The 2018 hurricane season still has a few weeks to go, but it has already been one for the record books. Warming-fueled waters led to some of the strongest, most rapidly-intensifying hurricanes ever recorded.
Hurricane Michael was third-most intense Atlantic hurricane to make landfall in this country — and the most intense October hurricane to hit ever hit the United States. It caused 54 fatalities and more than $8 billion in damage, while obliterating the city of Mexico Beach.
Hurricane Florence arrived late in the season and, like last year’s Hurricane Harvey, brought a historic amount of water. Florence deluged Elizabethtown, North Carolina with a stunning 36 inches of rain, making it the Carolinas’ wettest hurricane on record. It triggered record flooding and is responsible for more than 50 deaths and $13 billion in damages.
Willa capped off the eastern Pacific’s “most active hurricane season on record (since 1971),” as atmospheric scientist Michael Lowry tweeted Sunday. Lowry, a strategic planner at the Federal Emergency Management Agency (FEMA), noted that Willa was “the 9th (!) Category 4 or 5 hurricane of 2018.”
The eastern Pacific has just experienced its most active hurricane season on record (since 1971). Today #Willa blossomed into the 9th (!) Category 4 or 5 hurricane of 2018. This record is especially astounding in the absence of a strong El Niño. (satellite via @UWSSEC) pic.twitter.com/WOqHhgBjPU
— Michael Lowry (@MichaelRLowry) October 22, 2018
Lowry added, “This record is especially astounding in the absence of a strong El Niño,” to warm up Eastern Pacific waters.
What’s especially worrisome is that these three hurricanes all intensified at a very rapid rate, which complicated forecasting for Michael and Willa in particular.
As human-caused global warming continues to accelerate, both sea-surface and deeper-ocean temperatures rise, which provides a growing fuel source for hurricanes.
“Storms are intensifying at a much more rapid pace than they used to 25 years back,” explained the author of a 2012 study on hurricane intensification trends. “They are getting stronger more quickly and also [to a] higher category. The intensity as well as the rate of intensity is increasing.”
A 2015 study on the impact of sea-surface temperatures on the intensity of hurricanes in the North Atlantic found “intensification increases by 16 percent for every 1°C increase in mean SST.” A 2016 study warned that “the most intense storms” are those that undergo rapid intensification. A 2018 study found that hurricane intensification sped up in the past three decades in the eastern and central Atlantic Ocean.
“My own work shows that rates of intensification increase more rapidly than intensity itself as the climate warms,” MIT hurricane scientist Kerry Emanuel told wunderground.com earlier this month. As a result, “rapidly intensifying storms like Michael may be expected to become more common.”
In short, absent much stronger efforts to cut carbon pollution, hurricane seasons like 2018 and 2017 — and the rapidly intensifying superstorms they gave us, like Harvey, Maria, Lawrence, Michael, and Willa — are going to become more and more common.