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The long standing position on this site is that winter was going to get started with a bang this December. Now for those of you playing along, look at the month like a board game. There are 31 squares (or days) you have to advance through to reach months end and achieve a win. When I started preparing for the game back in late September, I clearly had no idea what day of the month (or square) we would be on when the hammer came down. In fact, there was no guarantee that it would ever happen. That's the chance you take when you start any game. You with me so far?

So December is finally here, the players are on the field in square one but the marching band has refused to yield. I can already see I've got a fight on my hands with the pattern still in flux. However, I've come this far and will fight the good fight. I'm going to get kicked around pretty good the next two weeks but it's still my contention this can still go the other way which is my way.

I will say this much, the last three weeks have been really frustrating with a lot of noise in the pattern. Models have been flip flopping and trying to feel out weaknesses in the atmospheric wave train that will deliver sustained cold. So much so, that I'm leaning more on teleconnections to show me the way. That's not something a lot of forecasters do. Their game is model driven and while you can win with that, my experience tells me that if the teleconnections are not in your favor, the models will ultimately fail you, especially in the long range game.

So, spinning the wheel of the MJO (Madden Julien Oscillation), I'm riding that train to get me to the finish line. What I'm seeing in the MJO phase forecasts today is that the EURO, GFS, JMA, and CFSv2 are unanimous in pushing the MJO oscillation with amplitude into phase 6 through at least December 6th. You can see it clearly in the phase diagram below. Notice too though that both models do progress it into phase 7 by mid-month. That's huge!

Phase 6 though is a real problem for me as it is the warmest of the 8 MJO phases during the month of December. In the temperature analog below, you can see how widespread warmth is across the nation in phase 6.

So clearly I've got major issues to start the month with 5 day mean temperature departures such as this. That certainly qualifies as a phase 6 look

However, it's my contention that if the MJO does indeed go into 7 as shown, at the very least we get into seasonal cold the second half of December with the threat for a period of well below normal temperatures, especially late in the month if the MJO can close in on phase 8. The GFS extended is indicating that potential with a 500mb jet stream flow that looks like this months end.

These are the temperature anomalies such an upper air pattern brings the last week of December and they are nasty.

Now the reason we play the games is because sometimes favored potential is offset by other factors and upsets do indeed happen. Things have evolved slower than I would have liked but they are starting to trend in the right direction. Even so, this remains a low confidence forecast. There are a lot of assumptions and contradictions on the table. This has the potential to go really bad for me if the La Nina is just too strong and disrupts the MJO amplitude and phase. Its ensembles show lots of variability and I don't like that spread because it leaves plenty of room for error. Even so, I'm not ready to throw in the towel yet and should have a pretty good idea where things are trending by the end of the week. It's do or die time for my December outlook.

Now this is interesting, we've established we are in phase 6 and temperatures have been (and are going to continue mild into the weekend). The GFS meteogram shows readings that look like this into Tuesday. We see a little dip Saturday but we go right back up Sunday. Overall this remains a very dry period with just slight shower chances early Wednesday morning and then again late Sunday afternoon.

Where it gets interesting is with the passage of a strong cold front that drops a healthy chunk of cold air on the region Monday and Tuesday. Highs go into the 30s and the air aloft is quite cold, certainly cold enough to support snow. With the cold air in place, models depict a wave of low pressure developing on the edge of the cold air to the south and there are indications that some snow is possible around December 7th.

Models have trended that way over the past 24 hours but are still in the midst of settling on the amount of phasing and the degree of intensity which drives the track. As it is, models are showing a surface scenario that looks like this on the GFS with low pressure down in Oklahoma.

That set-up produces a nice snowfall that looks like this on the GFS operational. BOING! White gold....

Not so fast. Nice as that looks for my area, there are other models and solutions. The EURO is much further north on the snow band showing the significant spread in models at this distance.

The Canadian GEM is more in the northern camp of the EURO than the GFS.

Needless to say, nothing is set in stone at this point in the game. As I always say snow numbers mean nothing at this distance. They are going to change on a daily basis going forward as will placement. Right now we are just trying to establish a trend. What I want to see now is consistency amongst models that continues into the weekend. Hard to say if that will happen soon but it was great to see snow back on the models less than a week away.

Okay, the last thing I will leave you with is a tease for a big announcement that's coming in my next post. It's severe weather school taught by yours truly and a host of other meteorologists. I've got a great agenda planned for this 5 hour event. I hope that many of you can join me as we make forecasting a reality for those who want to master the art. Stay tuned and roll weather...


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