It figures that when a major shopping and travel period is near, signs pop up that indicate adverse weather. Now let me say at the outset that snow and ice is not the major concern. Rather it is the advance of much colder air and higher north winds following a large storm.
You have heard the term “Blue Norther” before, which is a code word for a rapid drop in temperature through the Great Plains and Texas. Stronger north winds will kick up, and the gradient flow behind a “Panhandle Hooker B” cyclone should get the surface nocturnal freeze line as far south as Mexico City and Monterrey around November 28. You might think of this cA intrusion as something of an upgrade from the Halloween event.
Rain and thunderstorm threats may precede the cold shot, as the low pressure may move from N TX to W NY and on into far E QC. A difference this time is that rather than a fast rebound in temperature after a few days, this cold wave may have a second helping and occupy most of the central and eastern two-thirds of the continent through about December 7. The West, along with Alaska will be under the ridge and stay relatively mild. The problem this time around is that the very strong blocking signature may ultimately cover northern Canada and Greenland. That might afford the chance for another case of anticyclogenesis, and with it a release of colder air.
If trends continue like was the case with November, the middle two weeks of December should be quite mild.
