The Mayan Express

  • A NASA satellite image of the cloud streaming northwards over the eastern Caribbean Sea and central southern USA, from 8th March 2016.

    Current sea surface temperatures, from 8th March 2016, courtesy of NASA.

    The predicted rainfall amounts for the coming ten days.

  • The Mayan Express
    10.03.2016 15:40

    The last few days have seen heavy rain lash down on the Mississippi Valley in the central southern USA, and especially across the state of Louisiana. This heavy rain has led to severe flooding and the loss of life as rain fell persistently through Tuesday afternoon, overnight and Wednesday. More than 400mm (16 inches) of rain fell in worst hit areas during this time. 

    This wet weather is unfortunately showing little sign of abatement, with more heavy rain expected to feed across the region due to a phenomenon known as the Mayan Express. This ‘atmospheric river’ is a result of very mild air feeding northwards across the eastern Caribbean Sea. Sea surface temperatures in the eastern Caribbean Sea are currently 2-2.5C above what they normally are at this time of year, thanks to the El Nino event in progress at the moment. Therefore, the air moving over the top is picking up a great deal of moisture which is then moving over the central southern USA, where the air cools over the land, dumping the moisture in the form of heavy rain over the region.  

    So, with this Mayan Express looking like continuing through the coming week to ten days, a great deal more rain can be expected, with 150-200mm across most of Louisiana and eastern Arkansas, but up to 270mm in places, and perhaps locally even more than this is possible. This amount of water is likely to lead to further flooding, and hamper the clean-up from the current flooding events. The majority of this rain is expected to fall between now and Sunday, before the rainfall eases a little in intensity through next week as the flow develops a bit more of a south-westerly component to it.

    By: Rachel Vince