Need Larry on this one, but statistically, how often does Siberian cold make a trek to the SE? I can recall maybe 3 occasions over a long span, but can recall more, or so it seems, when the cold just stayed put over there. Not editorializing here, just wondering if Larry (most likely) or someone has any data to this effect.
Based on my recollection, I agree with you that it usually doesn't lead to it getting real cold here. More often than not, my recollection is of folks complaining about it being so cold there and not coming to us. Most of our real cold airmasaes actually originate in the Arctic/Canada/AK as opposed to Siberia per Larry Cosgrove. The conditions that allow it to get so cold there (including air sort of getting stuck there) are usually not conducive to the SE getting very cold soon afterward. Also, with the global temp being fairly stable, think of real cold there often taking away from what we could have had.
This having been said, that doesn't mean there aren't times when it does indirectly lead to very cold in the SE.