Dangerous Cold Moving in This Week.
It's a brisk day out today, but (quite literally) on the bright side, it's a perfectly beautiful day. A bit on the downside, it's chilly, which you can't complain about given it's December, but that wind is SHARP - gusting up to 20 at times, with sustained winds at 10-15 out of the SW. Thanks to this, the wind chill is stabbing out there, hovering in the 30s for most of us.
We're looking at highs for today squarely in the mid-40s for the lot of us - S TN looks to stay a consistent few degrees cooler than NW Alabama, but that is often the case given those handful of miles make a difference when it comes down to it. Clear conditions stick around for tonight, with lows bottoming out tomorrow morning as we head into church in the lower to mid 20s. Tomorrow is, more or less, a carbon copy of today - sunny and 40s for all.
The changes begin by Monday, when some light showers may move in through the morning, of which an even more scant few may provide a brief spurt of wintry precipitation before temperatures fully establish themselves as above freezing. Don't expect any accumulation, but it's something to note as we begin our workweek.
While models seem to want to keep the Valley on the threshold of getting any meaningful precip, I think most of us can expect generally overcast skies through Monday, with some of us (especially in NW AL) probably looking at slightly better chances for a broadly cold rain for a few hours. Temps will probably not break 40s once more, so it'll definitely be uncomfortable if you find yourself in a little shower Monday! Luckily for us, this system is out of here fairly quickly.
As that system moves off the Coast of the Carolinas, we find ourselves wedged between high pressure to our west, and low pressure to our east from the aforementioned system. This sets the stage for the beginning of a very, very breezy and chilly week, but we have a couple decent days in Tuesday in Wednesday, which both stay dry and cold, with winds sharply out of the north and partly cloudy conditions lingering. That high pressure system isn't long for this world, though, and BIG changes are coming by late week...
The system we've been keeping an eye on seems to manifest through Thursday afternoon, providing some widespread rain for the Valley, and the chance of some snow on the tail-end of the system. We have our chances of seeing some snow in the Valley at around 40%, but we'd like to get closer before we start making any affirmative statements as to whether or not this will be more notable snowfall, or if it fizzles out due to certain variables in the atmosphere. We're keeping a very close eye on that, and will have more info in the coming day or two as models become clearer. One thing is for certain, however, and that is that behind this system will provide the Valley with VERY cold conditions, the likes of which we haven't seen down here in quite some time.
Above is the projected wind chill temperatures as the system moves eastward and we find ourselves on the back edge of it - with strong gradient winds and the possibility of a more substantial snowpack to our north and west, conditions are favorable for dangerous cold as we wrap our workweek up, with many models favoring anywhere from -10 to -15 degrees below zero for our wind chill. Actual temperatures are not much better, likely hovering in the low single digits/near zero for almost all of us in this same crucial timeframe. Conditions like this are no joke - like major heat waves, you don't want to stay outside for extended periods of time in conditions like this. If you must, it is imperative you bundle up like you've never bundled up before, because hypothermia can set in very quickly when you start talking negatives.
For reference, the CPC temperature anomaly map puts thing's in perspective - much of the Eastern US is WELL below average for this time of year, which itself is already probably the coolest portion of the year, so we aren't alone in this explosion of arctic air putting the kibosh on good conditions for our Christmas week.
The 7 day forecast helps put things in perspective - the beginning of the week looks warm in comparison to what follows afterwards. I'll reiterate again that we are keeping a close eye on Thursdays wintry precipitation chances, because it is that time of year where a few inches of snow can sneak up on you, and a system that looks like it'll give you a foot of snow can swing back to a cold rain in a heartbeat. It's a very delicate forecast, but precedent is there to support us watching it very closely. All and all, the end of the week is, one way or another, going to show us winter like we haven't seen in a while. Get your fireplaces and heated blankets ready, because it's coming!