A Winter Wonderland New Year’s Morning? Mainly In The Hills

11am Saturday…

As mentioned in the previous posting, a very weak weather system moves over the Pacific Northwest tonight and New Year’s morning.  During much of the system’s passage, temperatures will be too warm at the lowest elevations for snow to stick.  But near the end, as showers are tapering off, snow may stick in spots all the way down to the valley floor.

METRO AREA HIGHLIGHTS

  • Your New Year’s Eve plans are safe  There won’t be any snow on roads in the lowlands through at least 2-3am.
  • But any of us could see snow mixed in with the rain during the overnight hours.
  • Near/above 1,000′ (top of the West Hills), some accumulation is possible, but even then it may be a degree or two too warm for sticking snow.
  • 4am-10am a dusting to 1/2″ is possible anywhere, but I’d lean towards a dusting and not that half inch.  Many of us get nothing tomorrow morning.
  • The rest of tomorrow we’ll be above freezing, at least through 3pm, so I think roads will be clear.
  • An arctic front passes through the area tomorrow evening; that means a sudden arrival of cold east wind and all wet areas will freeze.  At that time we’ll be dry, or just a few flurries maybe.

CASCADE FOOTHILLS AND COAST RANGE

  • Rain or rain/snow showers change to mainly snow showers above 500′ by midnight.  At that time some roads will start getting snow-covered above 1,000′.
  • Anytime after midnight and through Sunday any road in the Coast Range and above 500-1,000′ west slopes of the Cascades could get snow-covered.  That includes Sandy, Estacada, Beavercreek, Mill City etc…
  • Expect 1-3″ in these areas, more above 1,500′.

 

The NWS is going for a Portland snowstorm tonight and Sunday morning, but I think it’s unlikely.  They are forecasting 1-3″ in the metro area (3″ on hills) and have a winter weather advisory up starting at 10pm.

I feel that’s way overdone for several reasons.  The biggest is that we’re in mild onshore flow through around sunrise Sunday.  In fact southwest wind picks up this evening and continues until almost day break.  Freezing levels are above 1,000′ through 7am tomorrow, when almost all of the moisture will be falling out of the sky.  I’ve seen this many times here in Portland.  We’ll be too warm down at the valley floor until sometime after 4am to even think about snow sticking down here.  There is excellent model agreement on this as well.  That southwesterly breeze is a real killer (for snow) UNLESS the atmosphere is colder than what we’re expecting now.   Take a look at model snow forecasts from the ECMWF, WRF-GFS, & RPM and they agree.  Note the RPM snow is mainly after 4am:

rpm_4amsnow1km ecmwf_snow_18z rpm_snow_12z-1

 

None of those inspire a lot of confidence for a sledding day Sunday in Portland do they?

Now during the day on Sunday cooler air gradually filters in from the north, but we’ll be battling daytime heating (a little) too.  Leftover snow showers could dump a dusting anywhere during the day, but most areas will be slightly too warm still for stickage.  So we should stay above freezing through 3pm, then we plunge into a frozen abyss.  Okay, that’s a bit dramatic, but I don’t know when we’ll go above freezing again…maybe about 6 days from now?  We’ll see about that.

To wrap it up, I think many of us will wake up to a white dusting, but a frozen city with snow all over the roads like we had with the big fiasco in mid-December is unlikely.

Happy New Year!

Chief Meteorologist Mark Nelsen

 

 

 

 

 

99 Responses to A Winter Wonderland New Year’s Morning? Mainly In The Hills

  1. Jason hougak says:

    Looks like if we work together we can get Mark to boot the troll. Great job in working together team. Way more fun to blog when it’s not interrupted by others.
    Snowing heavy big flakes now with a strong gusty SW wind. Nice day to go enjoy church!

  2. Some snow on the hills, only mixed precip here with no accumulation :-(. It’s hard to get snow when you’re surrounded by 50-degree salt water.

  3. Longview 400 ft says:

    Currently 32.5
    All White
    3 inches

  4. GTS1K' says:

    3-1/2″ now

    31.2

  5. Paul D says:

    Just made a round trip from Hillsboro to PDX. Hillsboro was very slushy at 5:30, just rain on the freeways to the airport, but coming back it was like someone flipped on the winter switch west of the tunnel! 32 degrees and snowing. Very slushy on Hwy 26 and luckily people were slowing down and driving mostly reasonable. When the altitude went down past Murray Rd, it was mostly rain until Hillsboro, and back to slushy snow.

    Glad I’m safely tucked away inside again!

  6. Deer Is. at 750' says:

    5 or 6 inches her.

  7. Jason Hougak says:

    Thanks so much for crowd control Mark and getting your blog back to what your blog is about. There are a few other trolls which would be nice to wrangle as well if you have time.
    It’s been snowing really hard off and on up here in the foothills between showers. 32 with 1″ maybe 1-1/2″ on the ground. It’s B-E-A-utiful outside anyhow!
    Happy New Year Mark and loyal weather lovers

  8. Aleta- West Gresham says:

    Has turned to snow for now in my area of Gresham. Was rain not that long ago.

  9. Max in Fairview says:

    Nothing but rain here at the moment. Could be some nasty roads tonight.

  10. JERAT416 says:

    Haven’t gone out to measure it, but looks like a half inch or less up here at 650′ on Bull Mtn. Sticking to the road also. Still snowing, but not all areas are getting anything. Looks very spotty on the ODOT cameras for now. Let’s hope this all dries up from the road before the arctic air gets here. By the way, is that coming from the east or north? The gorge is above freezing right now. So either the cold air is hundreds of miles away, or not coming directly east this time. Happy New year everyone!

    • pappoose in scappoose says:

      National Weather Service Portland Oregon
      310 AM PST SUN JAN 1 2017

      With the strong high pressure sliding into the northern Rockies on
      Mon and Tue, will see increasing offshore flow. This will deepen the cold arctic air mass, and bring strong gusty east winds to the
      Cascades and especially through the Columbia Gorge. With east winds gusting 50 to 70 mph in the western Columbia Gorge. Gusty winds and cold air will create wind chills of 0 to 10 above for many areas across the interior, and 5 to 15 below wind chill in the Columbia Gorge and over the Cascades. Bundle up! Rockey.

  11. Lee Wilson says:

    Happy New Years.
    It has been very eventful here.
    Were 34 All night and we had heavy snows..but it was to wet to stick at the lowers elevations.

    How ever places like Wood Side Drive in Long view had sticking snow.

    Micro climates are fascinating to say the least.

    We have iceforming on our solar panels sure to Evaperative something rather.

    Grass is crunchy in areas wet in others.
    Looks like the next 4 days will be good news for solar.

    I had been offline due to Q links False Advert on unlimited internet
    Yeah 60 Bucks for unlimited my foot.

    Woke up to having service…Not sure if that was the work of the Attorneys General or Not..
    Or perhaps an error in their system.
    At any rate..Happy New Years..

  12. GTS1K' says:

    32 and still at it.
    Light but steady
    2-1/2″

    Beautiful!

    Thank you, Mark…

  13. Longview 400 ft says:

    Currently 32. 5
    Snowing
    1 1/2 inches

  14. Diana F. says:

    Thanks Mark! Perfect ending to 2016. If we can’t have a snowstorm….at least we can have a little peace, quiet and camaraderie!

  15. Registered Nerd says:

    Thanks Mark! Happy new year to you as well…I’ve been a weather blog stalker for quite a while reading and learning, but haven’t ever posted. Scooter was taking all the fun out of reading it… In fact he made weather Dan seem great! I like Dan’s insight now. Thanks again, hoping for at least one snow event out of this colder regime.

  16. Mark Nelsen says:

    I think we are Scooter-free…if I did it right. I had enough of that. That’s my Happy New Year to you folks!

  17. Tyler Mode in Battle Ground says:

    1″ of snow here in Battle Ground at just over 300′. 32.9 degrees

  18. Justin Rogers says:

    Feeling a bit lonely tonight? I wonder why…

  19. Jake-(Gresham) says:

    Actually with XNA and synthetic RNA insertion we will probably get rid of retrograde evolution in the next 50 years or so. Thanks for the gibberish post though.

    Helps to know which post to just scan right past.

  20. Ash Qelon says:

    9;03PM, mall 205 -Gateway area,
    NOTHING here, a few earlier snowflakes but they signed off the internet.
    Too warm now for any real snow accumulations for entire area metro Portland.
    Go see the metering reports..
    Even in gorge is still too warm.
    May change but too minimum moisture and TOO
    high temps right now.

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