Kevin Myatt is The Roanoke Times' weather columnist.

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• Sprinkles or flurries possible Tuesday, but maybe something bigger for the weekend?
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This Arctic blast isn't a blast for anyone who wants sunny warmth or a big snowstorm.

We are halfway through the month of January, and aside from some spotty light snows and some scattered icing in localized areas that always seem to get snow and ice, we have not yet had anything resembling a winter storm in Southwest Virginia.

Roanoke has a whopping four-tenths of an inch of snow for the season -- and that's only because one of the harder snow showers happened to move over the WDBJ (Channel 7) studio, where Roanoke's official snowfall is measured, way back on Nov. 18. Roanoke continues to trail New Orleans and Las Vegas in seasonal snowfall.

Blacksburg has managed to cobble together some snow showers and light snows here and there for 5.4 inches for the season, but an inch hasn't fallen on any single day since November.

This snow dearth is happening because the current weather pattern is like herding cats -- too many fast, little disturbances spinning around, and nothing to organize them.

You may remember a few weeks ago I wrote about the three atmospheric features that are needed to give our region a prime shot at snow.

• Strong high pressure near the West Coast to drive Arctic air southeastward. That's happening with rare intensity right now.

• Strong high pressure over Greenland that causes the jet stream behind it to buckle southward into the Eastern U.S. This acts to lock in Arctic air, keeping the air masses from sliding offshore. It also pushes the storm track farther south and causes upper-air disturbances moving through the jet stream to slow down, giving them a better chance to spin up strong low pressure systems. The Greenland high was in place for a few days earlier this month, but now it's gone.

• A distinct southern branch of the jet stream moving west to east near the U.S.-Mexico border eastward along the Gulf Coast. The southern branch brings wet storm systems into play. This hasn't shown up very often in the past two years. Hence, the drought.

So we have only one out of those three working right now.

As a result, the spigot is wide open to the Arctic Circle, and frigid air is pouring relentlessly into the eastern half of the United States. But there is limited moisture, and the strong flow of air high in the atmosphere is shooting upper-level disturbances through at a fast rate of speed.

Many of these cold swirls of air aloft don't have time to pick up much moisture, spin up surface lows, or join forces with each other for bigger storms. They zip past with a few snow showers at best.

Sometimes, there will be some setups in an imperfect atmospheric pattern than can produce significant snowfall. Some runs of computer forecast models have been trying to do that early next week, getting a couple of these fast moving disturbances together and spinning up a low near the southeast U.S. coast.

But the speed of the systems moving through makes that doubtful, and even if a bigger storm does form, it would likely be too far east to spread much snowfall on our region.

So if it's going to snow the next week or so, it will probably have to come from one of these fast-moving disturbances. On rare occasions, we can get as much as a 3- to 5-inch snowfall out of one of these, but usually it's a lot less, and quite often, it's flurries or nothing.

New disturbances will make a run toward our general region Sunday and then again about Tuesday.

Beyond the deep freeze today and Saturday, the future of the weather pattern is, pardon the expression, up in the air.

It will definitely get milder, but perhaps only gradually in the coming week. We should get back to seasonable cold -- 40s in the day, 20s at night -- by the middle of the coming week.

Beyond that, it does appear as if the big West Coast high pumping in the chill will break down. There is some evidence we will finally develop some semblance of a southern branch of the jet stream in the next couple of weeks, but by then, the cold-pumping high may be gone.

And we would be back to one out of three again.