MJO and the Weather Geek Language

I had to re-post this here. Here's some of the geek talk I have to wade through... this just happened to be a little more geeky than normal! :-) Part of the fun of tracking weather is trying to pick out patterns well in advance of the actual weather systems. There are a lot of indices that meteorologist use to help predict the future patterns that will affect the weather, and in the quoted discussion below, several of those are discussed. The one I would like to focus on is the MJO (Madden - Julian Oscillation). I have bolded points that I think are important for us.

"Until we can get the MJO into a more conducive octant, we're going to be struggling with -NAO development over the next 10-15 days. PNA values will be reaching a minimum by D 5-7 which should culminate in a strong trough amplifying in the Western US. At week 1 we've got the unholy trifecta in place: -PNA, +AO and +NAO. However, there are clues that the pattern will be changing down the road, probably by the end of the 15 day period noted in this thread. My target time frame for a full scale pattern reversal in the East is week 3-4, essentially around mid-December. MJO will be propagating through p 3-6 in the late Nov-early Dec period, which is unfavorable for any polar air penetration into the US. In fact I wouldn't be surprised to see a torch for much of the CONUS the first week of December. With that said, by D15 we see GFS ensembles beginning to retrograde the PAC NW trough into the Gulf of Alaska, and heights rising in the north Atlantic as well. MJO should be approaching more conducive phases by Dec 10th-15th, and given the continued low geomagnetic indicators, I expect the -NAO block to initiate fairly easily by week 3-4. This is kind of getting past the time frame for this thread, but the main points I think for the next 15 days -- 

1) Strong RNA pattern w/ troughing in the west, burgeoning SE ridge, negative heights flooding the arctic, 

2) Western US trough retrograde toward the GOA by day 15; NAO region heights starting to rise 

3) MJO in phases promoting warmth/pac orgin air for the remainder of November and early December."

He's basically talking about multiple teleconnection indices and how they are forecasted to change. Remember, what we're looking for is a -NAO (a negative North Atlantic Oscillation) in order to get cold air in our area, at least during a La Nina period. In layman's terms, it looks like a warm couple of weeks before things begin to change toward a more winter like atmosphere for us. Noticed he mentions a torch for the first week of December… winter isn’t here just yet.

Here's a great explanation of the MJO (which stands for the Madden-Julian Oscillation). The MJO, also referred to as the 30-60 day or 40-50 day oscillation, turns out to be the main intra-annual fluctuation that explains weather variations in the tropics. The MJO affects the entire tropical troposphere but is most evident in the Indian and western Pacific Oceans. The MJO involves variations in wind, sea surface temperature (SST), cloudiness, and rainfall. Because most tropical rainfall is convective, and convective cloud tops are very cold (emitting little longwave radiation), the MJO is most obvious in the variation of outgoing longwave radiation (OLR), as measured by an infrared sensor on a satellite. 

I also have a page with the MJO indicies if you're interested. 

Right now the atmosphere is going through an unstable period as we move from warm weather to cooler weather. Watch for the indices to begin flipping in a few weeks, just in time for the Christmas holiday season. Are we looking at a repeat from last year? Can't wait to see what happens!