I have been repeatedly trying to emphasize the ideas on blocking can be very overstated. You can have all the blocking in the world but if the blocking is not in the right place, or if the resulting ridges and troughs are not in the right place, it won't produce the outcome that you might expect for might like (pay attention snow lovers).
Today's index are rather astounding considering how off the wall extreme they are forecast to reach. The East Pacific Oscillation and the North Atlantic Oscillation both reach strong levels. The EPO actually goes to an extreme negative late next week. The Pacific North America pattern index which produces a strong ridge in the west and a deep trough in the east when it is positive, is about as off the wall negative as they come. This would normally mean you can't have a big snow storm in the east. Or can you? Big classic storms are not the only way we could see a big snowfall. The state of the indices suggests that rather than the so called classic set ups, we could see setups in a different way. The state of the indices suggests we could see overrunning events. Overrunning is...READ MORE AT http://www.meteorologistjoecioffi.com/index.php/2016/12/30/snow-chances-depend-blocking/