Vince_Condella's Blog

It is tempting to think the world's weather has gone crazy as Hurricane Ike pummeled the Texas Gulf coast region Saturday.  Despite the media over-coverage of this event, and despite television coverage that used superlative language to describe this storm, Ike was a run-of-the-mill category 2/3 hurricane that struck a vulnerable and populated area.  (As it came ashore, Ike was right at the threshold of category 2 and 3.)

 

In no way am I diminishing the anguish and fear of the residents who suffered at the hands of this hurricane.  Our thoughts and prayers should continue to be with the residents of Texas and Louisiana affected by Ike.  However, as you know, there was ample warning and pleading by officials for residents to evacuate Galveston, yet thousands decided to stay and tough it out.  One resident who stayed said on TV, "I didn't think the storm was going to be this strong."  Really?  Are you serious?  Okay, enough said about the judgement of some people.

 

This is the peak of hurricane season.  Statistically speaking, September 12 is the peak date for hurricane and tropical storm activity.  (See chart below.) This is prime time.  Category 2 hurricanes are not rare.  What made Ike so spectacular was the fact that it struck a part of our country that is so vulnerable to hurricane destruction.

 

Fifty percent of our population lives within 50 miles of an ocean.  It is a desirable place to live, I'm sure.  And for most locations near the ocean, it can be spectacular all year.  But Gulf coast residents know that from June through November, they are prone to hurricane or tropical storm strikes.  That includes wind, rain, and storm surge.

 

Ike was also the perfect media storm.  The National Hurricane Center predicted its path many days in advance, so TV crews had a chance to set up along the bullseye and give you those "reporter gets blown away" live shots we so love.  :)

 

Statistically speaking, from 1944 - 2002, the Atlantic Ocean hurricane season averages 6 hurricanes and 10 named systems (either tropical storm or hurricane).  So far in 2008 we have seen 5 hurricanes and 5 tropical storms for a total of 10 named systems.  But there is wide variability.  In the record-setting season of 2005 that gave us Hurricane Katrina, there were 15 hurricanes and 28 named systems.  The chart below shows the year-to-year variability for Atlantic tropical systems from 1850 to 2004.  It does NOT include the record season of 2005.

The yellow are named systems (hurricanes and tropical storms), green are hurricanes, and dark red are Category 3 or larger hurricanes.  It is difficult to know the accuracy of the early years because this was before the age of satellites and extensive weather data like we have today.  It is likely that in the 1800s and early 1900s, some tropical weather systems occured that were not detected or recorded.

 

And while 2005 was a record year, 2006 was a very quiet tropical season with only 10 named storms, 5 of those being hurricanes.  The only storms to hit the U.S. mainland that year were 2 tropical storms.  2007 saw 17 named storms including 6 hurricanes.

 

Why were there so few hurricanes in 2006 following such an active 2005?  One study suggests that a high concentration of African dust in the air over the tropical Atlantic may have tempered the atmosphere in such a way that it became less conducive to tropical storm formation.  And there has been recent evidence showing that tropical storm numbers have nothing to do with global warming, but rather depend on other factors such as the Atlantic Multidecadal Oscillation (AMO).  The AMO refers to Atlantic sea-surface temperature variability and its fluctuations over time periods of decades.

 

The bottom line for this tropical storm season is that so far it has NOT been unusual, Ike was not an out-of-line monster but a large category 2/3 hurricane that happened to hit a vulnerable area of the U.S. Gulf coast, and there is tremendous variability in season-to-season tropical activity that could be due to numerous reasons.

 

As is usually the case with phenomena of the atmosphere, there is rarely a simple relationship between cause and effect.