te of the Climate in 2021 report was released today by the American Meteorological Society, showing greenhouse gas concentrations, global sea levels, and ocean heat content reached record highs in 2021 despite a La Niña event taking place in the Pacific Ocean.
Tropical cyclones intensify by extracting heat energy from the ocean surface, making the sea surface temperature under storms crucial for storm development. A recent study by researchers at the Pacific Northwest National Laboratory and NOAA’s Atlantic Oceanographic and Meteorological Laboratory found that large amounts of rain under tropical cyclones can reduce the sea surface cooling induced by them.
Observations obtained by the Coyote small Uncrewed Aircraft System led to a significant improvement in the analyses of Hurricane Maria’s (2017) position, intensity, and structure, according to new research published in the journal Monthly Weather Review. The study by scientists with the University of Miami’s Cooperative Institute for Marine and Atmospheric Studies and Atlantic Oceanographic and Meteorological Laboratory (AOML) highlights how the Coyote’s novel near-surface measurements helped to more accurately depict Hurricane Maria’s inner core, demonstrating their ability to improve forecasts.
The amount of wind shear, i.e., the change of the wind with height, is one of the most commonly used predictors of tropical cyclone intensity change, with large amounts of wind shear generally being unfavorable for intensification. Regardless of the direction of the wind shear, tropical cyclones in the North Atlantic basin usually have warm, moist air from the environment near the sea surface on their east side (solid red arrows in the images) and cool, dry air from the environment on their west side (solid blue arrows in images).
The active 2021 Atlantic hurricane season ended on November 30, producing 21 named tropical storms (39‑73 mph winds), seven hurricanes (74 mph winds and above), and four major hurricanes (111 mph winds and above). The year will be remembered as the third-most active on record, as well as the third costliest, causing more than $80 billion in damage.
Hurricane scientists at AOML sampled multiple storms this summer as the Atlantic entered its peak period for hurricane formation. From Elsa to Sam, the observations they gathered supported NOAA’s mission of preparing the public for severe weather by providing critical data for accurate, up-to-date forecasts.
