The 2014 Atlantic hurricane season is living up to expectations as a very inactive one, so far. There have been just five named storms this year — Arthur, Bertha, Cristobal, Dolly, and Edouard — four of which became hurricanes, and just one of those briefly reached major hurricane status (Category 3+).
While the measure of cyclone energy in 2014 is actually higher than the entire 2013 season, the last time there were so few named storms by this point in the season was 1994. However, hurricane season is not over, and it would only take a single strong and destructive landfalling storm to make 2014 memorable.
An interesting feature of this season is that no storm achieved hurricane intensity in the tropics — all four hurricanes have occurred in the subtropics, which is north of 23°N.
In terms of Accumulated Cyclone Energy, or ACE, this season has already surpassed the entire 2013 season. But prior to 2013, we have to go back to 1991 to find a less active season to-date. The climatological ACE by this date is 85 (using 1981-2010 for the period of record), and 2014 is at 36.4, or 43 percent of average.
ACE is a commonly-used metric for activity because it is not dependent on exact numbers of named storms or hurricanes, but rather is based on both the intensity and longevity of all tropical storms and hurricanes (so a long-lived tropical storm could contribute as much ACE as a short-lived storm that reached hurricane intensity).
Now that October is upon us, the ACE typically drops precipitously from its peak in August and September.
Another key shift to be aware of in October is the areas of formation. The eastern Atlantic and African wave season are essentially finished, and our attention shifts westward to the western Caribbean, Gulf of Mexico, and off the U.S. east coast.
October is definitely not a month to ignore, as many notorious landfalling storms have occurred during October, including Sandy (2012), Wilma (2005), Michelle (2001), Iris (2001), Mitch (1998), Joan (1988), Isbell (1964), Hattie (1961), Hazel (1954), Fox (1952), King (1950), etc. Some select tracks of notable October hurricanes are shown below:
Dry air and strong wind shear have dominated the usual formation regions during the peak of the season, and that remains the case now. A satellite image from this morning confirms the absence of any interesting features, and the presence of dry dusty air and hefty shear in the deep tropics. It looks like winter has already settled in! Looking ahead with the guidance of long-range global models, there are no storms forecast to develop in the foreseeable future.