Update on the Atlantic hurricane season 2016

Advertisment
  • Atlantic Tropical Cyclone tracks in 2015 when there was a strong El Nino. Courtesy of National Hurricane Centre.

    Atlantic Tropical Cyclone tracks in 2011 when there was La Nina. Courtesy of National Hurricane Centre.

  • Update on the Atlantic hurricane season 2016
    25.08.2016 14:41

    As mentioned in previous weather reports this year’s 2016 Atlantic hurricane season started extremely early with a tropical storm on 13th January which strengthened to a hurricane called Alex which struck Bermuda. It has continued to be quite active since the second named storm Bonnie in mid-May. There have now been seven named storms so far this season with three reaching hurricane status. Environmental conditions look like remaining favourable for hurricane formation over the next week or two with above normal tropical cyclone activity expected to continue.


    The hurricane activity in the Atlantic basin has been classed as below average over the last few years. However this year, forecasts predicted a more active season and this seems to be proving to be the case. The reason for the reduced hurricane activity in previous years was partly due to the strong El Niño that occurred in 2015. El Niño tends to disrupt the usual weather patterns across the Tropics favouring stronger hurricane activity in central and eastern Pacific and suppresses it in the Atlantic. This is primarily due to changes in the vertical wind shear which refers to the change in wind speed and direction between roughly 5,000 and 35,000ft above the ground. If there is strong vertical wind shear then it can rip a developing hurricane apart and prevent it from forming. El Niño leads to high vertical wind shear in the Atlantic which is believed to be the reason that last year or two, the hurricane activity has been below normal.


    Since last summer, the strong El Niño has disappeared and conditions in the Tropics have returned to around normal.  However, over recent months we have seen a weak La Niña start to develop. This is the opposite of El Niño and is believed to be the reason the hurricane activity this year is already much more active than previous years. La Niña results in suppressed vertical wind shear in the Atlantic which leads to more favourable conditions for hurricanes to develop. This was seen in 2011 when La Niña conditions led to a very active hurricane season as seen in alongside. 


    Hurricane Gaston is the latest hurricane to develop in the Atlantic and has reached its peak today with gusts up to 85-90mph, although this system is expected to slowly weaken and track north-westwards. It will eventually head north then north-eastwards towards to the UK as a low pressure system, potentially disrupting our weather next week, although confidence is very low on its exact track.


    Another area of close interest at moment is the potential for a low pressure system near to the Bahamas to develop into a Tropical Storm or Hurricane that could track close to or across Florida early next week. This could bring disruptive conditions of strong winds and heavy rain. There is also the potential it will track into the Gulf of Mexico where high sea surface temperatures could intensify it further.  There is still a lot of uncertainty of the track of this system at present, but due to the risk for destructive conditions across parts of Florida, Gulf of Mexico and the Eastern Seaboard, this system will be followed very closely over the coming days.