Global Hurricane activity collapses

[cobalt1999]

www.coaps.fsu.edu/~maue/tropical/

Global and Northern Hemisphere Tropical Cyclone Activity lowest in 30-years

Tropical cyclone (TC) activity worldwide has completely and utterly collapsed during the past 2 to 3 years with TC energy levels sinking to levels not seen since the late 1970s. This should not be a surprise to scientists since the natural variability in climate dominates any detectable or perceived global warming impact when it comes to measuring yearly integrated tropical cyclone activity. <snip>



Why the record low ACE?

During the past 2 years +, the Earth's climate has cooled under the effects of a dramatic La Nina episode. The Pacific Ocean basin typically sees much weaker hurricanes that indeed have shorter lifecycles and therefore -- less ACE . Conversely, due to well-researched upper-atmospheric flow (e.g. vertical shear) configurations favorable to Atlantic hurricane development and intensification, La Nina falls tend to favor very active seasons in the Atlantic (word of warning for 2009). This offsetting relationship, high in the Atlantic and low in the Pacific, is a topic of discussion in my GRL paper, which will be a separate topic in a future posting. Thus, the Western North Pacific (typhoons) tropical activity was well below normal in 2007 and 2008 (see table). Same for the Eastern North Pacific. The Southern Hemisphere, which includes the southern Indian Ocean from the coast of Mozambique across Madagascar to the coast of Australia, into the South Pacific and Coral Sea, saw below normal activity as well in 2008. Through March 12, 2009, the Southern Hemisphere ACE is about half of what's expected in a normal year, with a multitude of very weak, short-lived hurricanes.

All of these numbers tell a very simple story: just as there are active periods of hurricane activity around the globe, there are inactive periods, and we are currently experiencing one of the most impressive inactive periods, now for almost 3 years.




What sucks for us on the Gulf Coast is the North Atlantic is projected to be as a little more active this year.

[Lost in CT]

1. I blame the economy... nt

[cobalt1999]

2. You know, that chart in some ways mirrors the stock market.

Drop in the 70's, recovering in the 80's, drop at the end of the 80's, high in the 90's, drop around the 9/11 2001/2002 hit, rising until last year and dramatically dropping off.

You may be on to something! We just need to run the regression analysis. :)

[alfredo]

3. Here's a chart from Weather Underground

More here: http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1199