This is the first time in known history the Atlantic has had two storms with 150+ mph winds raging at the same time: Irma and Jose.
Maria went from a tropical depression to a Category 5 storm in two-and-a-half days, a speed that Mark DeMaria, acting deputy director of the National Hurricane Center, told the Washington Post is most likely the record for fastest intensification in the Atlantic.
This year also set a record for cyclone energy generated in September. But this season isn’t the worst ever seen, as much as it might seem that way. That distinction belongs to 2005.
That year, there were so many named storms that officials ran through the whole alphabetical list of names (the letters Q, U, X, Y, and Z are not used) and then had to run through the Greek alphabet, using Alpha, Beta, Gamma, Delta, Epsilon, and Zeta. Fifteen storms in 2005 were hurricanes, with seven being major hurricanes.
Five storm names were retired that year because of the devastation the hurricanes caused: Dennis, Katrina, Rita, Stan, and Wilma. Most likely at least three names will be retired retired after 2017: Harvey, Irma, and Maria.
The National Oceanic and Atmospheric Organization has a formal definition for an “extremely active” Atlantic hurricane season — and this year certainly meets the requirements. In an “extremely active” year, storms have to generate at least 152.5 units of accumulated cyclone energy — a measure of storm intensity, duration, and frequency.
As of October 6, the 2017 season was up to 204.9 units. The season also has to meet two out of these three conditions: 13 or more named storms, 7 or more hurricanes, and 3 or more major hurricanes. This year hit all three.
In fact, according to Phil Klotzbach, a meteorologist at Colorado State University specializing in Atlantic hurricane forecasts, the definition was met by September 20.And hurricane season isn’t over until November 30, so there’s almost certainly more to come he claims.