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The rest of the week and the weekend doesn't present anything overly interesting in terms of precipitation-makers. It will be cold many mornings with lows slipping back into the teens and maybe some single digits. Weak disturbances moving through the next couple of days from the northwest could trigger a few snow showers, and another weak system approaching from the west could bring another borderline rain/ice/snow situation over the weekend, but not a very heavy one, it would appear now. It's well into next week when the next significant chance of widespread precipitation occurs, and temperatures may begin moderating above their present cold levels by then. Still, we've always got to keep an eye on each weak disturbance because it doesn't take much of a change to make something a little bigger than it looks now. But cold and mostly dry appears to be the mode for the rest of the week.

Warm air advection at relatively low levels is overcoming any evaporational cooling effects, and very little precipitation is falling. So we've mostly been getting some very light rain with a few pings of sleet as temperatures have warmed above freezing. The sun has even come out briefly in the Roanoke Valley. This winter weather threat, if you can call it that, looks to be about over locally. If the precipitation had been harder, it might have cooled things enough aloft for more sleet and snow to make it to the surface. But this was not a really solid setup for wintry precipitation, so this marginal event not really coming through with anything significant is not a big shock.

I'm writing extensively about evaporational cooling for Wednesday's Weather Journal column in The Roanoke Times, but today we're seeing a good example of the push and pull dry air has on precipitation events. On the one hand, it tends it eat up moisture moving in and stop precipitation from reaching the ground. But it also can cool the atmosphere a lot more, so that once the precipitation does reach the ground, if it does, it begins as something frozen. Precipitation is struggling to move eastward into our area today, but our dew points are very low in the single digits. I'm still not terribly impressed with this setup, but I think it's quite likely that if we ever do see precipitation today, it will begin as a round of snow and/or sleet and then change to freezing rain or rain depending on how cold it is at the surface by that time.

Latest National Weather Service radar

Hourly conditions across the area

Very early this morning, clouds are starting to stream in from the southwest ahead of the next weather maker that may give our area another borderline rake with wintry precipitation today. Normally, this kind of atmospheric setup -- with a low-pressure system crossing the Great Lakes dragging Gulf moisture ahead of a cold front -- wouldn't even be close to a wintry threat in our area. But the depth of the cold air mass that has been place, some leftover snow cover in many places locally, very low dew points to start wtih and just the fact that it is the point on the calendar which is historically coldest all mean that the cold air has a better chance to hang on for a while against the raging tide of warmer, moist air from the Gulf of Mexico. The amount of moisture that will fall to the ground doesn't look like much, and the key will be how much of it arrives early in the day before the warmer air can take hold and get us above freezing. If the system can lay down any kind of ice and snow layer early in the day, warming above freezing will be harder and slower. With the precipitation barely crossing the Mississippi River as I type this, it'll take some new development out ahead of the main band to make that happen.

We might see a quick burst of snow on the back side of the rain shield with the cold front tonight. The next few days look cold as the Arctic air is renewed over our area. An Alberta clipper might brush us with some snow from the northwest Wednesday night and Thursday, and then there could be another moist system from the west by the weekend.

Follow the latest National Weather Service-Blacksburg radar here

Click here for the latest advisories from the weather service

Current hourly reports from Roanoke and Blacksburg

As southwest winds try to bring in warmer air on Tuesday, they will bring in some added moisture, too. This moisture moving into cold air will bring the chance of precipitation ... snow, sleet and freezing rain in the morning cold air, gradually mixing with more rain as temperatures rise above freezing. Then, as a new cold front arrives early Tuesday evening, the whole thing could go back to snow for a while. It looks like precipitation amounts will be light, though it doesn't take a lot of freezing rain to cause problems. Don't expect a lot of accumulation out of this one, just some nuisance precipitation.

UPDATE 5:30 PM: The National Weather Service has issued a winter weather advisory for muc of the area on Tuesday. Again, it doesn't look like a whole lot of preciptiation, but it could be cold enough for some ice or snow for a while, enough to possibly be a nuisance for a short while. Click here for the latest advisories and warnings from the weather service and click here for the latest National Weather Service radar.

With widespread lows in the single digits to low teens -- and a few snow-covered valleys and higher mountaintops possibly dropping below zero -- Monday morning may be one of the coldest if not the coldest in the last decade.

But there is virtually no chance of any daily records being set for January 21. That's because it is the 23rd anniversary of the massive Arctic plunge of 1985, when temperatures across the eastern two-thirds of the U.S. dipped to levels rarely or never seen. Roanoke's all-time record low of -11 and Blacksburg' all-time record of -18 were set on Jan. 21, 1985, as was the state's all-time official record low of -30 at Mountain Lake.

Tuesday is our next precipitation chance. A surge of warmer air will bring in Gulf moisture, but how strongly the cold air holds its ground will determine how much of that moisture falls as something frozen. We'll get back to that question on Monday.

Roanoke's hourly temperature

Blacksburg's hourly temperature

You've got to love it when the Deep South gets a taste of snow as parts of Mississippi, Alabama and Georgia did today. The snow tonight has been raking central and eastern North Carolina up into the Tidewater area of Virginia.

The week ahead will bring a sharp shot of Arctic cold the next couple of days, with lows in the single digits to low and mid teens likely across the area by Monday morning. After that, there will be a couple of shots at precipitation -- the first around Tuesday or Wednesday, the second very late in the week or during the weekend -- as disturbances move eastward. From here, there doesn't look to be any blockbuster storms on the horizon, but the split-flow jet stream pattern that is expected to set up later this week -- dividing the jet stream into a cold-supplying northern branch and potentially moisture-supplying southern branch -- will offer a few shots at wintry precipitation. Each one will have to be monitored for its specifics, the most critical being the storm tracks and depth of cold air available.

The early outlook is for warmer-than-normal temperatures to return near the start of February, but that is subject to change, and how February turns out overall is still very much in question.

I like the high-resolution national radar available by clicking here, but our ancient home computer can't handle it (works well here at the Roanoke Times, though). If your computer has the juice, you can follow today's storm system to see if it can scrape closer to us than expected or even surprise us with more snow than we think now. Just because you see echoes over us doesn't mean it'll be snowing ... there is dry air to overcome by any falling precipitation. But if there are many shades of green streaming in, we would have to re-think things.

There is more and more indication that the low on Saturday will be too weak and track too far to the southeast to do more than throw a few snow showers into our region, and even that is doubtful. The trend on the forecast models is for the back edge of the precipitation to be farther east. The Hydrometeorological Prediction Center is now highlighting an area farther southeast, mostly in North Carolina, for a slight chance of 4-plus inches of snow. All the winter storm watches and snow advisories are going up along that general path, with the closest snow advisory to us in the Danville area. There is still a chance that the system could make a jog farther to the northwest, or throw back a larger shield of precipitation -- I've seen each of those happen before -- but this will probably not be our snow, but rather Greensboro's, Raleigh's, and maybe Richmond's and Norfolk's. Be cautious if traveling in that direction.

In some ways Saturday is a more tricky forecast than even Thursday was. There came a point Wednesday when it looked almost certain we would see precipitation and most of it would be frozen. The frozen part is even more certain for Saturday, owing to very deep Arctic air moving into many layers of the atmosphere, but the precipitation part is not certain. A fast-moving low to the northeast from the Gulf toward the Carolinas could (1) spread precipitation into our area, (2) spread moisture but not enough to reach the ground through drying air or (3) skirt by us to the southeast. And even within possiibility 1, still a slight favorite of the three, there is the question of how much moisture.

As of now, it looks like light amounts, translating to an inch or two of snow mostly from Roanoke south and east. But if the low takes a slight northward jaunt, it could spit out more snow. Also, with the atmosphere as cold as it will be aloft, we are likely higher snow-to-liquid ratios than in Thusday's storm. In other words, the snow will likely be drier and fluffier, smaller flakes with longer arms, and we could get more snow out of less moisture. The same amount of moisure an inch of snow on Thursday might be enough for 2 on Saturday.

As of early afternoon, the Hydrometeorological Prediction Center still has our region in a slight risk of 4-plus inches of snow for Saturday. (If this linked map now longer shows us in the circle for 10 percent chance of 4-plus inches, you'll know HPC has changed its mind. A new update is due around 4:30 p.m.). The winter storm watches, however, are going up in central and northeast North Carolina.

So if I am breaking down percent chances for Roanoke and Blacksburg right now, it would look like this:

1-3 inches of snow: 30 percent
<1 inch of snow: 30 percent
No mesurable snow: 25 percent
More than 3 inches: 15 percent

In other words, still pretty even odds of any of those things. Hopefully, things will be clearer by evening. Thursday's forecast only really came into focus by Wednesday night.