ERIC BRADY The Roanoke Times

A pedestrian walks across Williamson Road in Roanoke on a rainy afternoon this week. More wet weather is forecast into the weekend.

Kevin Myatt is The Roanoke Times' weather columnist.

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Winter begins Dec. 1 on the meteorological calendar and Dec. 21 on the astronomical calendar.

But for a lot of folks, it begins the first time they see snowflakes.

Winter may begin for some people in Southwest Virginia tonight or Saturday. There will probably be some snow, especially at elevations above 3,000 feet, as already cold air thickens behind a front and disturbances squeeze out some moisture.

A few flakes will probably drift into the New River Valley, and they can't be ruled out even in the Roanoke Valley, though it will probably be a little too warm. The best chance to see the season's first flakes at lower elevations will be Saturday morning, when lows may dip into the upper 30s in Roanoke.

Due to dwindling moisture, borderline air temperatures and warm ground, this will likely not be an accumulating snow anywhere, though a dusting to possibly an inch can't be ruled out at the very highest elevations near the Virginia-West Virginia border, especially if upslope northwest winds get involved.

So, before the leaves can fully change colors, winter may be beginning, in a sense.

And whether or not winter is beginning, the winter forecast season has certainly begun.

On Thursday, the National Oceanic and Atmospheric Administration issued its annual winter forecast.

There were no big surprises as government forecasters pretty much stuck to the El Nino template. El Nino, the intermittent warming of equatorial Pacific sea surface temperatures, is ongoing and expected to strengthen some into the winter.

The El Nino template is warmer than normal across the north-central and northwest U.S., cooler than normal across the Southeast, along the Appalachians into the Mid-Atlantic, wetter than normal across the far southern tier, and drier than normal in the Ohio Valley and the Pacific Northwest.

The expectation of cooler than normal weather in our region and points to the south reflects a tendency for more cloudy, wet days during an El Nino rather than several massive intrusions of Arctic air.

Whether that ends up being cool, rainy days or cold, snowy days depends on a lot on other climatic factors, principally the North Atlantic Oscillation, the varying positions of high and low pressure from Greenland to the equator. Unlike El Nino, which changes on irregular cycles of months and years, the NAO can shift back and forth in days or weeks, and therefore isn't easily forecasted across an entire winter season.

The NOAA winter forecast purposefully makes no effort to forecast snow, which is really what most people want to know about with a winter forecast.

"This seasonal outlook does not predict where and when snowstorms may hit or total seasonal snowfall accumulations," a NOAA news release stated. "Snow forecasts are dependent upon winter storms, which are generally not predictable more than several days in advance."

There is already a buzz about the potential for a big-snow winter after a couple of prominent forecasters for Accuweather.com, a private forecasting company, came out with projections of above-average snowfall in much of the East. The NOAA forecast does nothing to either bolster or dispute those forecasts.

So that leaves two questions: What do I think winter will be like? And what do you think winter will be like?

In two weeks, I will offer some early thoughts. And you will get your chance to compete against other readers in the second Weather Journal snow forecast contest.

Weather Journal runs on Monday, Wednesday and Friday.