Hurricane Erin drew near-round-the-clock television attention and untold thousands of headlines and with good reason — it was an exceptionally large storm, one that also went from tropical depression to full-blown monster in a remarkably short time. Erin was important for more than meteorology: It was an example of what experts say will become more frequent as the ocean continues to get warmer.
Erin earned a place among the most-expansive Atlantic hurricanes on record. Hurricane-force winds spanned 150 miles last Thursday, with a tropical-storm wind diameter of at least 480 miles. This made Erin wider than Hurricane Katrina in 2005, which had tropical-storm-force winds of 380 miles in breadth. Another way to get a sense of Erin’s size is that it reached from off North Carolina to South Florida. It was also compared to the State of Texas. After touching Cape Hatteras, Erin’s tropical storm conditions came within a hair’s breadth of Long Island and just skirted Martha’s Vineyard and Nantucket. At its peak, Erin had winds of about 160 miles per hour, making it a Category 5 hurricane. Waves in the open Atlantic reached 40 feet, according to the National Data Buoy Center.
The hurricane was also one of the top five most quickly intensifying Atlantic storms on record. In one 24-hour period, Aug. 15 and 16, Erin’s wind speeds increased by nearly 85 miles per hour, peaking at 161 m.p.h. As the planet warms, rapidly intensifying hurricanes are becoming more likely, scientists say. Also concerning is that a Category 5 storm erupting before the end of August is rare.
Storms like Erin are becoming more frequent. There have been 11 reaching Category 5 strength in the last 10 years — a total that had previously taken 27 years to accumulate; the 11 before that came over the course of 34 years. There is a similar pattern for Category 4 storms: There have been 27 of them in the past decade, more than the historical average.
Heat powers storms; warmer ocean water can create more and bigger storms with ever-greater amounts of rain. Researchers have concluded that powerful hurricanes will continue to be more common. The western arc of the North Atlantic, in particular, is warming faster than many other places on the globe. The implication is that the most dangerous storms could power up more often right in our own backyard. Coastal policy and preparations that do not take this into account will not be up to the task.