WEATHER

So long, 2020 hurricane season. We won't miss you | WeatherTiger

Ryan Truchelut
WeatherTiger

How it started: The Roaring '20s are back! Easy prosperity! Obvious prom themes! Color symbolism in "The Great Gatsby"!

How it went: The 2020 hurricane season. Also, Carol Baskin.

When the season ends on Nov. 30, tropical activity won’t necessarily be over for the year. Counting on the 2020 hurricane season to be done is like being confident Jason is actually dead after a "Friday the 13th" movie. One or two more late-season storms are possible.

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But with no U.S. threats on the horizon and no landfalls ever after Dec. 1, we can cautiously canvass a punishing hurricane season that ripped up the record books with 30 named storms, 13 unlucky U.S. strikes, and more eyes than a billboard of Dr. T.J. Eckelburg.

If you’re ready to be borne back ceaselessly into the past, let’s review a year in the Tropics that unrelentingly roared, and what we can learn from it.

May

Fueled by negative $40 oil prices, Atlantic tropical activity again began prior to the formal start of the season. Arthur and Bertha were the 6th and 7th May tropical storms requiring U.S. warnings since 2012, spreading gale-force winds to the Carolinas. This was only the second time two tropical storms affected the U.S. in May, the first of many records set.

June

The official start of hurricane season was ushered in by Tropical Storm Cristobal, which set the tone for 2020 by developing in the Gulf and making landfall in Louisiana. Cristobal spread heavy rainfall with localized flooding over much of the eastern Gulf Coast. Otherwise, June was quiet with the exception of short-lived Tropical Storm Dolly in the North Atlantic.

July

July offered a taste of the madness to come, as each of its five storms was the earliest to form for its letter. Shortly after Eduoard followed Dolly’s track, Tropical Storm Fay came ashore in New Jersey, causing some mid-Atlantic coastal flooding. Gonzalo was an early Cape Verde tropical storm, but dissipated before reaching the Lesser Antilles.

The strongest storm was Hurricane Hanna, which formed in the central Gulf in late July. Hanna made landfall as a Category 1 in a remote portion of south Texas, but brought severe flooding in the populous Rio Grande Valley. Finally, Isaias developed in the eastern Caribbean at month’s end.

August

Hurricane Isaias stole headlines to open August, menacing the Florida East Coast but ultimately yielding light impacts in the state due to shear. Isaias struck North Carolina as a Category 1 hurricane and rocketed northeast, spreading wind gusts of 50 to 80 mph to much of the East Coast, including New York City.

Mid-month was quiet as Josephine and Kyle crossed the open Atlantic. Entering peak hurricane season, late August brought the first of several instances of tropical double trouble in Marco and Laura. Marco reached Category 1 intensity in the Gulf before crossing eastern Louisiana as a weak tropical storm and bringing heavy rain to the Florida Panhandle.

Laura was the evil twin. Biding its time as it crossed the Greater Antilles, Laura pitched into a dizzying rapid intensification cycle en route to landfall in western Louisiana, strengthening by 65 mph in its final day over the Gulf. Laura’s provisional sustained winds of 150 mph are tied for the fifth-strongest continental U.S. hurricane landfall, and catastrophic wind damage occurred well inland into northern Louisiana. Despite striking one of the less densely populated sections of the Gulf Coast, total damages from Laura are estimated at $15 billion.

September

The climatological apex of hurricane season in September was met with an unprecedented profusion of named storms, though the month thankfully lacked a historical showstopper like Irma. A record-breaking 10 tropical storms developed, with a record-tying five occurring simultaneously during peak multi-ball mode on Sept. 14. Of these, Omar, Rene, Vicky and Wilfred were weak, brief storms. Category 1 Nana made landfall in Belize, and Category 2 Paulette and Category 4 Teddy passed close to Bermuda, bringing wind and rain there but otherwise remaining over the open Atlantic.

In terms of U.S. impacts, September was all about Sally. Confounding forecasters with erratic center reformations and intensity fluctuations over the northern Gulf, Sally feinted at Louisiana before striking Alabama and the western Florida Panhandle at Category 2 intensity. In addition to damaging wind, surge, and barge impacts, Sally’s glacial movement unleashed up to 30 inches of rainfall and widespread inland flooding in the Deep South.

By Sept. 18, the typically sufficient allotment of 21 storm names had been exhausted, bringing the backup “Elon Musk/Grimes baby names list” into play. Subtropical Storm Alpha made landfall in the hurricane hotspot of Portugal, and Beta mounted the first-ever U.S. Greek-named tropical storm strike with modest impacts in Texas.

October

The combination of light wind shear due to a strengthening La Niña and extremely warm water temperatures in the Caribbean made an active latter third of the hurricane season likely. Another set of twins quickly took advantage of these conditions at the start of the month, with Tropical Storm Gamma crossing the Yucatan at near-hurricane intensity. Gamma was soon subsumed into Hurricane Delta, which blazed one of the Atlantic’s steepest rapid intensification events ever, intensifying by over 100 mph in just 36 hours before passing south of Cancun. Delta re-strengthened to a major hurricane in the Gulf, reaching the U.S. coast as a Category 2 a few scant miles from Laura’s landfall point, and compounding wind and surge damage across much of western Louisiana.

Scary trend::Major hurricanes in October and November - why is it happening?

Yet Louisiana’s misery was not complete. As Major Hurricane Epsilon passed northeast of Bermuda, Zeta developed in the Caribbean and retraced Delta’s steps across the Yucatan. Zeta continued to intensify all the way to landfall in eastern Louisiana as a high-end Category 2 hurricane. The storm spread wind damage from New Orleans to Mobile to Atlanta and beyond, hoisting tropical storm warnings into the mountains of southern Virginia. In sum, October hurricane activity was nearly triple historical norms.

November

November 2020 was the busiest November in Atlantic hurricane history, clocking a muscular 600% of typical activity. About half is due to Eta’s two-week amphibious assault on the Americas. Eta first rapidly intensified and struck Nicaragua as a Category 4, leaving behind catastrophic floodwaters. The storm then reformed in the western Caribbean, made an abrupt left through the Florida Keys and South Florida as a tropical storm with locally flooding rains, looped north, became a hurricane again, and finally made landfall as a weakening tropical storm on the west central Florida coast. Meanwhile, Theta in the eastern Atlantic snapped the all-time named storm record from 2005 on the 10th.  

Absurdly, the final (as yet) hurricane of 2020 was the strongest, accounting for the other half of November’s anachronistic fury. Category 5 Iota, the second most powerful November hurricane in history, uncannily followed Eta’s track across Nicaragua and Honduras, though it did not turn north. Widespread 10-inch to 20-inch rainfall totals exacerbated severe flooding across much of Central America, with pockets of catastrophic wind damage noted along the coast.

Exhausted from reading that rundown? Here’s why:

This year’s 30 named storms are likely the most since 1851, even accounting for “missing” storms prior to satellite imagery. Hurricane (13) and major hurricane (6) tallies are also the second-highest on record.

The grim efficiency with which these numbers translated into hit after hit was brutal. While the seasonal Accumulated Cyclone Energy of 180 units is greater than about 10 of every 11 years, this much net U.S. landfall activity (13.5 ACE units, 13 tropical storms, 6 hurricanes) would only be expected roughly every 20 years. For the Gulf Coast, it’s more like once every 25 or 30 years. The entire U.S. shoreline was under at least a tropical storm watch at some point, with the exception of 15 miles of the Florida Panhandle coast in Wakulla County.

Just the Greek names themselves would be considered a pretty bad hurricane season. Relatedly, don’t expect the Greeks to necessarily return: With multiple cataclysms on the backup list this year, there is a decent chance the World Meteorological Organization will retire the whole Greek letter concept and replace it with a more sustainable fallback. I say  yes, and let’s retire the entire concept of 2020 as well. Integers can go straight from 2019 to 2021 from now on. If absolutely necessary, reference 2*** like the four-letter word it is.

That’s an idea you can get behind if you live in Louisiana, which was pummeled by a Category 4, two Category 2s and two tropical storms, and spent a whopping three weeks or more in cones. Support those recovery efforts, because it’s a long road back to anything resembling normal for the people of western Louisiana. Also, give your local meteorologist a raincheck for a post-social distancing hug. We’ll still need it.

In the end, 2020 hurricane season dramatically underscored the rising vulnerabilities of the United States’ increasingly crowded coasts. Phenomena like early- and late-season activity in defiance of climatology, head-spinning rapid intensification through to landfall, and extreme flooding from stalled and slow-moving storms, all with minimal historical precedent, became numbingly normal.

Still, the season somehow avoided the absolute worst-case scenarios. Laura’s Category 4 landfall was devastating, but fell short of the four major hurricanes striking major U.S. urban areas in 2005. Florida avoided all but Sally and Eta by the grace of a ridge of resilient high pressure aloft.

And yet, even this reprieve contains a warning. Between 2010 and 2019, the Gulf and Caribbean were significantly quieter than normal, even while the Atlantic was atypically busy overall. In 2020, the Gulf and Caribbean hurricane activity reverted to the mean with extreme prejudice. Hurricane history says the Florida East Coast’s lucky streak will end at some point.

The only relevant part of "The Great Gatsby" this year was that the 2020 hurricane season had exceptionally poor etiquette about when to leave a party, so I’ll wrap it up. Here’s to a 2021 with fewer reasons to doomscroll Atlantic articles on your phone in bed at 2 a.m. Here’s to a 2021 that doesn’t play around with the idea of letting society collapse without finding out what happens to Kim on "Better Call Saul," an obviously terrible idea. And here’s to a 2021 with many, many, many fewer hurricanes to write and worry about. One can hope.

Ryan Truchelut, president and chief meteorologist at WeatherTiger

Stay safe, weather fans. I’ll see you next year.

Dr. Ryan Truchelut is chief meteorologist at WeatherTiger, a Tallahassee start-up providing advanced weather and climate analytics, forensic meteorology and expert witness consulting, and agricultural and hurricane forecasting subscription services. For more information, visit us at weathertiger.com or get in touch at ryan@weathertiger.com.

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