Record breaking hurricane seasons: A look at 2005 vs. 2020
We look at similarities between what we are experiencing now to the most active season to date.
GREENVILLE, N.C. (WITN) - Back on September 15th, we stepped on to rarely traveled terrain. The naming of Alpha marked the second time in recorded history where we exhausted the 21 names issued by the National Hurricane Center and began using the Greek alphabet. The last time we found ourselves here was after the devastating 2005 hurricane season. There are plenty of similarities and differences to the 2005 hurricane season and the 2020 season. Today, we’ll be going over the similarities. The first one being the number of storms each season experienced.
In 2005, we started the season with most projecting above average activity in the Atlantic Basin. Colorado State University projected 11 named storms, 6 hurricanes and 3 major hurricanes. They also made a stipulation that the Caribbean and U.S. East Coast had a higher chance of experiencing a major hurricane landfall during the season. Similarly, earlier this year, C.S.U. forecasted an above average number of tropical activity, calling for 16 named storms, 8 hurricanes and 4 major hurricanes. While these forecasts both verified their broad assumptions of above average activity, we now know the projected numbers undershot the total number of storms both years. This is understandable as forecasting record breaking hurricane activity would be incredibly difficult in December of the previous year and is why many organizations issue midseason updates to their forecasts.
During both years, the El Niño Southern Oscillation (ENSO) played a role in the increased activity. In 2005, initial forecasts were low because there was a weak El Niño event that had been consistent, starting in June 2004 and lasting to January 2005. El Niño events adjust trade winds and the jet stream over North American and Atlantic Basin that lead to increased wind shear and suppressed tropical cyclone development. However, the El Niño event started to quickly fade by the end of January 2005 and flipped completely into a La Niña event, which has the opposite effect on tropical development in the Atlantic, by late August. We saw the same flip occur this year, going from a weak El Niño event in January to a La Niña event by the start of the summer. These flips in ENSO conditions combined with above average sea surface temperatures brought us the record breaking tropical cyclone numbers.
Speaking of the actual numbers, 2005 is an interesting year. Technically, the N.H.C. only named 27 storms. However, reanalysis of a system near the Azores that occurred in late September into early October proved that the count should have been 28. At the time, the Hurricane Center classified the system as a broad area of low pressure, however post-season review of satellite data showed the low had actually achieved subtropical storm status on October 4th. It was later absorbed into the low that became Hurricane Vince. This system has been referred to as “Unnamed Subtropical Storm” and is why the record of named storms is 27 but the record number of tropical storms is 28. It’s a mere technicality, but one that should be noted as we approach the end of a season that could potentially break both of those records.
Finally, both years brought devastating storms to the Gulf Coast. 2005 saw the landfall of Tropical Storm Arlene, Hurricane Cindy, Hurricane Dennis, Hurricane Katrina and Hurricane Rita. So far this year, the Gulf Coast has had landfalls from Tropical Storm Cristobal, Tropical Storm Fay, Hurricane Hanna, Hurricane Laura, Hurricane Marco, Hurricane Sally, Tropical Storm Beta and Hurricane Delta. The National Hurricane Center is currently projecting Zeta’s landfall between Marsh Island, LA to Gulf Shores, AL Wednesday night. While 2020 has seen more landfalling systems along the Gulf Coast, the frequency of storms and hurricanes is reminiscent of 2005.
Next week we’ll be going over the big differences between the seasons. If you are interested in researching historical tropical activity further, the National Hurricane Center has many useful resources.
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