If you can believe it, hurricane season isn't too far away! Don't fret too much about this, as last year was certainly a rarity for our region, and the devastating impacts Irene is something most of us will only see once in a lifetime.
That said, hurricane forecasters are already thinking ahead and preparing for the 2012 hurricane season. They will make a few changes this year, including a modification to the hurricane wind scale, known as the Saffir-Simpson scale. Forecasters also expect fewer hurricane season for the year 2012. (scroll down a bit to read all about that!)
First, though, a look at the changes going into effect by the National Hurricane Center tweaking the Saffir-Simpson Hurricane Wind Scale (SSHWS). This is the scale of the wind speed range that classifies a hurricane's category. The scale goes from 1 to 5, with 1 being a "weaker" hurricane and 5 being a strong, destructive hurricane.
The modification will resolve rounding issues associated with the conversion of units from knots to mph which are used for wind speed. This change follows a public comment period conducted in 2011.
Here is the old scale:
Category 1: 74-95 mph (64-82 kt)
Category 2: 96-110 mph (83-95 kt)
Category 3: 111-130 mph (96-113 kt, 178-209 km/h)
Category 4: 131-155 mph (114-135 kt, 210-249 km/h)
Category 5: 156 mph or higher (136 kt or higher, 250 km/h or higher)
...and here are the modifications, which will only be applied to category 3 and higher...
Category 3: 111-129 mph (96-112 kt, 178-208 km/h)
Category 4: 130-156 mph (113-136 kt, 209-251 km/h)
Category 5: 157 mph or higher (137 kt or higher, 252 km/h or higher)
Hurricane forecasters at Colorado State University are forecasting a less-active hurricane season this year than last. The liklihood of a major hurricane (category 3 or higher) making landfall in the US or Carribbean is below-average.
They forecast 10 named storms in the Atlantic basin, only 4 of which become hurricanes, and 2 of which will be major hurricanes. That compares to an average of 12 named storms, 6.5 of which become hurricanes, and 3 of which become major hurricanes based on climatological data from 1981-2010.
The probability of at least 1 major hurricane making landfall in the US is 42% according to forecasters. The average for last century is 52%.