WeatherWatcher: Snow suddenly in Monday's forecast

 

Marginal snow in Shoreline.
Photo by Carl Dinse

Overnight Saturday and throughout the day Sunday forecasts models started having a sudden shift in expected weather for Monday. It has become more certain that we will not only receive 1-3 inches of rainfall on Monday, but at least at some point snow flakes will mix in with all that rain by the afternoon or evening.

This storm is causing very uncertain forecasts and has potential to be a moderate to major snow event, but is likely to remain slushy with little to no impacts to roadways. 

The chance of this being anything but a slushy 1 inch of snow on the lawn is pretty low, but there is a chance. 

Several factors are at play, and worst case (or best case for snow lovers) scenario is a convergence zone developing and parking over Shoreline and Lake Forest Park.

Bottom line: On Monday we are looking at a lot of rain as the center of the storm passes overhead. That rain could mix with or make a full transition to snow. Depending on how the storm tracks and interacts with the terrain, a Puget Sound convergence zone could form. 

Convergence zones are very tricky and can bring a surprise 2-11 inches of snow. 

The most likely scenario right now, though, is snow mixed with rain, possibly changing over to snow with maybe 1 inch of wet accumulation on lawns and other unpaved surfaces.

Any snow that does accumulate likely will not survive very long unless we somehow manage a massive snow dump. Tuesday through Thursday evening skies clear up for mostly sunny days and cold nights. High temperatures are expected to be in the low 40's and low temperatures down to the upper 20's or low 30's. 

Icy roads, especially on overpasses are possible in the overnight and morning hours from Tuesday through Thursday as well. Thursday evening is expected to start clouding up as our next storm approaches, with a chance of showers through Christmas day.

For current weather conditions visit www.shorelineweather.com