Tropical Cyclones Forecast Errors

[Mariner]

With regards to intensity errors in forecast for tropical cyclones, if a tropical system enters an area with higher Sea Surface Temps then expected  it seems as if the resulting  increase in intensity would cause an increase in heat uptake from two sources. There would be an increase in intensity  because of the cyclone would increase in size, therefore drawing heat from a larger area, and mixing would take place to a greater depth.

 

So it seems that small errors in track could have much magnified effect on intensity. Is this right or is there some mechanism that would limit this feedback loop?  Assuming no changes in shear etc. 

[Mariner]

I'll put the question this way.

 

From this paper The Theory of Hurricanes    the model used for a tropical cyclone is a Carnot heat Engine. So with this simple model,  when a TC undergoes rapid intensification  due to an increase in sea surfaces temperatures (SST), it seems  like there is a positive feedback loop in that the TC draws more heat from both a wider area and by  mixing into deeper waters.

 

By contrast, if the intensification is due to other factors, say less shear or better outflow, that same feedback loop (more heat uptake)  would exist but to a far lesser extent. Is this true in practice or is that an over-simplification? Or just plain wrong? Maybe any source of rapid intensification would have the same (more or less) feedback loop.

[the ghost of leroy]

yeah, of course track errors mean intensity differences. 

i would encourage you to think in terms of heat content instead of SST's, though...they are a better gauge for RI/the feedback loops you are wondering about...

[Mariner]

This document is the one recommended for mariners to use.

Mariner's Guide for Hurricane Awareness in the North Atlantic Basin.

From that document.

Quote

Similar to the historical development areas and climatological tracks, there are also certain areas in the Basin that often support rapid intensification of tropical cyclones. Understanding the significant contribution that warm water plays in the growth of a tropical cyclone, it is easy to appreciate that ocean regions with high sea-surface temperatures (greater than 79° F or 26° C) are often dangerous locations for the mariner to be caught in or near as a tropical cyclone threatens.
Knowledge of North Atlantic sea-surface temperatures and ocean current/eddy structures are important factors to consider in the risk analysis. Areas with high sea-surface temperatures (SST) often coincide with historical instances of rapid tropical cyclone intensification.