UNITED STATES—December 2, 2019—The 2019 Atlantic hurricane season came to its official end on November 30 with 18 named storms in the books—including six hurricanes, three of which developed into major hurricanes at Category 3 strength or higher. After a slow start, hurricane activity peaked August through October ultimately bringing in the fourth consecutive above-normal Atlantic season, according to the National Oceanic and Atmospheric Administration (NOAA). The only other 4-year above-normal stretch on record occurred 1998-2001. According to NOAA, an average season sees 12 named storms, six hurricanes, and three major hurricanes.

In addition to continuing this active streak, the 2019 season matched or broke several other records. According to Scientific American, 2019 is just the ninth season since 1851 to produce 18 or more named storms. Of these, a record seven storms in 2019 lasted 24 hours or less at tropical storm strength. However, short-lived does not mean insignificant as one of these brief cyclones, Tropical Storm Imelda, became the fifth-wettest tropical storm in continental U.S. history, dumping up to 44 inches of rain in three days between Houston and Beaumont, Texas, according to Scientific American.

With 185 mph winds, Hurricane Dorian is tied with three other storms as the second strongest cyclone on record in the Atlantic in terms of wind. At peak strength, Dorian also made an unprecedented stall, lashing the Bahamas for 27 hours as it moved at no more than 5 mph. No Category 5 storm on record has ever impacted a land area for that long, according to Scientific American. In the Bahamas, Dorian left behind 25 feet of storm surge, 3 feet of rain, and $3.4 billion in damage. Sixty-nine people died and 282 were still missing as of late October. Dorian went on to strike North Carolina as a Category 1 storm, killing 10 people and doing $1.2 billion in damage before taking aim at Canada as an extratropical storm with a massive wind field and up to 100 mph winds. Over half a million customers in Canada lost power as Dorian delivered $79 million in damage in its final blow.

Hurricane Dorian

Hurricane Dorian makes landfall in North Carolina. Image courtesy of NOAA.

As the 2019 Atlantic hurricane season comes to an end, researchers are considering how climate change could be affecting these record-setting events. According to Scientific American, record heat waves and warming ocean temperatures mean that more moisture is able to evaporate into the air. Storm systems and tropical cyclones concentrate this moisture, resulting in exceptionally heavy rainfall. Scientific American reports that two-day extreme precipitation events on the Gulf Coast are becoming more common due to climate change. In Southeast Texas, Imelda brought the fifth 500-year flood to impact the region in the last five years.

Hurricane Barry also set precipitation records, bringing 10 to 15 inches of rain or more across Louisiana and setting the all-time state record in Arkansas for both tropical cyclone and single-day precipitation, dumping more than 16 inches of rain in a 24-hour period. According to Scientific American, the data shows that slow-moving storms like Barry, Imelda, and Dorian are becoming more common, and with them, record-breaking rainfall that causes millions of dollars in flood and water damage.

As of late October, Accuweather estimated the total economic loss from the 2019 Atlantic hurricane season at $22 billion in the U.S. and another $5 billion in the Bahamas. This estimate includes damage to homes, businesses, and infrastructure, as well as wage losses, farm and crop losses, environmental contamination, and health effects