WeatherWatcher: Winter Weather Advisory - dreaming of a White Christmas

Snow in Shoreline, Washington January 17, 2012.
Photo by Carl Dinse

The National Weather Service in Seattle has issued a winter weather advisory for Shoreline and Lake Forest Park. The advisory is in effect from 7pm Christmas Eve until 10am Christmas Day. A weak weather system is moving in Sunday afternoon and will bring with it light rain or snow to start. After 7pm the temperatures are expected to drop enough for most areas to turn over to all snow.

Snow accumulations are expected to total out between 1-3 inches of snow. Snow showers may continue in the convergence zone anywhere between downtown Seattle and Everett through the afternoon, that could bring an extra inch or two for the area the zone forms.

There is a high chance that this forecast could fail. Models have been very inconsistent on where snow is expected to fall, and how cold it is expected to get. But given that many models have been intermittently showing snow in this time window since Thursday last week I think it's a safe bet we'll see something at the least.

A White Christmas is defined as having 1 inch of snow accumulated on the ground at 7am Christmas morning. Our last two White Christmases occurred in 2008 and 1990. We may have another one this year to add to the record books.

For updates on this winter advisory and any forecast changes that come up, you can follow me on twitter @SWeatherWatcher or visit www.shorelineweather.com