A hurricane is a gigantic heat pump. Lop off the top half - which is what wind shear does - and the pump breaks.

Everyone has had problems with seasonal estimates recently. Colorado State's contribution was that such analysis could be done at all - that conditions dis/favorable to hurricanes were the result of other _observable_ conditions months earlier - at a time when hurricane seasonal forecasting was as credible as watching goats to predict earthquakes. It's still a hard problem and I suspect the annual press releases have more to do with getting research funding than providing homeowners with actionable information.

It's interesting that Bill Gray's name is on the paper. At one time he was nearly forced out at Colorado State (politics).