Since the last hurricane related post, some news has occurred on the hurricanes front.

Nature Geosciences article by Knutson et al. (2010) discussing the linkages between tropical cyclones and climate change / global warming — as an update to the IPCC AR4 statements

Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes. However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100. Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this, higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre. For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies.

Dr. Gray and Dr. Klotzbach released their December North Atlantic seasonal forecast (Above average…)

Accuweather via Joe Bastardi previewed a doom and gloom 2010 Atlantic Season (Extreme…5 hurricane landfalls)

The Southern Hemisphere TC season has become more active with Category 5+ Ului and a somewhat weaker companion storm Tomas. The brewing El Nino has provided plenty of favorable oceanic and atmospheric conditions for powerful storms in the Southwest Pacific.

A brief comment on the Knutson “consensus”: …told ya so.



