Atlantic hurricane season getting longer, storms getting stronger

There may be evidence that the Atlantic hurricane season is getting longer and hurricanes may in fact be getting stronger, according to research summarized in Partner Re’s Hazard & Risk Science Review 2009. 
The Review is a digest for the insurance industry of natural hazard and risk science research.
The Review cites an article from Geophysical Research Letters by J.P. Kossin, who notes that in 2007 storms occurred in both May and December.
The hurricane season officially starts on June 1 and ends on November 30.
Kossin’s article also observes that anomalous activity occurred both early and late in the 2005 season.
“Examining observed historical trends in the annual distribution of North Atlantic tropical storm formation events, and their relationship with tropical Atlantic SST (sea surface temperatures), Kossin detects an apparent tendency towards more common early and late season storms that correlates with higher SST,” Partner Re’s Review says.
Kossin’s research goes on to say that the uncertainties in the correlation are high, and so the observed trends “cannot be used to reliably predict future changes to the season.”
In addition to the season getting longer, it also seems that Atlantic hurricanes are getting stronger, the Review notes.
“Writing in Nature, J. Elsner of Florida State University, and colleagues, confirm a 30-year trend that shows tropical cyclones in the Atlantic getting progressively stronger, in line with SST rises in the Atlantic region and elsewhere,” the Review says.
“As explanation, Elsner and his co-researchers note that their result is consistent with the simple and straightforward idea that as the oceans warm, they have more energy to convert to tropical cyclone wind.”