Friday: How Will the Start of Winter Look this Year?

That's the million dollar question. If you read my winter forecast you know I do expect the first half of winter to be more impressive than the last. That means Dec and Jan I would expect to feature at least average snowfall for the region and above average for the interior.

So how are things looking? Well there is a lot of talk out there about a warm December based on a strong PV, placement and strength of the La Nina pattern and projections from climate models. As of now I am no in that camp. I certainly understand the research behind that view and it has merit, but the weather is not perfectly predictable. My observations of how everything has played out so far does not concern me. My conclusion is December has the chance to feel like a winter month this year. I share more details below...

A few things I like to see..

So far as we have gone through the fall season, the weather pattern hasn't been too unusual minus a 3 day stretch where things got super warm. We have had our seasonable periods and some impressive short lived cold shots. To me this is very typical of a la Nina pattern- a lot of volatility.  So I do not conclude from this , I will admit simple observation, we will see sustainable warm or cold outbreaks. it will be a mix which is perfectly normal. Remember to snow we don't need crazy cold episodes as we do not live in NC.

The models so far have over estimated the impact of the trough over the northwestern Canada. It always seems at first glance the trough will strengthen and stay over land which would result in a very warm pattern. However, I have noticed so far this year that as the forecast periods gets inside 120 hours the models have tended to correct and pull the trough more west and deepen it. This has resulted in colder than forecasted conditions for the east coast.  We just saw this happen with the recent cold spell. That was no where to be seen on long range models a few weeks ago...

As you can see the forecast on the left from the long range European did not pick up on the deepening trough off the west coast which on the right image is what actually happened. This resulted in our cold spell we just had.

So moving forward when people look at middle of December forecast projections like this below. I would not take them at face value....

Of course this is a simple way of looking at things. There are other factors that will drive the weather pattern that if they evolve incorrectly it would mean a warm December. I just do not see that at this time. The MJO (tropical influence) looks to stay weak and even though we have a strong Polar Vortex a little slight wobble towards our end of the hemisphere could do the trick. We just don't want to see a super tight wound vortex sitting right over the pole.

Even the models in the shorter range (early December) are hinting that wide spread warmth will not be the case...

Now for any signifigant winter storms you would need more blocking or in other words higher pressures over Greenland and Canada. But the point I am making today is this pattern is not awful.

Bottom line:

Lets be patient and let it play out. My December forecast seems to be on track.