Currently: Arctic high pressure over the Appalachians is in control of our weather today. This will keep very cold temperatures over the region the next few days, with a small moderation trend. This will also shield the region from a coastal low, that will remain hundreds of miles out to sea, thanks to the high pressure.
Tonight: With warm air advection commencing, I will go with the warmer NAM MOS guidance for tonight. Under clear skies, temperatures should only fall slightly, with lows generally in the teens. Although a few single digits are possible in the NW hills.
Tomorrow: I'll go with the cooler GFS guidance for tomorrow's highs. With most areas still with at least a little snow and ice on the ground, temperatures should struggle to rise. Expect highs somewhere around the freezing mark for most places.
Tomorrow Night/Saturday: The combination of one final small push of cold air advection and some high clouds spreading in from the coastal low well to our southeast (although high clouds is all we will see), I'll go a degree or two below all guidance. High temperatures should be strikingly uniform, given that the clouds will be thicker to the south. I'll go with highs of 30-35. Although it is possible that I could be a bit too cool if the coastal low goes further south than expected. But for now, this looks like the best way to go!
Long Term (Sunday and beyond): Look for normal to above normal temperatures and fairly tranquil weather (at least no large, deep storms) during this period. I am not going to write a very long discussion, when there really isn't all that much to talk about. So let's take a quick look at the dailies.
Sunday: Despite warm air advection and sunshine, surface albedo and a lingering bitter air mass do not usually promote warming as fast as the GFS statistical guidance thinks it's going to happen. Therefore, I'll go a few degrees under MOS guidance and call for low 40s for highs.
Monday: On the other hand, Monday looks to feature plenty of sun again, along with some downslope flow. This presents itself as a good opportunity for temperatures to rise. In addition, being the 2nd day with a warmer air mass in place lends itself to being able to warm much more easily at the surface. Therefore, I'll go a couple degrees above guidance on Monday. I'll call for highs in the mid 40s. A few places in the I 91 corridor may get into the upper 40s!
Tuesday: Clouds may increase a little, but no precipitation is expected. I see no reason at all to quibble with temperature guidance and will just ride it. Expect highs in the mid to upper 40s.
Wednesday (Christmas Day): Now for Christmas Day, I don't see any reason to go as warm as guidance is advertising. There will be more clouds and a slightly cooler air mass aloft. So I'll undercut guidance by a few degrees. This results in temperatures almost exactly the same as those on Tuesday.
Finally for Thursday, I'll undercut guidance fairly significantly here. With pcldy/mcldy sikes and a developing NE wind, I can't see how we get nearly as warm as MOS indicates. I'll go with highs in the low to mid 40s. The only caveat is that we get a bit more sun than I am expecting. Then we could be a few degrees warmer than what I am forecasting.
One more addition to the long term forecast, an Alberta Clipper system looks to pass over the region later Thursday into Friday. Right now, it looks like the most this system will produce for the state is light rain showers, gradually transitioning to sleet or snow showers later Thursday into early Friday. However, there has been a trend in some of the modeling to develop a coastal low near Cape Cod on Friday. This location is probably too far NE to affect most of the area, some models do give NE CT a period of decent accumulating snow on Friday, so this could be something to watch.
Looking into the long range, the long range is a bit muddled today, but most LR models are at least hinting at something of a pattern change in the long range, back to something more wintry, perhaps centered around or just after the New Year. We are also getting into the time of year where you don't need a perfect setup to get a moderate winter weather event.
Now, let's take a graphical look at some of the features affecting our weather in the near term. Since we don't have a whole lot going on, I'll post the low temperatures for tonight and then a quick look at the day 7 Miller B potential (although it is day 7 and models are bad at resolving a situation like that on day 2), but there really isn't that much to post about.
This map shows the entire state in the teens. I think these temperatures may be a degree or two too warm, since they're an hourly snapshot, rather than min temps, But you can get an idea.