Sunday, December 13, 2009
Not Much Snow Yet in Central Sound--Snow Showers to N and S
As the radar shows, central Puget Sound is rainshadowed by the Olympics, which is what you expect under this situation (winds aloft are westerly and northwesterly). The upward motion from the upper trough (which brought the earlier snow showers) is quite weak. The convergence zone is weak since it doesn't have good low-level support (winds along the coast are not strong NW as you would like).
The convergence zone may rev up a bit later. So we have some light snow in the south Sound, in the weak convergence zone, and over NW WA. The coast is getting a few rain showers (a little too warm there). Mostly flurries, but north and south of the snow shadow the ground may whiten with perhaps a 1/2 inch of snow.
Posted by Cliff Mass at 3:01 PM