Stalling Hurricanes Are A Rising Concern In The Age Of Climate Change

Hurricane Harvey caused extreme flooding in 2017
when it stalled around eastern Texas. Research indicates
hurricanes and tropical storms are stalling more
frequently, causing worse flooding. 

 To be Captain Obvious here, any town or city struck by a hurricane gets a rough ride. 

The destructive winds, the storm surges that batter everything to death along the coast, and the inches and inches of rain that create instantaneous floods are to say the least, scary and depressing. 

If you can find any good news in these awful scenarios, hurricanes more often than not move right along. 

They'll batter coastal communities for maybe 12 hours before moving on to wreck somebody else's life either further up the coast or somewhere inland. 

Here's a problem, though. Hurricanes are becoming less likely to be "hurrycanes" if you will. 

Sure, the two most recent big destructive hurricanes -Helene and Milton - cruised along at a fast forward speed. And both caused horrible deaths, damage and suffering. But researchers are becoming increasingly wary of what seems to be a rising trend in slow movers.

As the Washington Post reported last month:

"That is raising threats that even weaker storms, the kind hardy residents might shrug off, could unleash outsize impacts as they batter communities with uninterrupted downpours and unrelenting winds. 

The finds add to proof that human- caused global warming is intensifying rainfall and encouraging hurricanes to rapidly strengthen, revealing yet another sign of storms' increasing potential for destruction."

Researchers who have been looking into these sloth like storms, needing parameters, defined stalled hurricanes or tropical storms as those that stay within 250 square miles for at least 72 hours. 

 Between 1966 and 2022, the frequency of stalled storms rose at a rate of 1.5 percent each year. The stalling seems to occur most often in the Bay of Campeche, the central Gulf of Mexico, the western Caribbean, near Florida and near the Carolinas

 These stalled storms can happen anytime during hurricane season, but seem to be most common in September and October. The oceans supporting the storms are warm, and steering patterns are often weak in the tropics that time of year, so things tend to get sluggish, making these storms prone to stalling

The Washington Post notes that the new research is in line with previous work on the subject.

A 2018 study said the forward speed of Atlantic tropical cyclones decreased by 10 percent between 1949 and 2016. Polar regions are warming faster than the tropics, and this change tends to slow circulation patterns, so hurricanes and tropical storms don't get a push to move along. 

In the United States, tropical storm stalls are most likely near Texas and Louisiana, the western coast of Florida (the fast forward speed of Helene and Milton notwithstanding) and near the northeastern Florida/Georgia and Carolina coasts. 

There's plenty of examples of nearly stalled extreme havoc in recent years. Hurricane Harvey is perhaps the most famous example. It stalled over east Texas for days in August, 2017, dumping more than 50 inches of rain in some spots and causing the the worst flood in metro Houston history. 

Other stallers include Category 5 Hurricane Dorian, which stalled near Great Abaco, the Bahamas, blasting the island with catastrophic winds, which maintained hurricane force winds for 24 hours an d at least tropical storm force for three days.  Hurricane Florence stalled in the eastern Carolinas for days in 2018, producing a catastrophic flood there. Nearly three feet of rain fell in some spots.

Just last week, Tropical Storm Sara stalled near Honduras, dumping up to 40 inches of rain and causing intense flooding. 

The recent research didn't get into why more tropical storms and hurricanes are stalling. They often stall near coastlines, so maybe it has something to do with differences in temperature between land and sea in those locations.  Also, polar regions are warming faster than mid-latitudes, and that might have something to do with it. 

The study does suggest emergency managers who deal with hurricanes might want to factor in what to do if a hurricane stalls nearby.  

Separate research also says climate change is making hurricane wind speeds higher. So the news is basically all bad. I'll have a separate post on those hurricane wind studies in an upcoming post.