The most recent, Aug. 5, Atlantic Hurricane season update from Colorado State University (CSU) forecasts in total tropical activity take a large step up, enough to make the 2020 hurricane season the second most active on record.
As of Aug. 5, nine named storms have formed in the Atlantic Hurricane basin, which includes the Gulf of Mexico. That is on pace to break the record, last set in 2005. Given this, CSU forecasts 24, named tropical storms or hurricanes to occur. That is an increase from the 20 last predicted in the July update. Out of the 24, 12 hurricanes and 5 major, category 3 or greater (at least 111 mph sustained winds) are forecasted.
In July, the number of forecasted hurricanes and major hurricanes were 19 and 9, respectively.
Comparison of recently-released @ColoradoStateU and @NOAA seasonal #hurricane forecasts for the 2020 Atlantic hurricane season. Both call for very active season - CSU forecast generally slightly to somewhat higher than midpoint of NOAA range. pic.twitter.com/AiM0caox5k— Philip Klotzbach (@philklotzbach) August 6, 2020
The 1981-2010 average of activity includes 12.1 tropical storms, 6.4 hurricanes and 2.7 major hurricanes, respectively.
There still remains an above average risk of a major hurricane making landfall on the East Coast of the United States, including the Florida Peninsula. The 49% chance is an increase from 45% in the July update. On average, there has been a 31% probability of a strike in the last century.
CSU attributes warmer than average waters in the subtropical Atlantic Ocean, slightly warmer than average waters in the tropical Atlantic as reasons for the active forecast. Furthermore, there's a lack of wind shear, or change of winds with height, which can rip storms apart. A transition from the current El Nino Southern Oscillation (ENSO) neutral state to a La Nina late in the summer puts more confidence that wind shear will remain light.
Tropical cyclone names rotate every six years. Exceptionally notable hurricane names, such as Sandy, become retired by the World Meteorological Organization. However, no names were retired in 2014, meaning 2020 will have the same list as then.