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    1/24 - 1/26 Clipper Train, and Arctic Frontal Passage

    Tom
    By Tom,

    The Clipper Train continues to flex it's muscles into this weekend.  2 shots at some decent snow events this coming Friday night into Saturday and another Clipper on it's heals poised to hit the region Sunday.  Discuss...

     

     


    MJO Discussion

    Bryant
    By Bryant,

    It was encouraging to have a few people message me and ask me to start this thread back up, and it's something I planned on doing anyways. While I continue to learn about the MJO and use it to help make forecasts, this thread not only helps me strive to learn, but allows me to go back and see my errors for further learning.

     

    Back on Dec 22nd, I made a call that a new MJO wave would emerge over the Indian Ocean sometime around mid January, and I was completely wrong. I anticipated things to move quicker than they have been, but that's exactly why I'm watching everything much closer this time around. This is my first time closely watching the MJO, so I'm definitely prone to multiple errors =P. The MJO is currently over the Western Hemisphere (8-1), where the signal is very weak. Typically during neutral ENSO, once the MJO passes by the dateline, the convection associated with the MJO dies off. The upper level winds associated with the MJO are still evident however.

     

    If you've looked at an MJO forecast recently, you've noticed a strengthening signal in the Western Pacific.

     

    http://i39.tinypic.com/30kslz7.gif

     

    I've mentioned before that other "noise" in the tropics can easily alter the above plots, and this is one of those times. The strengthening signal you see is actually a Kelvin wave in the West Pac which is typical while he MJO is in the Western Hemisphere. As shown in the forecast, it's likely we'll quickly see this signal die off and head back towards the inner circle. As this Kelvin Wave travels east however, the convection over the tropical Pacific diminishes which also removes the support for an extended Pacific jet. This in turn will allow the +PNA ridge to break down and be replaced by cooler conditions, as well as bringing relief to California hopefully.

     

    http://i42.tinypic.com/259aijc.gif

     

     

    Taking a look at forecasts and previous history, I'd say it's possible we see an MJO wave emerge over the Indian Ocean in the next 2-3 weeks. Until that happens, we may return to an overall +PNA pattern after the potentially brief breakdown beginning of the month. Taking an educated guess (once again based off history), I'd say the MJO reaches the eastern Indian Ocean/ Maritime Continent, which are favorable for cold in the west, in about 3-4 weeks. This is still a huge learning process for me, and I could easily end up being completely off or wrong all together... but time will tell.

     

    http://i39.tinypic.com/21b4y13.gif


    January 2014 Observations and Discussion

    Alec Isaacs
    By Alec Isaacs,

    Discuss any weather related East Coast topics here. You can create additional threads for large-scale events.


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