We are quickly running out of adjectives to describe the destructive potential of Hurricane Irma. As of 2pm ET on Tuesday, the National Hurricane Center upgraded the storm’s sustained winds to 185mph. This is near-record speed for a storm in the Atlantic basin, which includes the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico.
Such high, sustained winds tie Irma for the second-strongest storm on record in the Atlantic, along with Hurricane Wilma (2005), Hurricane Gilbert (1998), and the 1935 Florida Keys hurricane. Only Hurricane Allen, which reached 190 mph in 1980 before striking a relatively unpopulated area of Texas, reached a higher wind speed. Globally, the all-time record for hurricanes is held by Patricia, which reached a staggering 215 mph in the Pacific Ocean in 2015.
Although sustained winds capture the most public attention, meteorologists generally measure the intensity of a storm based upon central pressures, which are considerably lower than sea-level pressure on Earth, 1,013 millibars. Typhoon Tip, in 1979, holds this record at 870 millibars. For now, at least, Irma has a relatively high central pressure of 927 millibars. Why the storm has such an odd wind-speed-pressure relationship isn’t entirely clear.