Well, you may have noticed that we really haven’t said much about the tropics lately. We are about to wrap up the season’s second month with only three named storms so far. The Atlantic Hurricane Season is from June 1st through November 30th. This time last year there were a total of five named storms, so why aren’t any storms forming?
In order for a tropical system to thrive specific environmental parameters need to be met. The first parameter would be warm sea surface temperatures. Warm water, temperatures of 80 degrees or higher, is a key factor to support a tropical system. The warm, moist air rises causing clouds and storms to form. With a continuous rising motion, storms are able to continue developing. Another factor that will help tropical systems thrive is weak wind shear. Unlike tornadoes, high values of wind shear will break down a tropical system. There also needs to be a very saturated environment, at this point There is a large amount of Saharan Dust traveling from the African coast over the Atlantic. The Saharan Dust is limiting the potential for development, due to the dry air.
As July ends and August begin we venture into the active part of the season. The peak of hurricane season is mid-September, and the activity will begin to drop back off during the fall. The National Oceanic and Atmospheric Administration (NOAA) is still predicting an above-average season. A total of 14 to 21 named storms are expected to form this season. Of these, six to ten will be hurricane strength. NOAA will update their season prediction again in early August.
Here in the Tennessee Valley, the main threats we see from tropical systems are flooding, strong winds, and tornadoes. Inland flooding can really become an issue if there is rainfall right before remnants move over the region. It would lead to saturated ground. With saturated ground, any additional rainfall would lead to the potential for inland flooding. The tornado threat for our region would come from some of the rotating rain bands around the remnants of the tropical system.