Kevin Myatt is The Roanoke Times' weather columnist.

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• Sprinkles or flurries possible Tuesday, but maybe something bigger for the weekend?
• For now, it looks like a quiet, mostly mild week ahead for SW Virginia
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The gullywasher low pressure system passing through Southwest Virginia will not turn into the blockbuster winter storm some models advertised for the Northeast earlier in the week, but it is the start of a pattern change that will gradually reveal itself over the next several days.

Some years, winter starts like a punch in the gut. The last two seasons have given us winter storms in the first week of December. Last year's busted us out of a mild November pattern not unlike what we just had. But it looks like Old Man Winter will have a slower hand, more of an easy touch, in the '04-'05 season.

The low passing now will begin to funnel chilly Canadian air down behind it over the weekend. If you like snow, the pattern will be more favorable after this weekend, but far from ideal. Some of you will see enough snow to turn your ground white this weekend.

On Friday night and Saturday, and then again Monday and Monday night, passing fronts promise to bring strong northwest winds against the mountains. These winds will carry what moisture there is up the mountain slopes, cooling it, condensing it, and producing snow showers. A few particularly favored west-facing slopes in West Virginia or far southwestern Virginia, or especially high elevation areas, might see a few inches.

Most places west of I-81 will get a dusting or just see a few snow showers. East of I-81, the downslope effects begin to take over and wash out the squalls. Unless there's some kind of vigorous upper atmospheric support to bolster the upslope effects, that usually means partly cloudy skies, or just a couple of flakes or sprinkles,in the Roanoke Valley and points eastward.

In fact, it's not going to be terribly cold here in Roanoke through most of next week. Seasonal cold, yes, with highs in the 40s and 50s and lows in the 20s and 30s. It will be just cold enough that should any stronger low pressure systems make themselves known, we'll have to scratch our heads a bit about the precipitation type.

But zoom out to the bigger picture, and quite a bit is changing. Stronger high pressure is expected to build in the west. A ridge of high pressure that's been blocking cold air masses over the southeastern U.S. will be pushed out to sea. And a sizeable low pressure trough, or a southward dip in the jet stream, will begin setting up over the central and eastern United States.

This is definitely a prescription for more seasonably cold weather, and perhaps, an occasional wintry precipitation threat.

Other than the upslope snow showers, there is nothing specific on the horizon as far as winter storm threats, but you have to begin to watch the western horizon when the weather pattern gets set up like this. We can't just assume rain anymore.

If the coldest core of air begins moving over the pole from Siberia into North America, or high pressure in the north Atlantic begins "blocking" the jet stream so that it's southward dip gets held in place, or an upper low becomes stalled east of Newfoundland with a constant fetch of cold air circulated down the Eastern Seabord, then winter will get a bit more punchy.

But for now, it will at least feel a bit more like Christmas. We'll have to wait and see whether it will look that way, too.