Snow Likely Tuesday Night Metro Area


Confidence has grown that we’ll see at the least a coating of white (1″) in most of the metro area Tuesday night and Wednesday and possibly as much as 4″.

All evening models are in and they all show something similar.

  1. The main precipitation shield from the storm moving through southern Oregon tomorrow doesn’t make it to the metro area.
  2. Instead we get a widespread area of light snow that develops tomorrow evening through much of Wednesday over much of NW Oregon, including the metro area and Salem/Albany.  This is generated by moisture lifting up under an upper-level low.  The low sits over us through much of Wednesday

The WRF-GFS, NAM, GFS, & ECMWF all show the same general idea.   They also generally show heaviest totals west metro as opposed to east.  ECMWF wasn’t as particular though showing that east-west divide.  Check out the precipitation forecast for the 24 hours ending Wednesday at 4pm:


And the accompanying snow forecast, noting that in the first 6+ hours it might be too warm for sticking snow in Salem/Albany:


So the 1-4″ forecast seems good for now, at least until the 12z runs come in.  I’ll be blogging again in the morning once I wake up and get going.

For now I think a major point is that we DO NOT EXPECT issues for the evening commute Tuesday.

This all happens later in the evening and into Wednesday.  Obviously if we do get the snow then Wednesday is a different story.

Chief Meteorologist Mark Nelsen

60 Responses to Snow Likely Tuesday Night Metro Area

  1. W7ENK says:

    Watching the models struggle over tonight’s potential for snowfall, and I’m seeing one very evident signal coming out of the mix.

    I’m about 75% confident this thing busts for all of PDX metro.

    If not, then this is a CLASSIC setup for moderate to significant snow accumulations for nearly all of PDX metro, especially the Westside. HOWEVER, the cutoff line sits right around Foster Road, and down the Willamette River. Immediate Downtown Portland and points South of Foster Rd and East of the river get screwed. Temps remain just a tad too warm for falling snowflakes to stick in inner SE, and South of JCB — Milwaukie through Gladstone, and OC at river level (The Dome) — gets cold, cold rain. You’ll all be waking up in the morning to inches of snow everywhere, TV reporters LIVE in the field reporting on conditions from Troutdale to Sylvan, Vancouver to Wilsonville. Messed up traffic all over, school closures scrolling across the bottom of the screen listing every district in PDX metro… except NC12 will be disappointingly absent. We here will wake up to green, brown, and wet, but be completely surrounded by inches of snow.

    Here’s my map highlighting areas that should expect strong to severe disappointment:

    95% confidence in this solution.

    The Dome will be strong with this one.
    I’ve witnessed it happen a hundred times.
    This setup is perfect for it.

    I sincerely hope I’m wrong.

  2. Jake-(Gresham) says:

    Breezy now of 5+ mph with gusts at 10mph now and a temperature of 37F from 38F. I was hopeful to see this at noon but was anticipating 3pm. This is going to be good.

    I can feeeeelllll it! 😀

  3. GTS1K' says:

    Dense fog here last half hour. I can now hear truck/river/industrial sounds from NW Portland which means there’s at least an easterly drift. Temp has gone from 35.9 to 34.0 since 10:30.

  4. Jake-(Gresham) says:

    Alright since we’re not into the 12 hours window of this event starting looking at the Euro’s latest run here (slide 2 to see the low pressure system’s position), latest GFS, and NAM:

    My assessment is that real live trajectory of this storm will be trending Northward. Euro slipped on previous run but current and all the major models indicate a Northward theme.

    I’m not going to wait till this evenings runs (not really fun if I wait that long haha!). I’m betting on 4 to 7 inches of snow for all of PDX areas.

    Highly unlikely in my eyes at seeing less than 3 inches up into Clark County.

  5. Andrew says:

    Updated NWS forecast for Beaverton:


    Rain, possibly mixed with snow, becoming all snow after 10pm. Low around 28. Blustery, with an east northeast wind around 24 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New snow accumulation of 2 to 4 inches possible.


    Snow likely before 10am, then snow showers likely, mainly between 10am and 4pm. Mostly cloudy, with a high near 32. East wind 15 to 17 mph, with gusts as high as 30 mph. Chance of precipitation is 60%. New snow accumulation of 1 to 2 inches possible.

    • Jake-(Gresham) says:

      Wow. That plays right into what I just said. Alright, we got ourselves a ballgame!

    • Diana F says:

      °NWS forecast Tonight: East Vancouver
      “New snow accumulation of less than one inch possible”.

      °NWS forecast Tomorrow: East Vancouver
      “New snow accumulation of less than one inch possible”.

      Son of a nutcracker!

      °NWS forecast 2″ to 4″ LAST NIGHT (Monday). Issues a warning to Vancouver metro north. Got zilch.

      °NWS forecast 2″ to 4″ TONIGHT but has now changed it to the “less than an inch” bs.

      Eye rolls all around, Weagle and co! Yer killin’ me! The sheer disappointment!

  6. Mark says:

    Thanks for the model snapshots Mark. Great to see most all models coming into agreement with one another. Now watch them all agree to be wrong! Doah! ; )

  7. Joshua Downtown PDX says:

    12z GFS is good for 2-4″ metro-wide. Canadian is good for 3-4″. NAM is buck wild… 1-7″. RPM is less than 1″. Mark is probably waiting for the EURO before he puts his chips on the table.

    • HAWKEYES23 says:

      What time is EURO?

    • Joshua Downtown PDX says:

      It should be done in the next 30 minutes – 1 hour.

    • Jake-(Gresham) says:

      For those wondering why the potential is not even more if this setup is so ‘ideal’ for PDX. This is why. Some models more trusting like the Euro put the low pressure system South of Eugene which translates into a lot of energy going into California:

      Next Euro run starting now. Let’s see where the system shows up. Rolling them dices! Now I’m just getting greedy lol!

    • Diana F says:

      The wait for Mark’s $100 bucks is killing me!! (you know, more than 2 cents?)

      Gaaahhhhh I admit it…..I’m literally clock watching!

    • Anonymous says:

      I really need some guidance here. I have a school concert scheduled to take place (including prep and takedown) between 5 and 10 tonight. I need some idea (not wish-casting) of how things are going to play out before 10. To my untrained eye,the time table seems to be speeding up. South valley appears to be getting the rain they were supposed to get later this afternoon. Again, not a trained eye. Thoughts?

    • Jake-(Gresham) says:

      Alright so the Euro has shifted the low pressure system about 50 ~ 80 miles North. Tough to see but frame by frame it shifts a lot but by looking at the high pressure in British Columbia it appears to be blocking less to its trajectory toward Oregon. Interesting.

    • Jake-(Gresham) says:

      Tough to see as the model frame by frame shifts a lot.*

      Alright, time to grab some coffee.

  8. Jake-(Gresham) says:

    Me’s thinking if I see an East wind around noon this could play out very well for snow. I don’t see any movement yet with the trees but we shall see’th.

    Currently 38F and a slow, dank, and dark drizzle here.

  9. W7ENK says:

    Who’s back?

  10. Diana F says:

    …..AND the KPTV forecast at 6 am Tuesday is calling for 1″ to 4″ for the metro area overnight into Wednesday.

    Today rain all day, up to 39°, then drop down to the appropriate, freezing’ish temp / dew point / precipitation, and BAM…..glorious, white, soft snow blankets our part of the world!

    Ok, guys and gals, I’m passing something out to everybody.

    It’s a piece of 8.5″ x 11″, lined paper that is no longer white. It’s been folded about 100 times, and has seen MUCH better days. When you unfold yours, this is what you see:

    What will you look like….on Wednesday Morning?
    1) 😍 (____)
    2) 😲 (____)
    3) 😭 (____)

    And just like we all did in the second grade, feel free to vote / check your choice!

    Those who guess themselves correctly will post a photo confirming their results on Wednesday morning, preferably as they roll out of bed….

    *Valid for #fellowweathergeeks only, void where prohibited 😈

    • Scott says:

      I like it, sounds like fun!!! I am hoping to look like #1 finally, My area, Bethany, has mostly missed out….too much wind, kills all my moisture…..

      This is the time, I will stay up all night!

    • Stan says:

      Take a breath lady…. Step away from the computer.

    • Diana F says:

      Scott, I know right? We’ve had just a touch here and there in East Vancouver. It has to be our turn, sooner or later. This one sounds almost too good to be true….! Anxious to hear from Mark….

    • Garron 1/3 of a mile from Hillsboro Airport says:

      Diana yeah, praying for the mother load this time!!! Love your enthusiasm!!!

  11. Marc (Brush Prairie, WA) says:

    I’d sacrifice no snow if it meant Battle Ground Lake gets nothing as well. The meltdown is worth it.

  12. Andrew says:

    Based on current models and forecast, what would need to happen for Portland to get a bigger snow event – say 4-6 inches versus 1-2? What will the forecasters be monitoring the closest over the next 12 hours?

  13. Anonymous says:

    Why is their always lesssnowacculmation on the foothills of the west slopes of the cascades? Silverton, stayton, molalla area.

  14. Diana F says:

    Hey Tyler, I thought for sure Battleground was going to get some snow last night!
    And according to Good Day Oregon, you guys are the hot spot right now (6:39 am Tuesday) @ 39 degrees!!!

    AYE YI YI!

  15. Trevor W. says:

    Went over highway 6 in the coast range early this morning. It was a mess! Trees down and tons of wet, slippery snow.

  16. Alohabb says:

    Winter weather advisory now out. NWS is calling for 1″ in Portland with the hills possibly 2″

  17. Near Durham elementary 167' says:

    Rpm finally solidly on board for 4-5 inches in pdx…

    • Joshua Downtown PDX says:

      Those are old, friend. Anyway, it’s just one model. If Mark is feeling pretty confident about things, then so am I.

    • Joshua Downtown PDX says:

      Today’s 12z RPM is no bueno either. .4″ in Portland. Not much more for our friends to the south.

      • Andrew says:

        Wow that’s a bummer. Seems like latest model runs are majorly pulling back the precip. We just can’t get things to align this winter in PDX for real snow.

  18. Diana F. says:

    😶I’ve been up all night with a sick 8 year old, so of course I am taking some time to review models, statements, forecasts et al as the night progresses….specifically I was just recapping the 930pm NWS FD, and I got a bit of a chuckle over this part…..”….am becoming increasingly convinced……won’t see snow to the valley floor in Vancouver tonight …” when just a few hours earlier, they put out a weather advisory for 2 to 4 inches Vancouver and North, even specifically leaving PDX out of the affected area. 😶

    That in itself seemed a bit strange to me, as in I don’t think that happens very often, therefore IMO, not a good thing to hear for those 👀 looking forward to those inches!!!
    Anyhoooooo……so then nothing materializes, and finally they ARE in fact convinced, based on temps that never did go down, (nor btw did they even appear to maybe be going down lol) and of course, no snow falling did help convince them as well. Aw those poor fellas! Meteorologist Mark, our very own M and M, had already expressed a “no way” stance for Monday night snow (now remember, this was supposed to be accumulating snow per NWS) and he’s betting on Tuesday/Wednesday 😉

    Since Monday night was a bust (and it’s 4:50 am Tuesday right now, I am now looking forward to Tuesday night!!

    Thanks Mark—-between the tv telecasts and the blog, we are, by far, and literally, the most well educated and well informed bunch of geeks in the entire PAC NW! I think it was Jake who commented last post about Mark letting US know things before even the NWS knows things!! Now that’s a BLOG extraordinaire!

  19. Jerry says:

    Well, guess it’ll give me more time on my new snow blower!

  20. muxpux (Longview) says:

    I commute from woodland to Castle Rock. Not excited about tomorrow night.

    • muxpux (Longview) says:

      Let me clarify, im off work in woodland at 11pm and commute to CR. Should be fine in the afternoon. Coming home could be white knuckle…

  21. sds says:

    We got two sticking snow squalls today that whitened the trees and ground at 250 ft up the Lewis river out of Woodland. Still have 3 in. on frozen ground. Let it snow–this is more like the winters in the 70’s.

    • JJ78259 says:

      Nice to the 70s back again there were a lot people on this blog saying those days were over with Global Warming. Their Back!

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