February 09, 2009

Tomorrow's Snow

The convergence zone is still evident at 8 PM, but appears to be weakening. It should fade out this evening. The latest winds really show the convergence...take a look at the dense winds over the Sound from the Washington State Ferries....very dramatic difference in direction over the waters between the Vashon Is and Bainbridge ferries.
The offshore weather system is now approaching (see image). The UW flagship model (WRF-GFS) indicates that the precipitation should reach the Sound between 7 and 10 AM. The model suggests that the Kitsap and lower Hood Canal area..the zone immediately SE of the Olympics..is going to get hit by substantial snow (see 24hr snowfall ending 4 PM). Six inches or more are possible..with higher amounts closer to the Olympics. Snow in the mountains and over SW Washington, and even NW Washington gets a piece of the action. Looking at other model diagnostics that show the snow distribution with height, I suspect that some snow will reach the surface even over the eastern side of the Sound...but will be the wet, melting variety . There will be considerable precipitation over the whole area....so where there is no snow there will be rain. Temperatures should warm up aloft by mid-afternoon..which will contribute to a change to rain after lunch in most areas away from the Olympics.
What worries me about this situation is that the temperatures are right on the margin..it would not take much of an error for there to be substantial snowfall over Seattle during the morning. So those of you who are responsible for public safety and the roads need to be prepared for plan b if more snow does hit.


  1. Well I certainly like snow and hope we see more of it here in the central sound! :o)

  2. In West Seattle it's snowing really hard right now with a temp of 32. It's sticking all over and the flakes are huge. We have about a trace to a half an inch, but if this keeps up steadily for another half hour we could be looking at an inch.

    Cliff, temps have cooled off very rapidly. Will the stay sub-freezing till the snow hits tomorrow?

  3. east olympia - 200' - 33* on a perfectly clear night. what a gorgeous bright moon.

  4. Snow in Bellevue, freezing rain earlier. Hope there's no school

  5. East Woodinville (lake tuck). Temps hovering at 32 and 3" snow. Snowfall stopped. It is going to be a iciy slick mess in the morning.

  6. Good coating of snow in North Hoquiam. Roads are still clear, so far.

    It's pretty, but I wanted to drive to Seattle tomorrow!

  7. Cliff is there a reason why Olympia always seems to be right on the edge? We here in lacey want no school :D. Any ideas on which way it might shift ?

  8. Well hello! :o)

    I`m at 32 and been pretty steady for last several hours with dp of 30. Still only 1/2" today so far. Currently it`s LIGHTLY snowing but also a fine snow(tiny), so probably wont get anymore accumulation.

    Wonder how the bottom of the Hollywood hill is doing? Would say probably less than what I have since I`m here at 300ft elevation.

  9. Any chance of snow in the Kent/Des Moines area? I'd love to not have snow as well:)


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