Good Thursday evening, my fellow weather weenies. December is off to a seasonally chilly start, but the pattern is about to take on a pretty wintry look across the country. I have this update loaded with maps, so let’s get after it. 🙂

The late weekend system continues to look on the light side, with some rain and snow possible late Saturday night into early Sunday…

nam

The next system rolling in here Monday and Tuesday is likely to bring another round of heavy rain. A general 1″-2″ will be possible. The GFS is forecasting totals to be a littler higher…

gfs-rain

This sudden change to a very wet pattern is the buffer between the dry and warm setup of the past several months, and the big change to winter coming next week.

That change happens as an arctic front works across the state Wednesday into early Thursday…

gfs-2

That should be complete with a MAJOR drop in temperatures, gusty winds and some, at least, snow showers and squalls behind the front. Temperatures behind this front will stay in the low and middle 20s for highs with lows dropping into the low teens. Wind chill numbers in the single digits, anyone? 🙂

Just look at the definition of the arctic air mass behind this front…

euro-2

That’s a lot of cold air that will then continue to hang tough across much of the country into next weekend. This should happen as a southern stream system rides eastward underneath. You can see that showing up at the end of the European Model…

euro-3

The GFS also has that potential snow maker…

gfs-3

The same GFS run then shows another arctic plunge a few days later, as a big storm develops…

gfs-4

Of course, I’m not showing these maps for anything other than illustrating how the pattern is taking a big turn to winter.

Some of those extreme December analog years continue to show up, and that should be an attention getter.

Have a great evening and take care.