One of the big questions facing climatologists regarding future climate is how warmer temperatures might change the intensity or number of hurricanes. A new study which compares hurricanes in cooler and warmer than normal periods was released in Geophysical Research Letters recent.
This study, which is based on past weather and not climate models, shows that hurricanes in warm periods produce significantly more rain than hurricanes in cooler periods. This is not surprising since warm air can help contribute to higher dewpoint temperatures, which help the raindrops form. You can read about this research here at Eos. The study does not address whether tropical storms would become more frequent as temperatures rise, but said that in the analog study the hurricanes were not more intense in the warmer periods compared to the cooler periods.