Record-busting hurricane season comes to a close

JACKSONVILLE, Fla. – Led by Colorado State and Dr. Phil Klotsbach, hurricane seasonal forecasters were all doom and gloom in April and May, as the Atlantic hurricane season was about to begin. Their forecast never really let up as we entered October. By November, we had registered our ninth Greek named storm, culminating with Category 5 Hurricane Iota, the 30th named storm of the season.

For comparison, a typical season has more like 12 named storms.

In a single season, tropical cyclones had spread themselves across the entire Atlantic hurricane basin, from Texas to Portugal and from Venezuela to Canada and the extreme North Atlantic.

A record 11 named storms hit the U.S., including 2 major hurricanes

We saw a record-breaking number of tropical cyclones hit the United States, with Louisiana and the Gulf Coast taking the brunt of their wrath, but even here there were hurricanes that stretched up the East Coast into Canada.

What this meant for The Weather Authority team was a near-constant, 24/7 watch from mid-May through mid- November when Hurricane Eta actually passed over Jacksonville (granted, it was a dud by then), but watch we did as Eta had powered up to a Category 1 hurricane just one day before passing over Jacksonville.

The team constantly watched as the macro-Global weather patterns were firmly entrenched to not just develop tropical cyclones but also hurl them like missiles at the U.S. It made for one of the most exhausting hurricane seasons ever — even more than in 2005, our second busiest season, and the year of Katrina and Wilma. It was much busier than 2016 (Mathew) and 2018 (Irma) when severe hurricanes impacted Florida (and Jacksonville).

The reality is, the past 16 years have been the most staggering we have seen since the 1950s-60s or the 1920s-30s, or the 1880s-1890s. During those times, we had extremely active periods, with numerous severe hurricanes impacting the U.S., particularly Florida. Over the years, we saw hurricanes Hazel (1954), Gracie (1959), Donna (1960), Carla (1961), Chloe (1964), Dora (1964), Betsy (1965) and Camille (1969).

The Great 1928 Lake Okeechobee hurricane killed 3,000 people in a single night — relative to nowadays, that would be about 21,000 people.

The greatest driver to the unprecedented season was a massive upheaval in the balance of the Pacific Ocean water temperatures. Known as a La Nina, opposite of the more commonly quoted El Nino, well below average water temperatures have been upwelling from down deep in the Pacific. These cooler water temperatures literally cover the largest ocean on the planet. The result is an amplified Atlantic Hurricane season.

There are global connections at play

The late Colorado State professor Dr. William Gray — the true pioneer in tropical meteorology — recognized the influence that La Nina and other global patterns have on hurricane seasons over the Atlantic Ocean.

Gray, and the dozens of graduate students under his direction, did much of the deep research to better understand global impacts to predict the key drivers of how severe or mild an upcoming hurricane season might be.

In 2020, the La Nina was the biggest driver. Seen below illustrates the magnitude of the current La Nina.

Global interconnections played perfectly with the La Nina. As cooler water over the equatorial regions of the Pacific Ocean developed, while at the same time the Atlantic Ocean had water temperatures run well above normal created the perfect scenario of:

1. Lower air pressures over the main development region (for tropical cyclones) over the Atlantic/Caribbean Sea and Gulf of Mexico.
2. Lower wind shear over the Caribbean Sea (in particular) to allow for intense major hurricanes to rapidly form.

And that’s why we saw such a huge 2020 hurricane season.

But what about the 2021 Atlantic hurricane season?

While 2020 did not create the biggest La Nina, (in fact, it may not make the top 5 over the past 40 years), it combined with Atlantic Ocean temperatures that were well above normal to produce the perfect pattern of destruction and storms for the U.S.

Dr. Klotzbach, having taken over the research being done at Colorado State, will be giving us some new clues when he does his end-of-the-year wrap. This will be released on the final “official” day of the 2020 hurricane season, Nov. 30. And I suspect he will be calling for one more named tropical cyclone in December.

By early indications, in 2021 we will see yet another active, if not as active, hurricane season. Keep in mind, “active” is a relative term — even if we saw half the number of tropical storms and hurricanes as we did in 2020, it would still be considered an “active” hurricane season.

That’s how far off the deep end 2020 took us.

Why was this hurricane season so unique? 🌀

Like most things in the year 2020, hurricane season did not go normally. From worrying early on about how we could safely evacuate to hurricane shelters, to figuring out what to do when we exhausted the list of names for the year, this season has been busy and exhausting.

Here are six reasons why this season was like no other.