In a little less then two months, the Atlantic Basin Hurricane Season will begin for the 2013 season. The first hurricane forecast that was issued in December had a thinking that El Nino was going to take the reins for the 2013 season. As you know, El Nino is a warming of the tropical Pacific waters and often leads to less hurricane activity in the Atlantic basin.
In the newest forecast, it looks less likely that this is going to happen. In fact, indications are that the waters in the tropical Pacific have actually cooled which would mean we would either stay in a Neutral state or possibly even go into a marginal La Nina.
A combination of the neutral conditions and warmer then normal ocean temperatures will help make the conditions ripe for a busy season. Remember that high oceanic temperatures are needed for fuel as a tropical system is born. The heat helps create the huge spiral engine that allows all the gears in the storm to operate efficiently.
There area also other factors that contribute to an active or dud season. The first factor is moisture. Moisture is needed in abundance in the upper atmosphere in order for the cyclone to survive. Things like dry air pockets and SAL (Saharan air layer) in the atmosphere will almost always throw a wrench into the workings of a tropical storm. SAL is actually a term that we use for sand that gets into the upper atmosphere from the deserts of Africa.
In addition, the NAO (North Atlantic Oscillation) is also in a mainly negative state. What this means is that steering currents in upper atmosphere will start to become weak. This will help potential storms to develop more easily. When you add up all these factors including warm ocean temperatures, weak upper level winds and a negative NAO you are looking at a busier then normal storm season. Conditions will be similar to the 2005 season.
As of this writing, the outlook calls for 18 named storms, 11 hurricanes with 5 of them becoming cat 3 or higher. There is also an increased chance of a landfall on the southeast coast compared to the 2012 season when almost all storms recurved out to sea.
Regardless of how weak or strong the coming season is, it is important to remember to be prepared! It only takes one bad storm to make it a bad season. Remember to be safe and be ready!