Sunday Morning Forecast Still On Track; Flakes Mixed In Rain For Most of Us

6pm Saturday…

I’m not at work today, busy getting all the snow preps done! Just kidding, I left my snow shovel at work for a promo shoot. I’ve been confident I won’t need it tomorrow morning, even at 1,000′. I don’t shovel an inch or so…

This little “event” coming up late tonight and tomorrow morning has been solid forecast-wise for four days! Nothing has changed in either models or our thinking. The previous post is still valid.

Sunday Highlights

  • We will all wake up (west of the Cascades) to rain or a mix of snow/rain at the lowest elevations. Precipitation arrives sometime after 3am…timing has moved up a bit.
  • If you live near/above 1,000′, there’s a decent chance you get at least a dusting on the ground. If you live below 1,000′ IN THE METRO AREA, I’d be surprised if anything sticks. The “1,000 ft” is an approximation, we can’t actually forecast snow level with precision more than 500-1,000′. See rant below…
  • Whatever happens will be done by noon, then temps rise a few degrees (up to around 40 or so) and steady rain changes to light afternoon showers. Nothing interesting happens the 2nd half of the day
  • If you live in the lowest elevations (90% of us), your life should continue as normal tomorrow. Except for that COVID thing, but you know what I mean. Normal for these times.
  • If you live well above 1,000′ (like 1,500′ or higher), you’ll have some nice snow to enjoy tomorrow! Probably 1-4″ up there. This includes northern Clark County foothills, the hills above Scappoose and St. Helens, and above Kalama, Longview etc…

This graphic summarizes it well

Tomorrow night and Monday we’ll see very light showers; could be mixed at times, but leftover wet roads freezing in a few spots Monday morning MIGHT be a bigger issue. I’ll tackle that tomorrow

SOME OTHER INFO

Latest ECMWF snow forecast looks the same as it has for the past few days

This will be the first test of IBM’s 4km (higher resolution) GRAF model for us. Actually it nailed the 1/2″ last March, but this is the longer range version (to 3 days) that came out last summer. It says “FORGET IT” in the lowest elevations.

The “reliable for the past 20+ years” WRF-GFS (UW) is reasonable…a bit of snow most areas above 1,000′. But all lowest elevations…forget it. I’ve noticed it tends to “over snow” these marginal events. So we’ll see if hills around Happy Valley and central Clark county picks up measurable snow… This is the highest resolution model we have for our area. 1.33km! This means grid spacing is so tight that the model’s terrain includes features not seen in coarser resolutions. You can see Chehalem Mtn, the West Hills, outer SE metro area buttes, and south Salem hills. Note this one can also clearly “see” the Gorge. Little or no snow on I-84 in the Gorge tomorrow.

Just taking a look at the text data from ECMWF says we’re coolest before midnight with the partly cloudy skies we’re seeing now, then a light southerly breeze plus cloud cover means temps actually rise a bit toward sunrise. Precipitation is quite light on this model as well. Only .10 to .20″ by noon, that’s not going to drag the snow level down very far. NOTE THAT TYPICALLY THE -3 to -4 850mb temps would mean a sticking snow level up around 2,000′. We’re lucky to see sticking snow below that elevation briefly tomorrow morning.

WE CAN’T FORECAST SNOW LEVELS IN 100′ INCREMENTS

You may remember my rant about snow level forecasting in the past. I cringed when the NWS folks issued a Winter Weather Advisory for elevations ABOVE 700′ in the metro area for Sunday. I have no problem with NWS; they all work hard and do a great job. But when is the last time you heard a Mt. Hood snow forecast of “3,700′ tomorrow”. Or “expect a 4,300′ snow level dropping to 2,700′ late this evening”. We don’t, and shouldn’t in this case either. That’s because snow level is also highly dependent on precipitation intensity. Heavier precipitation = lower snow levels generally. So don’t read the Winter Weather Advisory as “you won’t get sticking snow at 600′ but will at 800 ft”. Instead, I wouldn’t be surprised if some neighborhood gets sticking snow (somewhere) to 500′ Sunday morning, but somewhere else you get nothing at 1,000′. That’s why I use the “near and above 1,000 ft.” terminology.

So insert your eyeroll here and “oh geez, Mark is throwing a fit about THIS again?” One example below is from a blog post in 2016. Setup was a bit different, but same issue


We’re doing people a disservice by implying we have more accuracy than we do.  

This morning is a perfect example of why forecasters (and the NWS) shouldn’t be forecasting snow level in increments below 1,000′ in a snow shower pattern.  A snapshot at 8:30am:  Staley’s Jct. on U.S. 26 west of Banks…elevation 200 feet.  A snowy road and maybe a half inch on the ground:

us26-at-staleys-junction3_pid2985

At the SAME ELEVATION, but 15 miles east on the west side of Beaverton…all bare and wet with no snow in sight:

26bethany_pid524

Then over on the eastside of the metro area just above Sandy…at 1,200′.  NO SNOW. The white stuff is left over from yesterday’s hail/graupel showers.

us26-at-firwood-rd_pid2331

So what was the “snow level” at 9am???  Under the heavy showers it was near sea level, where very little precipitation fell it was higher, up around 1,500′.  


Alright, I’ll be on TV tomorrow evening at 5/10/11pm, taking a close look at Monday and Tuesday. Likely a couple more “near misses” for those days.

Chief Meteorologist Mark Nelsen

50 Responses to Sunday Morning Forecast Still On Track; Flakes Mixed In Rain For Most of Us

  1. runrain says:

    They already have evacuation warnings up for thd Santa Cruz Mountains in anticipation of 10-12” of rain coming this week.

  2. Andy says:

    It looks like snow chances extend into February…don’t give up hope. Those of you that live above the valley floor have the best chance of snow in the coming weeks. Fingers crossed.

    • tim says:

      Yes good news,apparently most of u on this blog live in the mountains from what I gather tough luck for us sea level folks.

  3. tim says:

    18zgfs has small eye candy at the end, snow at sea level is that even possible anymore time will tell , I have yet too see a single flake yet this season elevation 0 ft were I live and heat island effect to boot.

  4. Mountain Man says:

    Snow covered, just enough to crunch under my feet, looks like at least one more band coming, snowed all day, but just couldn’t really stick until 4pm, lighter again for the moment, hoping you Hood foothill people get something before it’s over. This is nothing worth even mentioning here except for this year, it is.

  5. Mountain Man says:

    Okay, when everything indicated that snow was a morning thing at best and snow levels would bump up a little by now, now it’s coming down hard and it’s sticking good and turning all white.

    • lurkingsince’14 says:

      Finally snowing in Welches, started slow but a good clip now temp 33.8 and falling; I see NWS extended the advisory until 4am 👏🏻 ❄️

  6. Mountain Man says:

    Well, it snowed all morning and into the afternoon here and didn’t stick except some really light slush a couple times, the sticking snow is just above me at about 1500 feet. What a disappointing situation!

    • lurkingsince’14 says:

      Nothing at 1300, maybe Tuesday AM? 🤷🏻‍♂️

      • Mountain Man says:

        Changed and I’m at that elevation well 1300 at the bottom of my place and 1410 at the top of my place, it’s coming down hard all white and half inch at least in the last half hour. Maybe this will make it south the the Mt Hood foothills in a little while. I’m in the Mt Rainier foothills.

        • lurkingsince’14 says:

          Here’s hoping! Feels like it’s been crawling down the ridge, temp dropping nicely too…

  7. JohnD says:

    34’ and all snow currently on top of Council Crest Park—but not sticking—at least yet.
    39’ and rain downtown. What a difference a thousand feet makes!

  8. Ted Stryker says:

    Winter is over Wishcaster’s…

    • Mike says:

      Is there any thoughts out there of the possibility that enormous amounts of air pollution from China is affecting our weather? I really think something is wrong with the atmosphere seeing so many winters together become so benign, less newsworthy, less of an impact. I just doesn’t seem like things are right with our weather any longer.

      I want you to know I do appreciate those that report year over year comparisons too.

      • Mountain Man says:

        These are often called Asian brown clouds in western North American, but I’m not aware of any direct affect on our local weather, but I do know research is being done about this. There’s a lot of pollution that makes it’s way from SE Asia to the atmosphere at around 500mbs over us. It’s well documented that this is why we often don’t have true blue sky anymore, it’s also not been tied to any any actual change in our weather… With an exception that globally, that pollution might actually be mitigating some effects of global warming as it filters some solar radiation from reaching the surface. Much climate research has noted, a sudden stop to pollution will rapidly accelerate global warming.

    • Al koholic says:

      STRYKER…..STRYKER…

    • JohnD says:

      Farmer Ted—aka many things. A real piece of work. You know he really loves us. ‘Just can’t figure out how.

      • Ted Stryker says:

        Oh JohnD… What’s entertaining is the paranoia exhibited by you and your fellow wishcasters….

  9. Larry says:

    Ready for round 2 on Tuesday?

  10. Andrew says:

    Any thoughts on whether the prospects of seeing flakes in air in Portland will be higher later in week or was this our best shot based on current models?

  11. A light dusting this morning in much of Whatcom County, WA. Basically a “conversational snow” as Mark calls it. Hopefully setting the stage for more to come. At least the overall pattern is favorable now.

    Would be nice to see you Portlanders break your snow drought this winter.

  12. lurkingsince’14 says:

    Hopefully that makes it over to the foothills at some point…bone dry and 34 in Welches area 😕

  13. Rick says:

    Snowing at a steady clip @ 1000FT in the
    Coast range

  14. runrain says:

    The groundhog is already out, sippin’ on a pina colada in shorts, tank top and straw hat listening to Jimmy Buffet tunes. Nothing left this year to scare him.

  15. Grizzly Bear says:

    Weather AlertNO SNOW WARNING again for Portland Metro Area for the foreseeable future ** Carry on with your normal lives until further notice. Of course “wishcasting” is always allowed and encouraged as your dreams and imagination are the best way to experience snow west of the Cascades.

  16. Paul D says:

    39 and completely dry in Hillsboro at 5:55am. Ho hum……

  17. W7ENK says:

    37 degrees at the onset of moisture…

    Gaw’ dazmnit, that sounds so fuggin’ familiar, dunnn’t it??

  18. Diana F. says:

    🎤 Well hello everybody, great to see y’all made it, thank you so much for stopping by!
    So it’s 1:25 am, in SE Vancouver, and it’s 40 degrees with E wind @ 4.
    Oooh here’s some exciting news, ammiright? NWS notes a 60% chance of snow.

    Meanwhile…..in Downtown Vancouver, it’s 41 degrees with SE wind @ 7.
    Oh my, the news just gets better and better and more and more exciting the farther…. west you go!
    Because these lucky ducks get an NWS prediction of 80% chance of snow!! 👏🏽

    Naturally, there is a winter weather advisory, so I imagine the airport will be closed for the day. How about those grocery stores, what can I say other than I just got back and suggest you don’t even try it !
    Of course, this snow threat will likely hit schools very hard, so in an abundance of caution, online virtual classes will be closed and that applies to just K-12. That will be a nice break for kids & travelers! I’m sensing an opportunity for social distancing…!!
    Well I’ve got some snow tires to out in, so I’ll just say “Goodnight” everybody!
    Thank you, thank you very much, you’ve been a great audience; no really, you’re great! No, yuuuuuuuur great! Well thank you very much, I’m here every…….threat-of-snowy Saturday night & it’s been great!!
    (I’m waving as a walk-run off stage)…….

  19. Anonymous says:

    Yep all true about current disappointment. But the trend is our friend. Epic Feb coming…

  20. Mountain Man says:

    There’s two ridge’s that run right behind my house and land, very steep straight up, one straight east the other northeast. The northeast one is the highest at 4200 ft. I looked today, it’s bare except one little patch, like a white stripe of snow in a crevasse. I have never seen that before this time of year, it was snow covered all of November and December, I’ll bet it’s almost never looked like that before in late January. So, here we go, at least I can look up at snow if it doesn’t make it to the 1300-1400 where I live. Maybe I can get a couple pics to post, I don’t know how to post them but it’s super beautiful sometimes so I can try.

  21. Andrew says:

    I at least thought chances of seeing flakes in air was reasonably high for tomorrow but not anymore. it’s still 38 at my place and with cloud cover not expecting dramatic cooling. this is looking like a total dud below 1000 feet. it was never a “real” snow chance anyway so can’t be too disappointed. But this is why i advise people to not take phone/app forecast at face value. models don’t always convey that to get snow down to sea level you really can’t have onshore flow, especially with a weak weather system coming in. Models often present false snow chances not adequately factoring in marine influence, and those feed the forecast apps in a purely automated fashion. That’s what leads to so many people saying weather forecasting is so bad. People like Mark nail this stuff time after time precisely because they know when to “veto” the imperfections of models. I’d still love to see snow tomorrow but would be a total surprise for me at 300 feet at this point. Here is hoping this pattern change delivers over next few weeks. i’m still hopeful given what’s happening around us.

    • Joshua Lake Oswego says:

      Looking like a day of cool drizzle. Ho hum.

      The Euro is trending towards the GFS. Shocker. That means Tuesday afternoon/evening is fizzling out. And beyond.

      A week ago everybody was talking about all the active weather coming up. That would be correct if you lived 300-1,200 miles south of here. For us, it means weak systems every few days, no cold, and weak snow for the Cascades. Mark is probably polishing the fork right now.

      • Zach says:

        I am seeing multiple feet of snow in the Cascades the next 10+ days…. Sure its not anything like what is about to go down in the Sierras, but not bad by any stretch. Also the freezing level looks to stay at 3,000ft and below as far as I can see, meaning the lower elevation snow pack will finally begin to (seriously) accumulate.

  22. ocpaul says:

    Sadness, disappointment, misery. Weather in the PNW.

  23. Al koholic says:

    Not gonna happen I’m so pissed

  24. yspofor says:

    BRING ON THE SNOW MARK!❄❄❄❄☃️❄Sent from my Verizon, Samsung Galaxy smartphone

  25. JohnD says:

    Basically we ALL know that to see significant accumulating snow at sea level in W Oregon, it is pretty much imperative that first and foremost there is a sustained easterly flow through the Gorge—supported by Arctic—of at least cool/cold Continental—air flowing into our region. There are occasional anomalies to this theme that can make it happen too. But BASICALLY, you gotta have the easterly flow. We all know it.
    —-
    I am utterly no expert. Just a lifelong W Oregonian with a weather-hobby passion—like many of us. We’ve seen it all. And have often been frustrated.
    I do have to say that it is heartening seeing the dramatic changes finally beginning to ensue to the North.
    Given the overall pattern, time will tell if any of that will migrate into our region. There seems reason for optimism. I’m excited about what Mark—and others—will have to say about that.

  26. W7ENK says:

    :YAWN:

    Southerly breeze, no matter how light, means it’s over before the clouds even moved in overhead.

    Green, brown, and wet. That’s my Sunday morning forecast for my neighborhood.

    The Dome™️ wins, yet again!

  27. Andy says:

    Down to 36 Albany at 630 pm…will be glad to see some new snow in the mountains. Maybe next time in the lower elevations or not this winter.

  28. JohnD says:

    Thanks Mark. As expected, buzz kill for tonight-tomorrow. (But I’ll savor every “splat test” on the drive up to 1000’+ Sunday!)
    Hopefully something more eventful upstream?!
    We’ll see.

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