Timing Speeds Up, Snow Arrival May Clip End of P.M. Commute

February 7, 2019

11pm Thursday…

As we get closer to a (big?) event like this, we narrow down the timing and snowfall forecast.  That’s happening this evening now that all model runs are in.  Nothing really new model-wise until late morning Friday.


1) If you have a choice between a two-wheel drive and 4×4?  Take the 4×4 to work Friday.  For example my wife & I have a pickup and a Subaru.  I just decided the 4×4 would be a much better choice just in case roads turn snowy quickly in the evening.  No, she won’t get stranded on the side of the road, the other vehicle will be at home.

2) Models are all faster with snow arrival, coming in right near the end of the evening commute (6-9pm).  At first it may not stick.  But considering the cold airmass over us and very dry air to start, I’m thinking temps may fall quickly and wet roads freeze up at some point in the evening.  Or snow starts sticking on top of slick ice underneath…you get the idea.  As of now I’m expecting that evening commute to be okay, but it doesn’t hurt to plan ahead JUST IN CASE we’re a few hours off!

3) Most of the snowfall will be tomorrow evening through very early Saturday.  Less now during the day Saturday with the faster timing.  This means roads will likely be snowy and icy right away Saturday, but the rising February sun angle could mean much better afternoon conditions…maybe.

4) I’m still thinking 1-4″ snow, although more dependable models are in the 2-4″ range.  Regardless there’s no reason to change the forecast for now.  Here’s what I’m quite confident with now…

2017 Snow Headlines Happening Now

And what is still a bit unresolved

2017 Snow Headlines Happening Now 2

I’ve sped up the timing for Wilsonville down to Eugene in the Willamette Valley and along the coastline.  The Columbia River Gorge will be windy, snowy, and cold Friday night and Saturday.

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Here’s a look at all the evening model run forecast numbers.  The colored contours are the ECMWF only

Snow Model Accumulation Long-Term

I’ll be posting again late tomorrow morning or around noon.

Chief Meteorologist Mark Nelsen

Saturday Snow Update

February 7, 2019

1:30pm Thursday…

Now we’re within a couple of days of a Friday night and Saturday “snow event” so it’s time to put out a few numbers.  I’ll make this posting quite a bit briefer than yesterday’s.  BTW, I know we have an issue with readability on mobile devices…we’re working on it

At this point it looks to me that at least PART (if not all) of the metro area will be getting “sleddable” snow from late Friday night through Saturday evening, when we dry out.  By that I mean at least 2″ snow.


(this is between Friday night and Saturday evening, subject to change in the next 36 hours as we get new info)

PORTLAND METRO UP TO LONGVIEW  1-4″, most near Gorge & Clark County, least south & west metro.

SOUTH OF METRO DOWN TO ALBANY Trace-2″, most likely not anything Friday night, a bit too warm

NORTH OREGON & S.W. WASHINGTON COAST  Trace-2″, highest total up around Cannon Beach to Long Beach

COLUMBIA RIVER GORGE  3-6″, This is from Corbett/Mt. Pleasant areas eastward.  A typical east-wind driven snow; expect blowing/drifting snow entire west end.  Cold, windy, and snowy!



Models are in a bit better agreement today, at least the dependable WRF, ECMWF, and GEM.  America’s pride, the GFS model, appears to be out to lunch.  Too warm and it produces little to no snow through Monday!  Our RPM model takes its input from that GFS so you see it isn’t doing much either

Snow Model Accumulation Long-Term

The GEM, not shown here is “wetter”, producing more like 3-6″ snowfall all the way from Longview to Eugene.  I’ve ignored that for now as well.

Precipitation arrives Friday evening in the valleys, and at that point it’ll be maybe 5 degrees too warm for sticking snow, except near the Gorge where evaporative cooling and leftover east wind will keep temps at/below freezing

ALL models show that we wake up to snow showers Saturday morning, with the WRF and ECMWF already spreading cold (below freezing) air through the central/east metro.

All models also agree that anything wet freezes solid Saturday evening, regardless of how much snow we get, or don’t get.  EXPECT ICY/SNOWY ROADS SATURDAY NIGHT AND AT LEAST THE FIRST HALF OF SUNDAY


  • Do we just get scattered light snow showers Saturday?  Just one inch?  If so, then metro area roads could remain in good shape due to strengthening February sun energy keeping pavement temps above freezing
  • OR…is it steady snowfall, freezing up metro roads right away in the morning as the cold east wind arrives?  If so, that’s a real snowstorm (several inches) and traffic grinds to a halt right away or during the day in our area.  That would include blowing and drifting snow in the east metro and hills.

I know many of you have events on Saturday and it’s a tough call.  I’m leaning toward at least the central/east half of metro turning snowy/icy during the day or even starting out that way at daybreak.  I do feel pretty confident that from Wilsonville south there’s a decent chance roads are just fine until late in the day.  ‘ll have a better idea tomorrow.


  1. NO SNOW, A DRY DAY  A very slow thaw on some roads, but shady areas and hills stay locked in ice.
  2. Cold east wind keeps us mainly frozen through the middle of next week!
  3. A 2nd system arrives Sunday night and continues through Monday morning.  We could see at least 2″ with this one, possibly more.  Yes, Monday morning we will likely be locked in a beautiful white coating of snow across the entire metro area.
  4. This is crazy, but a THIRD system with possibly a lot more moisture runs right over the cold east wind Monday night and Tuesday.  Models are all over the place with this one.  Anything from just light snow up to many inches.


Chief Meteorologist Mark Nelsen