Monday, May 17, 2010

2010 Atlantic Hurricane Season: Why all the Hype?

On the heels of already alarming predictions of an active 2010 Atlantic hurricane season, the Climate Prediction Center (CPC) will issue its official forecast this Thursday, May 20.

AccuWeather issued its forecast earlier this Spring, calling for an extreme season, and just last week noted we might even be looking at a top 10! Several weeks ago hurricane pioneer, Dr. William Gray of Colorado State University, issued his forecast, calling for an above average season. So with all this talk about what lies ahead in coming months, and as we prepare for this week's forecast by the CPC, let's talk about all the hype surrounding the 2010 Atlantic hurricane season. After all, last year was one of the quietest in decades...

Sea Surface Temperatures (SSTs)
SSTs in the Atlantic's main tropical development region have been some of the warmest recorded this early in the year. The main development region is the area where virtually all African waves turn into tropical entities. They traverse across these warm waters and generally account for 85 percent of all Atlantic major hurricanes and 60 percent of all named storms. Seeing as this area is already experiencing warmer than average SSTs, historically it does not bode well for the hurricane season.

El Niño vs. La Niña
Climate experts declare El Niño to be over. As El Niño years tend to have fewer storms than normal in the Atlantic and Gulf of Mexico, the conclusion of this year's El Niño could mean a more active season than the previous two. So-called La Niña years, when the Pacific is colder than usual, can lead to an increase in Atlantic hurricanes.

Wind and Ocean
High and low pressure systems over the Atlantic work to slow the trade winds. The trade winds this hurricane season are forecast to be relatively light, promoting storm development. Meanwhile, when there is a strong ocean current moving to the north, as is the case this year, it is able to draw warm water from southern latitudes into the region where hurricanes form. When the two work together, hurricane seasons most definitely tend to be busier.

African Dust
A wetter than normal weather pattern in the African desert regions have kept the amount of dust that becomes airborne in the atmosphere to a minimum. Typically, when this dust enters the atmosphere and moves across the Atlantic, it inhibits storm growth, therefore affecting overall tropical storm formation. This does not seem to be a major factor this year.

Well there you have it – several major indicators supporting predictions for an extremely active hurricane season. More on this when the CPC issues their forecast this Thursday!