Kevin Myatt is The Roanoke Times' weather columnist.

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It's January, so that can mean only one thing: mild weather.

That's probably not what you were expecting or what came to mind, but during the past three years it certainly has been true.

It looks like this January may continue that trend, despite a cold start. Temperatures in the teens were common in Southwest Virginia on Thursday and Friday mornings. But by Tuesday, our afternoons could be challenging 70 degrees.

A January warm spell that goes beyond merely a "thaw" has been a tradition of late.

Last January started with highs in the 60s on four of the first six days, then another run of four straight days above 60 (one above 70) at midmonth. January 2007 as a whole averaged 5.4 degrees above normal.

January 2006 had nine days above 60 and only two days with lows below 30 on its way to an average temperature almost 8 degrees above normal.

In January 2005, 10 of the first 14 days had highs above 60 degrees as the month ended up almost 5 degrees above normal.

Historically, our coldest weather of the year occurs during the third week of January. But since 2005, our coldest weather has tended to come in February or December rather than in January.

After a punch of Arctic air to open the new year, the atmospheric pattern over North America will allow a prolonged period of mild to even warm weather to set in for the eastern United States.

It's really not so much a pattern change as a new phase of a pattern that has been occurring for several weeks.

Strong high-level winds have been moving across North America, allowing air masses and storm systems to move swiftly across the United States.

Downstream from these strong westerly winds, over the Atlantic Ocean, high pressure systems have not built in the right location to interfere with the air flow.

Think of a boulder in a stream that causes the water to divert around it. Without this boulder in the stream, the water doesn't back up and flow around, but keeps moving on its merry way. So it is with the air flow over North America without blocking high pressure in the North Atlantic.

We can get punches of arctic air, like earlier this week, but they don't hang around long before moving on. This winter, we have yet to see a pattern develop where cold air settles in for more than a few days, continually reinforced by new cold fronts from the polar regions.

So our cold spell of the past few days will move on, and it will be replaced by southwesterly winds that will bring warmth to the region.

The cold and storminess will be centered over the western U.S. the next several days. It would be a great time to go skiing in the Cascades, the Sierras or the Rockies, which are going to get multiple feet of snow from strong storm systems repeatedly moving off the Pacific.

These storms will be swept northeastward toward the Upper Plains and Great Lakes by the swift air flow. This path will drag in more warmth to our region. As a result, the coming week will border on balmy at times.

But this, too, will pass.

After about a week, the pattern will break down some. The cold and wet weather in the West will be pushed eastward, and the newfound warmth in the East will be pushed out to sea, just like the arctic cold will be this weekend.

Still, the warmth may be extreme and lengthy enough that there would have to be a rather extreme cold snap later in the month to keep this from being another warmer than normal January.

So the snow fans will just have to chill while the winter-warmth fans get to bask.