Comparisons are always tricky. Go ahead and pick the data and sure enough, you can find some correlation or causal relationship to the current weather situation. The operative word here is "CAUSAL". Is the information or data giving you an accurate snapshot of what is driving the current weather? In other words, is there a direct cause and effect relationship?
The index we look at as a direct measure of the strength of the arctic air to the north is the ARCTIC OSCILLATION. Pressure differences over the arctic and temperatures high in the atmosphere can make the arctic air more or less changeable for us living around the Great Lakes. If the AO index is negative, the arctic air becomes unstable and has a tendency to drive southward. If its positive, its stays locked up in the higher latitudes of the arctic.