March 08, 2009

Arctic air in March

Yesterday was a fairly successful day for the forecasting community, and the NWS forecasts of light snow amounts with the CZ were on target. The predicted heavy snow fell in the mountains...and the radar really helped us follow the action over the lowlands. Do you see how valuable having the radar is? Isn't it clear why the coastal zone, with its extraordinary active weather needs it? Isn't it outrageous that they don't? Well, you know how I feel about it. My other pet peeve...the failure of Metro's bus tracker software during snow periods when the hit rate climbed...appears to be on the way to being fixed, according to Metro management who emailed yesterday with their assurances that this problem will be addressed before next winter.
A look at the latest satellite pictures shows that shower activity is greatly reduced particularly over the northern portion of western Washington. Mountain snow showers have also declined. The radar shows the weak remnant of the convergence zone across Whidhey and northern Snohomish counties, and some showers basing eastward south of the Olympics. All snow showers.
The next stage in this event will be the movement of much colder air into the region...first evident as gap flow starts to push through the Fraser gap later in Bellingham and NW Washington, the cool northeasterlies should come in late today and tomorrow AM..with some snow showers possible on its leading edge. I have included a prediction for sea level pressure, temp, and wind for 2 PM, you can see the cold air and higher pressure to our north. Upslope snow showers on the NE side of the Olympics should occur tomorrow..but at this point they look light due to the dryness of the air. Monday AM and particularly Tuesday AM should be very cold..perhaps record breaking, with minima in the 20s. So protect those sensitive plants. Tuesday and Wed a major ridge develops over us for sunny, cool and dry conditions.

Finally, for all of you who look at weather charts and obs, remember we are in PDT now and the difference between GMT (UTC) and PDT is 7 hours.


  1. Very helpful info, Cliff, and appreciated!
    Was looking at that cloud mass in BC moving this direction today and wondered if it has much moisture in it.

  2. So Cliff, does this arctic boundary have much moisture with it? I just read the NWS forecast discussion and it sounded like a pretty good chance of moisture coming in with it on Monday morning.

  3. Cliff, why does Daylight Savings Time start so early? Early April was already too early - why did they move it a few weeks even earlier? All it does is make us have to deal with another hour of light after work/school every day. It'll be nice that it'll be a little darker when we wake up (but only for a few more weeks probably), but the extra light at the end of the day is so annoying.


  4. Good news about the Metro tracking system. During the snow in December there were no - NO - buses on Queen Anne Hill.

  5. Months after Indiana passed the law that got it in step with the rest of the country, the federal government announced a major change in Daylight Saving Time. In Aug. 2005, Congress passed an energy bill that included extending Daylight Saving Time by about a month. As of 2007, DST starts the second Sunday of March and ends on the first Sunday of November.

    U.S. Daylight Saving Time Schedule
    2007: March 11 - Nov. 4
    2008: March 9 - Nov. 2
    2009: March 8 - Nov. 1
    2010: March 14 - Nov. 7
    2011: March 13 - Nov. 6

  6. Cliff, I don't actually see how valuable the radar is but would love to find out. Could you let us know how being able to follow the action yesterday provided any substantial benefits? That is, by the time you are seeing something on radar (vs. satellite), what really can be done to negate any "costs" associated with the weather system? Thanks.

  7. Extra light at end of the day annoying? How so?

    Extra light at end of the day is a good thing! Having light longer means you can do more stuff outdoors before it gets to dark to see what your doing.

    Seems kinda silly that anyone could say that extra light at the end of the day is annoying to them. I bet most folks enjoy the longer daylight hours!

  8. "Extra light at the end of the day annoying"? You must not go outside.

    That is one of the strangest opinions I have read here. It even beats the "I like it grey and cloudy", something I never thought I would see. To each his own I guess.

    I hate being limited as to what I can do by the lack of daylight, and love this time of year when you can hike,garden,dog walk, etc... after work.

  9. "...fairly successful day for the forecasting community"
    Fairly for the Northwest Interior.
    Here is the discussion from Friday Afternoon.



    So with the NWS , Whatcom County had a 50/50 chance of snow with their ensemble. Whatcom line northward never made it into advisory despite the posting of it on Friday. (In the lowlands)...Maybe this is the new way to be looking at forecast as Cliff describes in his chapter about Pacific Northwest Weather Prediction.

  10. Hey Cliff,

    I think I understand how the PSCZ works fairly well but I don't know if I've ever heard an explanation of what causes it. My very limited NW weather logic tells me that it would occur when a low passes over Puget Sound and the air from out towards the coast rushes around the Olympics and converges towards the low, is that accurate?


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  12. "Extra light at the end of the day annoying?"

    Could it be that some people work very early in the morning and thus go to bed really early? The light might make sleeping early difficult.

    Please, can we relish in one another's differences rather than criticize them?

  13. Yes!!! Finally, SE Auburn is in the a C Zone! As of 1:30pm Hvy Snow squall and 33.5 deg. Snow started around noon with huge cotton ball flakes and hasn't stopped since. Going on 1" and snow starting to stick to streets. Looks like the arctic front is still north of BHam. If this keeps up tomorrows commute for Southenders is going to be nasty. For be fun to see how this plays out. ;)

  14. 32 East
    I will give you an example of some values of the radar. One is that it allows us to determine whether our forecast is even correct...did we get the PSCZ precip in right place? If not, it tell us what our error is and we can work on improving the modeling system. Another is short-term allows us to see the evolution of the system and what will be happening in the next few hours. In fact, I am working on an automated system to do exactly that for Seattle Public Utilities...will be constantly diagnosing the precip from the radar and then allowing warnings when the intensity gets above a certain level. Could give you a dozen more, but you get the idea...cliff mass

    Others asked about snow with the arctic boundary. That has often occurred, but generally is not more than an inch or so, unless there is significant moist southerly flow overrunning it--which is not evident in the models at this time.

  15. "Could it be that some people work very early in the morning and thus go to bed really early? The light might make sleeping early difficult.

    That is me, I get up at 3 am for work. The bad time is summer, people mowing lawns and using leaf blowers at 8 pm. I've even had door to door sales people after 8pm. It's more than worth it though, I get more free time, I'm home when most people are only half way through their work day, and I never get stuck in traffic. It's always dark when I start my work day, but it's never dark when I get home.

  16. Maple Valley just got over two inches in about the last hour. Still coming down lightly.

  17. Hey Joe..

    There is certainly a down side to summer, and one of those you mentioned is lawn mowing in the evening. You would think that would be a weekend thing and done during the middle part of the day. And for folks with allergies, I`m sure that can be pretty bad when adding to the dust/haze/humidity/ pollen in the air.

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  21. It's shoooooooowtime in Sammamish.

  22. Snowing on Union Hill in Redmond (600'). Starting to make the trees, and parts of the grass that weren't already white, white again. Keep going! Keep going! :)

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  24. I had a snow shower just a little while ago that lasted for a little bit and put down a LIGHT dusting of white on the grass & trees and shower was moderate toward end of the "precip band" if ya will..

    So was nice to see snow falling again.

  25. This is certainly a fascinating weather season, and those that have forecasting as a vocation or for us who enjoy it as an avocation are really enjoying it!

    Record cold temps in the next two days? Snow on March 9th? Random snow showers and a high that doesn't reach 40 degrees the second week of March? Amazing.

  26. We had a torrential downpour of snow, but now?

    Sun, blue sky and very interesting cloud configurations in the distance.

  27. The roads are going to be a sheet of ice in the morning. I really don't like the snow, but it's not nearly as bad to drive on as ice.
    Please people, slow down and take it easy tomorrow as there will be lots of black ice.

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    Hey Cliff. System in California to help alert EMS when certain permitters are met at a station IE high wind,low rh, high fuel temp. Didn't know if you knew about it. They were able to get funding through numerous forms.

  31. Cliff, it looks like the currnet FY09 Omnibus Bill has 2.0 million dollars allocated for 'a doppler radar station in Washington state'.

    The catch here is that this is the bill that everyone is all upset about because of the 'wasteful' earmarks. This is listed as a 'Congressionally-designated item' and is listed as an earmark on the OMB from Sens. Cantwell and Murray. So, here's hoping they're able to get it passed and don't settle for an FY09 Continuing Resolution.

    On a positive note, the radar didn't make McCain's twitter page.

    You can see the listing in the FY09 Omnibus bill by following a pdf link to make your way to page 40.

  32. Cliff - is the stimulus bill going to have any money for coastal radar?

  33. Teresa, please email me at I need to talk to someone who understands how I feel, that's all. Thanks much, Paul.


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