No, hurricanes aren’t more frequent or severe

Right off the bat, let’s understand that no one, much less those of us who live in Houston and other areas along the Texas coast along with my numerous friends in the entire state of Florida, need to be reminded of widespread terror and tragedy which can be wrought by a single tropical storm or hurricane event. At the same time, let’s also realize that such occurrences have been experienced with far greater frequency and fatal consequences by generations who preceded ours.

A review of North Atlantic tropical storm and hurricane patterns fails to reveal any worsening trend over more than a century. The recent Hurricane/Tropical Storm Harvey and Hurricane Irma actually ended an almost 12-year-long drought of U.S. landfall Category 3-5 hurricanes since Wilma in 2005, whereas 14 even stronger Category 4-5 monsters occurred between 1926 and 1969.

Harvey lost its Category 4 status shortly after making landfall, but nevertheless caused catastrophic flood damage as a rain event along the southeast Texas coast. The Houston area received 52 inches of rainfall in four days.

Nevertheless, this wasn’t entirely unique, either. Tropical Cyclone Amelia dumped 48 inches on Texas in 1978; Tropical Storm Claudette inundated the town of Alvin, Texas, with 54 inches in 1979, emptying 43 inches in just 24 hours; and Hurricane Easy deluged Florida with 45.2 inches in 1950.

The 2005 and 1961 seasons shared records for their seven major U.S. landfall hurricanes since 1946 when the instrumented wind and pressure database was first considered to be relatively reliable. The year 1983 set the record for the least number with only one.

Many intense Atlantic storms formed between 1870 and 1899 — 19 in the 1887 season alone — but then became infrequent again between 1900 and 1925. The number of destructive hurricanes ramped up between 1926 and 1960, including many major New England events.

Major hurricanes really blasted the U.S. coast from Florida and northward over a decade between 1950 and 1960, including Hazel (1954), Carol (1954), Connie (1955), Ione (1966), Audrey (1957), Gracie (1959), and Donna (1960). Twenty-one Atlantic tropical storms formed in 1933, a record only most recently exceeded in 2005, which saw 28 storms.

Some major tropical storms and lower category hurricanes also caused major havoc worth noting. “Superstorm Sandy,” which ravaged the northern East Coast, resulted in more than a hundred fatalities.

In terms of known human tragedy, the deadliest event was the Great Hurricane of the Antilles (1780), which struck Barbados causing 22,000 fatalities. The most deadly to hit the continental U.S. was the Galveston Hurricane of August 29, 1900, which may have killed up to 12,000 people. The Okeechobee Hurricane, also known as the San Filipe Segundo Hurricane, struck Florida in 1928 and produced 2,500 fatal casualties.

Katrina, which had reached a Category 5 level hurricane level in 2005 before hitting the Louisiana coast as a tropical storm, resulted in about 1,800 deaths. It packed wind speeds reaching 175 miles per hour, with a 20-foot storm surge that topped levies.

Strong storms frequently form in warm waters of the Gulf of Mexico, the Caribbean Sea, and the tropical Atlantic Ocean as far east as the Cape Verde Islands. They often strengthen over the Gulf Stream off the coast of the eastern U.S. whenever temperatures exceed 79.7º F.

Although the surface water temperature in the Gulf is recently about 4º F above average, the extent, if any, of this influence on Irma and Harvey is subject to question. The record of hurricanes between 1870 and 2010 shows that they occurred with equal frequency both when those conditions were below and above average — the storms didn’t seem to care in the least either way. The Gulf is warm enough every summer to produce a major hurricane.

As with Irma, it seems that the bigger the storm, the more it weakens upon coming to the coast and onto land. Harvey got stalled as a major rain event by a major cool trough associated with the eastward-moving disturbance of clouds, rainfall, winds, and pressure that traverses the planet every 30 to 60 days or so. The ones that “blow up” tend to be smaller, weaker storms like Charley (2004), which still packed a fist of fury.

In reality, whereas we can’t change the weather, it truly is in our best interest to anticipate those bad-case circumstances and prepare our communities and households to mitigate against the outcomes. Whether or not one such event gets hyped on the media as the “biggest ever,” “strongest ever,” “deadliest ever,” or “costliest ever,” it may qualify as the worst ever for you.

Consider this grim reality well in advance of every storm season when there is still time to plan and take prudent preemptive actions. Unfortunately, it’s all too easy to forget to do this on nice sunny days.

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About the Author: Larry Bell

Larry Bell

CFACT Advisor Larry Bell heads the graduate program in space architecture at the University of Houston. He founded and directs the Sasakawa International Center for Space Architecture. He is also the author of "Climate of Corruption: Politics and Power Behind the Global Warming Hoax."