Look beyond!

Short update on Alex
Most of you probably already heard that the models trended quite a bit west over the last few runs. This is pretty much what I thought would happen in the beginning. While this may not be the end of the world, it does make the chance of seeing significant snowfall less likely. I am still sticking with 2-10cm of snow for Golden Horshoe and Southwestern Ontario with the extreme western edge likely seeing over 5cm of snow from this.

"Arctic" Outbreak
Cold air is coming! Despite a lack of snow/cold the last little while, cold air will be arriving shortly after the "winter storm". When, What, Where, Why, How? Let me explain this in some details.

What we have after Alex is a typical ridge trough pattern. Cold arctic air ushering in from the northwest, pushing a trough in the jet stream in the East. Pacific Warmth rush inland, pushing a ridge in the West . We will be in for this general pattern for quite a bit this December, I am guess til at least the 20s(Perhaps most of the winter will consist of this type of general pattern). When this type of pattern occurs, we will definitely have below normal temperatures. However, the snowfall amount could vary.

If the high pressure is just offshore most of the time(Bermuda high provinding a ridge in the extreme SE). When low pressure systems arrive, they will be pushed inland, providing us with the cold side of a winter storm. Translating to above normal snowfall. If the high pressures sit inland as will as above greenland for most of the time. We will be in for a blocking pattern. Low pressure systems will generally stay offshore, providing us with slightly normal snowfall( possibly seeing more though with Alberta Clippers).

I think we will be in for the first scenerio for the first part of this pattern and trancents to a blocking pattern when the arctic air is firmly in place. This particular outbreak will come in a few waves, interrupted by possible winter storms. With each wave bringing colder arctic air.

Wave 1 - Dec 4 - Dec 7
Right after Alex, a cold front will bring the first wave of arctic air. Highs of near 0 and lows around -5 to -7 will be expected.

Wave 2- Dec 10- Dec 13
A second wave of arctic air will blast across after a winter storm around this period. A significant lake effect event should take place during this period.

Wave 3 - Dec 15 to late Dec
A blocking pattern cold lock its place. Lows in the negative high teens into the -20s are expected.

One mistake we often make is basing medium range predictions on models. Unfortunately, models such as the GFS never handle these types of situations well. They tend to fluctuate quite a bit model by model. For example, looking at the 00z GFS last night, it almost appears we are not going to have an arctic outbreak at all(also another reason the 14 days trend on TWN is bs)! The tools we should use for medium range forecast is 1) telecollections 2) general patterns of ensembles/models 3) common sense.

Next Storm?
We will definitely be seeing something in the period of next weekend to early next week. My early guess right now is that we will be seeing out first snowstorm of the winter sometime during the Dec 5-11th period. Right now the models are showing an offshore storm around 5-7th. I won't be surprised if it starts to shift west and track inland over the next few days. If not, there will be a Colorado low setting up around 9-11th. The thing to keep in mind now is that the arctic air is already IN place. The likelihood of seeing a good amount of snow out of a system during this time period will be pretty high.

Schedule?
Obviously, there isn't really a firm schedule on what I will be talking about each day since it is the weather! However, I have a rough idea on what the next few days should go on this blog.

Tomorrow - Winter Storm Alex full forecast
Wednesday- Storm possibility for next winter storm,
Thursday- Alex Observation/Post Storm, more in depth analyzes on the upcoming pattern
Friday to Sunday - Forecast period for next possible winter storm