The 2019 Atlantic Hurricane Season officially ended on Saturday. It marked the fourth year in a row with above-average activity.
According to NOAA, there were eighteen named storms this season. Of these, six developed into hurricanes and three were major hurricanes with ratings of category 3 or higher on the Saffir-Simpson Scale. It also posted an Accumulated Cyclone Energy (ACE) index of 129.8 An average season produces twelve named storms, six hurricanes, three major hurricanes, and an ACE of 106.
Officially running from June 1 to November 30, the season got off to an early start with Subtropical Storm Andrea forming in May. This was the fifth consecutive year to see a pre-season storm develop. The biggest names of the season, however, were Dorian and Lorenzo.
In September, Hurricane Dorian made landfall in the Bahamas as a category-5 storm with winds measured up to 185mph and a minimum pressure of 910 millibars. It was the strongest storm on record to hit the island nation, claiming the lives of at least 60 people and leaving several billion dollars worth of damage in its wake.
Dorian also marked 2019 as the fourth year in a row to see a category-5 storm develop in the Atlantic basin, a new record.
Out at sea, Hurricane Lorenzo became the second category-5 storm of the season. It was also the easternmost Category-5 storm in the Atlantic on record. As for a possible connection to climate change, it is interesting to note that twenty-eight category-5 storms have developed in the Atlantic since 1950 with fourteen of them occurring since 2003.
For the contiguous United States this season, Tropical Storm Imelda caused the most damage. Moving slowly across Texas and Louisiana, it dumped between 30 and 44 inches of rain on the area over the course of three days. It unleashed catastrophic flooding throughout the region and became the fifth wettest tropical cyclone on record in the continental US.
This active hurricane season, according to NOAA, was largely the result of above-average sea surface temperatures in the Atlantic, a stronger than normal West African monsoon, and ENSO neutral conditions in the Pacific. In other words, the combination of warm water to fuel storms and reduced wind shear across the Gulf of Mexico allowed for unhindered tropical development in the Atlantic basin.