Winter Storm Watch: Snowstorm Likely Some Parts of Oregon & S.W. Washington

11:30am Saturday…

The coldest February in 30 years wants to go out with a bang!  A Winter Storm WATCH is up for much of the FOX12 viewing area, including north Oregon Coast, I-5 corridor, Gorge, Cascades, and north-central Oregon.

Why?

For the next two-three days, a boundary will be setup across the state of Oregon between cold/dry arctic air flowing south out of Canada (the chilly colors on the map), and TONS of moisture streaming in from the Pacific to the south.

Euro_925_MonPM

Wherever the moisture rides over the cold air, heavy snow will likely be the result.  TWO separate systems travel along that boundary; one tonight and early Sunday, then another one late Sunday night and Monday.  Most snowfall tends to fall close to and north of the red line, within about 150 miles or so (highlighted).

Euro_925_MonPM.png_Annotate

ALL numerical weather prediction models (THE MODELS) are showing this setup and have been since at least Wednesday.  As always the exact positioning is critical to whether it snows at YOUR house or not.  If the whole zone is south of you, most likely you just stay chilly and mainly dry through the period (Seattle).  If it shifts north of you (maybe Eugene or Roseburg?), then no snow for you!

West of the Cascades, the first system coming through tonight and Sunday morning is a bit too far south to produce snow in most of Northwest Oregon, plus we don’t have an atmosphere quite cold enough either.  So snow level hovers around 1,000′-1,500′ through Sunday afternoon here.

The 2nd system for Sunday night/Monday is why we have a Winter Storm Watch up west of the Cascades.  That one tracks a bit farther north, sends far more moisture overhead, and pulls in a cold east wind through the Gorge as it approaches.  Take a look at the WRF-GFS forecast for 7am Monday morning.  Low pressure passing over Willamette Pass headed east and cold air pulled down from the north.  This setup is perfect for producing a snowstorm many areas west of the Cascades (and north-central Oregon)

wrf_7am_Monday

If I were to look only at this model for Sunday night and Monday? I’d say no snow up at Longview and on the north coastline, just a Trace to 3″ in the metro area, but MANY inches Salem southward to Roseburg.  The GFS model is similar.

How about my favorite ECMWF?  It (along with the GEM model) buries the Willamette Valley in a major snowstorm by midday/PM Monday.  Many inches of snow from Portland to Eugene, a bullseye directly over Salem on that one.  GEM has even bigger totals as it brings the low from Florence right up to Salem.  By the way, the last 6 runs of that Euro have pushed a foot of snow into some location west of the Cascades.  It has been as far north as Olympia and as far south as Roseburg.  That’s some great model consistency showing that someone is going to get nailed westside.  The morning ECMWF shows the precipitation from late Sunday through late Monday.  Wow, that’s juicy (and white) south of the metro area.  You could get a foot of snow out of that much precip in the southern Willamette Valley, and only flurries at Longview and Astoria (with this model run).  This could be a historic February snowstorm somewhere in the Willamette Valley.

Euro_Precip_MonPM

WHAT DO I THINK IS GOING TO HAPPEN?

We still have three more model runs before this event, so plenty of time to figure it out

  • SOME OF US west of the Cascades between Longview and Roseburg are likely going to get buried by a beautiful, heavy, coat of wet snow between late Sunday night and sunset Monday; extra amazing that it’s happening on February 25th.  VERY late in the season!
  • I don’t have a good feel yet for exactly where that’s going to happen, but it’s time to assume your life could get messed up by weather at least Monday morning, maybe for the following 24 hours.
  • SOME OF US will get hosed by little or no snow, depending on where the low tracks
  • We’re still two days away, but the NWS is thinking 2-8″ is the possible range right now in the metro area.  It could be below or above that number for the reasons mentioned above.  Seems like a good starting number though.  Just like the last event, we’ll narrow it down as we get closer.
  • The Columbia River Gorge and north-central Oregon have the best chance at getting buried by two snow events, the weaker one late tonight and Sunday, then bigger Sunday night and Monday.  I can see 12-24″ falling out there.

IMPORTANT POINT

It’s late February folks!  Even if your town west of the Cascades gets 10″ of snow Monday morning, we’re not going to be in a snowy & frozen hell for the next week.  A few sunbreaks and snow starts melting off streets.  You are not going to be trapped in your home for several days.  Leave that kale alone… (west of the Cascades).

I’ll post again midday tomorrow as the drama continues to unfold…

Chief Meteorologist Mark Nelsen

 

 

 

 

145 Responses to Winter Storm Watch: Snowstorm Likely Some Parts of Oregon & S.W. Washington

  1. John Inner NE Portland 250' says:

    Does anyone have a favorite weathercam or group of weathercams, that they’d like to share links for?

    I only use the ODOT tripcams https://www.tripcheck.com/Pages/Custom-Cameras and would like to learn about others

  2. paulbeugene says:

    At EUGENE airport there has never been a low in the teens in March (since records kept there). Euro model has three consecutive mornings in mid to upper teens to start the month. That would be exceptional for sure. First the snow has to fall though

  3. Evan -- Cedar Mill says:

    Don’t worry guys there’s still hope for portland. It’s better to be on the cold/drier side than the warm/moist side. Just watch salem and eugene get a 35 cold rain. Guaranteed. I just wish that the low goes a bit farther north because I think the east will be strong enough to keep us cold unlike central/southern valley if they get the bulk of the moisture.

  4. Ken in Wood Village says:

    What’s with the NWS website. It’s been really slow since yesterday (angry face)

    • K says:

      No clue, but here’s the morning discussion. Sounds optimistic, and features a lot of evidence that a snow event is still on the table (also 12Z runs shifted north, so yay).

      “ Perhaps of more importance for the majority of the population in our
      forecast area is how the period from tonight through Monday evening
      evolves. East winds are already developing through the Columbia Gorge
      and although they may ease a little this afternoon, they are expected
      to return even stronger tonight and Monday morning. Confidence is
      increasing that temperatures will be cold enough for snow north of
      the frontal zone as it lifts slowly northward tonight and early
      Monday. Most 00z models keep the frontal zone further south than
      prior runs as another weak low develops offshore and moves onshore
      somewhere on the central or southern Oregon Coast. The 00z GFS,
      reinforced by its 06z run, keep the front so far south that the PDX
      metro area would barely receive any precipitation Monday while Salem
      and Eugene deal with the potential for a major snow event. However,
      the 00z ECMWF is further north (albeit south of earlier runs),
      certainly keeping anywhere south of Kelso and Astoria in play for
      significant snow. Looking further into the 00z GEFS and ECMWF
      ensembles, there remains significant support for a track well north
      of the one shown by the 00z deterministic GFS, with some members
      still even north of the 00z ECMWF track. Believe that much of the
      uncertainty lies in whether strong northern stream energy pushing
      southward into the Pacific from the Yukon can interact and phase with
      a progressive shortwave now near 38N/140W. The ECMWF has been
      initializing the southern shortwave better than the GFS for the past
      few model cycles, and based on latest water vapor imagery it appears
      doubtful that the southern shortwave will be completely left behind
      by the slow-moving upper trough off the WA coast. Thus I am still
      leaning toward the more northern solutions for the front and low
      track, as any phasing between northern and southern systems would
      likely lead to a stronger (but still modest) low than depicted by the
      00z GFS… and stronger lows tend to curl further north than most
      models suggest. ”

      • LO480 says:

        Yes, we have seen this in past scenarios. Thanks for sharing.

      • Ken in Wood Village says:

        I saw that, I was just wondering why their website is so slow. 🙂

      • Jim Rockfish says:

        K… you don’t know what you’re babbling about as ususual. Let the professionals handle this. Go upstairs and take your Hot Pockets out of the microwave before they get cold. – Mom

        • K says:

          Jim, wasting your time and energy again? So, so sad. Maybe you’d like to replace the NWS meteorologists who actually know a thing or two? Maybe stick to the menial stuff you’re good at instead of blabbing with no merit 😂

        • Anon says:

          Mr. big man over here 🙄

      • Ken in Wood Village says:

        What I liked about the forecast discussion was this,

        “and stronger lows tend to curl further north than most models suggest”.

        Hopefully that would be correct 🙂

    • Tanis Leach says:

      That’s government for ya

  5. Alohabb says:

    Usually you head south for the warmth , guess it will be for snow this time.

  6. JJ78259 says:

    Great to see the northwest getting some much needed winter weather. Looks like Eric was correct that El Niño was moving off Stage Right! Could be a normal wet and cold spring! Weather Dan could be getting tons of Snow.

  7. LO480 says:

    Something to consider: In past events more moisture than models predicted has migrated north into the Portland Metro area. Portland is well into the cold air, so it as all about the moisture lifting north.

  8. Joshua Lake Oswego says:

    12z WRF-GFS giving the southern metro area 2-4”. I know Mark likes that model.

  9. paulbeugene says:

    Gfs 12z has more snow for S valley than 6z run…aberration vs trend? At least maybe the moisture won’t be so quick to exit.

    Even with basically all models showing at least decent snow totals for the south valley, I remain bit skeptical. Roseburg and Eugene snow totals on Euro ensemble output a bit hard to imagine. At least snow mixing in up north is making me more confident than I was yesterday

  10. John Cripe says:

    Charlie on mt scott, 1000 feet
    4.5 inches of snow check picture on weather underground korhappy 5

  11. Anonymous says:

    Charlie on mt scott
    here at 1000 feet we have 4.5 inches on the ground at 8a.m.

  12. LO480 says:

    Had an inch of snow and road slushy but covered. Current temp 32.5.

  13. Scott says:

    2-3 inches of pretty heavy wet snow in West Linn @ 700ft.

  14. Jason Hougak says:

    Heavy Silver Dollar sized flakes and piling up fast.

  15. Jason Hougak says:

    Timberline getting close to 150” BASE could it reach 200”??? Looks very possible.

  16. Jason Hougak says:

    Heaviest snow I’ve seen fall the past 3 weeks falling right now.

  17. Jake in Gresham says:

    Currently 33F and snowing big flakes here. Wut

  18. ocpaul says:

    Surprise snow is the best! 34 and snowing at 349′ in OC. We’ve got an inch or so and everything is white. Nice, steady snow! More to come I hope.

  19. Joshua Lake Oswego says:

    The first 12z model is in. The NAM. Game over for Portland. We will take our 1” and like it.

  20. Jason Hougak says:

    Woke up Feb. 3rd with snow falling again last Sunday with a fresh 3” and again this morning with almost 4” of snow. Lost power about 1/2 hour ago. Got the generator out and could hear limbs snapping. This has truly been a remarkable February. With records for snow in Hawaii and Malibu. Could this be related with the solar cycle and the sun going into its solar minimum. I posted about this about a week ago and the article I found sure sounds like it coincidences.

  21. Alohabb says:

    Wow, a big ol dud according to Tracy Hinson

    • Alohabb says:

      More than likely we will see things move to the south versus pdx. Well, there you go per kptv this morning

      • JohnD says:

        I guess we believe who we want to believe. Not sure to what extent she is–or is not–in collaboration with Mark at this stage of the game.
        The NWS was pretty optimistic this morning!
        Probably will back off the Blog for a while. Starts getting petty.
        Enjoy all! Whatever happens! I know I will.

  22. 97015 says:

    Big ol’ fat flakes here in Clackamas

  23. PAUL D says:

    According to Tracy Hinson the models have backed way off for the PDX area. Another dud.

  24. JohnD says:

    Well, reason for optimism again!? Mods trending north again!? GOLU best for the foreseeable.

    • JohnD says:

      Currently 33.4′ with moderate snow shower here at 200′ in SWPDX @200′. Slush on cars. GOLU rules!

    • Joshua Lake Oswego says:

      Uh, what model is trending north? They are ALL trending south. Even the last hope, the NAM. At this point it isn’t so much trending, but way more likely what will happen. We are within 24 hours.

  25. Anonymous says:

    Woke up with snow covered roads in Tigard. Elevation 450ft.

  26. Don says:

    34 Snowing in Sherwood. On cars and grass.

  27. Joshua Lake Oswego says:

    Snowing pretty heavily here right now. Big wet flakes. Too warm to stick. 35 degrees. Wouldn’t hang around anyway. Looks like we are getting skunked or close to it for Monday. Probably a few hours of light snow and that’s it. Minor accumulations. The central/south valley wins.

    • Joshua Lake Oswego says:

      Sticking to certain surfaces now. Pretty. Too bad the precipitation is about to dive south and pretty much stay there for good.

  28. Jakeos 550ft OC says:

    It’s snowing and sticking in Oregon City, 32 degrees. Surprised me big time when I let the dog out. It was 41 and rain at 11 pm.

  29. SE Portland. Just east of Kelly Butte(east of i205) 300ft elevation

    Snowing hard- trace on cars and grass

    • Jake in Gresham says:

      Convergence zone looks like Salem for heaviest snowfall. Time will tell where the interaction between the cold air and warm moisture air meet but PDX is well within the boundary of cold.

  30. Larry says:

    Does anyone think the NWS jumped the gun with the winter storm watch?

    Or were they actually correct in all of this weather model mess?

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