WeatherWatcher: Snow in the Convergence Zone

Carl's Shoreline Weather Station

Later tonight, Thursday, November 17, 2011, colder air is going to start filtering into the region. We could start seeing some snow mixed with rain showers over Shoreline and Lake Forest Park by morning. Off and on showers are expected to move through the area now through Saturday afternoon.

Forecasters are now indicating a Puget Sound Convergence Zone could develop over Northern King County, or Snohomish County. It's really looking like this zone will develop and persist possibly right over Shoreline and Lake Forest Park. If this happens we could see 1-3 inches of accumulation or more, depending on how intense the Convergence zone gets. The zone may wobble north and south a bit and could go as far north as Everett and miss us completely. It also could intermittently shift over us, and shift away from us throughout tomorrow and Saturday. 

I'll be keeping a watch on this development and will send another update if I believe Shoreline and Lake Forest Park end up being the primary focus of the Puget Sound Convergence Zone storm.

As of 6:45 PM November 17th it is 39°F. This is normally too warm for accumulating snowfall, however a heavy shower, or a convergence zone cell can bring colder (below freezing) atmospheric air down to sea level in the matter of 30 minutes or less. This causes the precipitation to mix to snow, and start accumulating.

Friday and Saturday mornings, be prepared for winter driving. Saturday lows are expected to be in the mid-upper 20's which means any water on road ways will be ice. Be careful out there!