days. However, Critical Events has a new feature that allows shippers to locate ports and track ocean vessels carrying their precious cargo! On the left-hand side of the map above, areas of bright blue and yellow indicate large concentrations of ships, whereas light blue represents lower concentrations. Zoom in, and you can get detailed data about each ship. Contact FreightWaves today for more information.