2020 Hurricane Season

Bill’s Blog

Posted: Nov 20, 2020 / 02:12 AM EST Updated: Nov 20, 2020 / 02:17 AM EST

The map above shows the hurricane/tropical storm/tropical depression paths of the 2020 Atlantic/Gulf of Mexico/Caribbean Season. The hurricane season official ends November 30. Hopefully, we’re done here on 11/20.

Atlantic satellite picture from Sept. 14, 2020

This satellite picture shows five simultaneous tropical cyclones active in the Atlantic on September 14, 2020: Sally (left), Paulette (center left), Rene (center right), Teddy (bottom right), and Vicky (far right). The waves that would later spawn Beta and Wilfred are respectively located to the left of Sally and to the bottom-right of Vicky, and the extratropical cyclone that would later become Alpha is visible north of Rene.

The 2020 Atlantic hurricane season has been the most active Atlantic hurricane season on record, featuring tropical cyclone formation at a record-breaking rate. This is regarding the number of named storms. There have been a total of 30 named storms, 13 hurricanes, and 6 major hurricanes. It is also the second tropical cyclone season to feature the Greek letter storm naming system, after we went through the list of hurricane names. The other season to go into the Greek alphabet was 2005 season.

Of the 30 named storms, 12 made landfall in the contiguous United States, breaking the record of nine set in 1916. This season featured six U.S. landfalling hurricanes, tying with 1886 and 1985 for the most in one season. The season has had five Category 4 hurricanes – the highest number recorded in a single season in the Atlantic basin and the last such occurrence since 2005. The season was also the fifth consecutive season in which at least one Category 5 hurricane formed. During the season, 27 tropical storms have broken the record for the earliest formation by storm number. This season also featured 10 tropical cyclones that have underwent rapid intensification, tying it with 1995.[2] This unprecedented activity has been fueled by an ongoing La Niña.

Here’s a look at current tropical activity in the Atlantic, the Eastern Pacific, the Central Pacific and the Western Pacific:

Atlantic – Caribbean Sea – Gulf of Mexico
Current tropical storm activity in the Atlantic
Current Tropical Storm activity in the Eastern Pacific
Tropical Storm activity in the Central Pacific (Hawaii is in the middle of the graphic)

JTWC Tropical Warnings

Current Northwest Pacific/North Indian Ocean* Tropical Systems

Here’s a list of hurricanes/tropical storms this year and data on each individual storm.

Summary of Hurricane Activity by Ocean Area for 2020

This above table shows a summary of hurricane activity this year by Ocean area. In each box, you’ll see the number for this year and the average in ( ). The first line is the North Atlantic, which includes the Gulf of Mexico and the Caribbean Sea. We had a record 30 named storms (including a couple that would not have received names 25 years ago) compared to an average of 11.6. Thirteen of those 30 storms became hurricanes (winds up to 74 mph and higher), compared to an average of 6.2. Six of the hurricanes became major hurricane (Category 3 or higher), compared to an average of 2.7.

The column on the far right is interesting. It shows the ACE Index compared to the average ACE Index. The ACE Index is a measure of the intensity and longevity of tropical storms. In the Atlantic, the ACE Index this season stands at 179.8, compared to an average seasonal ACE Index of 102.3.

The distribution of hurricanes this year is related to the moderate La Nina going on this year:

Sea surface temperature anomaly

The map above shows sea surface water temperature compared to average. Blue is where the water is cooler than average and yellow/orange/red is where the water is warmer than average. The La Nina stands out, with colder than average water in the Equatorial Pacific. Note the warmer than average water over much of the rest of the Earth – including the Atlantic/Gulf of Mexico/Caribbean.

Table from Wikipedia

What’s interesting is that even though this was a record for the number of tropical storms in the Atlantic to be given names…it wasn’t even in the top ten years for ACE Index. That’s list is led by 1933, then the Katrina/Rita/Wilma year of 2005. Third place goes to 1893.

Back to the table above. Look at the ACE Index for the other Ocean Areas. While the Atlantic was very busy this hurricane season…the other tracked areas had low numbers of tropical storm activity compared to average. The Eastern Pacific had an ACE Index this season of 76.5 compared to an average of 131.3 and the Western Pacific had an ACE Index of 146.5 compared to an average of 271.8 (near a record low).

I can’t rule out another tropical storm or hurricane in the last weeks of 2020. Hopefully, it will stay quiet until next year.