What does this mean for hurricane season?
Written by Captain Mike
The first few months of 2015 have been marked by a rather active storm track across the Atlantic. Frequent wintertime storms have marched from offshore of the East Coast U.S. and Canadian Maritimes, while early spring cut-off gales have plagued waters from the Azores into Western Europe. These systems have brought several strong frontal passages and large swells that have posed challenges to trans-ocean crossings. There hasn’t been much of a letdown as the calendar has turned to April and May.
So, does this active first half of the year translate into an active tropical season for the Atlantic basin? There are two really good indicators that can provide a clue for the type of season we will experience. These indicators are the El Niño Southern Oscillation index (or simply ENSO), and sea surface temperatures across the Atlantic.
The ENSO index is the measure of sea surface temperatures across the East Pacific, which can affect global weather patterns. The ENSO status is currently a weak El Niño (or slightly warmer sea surface temperatures), and a weak to perhaps moderate El Niño is likely to persist through this autumn. El Niño events will typically bring the mid-latitude (non-tropical) low track farther south closer to the Tropical Atlantic. This can lead to increased upper level winds in the tropical latitudes, which is an inhibitor of tropical development. Additionally, below average to average sea surface temperatures are expected for the Tropical Atlantic over the next several months.
Taking the two above factors into account, we would expect a slightly below average Atlantic Hurricane season for 2015 with a prediction of 8-10 named storms (tropical storm or hurricane). This prediction falls in line with recent years where a weak to moderate El Niño has occurred. Since 1990, there has been 7 tropical seasons where a weak to moderate El Niño has occurred, with the average being approximately 9.5 named storms during those years. This includes 2014, where 8 named storms occurred across the Atlantic. In comparison, the 30 year running average for the Tropical Atlantic is approximately 12 named storms per year.
While a below average tropical season is a distinct possibility, one most keep in mind that it is individual storms, not seasons, that can bring severe impacts to coastal waters of the East Coast U.S. and Caribbean and over the open Atlantic. At the writing of this article, there was the potential for a sub-tropical or tropical system to develop to the north of the Bahamas. These systems that come into close proximity of land need to be given an especially watchful eye and, as always, we urge our clients to take the necessary precautions to ensure the safety of their crew and vessel.