December 31, 2009

New Years Eve Weather and then...

New Year's is rapidly approaching and so is a strong warm front (see satellite image above).Rain has now reached the south Sound and you can expect a relatively wet day. For those thinking of celebrating outside I have good news....most of the rain should be through by 10 PM...and with with warmer air and scattered showers, it won't be too bad to welcome the new year at the Space Needle or some other outdoor venue. I should note that it will be quite windy along the Oregon coast this afternoon (see graphic). This kind of situation can produce strong coastal accelerations and sustained winds of 20-40 kts and high gusts can be expected in that area.Sea level pressure (solid lines) and low-level temps (shading)

Winds shown by shading

Tomorrow will be showery and then Friday night a modest low will make landfall on central/northern Vancouver Island and move north of us (see graphic). It will be windy on the coast and offshore tomorrow afternoon, and as the low moves north of us (see next graphic) the pressure variations and winds will increase over the lowlands. However, but the winds will be modest (generally 10-25 kts) over the lowlands with higher gusts near water.

Saturday will have some showers and decreasing winds and then Sunday looks dry. Temperatures will be on the edge for snow in the passes today and tomorrow (there could well be several inches of wet snow before the temps warm enough to turn it to rain), but it will be cold enough for snow on Saturday in the post-storm showers.

The long term forecast is very interesting. A weak disturbance brings some light rain on Monday, but then a major ridge builds in the eastern Pacific and stays there for many days. We could completely dry out with no major weather for quite a while. Temperatures would be well above normal. Is the El Nino winter about to begin? I suspect most of our interesting winter weather will be behind us as we start 2010. And happy new year to those reading this blog...


  1. huge amounts of snow falling in Hood River/The Dalles as of 11:30am. According to the radar it looks to be just getting started!!!

  2. :(
    I want some interesting weather. How warm will it be?

  3. I sure hope you are correct about extreme weather being over. I know most people who read this blog love a good storm, but I read it because it has the best information for me to keep my property from flooding. No more big storms would be great.

  4. Tim Lofton, UW ATM SCI '96December 31, 2009 at 5:52 PM

    Happy New Year Professor Mass!

  5. Happy New Year, Cliff, and thanks so much for a great year of informative narrative and pictures. You've made our Northwest weather even more interesting than before. And Happy New Year also to all my fellow Mass-groupies!!

  6. I love this blog.

    Hopefully we don't get too much rain in the next couple months, because I need to work on my golf swing.

  7. this weather saddens me. this is like spring, not weather.

  8. we had a great burst of rain, complete with lightening and thunder last night (3-5AM?) in the Lynnwood area.
    Cliff, thank you for your work/passion and sharing it with us!

  9. That 3 to 4 AM heavy cell smacked us very hard in West Seattle. Sounded like a machine gun being shot at the house, caused some water damage. So much for "through by 10pm". Not a great way to start the new year.

  10. Heh..and looking out my window to the north here in West Oly, we are having more than just showers! But of course forecasts are for areas in general.

    I have mixed feelings about El Nino..I know it is hard on the ski resorts when we lose our moisture. It also can create conditions for destructive fires. But as one who commutes an hour each way to my teaching job, "weather events" cause a lot of stress for drivers, and at school when we have to figure out if we need to close for the day or start late.
    So, with drier weather, I can more easily get to work--(and teach Math in a way that I think would make Cliff happy) :)

  11. As an avid Mountain Biker/non-skier, I'm OK with the El Nino.

    Thanks, Cliff for all your amazing predictions/science in '09. Following your blog/career in ought ten will be just as fun, I'm sure.
    Happy NY to all.


  12. Looks like the ridge is short lived, only Thurs looks sunny.


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