January 09, 2009

The Snow Eater

Sometimes strong winds descend our local terrain, such as on the east side of the Cascades. As the air descends, it is compressed and warmed (just like air in your bike pump warms when it is compressed). These warm winds can rapidly melt snow and are often called Chinook winds, with Chinook being a Pacific Northwest Native American word meaning 'snow-eater'. The east wide of the Rockies are also well known for Chinooks.

Quite a Chinook occurred Tuesday evening into Wednesday morning along the Cascades slopes near Wenatchee. On the heights at nearby Mission Ridge ski resort sustained winds of 70-80 mph, with gusts to 121 mph were observed and some home owners with anemometers near Wenatchee reported gusts to near 100 mph. Substantial damage occurred, with power outages to thousands of homes (see picture of tower down).
Take a look at the observations at Wenatchee (see figures). As the Chinook began the temperature climbed from 26 to 45 F in ONE HOUR. And the winds increased from calm to 54 knots (62 mph) over a few hours. Strong winds and warm temperatures rapidly melt (eat) snow. One report I got was that a family went to sleep with 1-1.5 ft of snow on the ground...when they awoke, it was all gone. And many observers in the area that belong to the CoCoRaHs community network reported loses of around a foot overnight. In my book I talk about an even bigger wind storm that hit Wenatchee two years ago...

And did I mention that pineapple express junior is returning? Look at the satellite picture...another nice subtropical stream of moisture...and the computer forecasts show substantial rain...but nothing like what we had last week. Will slow up the dropping of river levels and contribute to soil saturation, which can help promote landslides. Seattle still lucks out with the rainshadow. Good location for the city!


  1. First, I'm very glad to see this post from Cliff, but very puzzled as to why, when I checked the blog around 9AM today, all I saw was the Thursday post, with comments as late as 9:00 last night, and now this post claims to have been before 8PM last night, and here I am posting the FIRST comment at 10:10AM today.
    What's going on here?!!!

    Second, I thought I recalled hearing the very end of Cliff's Weekend Forecast on KUOW Weekday just before noon yesterday when I was finally able to tune in after a Physical Therapy appt. So,I surfed into the KUOW website, located and downloaded the 11:00-11:58AM Weekday to RealPlayer, decided I really want to listen to the whole thing (see below for details), and indeed found Cliff's forecast as the last 10-12 minutes. I'll post another comment about a possible KUOW link from Cliff's blog next, but here are the details on the main topic, with a link so you can download and listen to Cliff or all of it too {oddly, it doesn't advertise Cliff's forecast -- why not?]:
    The Hope and Hype (and Money) of Cleaner, Greener Tech Solutions
    01/09/2009 at 11:00 a.m.
    Going green is the future. Millions, even billions of dollars are being spent on developing novel ideas to solve problems in energy, transportation, manufacturing and consumption. They call it "clean tech." And where do we begin to study this trend? Where we are often admonished to begin — by following the money. Today, we go to the root of the money: venture capitalists. Why are they chasing the promise of clean tech so fervently? And how is the economic downturn changing things?


    Gerry Langeler is a partner at OVP Venture Partners, a Northwest firm that invests in start–up companies including clean tech firms.

    Andy Dale is a partner at Burke Dale Victor, LLC and also co–founded its fund management business. He has been an entrepreneur, venture capitalist and investment banker for over 15 years. He currently serves on the board of nine companies, including HaloSource.

    John Kaestle is the CEO of HaloSource. The company is based in Bothell, Washington, and works on antimicrobial research, as well as treating drinking and industrial water.

    John Cook is executive editor of Techflash, a blog that tracks tech news in the Northwest. He also wrote the venture capital blog for the Seattle P.I.

    Kate Galbraith is a journalist for Green Inc., the New York Times's blog on green business. She previously was the Southwest correspondent for The Economist and was a Nieman Fellow at Harvard.

    {Bob's add-on Finale...}
    Cliff Mass is the Pacific Northwest's leading Weather Forecaster, Prof of Atmospheric Sciences at UW, and weather blogger at https://www.blogger.com/comment.do [needs correction...} where you can get DAILY updates on his KUOW Forecasts.

  2. Cliff, good work. Quick Q here. It looks as if the rainshadow will set up over the Hood Canal area moreso this time. Is this due to the direction of the incoming system vs. our last system's orientation? And I believe those Chinook winds melted a lot of snow in Spokane, as they had nearly 5-6 feet and now have around 1-2 feet.

  3. Follow-on --I have 2 suggestions:

    (1) Could Cliff (or one of us as assistant) supply a link from the main page of Cliff's blog to KUOW's Friday Weekday like the one in my last post: http://www.kuow.org/program.php?id=16680? Maybe we could also tell folks how to move the RealPlayer or iTunes pointer to skip over the other Weekday stuff and directly access the forecast conversation between Cliff and Weekday host Steve Scher, and maybe even provide a brief extract of the KUOW blurb about the rest of that hour of Weekday (which is often the 10:00-10:58 AM session, if I'm recalling correctly)--I copied the whole thing, which would be much too big to fit on the main page.

    (2) I'll recommend to Steve Scher, Jamala Henderson, and the KUOW web manager that they collaborate in this by

    (a) adding a paragraph about Cliff's Friday Forecast to the Friday Weekday blurb for the hour when he will contribute (or has) and maybe also in the one for the other hour so we know when/where to find it; and then

    (b)including a paragraph at least in each hour's blurb for the other 4 Weekdays (and maybe Friday too?, suggesting that folks surf daily into the Weather blog on the other 4 days of the week (and Friday afternoon/evening?) like the one I just posted (which might be too hype-y for NPR?):
    "{Bob's add-on Finale...}
    Cliff Mass is the Pacific Northwest's leading Weather Forecaster, Professor of Atmospheric Sciences at the University of Washington, and weather blogger at http://cliffmass.blogspot.com/ [correction added...} where you can get DAILY updates on his weekend KUOW Forecasts;" and

    (c) add a similar message to the last hour of Saturday's and Sunday's Weekend Edition, if we already have one for the KUOW part that Jamala hosts, and use this as a rationale {excuse?}to add pages for Weekend Edition if we don't have these already. (I can't find archives for them if they are there already, probably because KUOW doesn't usually archive "national-only" NPR shoes locally...)

  4. Cliff,

    I have read that one local affect of climate change would be that the northwest would receive increased precipitation. Are we beginning to see this or is our recent snow and rain within the normal range of expectation?

  5. Olalla: Thanks to the rain shadow we had a nice dry walk in the woods at about 11:30 to 1, with even a small patch of blue sky off to the southwest. Light rain started here about 2:30.

    - Pete

  6. Bob Moore, re: time puzzle. Blogger date/times a post from the moment you start it. If you don't finish and post it until later, or tomorrow, or next week, it still carries that original time stamp. It is possible to change it, but it's an extra step, and we really don't want to make this harder for Cliff. Communicating with us has to be easy and fun, or he'll stop...

    Meanwhile, it's raining in Port Angeles, a light drizzle.

  7. Anonymous who asked about are we in the normal range of precip, the snotel on Hurricane Ridge shows precip totals up there just now reaching the 30-average, and the SWE is still now up to average.
    http://www.or.nrcs.usda.gov/snow/maps/sitepages/23b17s.html click on Current Water Year Graph.

  8. typo oopsie. 'SWE still NOT up to average' is what I meant to say.

  9. Bob Moore,

    You can use WinAmp to play the KUOW podcast file. It features a positionable scrollbar which I usually put at about the 3/4 position. You will need to click on the mp3 option. I leave it to you to figure out how to play the file in WinAmp. HTH

  10. All,
    There is a a lot of unfounded loose talk about our global warming will cause more periods of heavy rain here. The reality is that there is NO real evidence of this...but a lot of us are working on it. ...cliff

  11. Whoever built the city of Seattle in a stupid rain shadow needs to be taught a thing or two.

    Please stop calling the lack of weather "good."

  12. Cliff,

    We have been studying the effects of last weeks weather, comparing it to the Dec 2007 event, and some of the others noted in chapter 3 of your book (which I just got as a B-day gift!). We have a question about flood plains. How are the hundred-year flood levels determined and do they correspond to the hundred-year storm?


    Ed and Megan

  13. "Chinook" is not a Pacific Northwest Native American word meaning "snow-eater". The Blackfoot called the west wind "snow-eater". The name "Chinook" was applied to it by indigenous tribes living east of the areas occupied by Chinookan tribes. The opposite, east wind was called a "Walla Walla".

    "Chinook" originally referred to the warm. moist west wind off the Pacific, such as the Poneapple Express. PNW floods often occur when such a genuine Chinook brings rain, while also melting the snow.

    Later, white settlers east of the Rockies picked up the term and incorrectly applied it to Rocky Mountain foehn winds.


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

Is Global Warming Causing Aircraft Turbulence to Increase?

 After the turbulence encounter by a Singapore Airlines aircraft,  there has been a slew of articles claiming that severe turbulence inciden...