March 02, 2009

Cold and Snow?


It is March 3, and the weather maps for later this week and the weekend, are a real eye-opener--some the coldest air I have seen this late in the season for an extended period of time. And yes, there are snow chances for the lowlands. But keep in mind that we are working against the clock. Significant lowland snow after the first week of March is increasingly unlikely--although we did get an inch last April (the frigid spring from hell--or I should say the arctic).
During the next day or so, we will be in the typical spring shower regime. Right now a band is heading towards us (see satellite pic) and should get to Washington overnight (the precipitation from it is visible in the Portland radar).

But that is not the fun part.

A major upper-level ridge develops over the eastern Pacific on Wednesday and a trough moves southward over us on Thursday (see map). Such a flow pattern will bring colder air, certain snow in the mountains, and perhaps in some high elevations...but it is not ideal for much lowland snow..the trough is too far inland. But this pattern doesn't go away and another trough moves in on Sunday...and is much more threatening..colder and and more favorable trough location with greater upward motions. The WRF model in fact puts down some lowland snow...but this is so far out, I would not get too excited yet (image). My rule of thumb is I don't get psyched about snow until we are within 96hr of the event. But I would get those salt trucks ready. And the cold air holds in. Just amazing.

PS: the Northwest weather workshop will be on March 20-21st..the major annual meeting of local meteorologists and hard-core weather enthusiasts. If you want more info or to register, check out:

http://www.atmos.washington.edu/pnww/

29 comments:

  1. Cool! Thanks for the warning. :-)

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  2. Hey there, Cliff! :o)

    I to am amazed on just how cold the 925mb temps are for later this weekend into early next week. Pretty cold for so late in the winter season.

    Just as a side note Cliff, I believe daylight savings time begins this Sunday. Think it was posted in our Woodinville Weekly. Anyway, if you feel like it, you might want to stick a little reminder on your page for us readers/posters.

    Longer daylight hours. Yay!:o)

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  3. Thanks for the warning here as well, I'll be driving to Moses lake and back this Sunday from the seattle area. At least my snow tires are still on!

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  4. Hey Cliff, is there a way to ask you a specific weather-related question? I don't see any contact info on the blog.

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  5. I'd love to know more about the wind patterns in Seattle. I bicycle commute many days, riding from North to South along 15th ave NW > Myrtle Edwards > Alaskan Way > Marginal Way > 1st Ave south.

    Much of the time the wind direction is consistent for my morning and evening commute. BUT, (and I swear I'm not making this up smoke, flags, etc. are evidence), I often have a headwind both ways!

    Why is this?

    Seems to happen a lot in the fall and spring, but I'm not sure if it's temperature changes throughout the day or maybe just the way the buildings are oriented along the street? I rarely have a tailwind both ways, though it does happen and makes me feel like I won the lottery.

    Hope this is within the scope of your blog, thanks!

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  6. Just wanted to say that I love your blog, Cliff. I can't wait to get your book.

    Is anyone else having issues getting the latest high resolution outputs? I have been getting them here:

    http://www.atmos.washington.edu/mm5rt/

    but the site seems stuck. I have become addicted to these since I first found them, and I am now feeling withdrawal.

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  7. Holden Village
    11 Miles S Stehekin WA
    48.2°N 120.75°W (Elev. 3224 ft)
    Snow total for this winter is 163 inches

    Not today!! Night before last we got 5 inches of snow and broke into sun yesterday afternoon. Today it began snowing at breakfast with a temp of 40 (white rain??) This after noon it was 50 in the shade and full sun. The road is down to bare dirt (mud) in one place now.

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  8. 'On This Day, March 03, In 1991, In Pendleton, Oregon, Where The Wind Was 48 Mph And Gusts Were As High As 74 Mph, An Apartment Building Roof Blew Off And Landed On A Car In The Parking Lot. The Roofs Of Willowcreek Elementary School And Kays Cafe Were Also Blown Off. Dust That Was Blown Around Because Of The Wind Caused Three Car Accidents."

    http://www.wrh.noaa.gov/pdt/

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  9. A question about the Probcast.

    It seems to way underestimate precip. Below are some stats from last week. I'm in Chelan Co., just east of Stevens Pass.

    ev and 10% are probcast expected value and max expected (<10% chance). Pt is precip from NWS point forcast. ac is measured precip.

    tue wed thu mon

    ev .06 .07 .01 .02

    90% .49 .75 .29 .26

    pt .81 .55 .40 .40

    ac 1.14 .54 .27 .27

    So, as you can see, Probcast grossly underestimates precip. NWS point forcast does a much better job. Is Probcast only meant for lowlands?

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  10. Andy, Daylight Savings does not mean longer daylight hours. We just shift the man-made clocks an hour... it's actually a pretty pointless idea. It's going to make it a lot harder to get to sleep in the evening, that's for sure... as usual. :(

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  11. Cliff, are there going to be TVs on with the NCAA Tourney games (particularly the Huskies) at this weather workshop? ;)

    Just kidding...

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  12. LOVE your blog, Cliff....but it's kinda hard to read the text that goes down the side of the images. If you click to "Center" them when loading them, the text won't revert to single letters and phrases down the left side of the page.

    Keep up the good work!

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  13. I'm tired of snow and this threat for Sunday is so ridiculus! How does this fit into Global warming? Global warming is a joke right? And whatever is causing this cold weather...will it be back next year???(I hope not).

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  14. scrapycandy, you are joking, right?

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  15. Letshavefun1536...

    Daylight savings dosen`t mean longer daylight hours?

    Then what do you call it when it`s about the middle of the summer and it`s nearly daylight at 5, 530am and doesn`t get fully dark till like 930 almost 10pm.

    Looks like longer hours of light to me.

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  16. Jimmy,
    You can get a tail wind both ways..I bike and have observed the same thing. This is most prevalent during the warmer time of the year. There can be southerlies in the morning...and then in the afternoon the northerly sound breeze develops. Check my book chapter on local diurnal winds..it explains this effect.

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  17. I photographed some very interesting clouds this evening, and wondered what they mean! I can't figure out how to post the photos here, but will try to figure out how and where to send them!

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  18. Peter..I just checked..the high resolution model output is accessible.

    cc: let me check this out. Can you give me your exact lat/long or some point I can id?

    Andy...Daylight savings time has nothing to do with length of day...just a shift in time.

    ...cliff

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  19. cc:
    what date/time for the forecast in question...cm

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  20. Thanks Cliff. I knew DST had to do with a shift in time....but thought it also meant longer hours of daylight.

    In regards to getting head wind when biking, I to have gotten head winds during the summer of when biking out on the Burke Gilman bike trail.

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  21. Cliff we have major problems here! Outside Spokane just 10 miles south we have massive thunderstorms with 1/2" hail that dented by hood completely. The cell is moving north with deafening claps of thunder. Currently it's 34F with winds gusting to 39 on the Davis. The hail is concerning. Massive squal line should weaken as it hits more stable air. The NWS has a NOW CAST out now for this. Will monitor all forecasts!

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  22. Andy, the longer daylight in summer is simply due to the tilt of the Earth and the fact that the northern Hemisphere is tilted toward the sun in the summer and away from the sun in winter. We have longer daylight hours in the summer for this reason only. If we didn't have Daylight Savings Time, we'd still have longer daylight hours in the summer than the winter (the same we do with DST); the sun would just rise an hour earlier and set an hour earlier.

    So yes, we have more daylight in the summer, but it's not because of DST.

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  23. Cliff, have you ever considered changing your middle name to "Air"?

    Cliff Air Mass

    Sorry, couldn't help a little chuckle in the morning... :)

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  24. Daylight savings time only FEELS like longer hours. It sort of "subtracts" light hours from the early day when we're sleeping then "adds" them back to the end of the day when we can use them.

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  25. DST-
    Spring forward- The official day is 23 hours
    Fall Back official day is 25 hours.

    So in effect the official day dose change on those days. I know, I know pretty silly to even bring it up.

    DST can get complicated

    The Gssaa The Golf Course Superintendents Association of America has lobbied to keep it going, among others

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  26. Cliff,
    I know that you are a busy guy but after your last post, which was quite a teaser for us snow-lovers, I'm DYING for an update!! What do you know now?

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  27. will update this afternoon....my day job...teaching...has to come first!..cliff

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  28. Hey Cliff, just a chuckle here....dont quit your day job! lol.

    Looking forward to your update.

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