October 05, 2011

Western Snow Season Begins

 In a real sense, the winter season began today along the entire West Coast.   Nearly simultaneously, snow struck higher elevations in the Cascades (including Paradise on Mt. Rainier) and in the Sierra Mountains (Donner Pass and Squaw Valley Resort), while rain wind hit southern California (see pics below).

Paradise at Mt. Rainier
Donner Pass
Why such widespread winter-like conditions so early in the season?  The answer is a very high amplitude meridional (north-south) trough of low pressure along the West Coast.

Take a look at the upper-level (500 mb) chart this morning.  Pretty amazing...low heights over the Northwest and a strong trough and strong winds (indicated by the closeness of the height lines) over central and southern California.

The latest Climate Prediction Center forecast for the next two weeks is for colder than normal and wetter than normal conditions over the Northwest....and the pattern looks very similar to last year's La Nina situation.  Forget about watering your garden.

And now the bad news--the computer models are more emphatic than ever that we will have to deal with a second La Nina year...yes, a double dip.   Here is an example of a collection of various models:

Most of the them are calling for negative sea surface temperature anomalies (differences from climatology) and the Climate Prediction Center's coupled atmosphere-ocean simulation system is even more emphatic.  Although this year's La Nina is a bit weaker than last year's, examination of previous double dips indicate that the second year can have a similar impact even if weaker.  The good news....skiing should be good this year and we will have lots of water next year.

Finally, some major radar news.  The Camano Island radar is back on line after being updated to dual-polarization.   So far there is no place for you to see the new dual-pol radar products on the web.   I am hoping that we can soon put some of the them on the department web site within a few weeks.  Several of you have also asked is there a place where are the radars are combined for your viewing pleasure...there is...my department is combining the U.S. and Canadian radars and you can access these graphics here.  This interface uses google maps technology, allowing you to zoom into the area of interest.


  1. talk about the tornado that touched down in st john, wa!

  2. Wahoo! Another real winter, I love it! Really.

  3. Cliff, thanks for everything you did to help get us the new Doppler. It's amazing. We here on the outer coast really appreciate it.

  4. Will the "show mask" option be updated on the UW Radar page to reflect the new blocking/limitations of the combined radars?
    Thanks again for all your hard work pushing for the much needed coastal radar!

  5. Hi Cliff,
    Great news about the Camamo Radar. I just talked to the NWS office about when we will be able to see the new products the dual pol radar will produce. They told me it won't be till the middle of next year until everything is upgraded and the new products are available to the public. I was wondering if the UW site will have some of these products available any sooner? It would be great to be able to see the advantageous of the dual pol technology.

  6. so we can just forget about the first 2/3 of next summer also?

  7. I don't mind La Nina unless it continues on into the spring. Last April-June were pretty tough... April especially.

    Here's to hoping we get a strong La Nina that dissipates by March!

  8. Love the La Nina in the winter and I can't wait for the snows to begin falling up at the ski resorts and in the lowlands (hopefully). As for the spring and summer I really hope it clears up by then so we have cold and snow from December to the beginning of March and then it can get warm and dry.

  9. Nice Dopler site you posted, but did you test with Firefox? Works fine with IE(9) but does not work with FF(7.0.1), at least not mine. But it is a cool site to be sure. Thanks Cliff.


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