A rare January hurricane may be evidence of changing ocean temperatures, which can result in stronger storms, says Katharine Hayhoe, director of the Texas Tech University Climate Science Center.
Hurricane Alex’s formation earlier this month marked only the second recorded time that a hurricane formed in the Atlantic Ocean during the month of January; the other was in 1938. According to NASA, Alex officially became a hurricane on Jan. 14, 2016. Alex is also the first January hurricane to occur in the Atlantic since Alice, which formed Dec. 31, 1954, according to the Texas Tech researcher.
Alex became the strongest January hurricane on record when its winds reached an estimated 85 mph, exceeding the 80 mph peak of both Alice and the 1938 hurricane. The Atlantic hurricane season officially runs from June 1 through Nov. 30.
Alex made landfall as a tropical storm earlier this month in The Azores, a group of islands in the North Atlantic Ocean about 850 miles west of Portugal.
According to Hayhoe, Alex’s strength is unusual because tropical storms occur mostly over warm waters, a condition not common in the North Atlantic Ocean in the middle of winter. “Hurricanes require warm ocean water. That’s what supplies their energy. The warmer the ocean water, the stronger the hurricane.”
According to NASA, when extra-tropical storms acquire enhanced convection the instability is due to being over warm waters, but in Alex’s case it appears that the instability was due to in large part to the cold air above it. The heat released from the thunderstorms, which is known as latent heating, is what allowed Alex to eventually transform into a hurricane.
There are climate change implications of such an early start to the hurricane season, according to the Texas Tech researcher. Human activity is creating more favorable conditions for stronger storms. Her research focuses on developing and applying high-resolution climate projections to evaluate the future impacts of climate change on human society and the natural environment. “As climate changes due to human activities, more and more of the excess heat being trapped by the carbon dioxide in the atmosphere is going into the oceans,” says Hayhoe. “This means the conditions conducive to hurricanes — particularly strong ones — will likely increase as climate changes.”
According to NOAA’s Atlantic Oceanographic & Meteorological Laboratory, though the official Atlantic hurricane season is between June 1 and November 30, outlier hurricanes can occur. The date range for the official season is based on statistical evidence that suggest the six month range encompasses more than 97 percent of tropical activity.