Despite a close call with Hurricane Arthur and a couple of storms reaching major hurricane status (category 3 or greater), last year ended up being a relatively quiet season for tropical activity in the Atlantic. So, the question is, “how are things looking for the 2015 Atlantic hurricane season?” The expectation here at WeatherWorks is that 2015 will be another season with below normal tropical activity.
While decreased activity is anticipated for this season as a whole, we could have a very early season storm on our hands. Although typically rare, tropical development during the first 10 days of May is not unprecedented. Luckily, this system is not expected to directly impact the Mid-Atlantic and Northeast, but we will be watching for development of Subtropical or Tropical Storm Ana off the southeast US coast over the next several days (May 7th visible satellite of the disturbance below).
Regardless of the early start, there are a couple of factors expected to impede overall tropical development. The first is the North Atlantic Oscillation (NAO). During the last several months, the NAO has been in a predominately positive state. This results in stronger than average easterly winds across the Atlantic, thus favoring increased wind shear and cooler than normal sea surface temperatures (SSTs) off the West Coast of Africa. Both wind shear and cooler oceans act as enemies to tropical development.
Another oscillation anticipated to impact the upcoming tropical season is El Niño Southern Oscillations (ENSO). Currently, El Niño conditions (the warm phase of ENSO) are present in the Equatorial Pacific. El Niño is significant, as it is generally tied to higher amounts of wind shear across the Atlantic Basin. As stated above, increased wind shear favors below normal tropical activity. All signs currently point to El Niño conditions continuing for most, if not all, of the upcoming season.
Positive Sea Surface Temperatures (SSTs) Anomalies Across the Equatorial Pacific (CPC) Show El Niño Conditions are Present
While overall decreased tropical activity is expected for this year, it is important to always stay vigilant. Remember, it only takes one landfalling hurricane along the East Coast to inflict major damage across our area. For a more in-depth look at forecast, make sure to keep an eye out for the WeatherWorks 2015 Atlantic Hurricane Outlook, due next week.
