Kevin Myatt is The Roanoke Times' weather columnist.

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As I'm writing this, a low-pressure system is diving southeastward toward us, and is already dumping snow.

I'll just let you look out your window to determine how deep the snowfall got, and move on to what happens after this Arctic outbreak relents.

For three weeks, we've been under the influence of a consistent flow of air from Canada and the Arctic Circle. The cold air reached its peak Tuesday morning, with a low of 10 in Roanoke and the single digits in many other places in Southwest Virginia. Lynchburg set a record low of 4.

As you may recall, I predicted in this column on Jan. 24 that we'd have at least one day below 10 degrees in Roanoke by Feb. 7, which is today. I missed it by a single degree.

We have a couple more shots of Arctic air due over the rest of this week and into early next week, but none of the severity of what we just experienced. It will be enough to keep things cold, but only slightly below normal, as opposed to extreme cold.

By the middle part of next week, around Valentine's Day, the Arctic air pattern will begin to relent.

Arctic air masses are not infinite resources. Imagine a giant pitcher in the sky near Hudson Bay full of cold water, and the eastern United States as the pan in which it is pouring. That pitcher has been pouring into the eastern United States for about three weeks, and it has almost been emptied.

But when you pour out a pitcher of cold water, it doesn't immediately warm up unless there is a heat source. Without a heat source, the water will remain cold, warming only gradually. With a heating source under the pan, like a stove, the water can heat fairly rapidly.

Somebody could also go refill the pitcher and start pouring cold water again.

In short, those are our three possibilities for the rest of February.

In the first, the Arctic air that's been poured out on us just sort of hangs around. It doesn't get much warmer, but neither does it get bone-chillingly cold again, as it has been lately.

In this scenario, we would have fairly normal temperatures the rest of the month, a few bounces up and down as is typical, but no real extremes. No 72-degree afternoons like Jan. 14 or 10-degree mornings like Tuesday. Any wet storm systems that move through would have the chance to be either chilly rain or wet snow, and we could frequently be riding the borderline between them.

The second possibility is that we get a strong heat source going, like that steady jet stream from the subtropical Pacific that made things balmy in December and early January.

If that weather pattern re-establishes itself firmly, then the groundhog should get his props: Winter will be over, well short of six weeks after Feb. 2.

The third possibility is that the pitcher of Arctic air will be refilled and then poured out on us later in the month. This is what I'll call the 3-R scenario: Arctic air relents, reloads and returns.

You can find some support for any of these scenarios on the long-term forecast models.

But it does look likely that we will get a break from the cold sometime toward the latter half of next week.

It is possible that a large storm system will occur near the time of the pattern change, though. That storm could be a parting shot of ice and snow from the old weather pattern, or an initial shot of rain from the incoming pattern. There's plenty of time to work out the details on that, the first being whether or not there will in fact be such a storm system at all.

Winter 2006-07 looks to be a three-act drama. The first was warm. The second has been cold but dry. Those two have been fairly well-predicted, but what the curtain will reveal for Act 3 is still unknown. We should have some better clues about it by early next week.

Wait until the end to judge if this winter has been a tragedy or a comedy for you.