I have been repeatedly stating over and over that the pattern change you get and the pattern change you want are two different things. The process is long and grinding and this one is no different. What is becoming increasingly evident is that the first change to a more active stormy pattern is going to happen faster then the change to colder. That part is going to take longer to play out. Blocking is developing and this is going to be one of the drivers in how the upper air jet stream sets up in Canada. While there will be no real cold air all week long, an onshore flow and higher pressures to the northeast will keep temperatures in check. They will be above normal but not crazy above normal.
First off with respect to blocking, the North Atlantic Oscillation will be going negative and today's models suggest that it will stay negative longer. A negative NAO means blocking. The more negative the index the stronger the blocking. This offsets the off the wall positive East Pacific Oscillation which favors warmer than average temperatures in the east. The Pacific North America Pattern will go strongly positive next week which is supportive for storm development. Later next week the East Pacific Oscillation trend to negative which signals a colder pattern returning though I do not see it as being anything extreme. Given all these complicated views of the atmosphere it seems reasonable that the forecast will be a bit chaotic over the next week...READ MORE AT http://www.meteorologistjoecioffi.com/index.php/2017/01/16/weather-models-active-stormy-pattern/