HAS THE "HURRICANE SEASON" BEEN DOWNGRADED?

THE EXPERTS: DR WILLIAM GRAY & PHILIP KLOTZBACH

More evidence is emerging to support the Powerhouse “modification hypothesis” that the 2013 hurricane season may not be as “hyperactive” as the experts initially suggested.

In a revised forecast (http://tropical.atmos.colostate.edu/forecasts/) released Friday morning (August 02), the top experts (Gray and Glotzbach) at Colorado State University, again repeated their prediction of an "above-average 2013 Atlantic basin hurricane season." But they have also slightly “moderated” their initial forecast to "accommodate" the PowerHouse “modification hypothesis” that the season may not be as active as they initially believed.

HURRICANE DAVID IN 1979 AT 175 MPH

A total of 18 tropical storms were “forecast to form, of which nine would be hurricanes”. Now, there is a slight downgrade in the numbers of expected hurricanes from nine to eight.

The reason they gave for the drop in the number is “the cooler waters”. Klotzbach claimed that "While the tropical Atlantic remains warmer than normal, it has cooled somewhat in the eastern portion of the basin". Two questions therefore arise: What cooled it? What is the new thermodynamic variable which came into play?

HURRICANE ALLEN IN 1980 AT 190 MPH

Klotzbach nevertheless claimed that an active season still looks “probable”. He said, "It appears that the chances of an El Niño event this summer and fall are unlikely." (The El Niño makes conditions for storm formation less conducive.) Again, Klotzbach’s prediction model seems to be based on “probability theory”; and this in itself introduces a host of logistic, scientific and philosophical issues beyond the scope of this article.

HURRICANE GILBERT IN 1988 AT 185 MPH

Nonetheless, an issue is: are the experts merely “erring on the side of caution”? As the USA Today rightly pointed out, they have not always got it right! “Since 2000, the team has under-forecast the number of named tropical storms and hurricanes seven times, over-forecast three times and been almost right — within two storms — three times”. Hence, their predictions have been "almost right" only 3 out of 13 times or 23% of the time. Will they be right this year?

In an earlier article (http://choiseulpowerhouse.blogspot.com/2013/04/powerhouse-hurricane-review-2013.html), the Powerhouse argued that pre-season thermodynamic conditions would theoretically have a moderating influence on the potential intensity of the hurricane season; and that those were largely expected to have an impact on the number and intensity of the hurricane/storms for 2013.

This is not to suggest in any way that we would not have a couple of strong hurricanes for this year. I would be naïve to think so – as hurricanes are absolutely necessarily to maintain thermal equilibrium and hence reduce global warming in the tropical Atlantic! Moreover, we are in “the heart of the hurricane season” and we expect hurricanes to strike! And whether or not they strike the Caribbean, we should always be in a state of high alert.

I will arguably refer to August and September as the most “vulnerable hurricane months” when the probability of strikes is at its highest. Indeed, three of the most dangerous storms to hit the Caribbean/Atlantic happened in the months of August and September. In 1979, Hurricane David struck and killed over 2000 persons; in 1980, Hurricane Allen struck and killed 269 persons and in 1988, Gilbert struck and killed 433 persons. The total cost of their impact approached US$10 billion.

St. Lucia is currently still reeling under the impact of Hurricane Tomas which happened late October 2010.

What I have said is not meant to take anything away from the research efforts of Gray and Klotzbach at Colorado State University. The research work of these academically esteemed gentlemen – even if seemingly incomplete - deserves a resounding round of applause. These guys have made significant theoretical and empirical contributions that have gone a long way in enhancing our awareness and level of “hurricane-preparedness” and this year is no exception. However, my simple personal and (to some extent) scientific position is they will be off-target again in their predictions for 2013. Admittedly, their recently-added “modification hypothesis” has gone some way to tentatively address the issue but they have done so too “cautiously”, suggesting a need for far more extensive research by them!