A January hurricane in the Atlantic

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  • Hurricane Alex, category 1. Credit: EOSDIS.

    Hurricane Pali over the Central Pacific and Hurricane Alex in the Atlantic simultaneously. Credit: MeteoEarth.

    Alex on Friday transforming from tropical storm into extra-tropical depression. Credit: EUMETSAT

  • A January hurricane in the Atlantic
    16.01.2016 16:54

    The only other one to do so since records began in 1851 was an unnamed hurricane in January 1938. The last to be present during January was Hurricane Alice in 1955 which had formed at the end of the previous December.

    A forecaster at the National Hurricane Center (NHC) pointed out that this was “remarkable”. It is rare to see such a storm so early in the year, well outside the peak of the hurricane season which runs from June to October as seas become warm enough to provide the necessary energy.

    Hurricane Alex passed through the Azores Islands on Friday morning, bringing down trees, cutting power and flooding some homes. However, there were no reports of casualties, and on Friday afternoon the hurricane was downgraded to a tropical storm by the NHC with the expectation that it would then degrade to an extra-tropical depression. The system accelerated northwards over the North Atlantic, and although confidence on its track is low it is expected to be absorbed into a mid-latitude low pressure system on Sunday.

    We also have the unprecedented situation of January storms simultaneously occurring in the Atlantic and Pacific Oceans. Over the Central Pacific, Pali became the earliest hurricane on record there on January 11th as a Category 1 storm, and temporarily Category 2 on January 12th, thereafter weakening to a tropical storm.  

    The previous earliest on record in the Pacific was Hurricane Ekeka in 1992, 19 days later. Not only that, Pali developed remarkably close to the equator and has been driven farther south by a strong high pressure circulation to its northwest. According to Philip Klotzbach of Colorado State University, only two storms that we know of have been stronger closer to the equator.

    An indication of next season?

    Due to El Niño, the hurricane season across the Atlantic basin on 2015 was below average. According to the NHC:

    “For the 2015 season, 11 named storms formed in the Atlantic basin. Four of the storms became hurricanes, and 2 reached major hurricane status. There was also one unnamed tropical depression. While the number of named storms, hurricanes, and major hurricanes was only a little below the long-term average activity levels of 12, 6, and 3, respectively, many of the named storms were relatively weak and short-lived. “

    Name                                  Dates                         Max Wind (mph)

    ---------------------------------------------------
    TS Ana*             8-11 May            60
    TS Bill*           16-18 Jun            60
    TS Claudette*      13-14 Jul            50
    MH Danny           18-24 Aug           115
    TS Erika           25-29 Aug            50
    H  Fred         30 Aug-6 Sep            85
    TS Grace*            5-9 Sep            60
    TS Henri*           8-11 Sep            50
    TD Nine*           16-19 Sep            35
    TS Ida*            18-27 Sep            50
    MH Joaquin      28 Sep-7 Oct           155
    H  Kate             9-12 Nov            75
    ---------------------------------------------------

     

    It is really complicated to forecast next hurricane season but we have three elements that can help increase the number of hurricanes and the strength of those forming, perhaps to become near average or a little above.

    First of all, is difficult to have to continuous seasons below average; secondly the sea surface temperatures are expected to remain anomalously high. Thirdly, and most importantly, El Niño is expected to weaken through the spring and disappear by the start of the “official” hurricane season in June. This will create more favorable conditions for hurricanes to develop, especially by decreasing the vertical changes in wind speed and direction, known as “wind shear”, that can hinder hurricane development.

    Although it is too early to say for certain we might even see La Niña conditions develop through the summer of 2016, which tends to encourage even more frequent hurricane development in the Atlantic while decreasing occurrence over the Pacific.

    Obviously, at this early stage there is no confidence about the track and exact numbers or hurricanes but, as we did last year, we will show you the best estimates as they become available.

    By: Mario Cuellar and Stephen Davenport