Status Quo through New Years

I figured I'd try my hand at running a blog again, and keep it based on weather, as I'm attending Mississippi State University beginning in the spring (3 weeks from yesterday). I am especially interested in long term forecasting. I think it's very interesting how we can go beyond the traditional one week forecast and look at clues from upcoming patterns to spot where storms or especially colder/warmer than normal periods are emerging. Very cool stuff.

Out in the northern Shenandoah Valley, we hit the mid 50s under cloudy skies, in the middle of December. This isn't especially common, but teleconnections as they are named, are indicating that these conditions aren't too surprising because of the pattern we are in. I am trying to research four patterns and the impact they have on winters in the East Coast: AO, NAO, MJO, and PNA. Given that it's a La Nina year, it's a bit harder to get extended cold/snowy outbreaks in our area.

For cold & snow to impact the Eastern USA, the teleconnections need to align in the following pattern (and it appears that 2 or more of them need to line up in this arrangement): -AO, -NAO, +PNA, and an MJO in phase 7, 8, or 1. Most or all of this fall & winter season so far, the AO and NAO have been positive, and the PNA has been neutral to negative. This explains the trough on the west coast/ridge in the east idea and the amount of storms that have been Great Lakes or Appalachian cutters, keeping the East mild and snow-free. The MJO was briefly in Phases 7, 8, and 1, but has since stalled out in Phase 4 and what is almost considered a "Circle of Death".

I've been keeping an eye on the forecasts for the next two weeks and a major pattern shift does not appear likely. The NAO and AO look to be remaining pretty positive, and the PNA will remain neutral to negative, according to the computer model forecasts. The MJO is modeled to circle around in Phase 4/Circle of Death area, and remember that an MJO in Phases 7, 8, and 1 are correlated with colder periods.

So, yes, it can get cold without the above aligning in the perfect setup, BUT the cold I'm referring to is significant and sustained outbreaks of cold, not the one to three day "outbreaks" of colder than normal air that come in after storms and do not yield themselves to a blockbuster snowstorm for much of the I-95 corridor. Then again, this pattern can certainly change, so winter is not called off... yet. But it is certainly a welcome break from the cold and snowy patterns of the past two winters!