Snow In Lowlands? An Update

The snow rumors are just getting going today, and they should be going crazy the next 2-3 days. A bit amusing since we have 3-4 days of beautiful sunshine ahead! I covered all that in the previous post, so let’s move on.
For those just checking in wanting the basics here you are:

  1. Our best chance of sticking snow to the lowest elevations (in the cities) this winter so far arrives Sunday and continues through Tuesday, possibly a bit longer.
  2. The possibility of an inch of snow in the city of Portland has increased a bit since last night…I give it a 50/50 at this time.
  3. Those of you in the hills (1,000’+) should get at least some snow, possibly quite a bit (6″+) during this period.  First chance is probably Sunday morning…we’ll fine tune the timing later.
  4. Finally, the Cascades should see quite a bit of snow next week.
  5. As of now, I don’t see any “arctic blast” or major snow/ice storm, we’re talking the heavy, wet, 32 degree snow.

Okay, so what’s changed?  The news snow-train has left the station…

The GFS has come into line with the ECMWF the past 24 hours, and all models seem to be in agreement for an “onshore flow” low elevation snow pattern. I hate these. This pattern has at least a light or even moderate southerly wind up the Valley the whole time, so some spots can get 2″ as a batch of showers moves through and other spots nothing.  The new GFS was signficantly wetter Monday and Tuesday as well.  It has been lowering upper-level heights the past few runs, thus the cooler temps.

Tuesday and beyond it’s quite the battle between cold air to the north and westerly flow pushing in from the west.  For now, I don’t see a setup for an easterly-flow type snow situation, but only a shift south in the models would bring surface low pressure systems in to our south, possibly setting up a big snow event.  Something to keep an eye on.  I notice the 00z GFS ensembles are almost all a bit colder than the operational GFS Tuesday-Thursday.  Could be a sign that the heights will be even a bit lower, along with those lows a bit farther south…we’ll see:

Anyway, COULD be fun times ahead, or we might just get some marginal snow Sunday-Monday.  Of course even that will be far better than anything else we’ve seen lately.

Chief Meteorologist Mark Nelsen

309 Responses to Snow In Lowlands? An Update

  1. Brad says:

    00z shows why you always delay getting on the train. Cold rain at best. Ick.

  2. Wendy-Silver Lake says:

    I don’t know, this looks awful wet and awful cold. I added up about 15 inches of snow from Sunday afternoon through Wednesday.

    Does this mean that further north of Portland has more moisture?

    • Wendy-Silver Lake says:

      Never mind, that was weird. It has less moisture now than it did when 10 minutes ago. Still showing about 9-10 inches, but nowhere near the 15 a few minutes ago. Must have been a glitch that got fixed real quick or something.

    • Wendy-Silver Lake says:

      And it stops on Tuesday now instead of Wednesday. Anybody run across something like this before? And yes, I was looking at the newest one, not an older one.

  3. WhiteEagle - Garden Home / SW Portland says:

    Seriously? We’re 6-8 days out and some people are already calling this a bust? I think we’ve got the models right where we want ’em. Enough cold air/baroclinicity to keep the storm track south but not quite enough to put is in dry arctic with the storms going into California. Meanwhile the arctic high hangs out in BC, just waiting for an excuse to come down. If not the midweek system, things will get interesting by the end of the week…just watch.

    Does anyone really expect a solution from 7 days out to actually pan out? I’d be more worried about all this falling apart if the models had us dead in the crosshairs.

    And the consolation prize of not getting a snow storm would at least be a healthy pineapple wind event. 🙂

  4. Mat the Salmon Killer says:

    Bob isn’t Mark. Its no snow or south wind. He’s playing a game of tomfoolery or monkey wrenches. Either way it’s comical. no one should take his texts for more than what they’re worth. Just play along. Kind of fun. Mark, it’s not a family member i promise. lol. Imɜ sure you know who itɜ is tho. Anyways, to the weather picture, not predicting anything but models look like so far that sticking snow can happen about anywhere starting late sunday and into wednesday. Moisture will be key. Daytime will definitively be different than night with the sticking snow. We shall see. By friday itɜ will be a lock as to what we get with this pattern next week. My fingers are locked. Good night “bob”. Do like the enthusiasm tho. By the way, where’s is Rob with all this? Would love to hear his take on all this

  5. kcteach says:

    We’ve lost power in SW Gresham

  6. flurball says:

    If you’re ready to give up on the snow chances you might want to shift your riding to the train of lows coming within 7 days or so. Looking fairly deep and in decent position for possible high wind the last few runs. Pass on the rusian vodka and order a mai tai or sea breeze instead?

  7. stevied (North Portland) says:

    Hmmmm… my initial take is the 00z sucks compared to what is possible with this pattern. It only gives a quick shot of chilly air Sunday with a few very light snow showers then moderation Monday with a few cool rain/snow mix showers then an average rainy pattern past hour 300. Not a good move by the 00z GFS. Hope this flips back to something better tomorrow, but not getting my hopes up too high.

  8. what did “bob/mark” do? mark….you cant ban yourself……yeah….someone help me…im confused

  9. Yevpolo1990 says:

    00z is weakening the low quite a bit this weekend…the good is we get more cold air, that bad is we get a bit less moisture.

  10. okay…..IS BOB MARK OR NOT?! IF NOT WHO IS HE….? sorry bob/mark…or whoever you are.

  11. Bob says:

    The 00z GFS WOW!!!

  12. Pics from Crown Point today:


    61. A dog that doesn’t look too comfortable

    86. Jeff measuring the wind

    138. Tim Gordon having some fun in the wind

    166. Rian training Riley to me the next Wx Ninja

    175. Perhaps the most bizarre thing I’ve seen up at Crown Point besides the Christmas tree being thrown over the ledge 🙂

  13. More evidence that the gradient isn’t the only thing driving the winds as was pointed out earlier:

    Gradient down to 8

    Wind just peaked at 80 MPH

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