A lot can go wrong when hurricanes stall. Their destructive winds last longer. The storm surge can stay high. And the rain keeps falling…
Research shows that stalling has become more common for tropical cyclones in the North Atlantic since the mid-20th century and that their average forward speed has also slowed.
The Arctic has been warming about twice as fast as the mid-latitudes, where most of the U.S. is located. That’s changing the distribution, or gradient, of temperature between the Arctic and the mid-latitudes. And that can affect the steering currents, such as those associated with the Bermuda high.
On average, the forward speed of hurricanes has been slowing down. Simulations of tropical storm behavior have suggested that this slowing will continue as average global temperatures warm, particularly in the mid-latitudes…
A warmer atmosphere also means storms can tap into more moisture. As temperature increases, it’s easier for water to evaporate into vapor…If a storm slows, and if it has access to more moisture, it can dump more rain and produce a greater storm surge due to the slow motion.
RTFA. Even more interesting, mostly unnerving, factors affecting the course of hurricanes to come.
Recent Atlantic ocean warming unprecedented in nearly 3,000 years https://www.eurekalert.org/pub_releases/2020-10/uoma-rao101420.php
Fluctuations in sea surface temperatures, known as the Atlantic Multidecadal Oscillation (AMO), are also linked to other major climatic upheavals such as droughts in North America and the severity of hurricanes. However, because measurements of sea surface temperatures only go back a century or so, the exact length and variability of the AMO cycle has been poorly understood.
“Annually resolved Atlantic sea surface temperature variability over the past 2,900 y” https://www.pnas.org/content/early/2020/10/06/2014166117