The Seattle Department of Transportation (SDOT) is preparing for the possibility of snow and ice on city streets again tomorrow. The forecast, which outlines temperatures just above freezing overnight tonight, could bring up to one-half inch of wet snow and the possibility of an additional inch of snow Wednesday morning.
Seattle skyline/view from Kerry Park under cover of snow, November 22, 2010.
After 10 p.m. tonight SDOT crews will proactively apply salt brine in roadway areas where frost or black ice is prone to develop, especially on bridges and other elevated structures around the city.
Starting at 4 a.m. tomorrow morning (Wednesday), SDOT spreader trucks will be prepositioned throughout the city, ready to spread rock salt on major arterial streets (primary snow routes, Levels 1 and 2) for the morning commute if conditions warrant.
SDOT’s snow plan calls for plowing when there is more than one inch of snow accumulated on roadways, which is not part of the forecast at this time.
Despite the potential for snow, University of Washington atmospheric scientist Cliff Mass says the likelihood that we’ll see a repeat of the snow and severe ice that blasted us on Thanksgiving week is low. He writes on his blog:
This is a VERY, VERY different situation than November 22nd. You will not see a powerful arctic blast associated with strong high pressure in British Columbia and a major coastal low over SW Washington. Temperatures will be far more marginal. Far less icing potential. But there COULD be some interesting wrinkles….like a chance for Puget Sound Convergence Zone snow.
Cliff estimates that “where precipitation is heavy enough, some snow showers could reach the surface, but nothing substantial.”
If the Convergence Zone is stronger than forecast then more snow could hit the Puget Sound lowlands. However, forecast temperatures are predicted to peak near 40F on Wednesday. This looks marginal to me…only heavy precipitation and the cooling associated with it…something that is not predicted… could bring several inches of snow to Seattle.
We will continue to monitor the evolution of this event, but right now it does not look serious event near sea level. Eastern suburbs could get few inches. Not an icing situation during the day…
Read more on SDOT’s winter weather response plan and to view a map of snow routes here.