A Cool Week Ahead; Snow Level Low Again Tuesday Evening

9pm Sunday…

Today generally worked out about as expected; no snow in the lowlands. There was plenty of “chunky rain” on my drive to work at 1-2pm. Models did well showing temperatures holding steady or even dropping as the day wore on.

Sticking snow level was all over the place. From around 200-300′ way out westside near Banks

to 2,000′ or a bit higher east of Rhododendron at mid-afternoon

This really points out how important precipitation intensity can be to snow level forecasts in these marginal snow setups.

Steady precipitation has ended for most of the area, and now it’s on to very spotty showers tonight through Monday in the post-frontal cool airmass. GRAF model says less than .10″ for most of us along I-5 through sunset Monday. There’s not going to be much of anything falling out of the sky tonight and Monday

Since temperatures are just a few degrees above freezing and wind is light, any clearing could lead to icy roads. This is far more common than snow in our climate. So keep a close eye on your car thermometer tomorrow morning as you head out and of course Andy & Tony have you covered on FOX12 OREGON. Of course if skies don’t clear much, we won’t have to worry about icy roads. I think it’ll be real spotty. A summary of the next 24 hours…

TUESDAY & BEYOND

An active weather pattern continues through the end of the month, and at least into the first days of February. But it’s not a strong westerly jet stream running right into the Pacific Northwest. Rather a series of cold upper-level troughs that drop down along the coastline, or into the Eastern Pacific. #1 is approaching now; will be right over us Monday

That one heads down through the Desert Southwest Tuesday/Wednesday while #2 settles in just offshore

Then by Saturday/Sunday, #2 has moved east of us and a larger/deeper low (#3) is plopped down in the Gulf of Alaska. This wouldn’t be quite as chilly for us since the cold air is dumping out over the northeast Pacific. It’s a long path over the mild ocean from Alaska to the Pacific Northwest!

This doesn’t tend to be a HUGE snow producer for the Cascades (until next weekend) since a lot of the energy is headed to our south. The Sierra Nevada pick up many feet more snow than the Cascades this week.

So the big question is…could we see another close call for lowland snow? Possibly, but it’s a stretch just like today.

One thing we know isn’t in play; there’s no source of cold air to the east. I don’t see a setup this week that would bring in 20-30 degree air through the Gorge with moisture riding over the top for a widespread snow event. What I DO see is another “close call” Tuesday afternoon/evening. As a Pacific frontal system moves toward the West Coast (2nd jet stream image above), most energy heads south. But we get the leftovers as a band of precipitation swings north over us. There will be a relatively strong surface low well offshore too. The GRAF model shows the precipitation moving over the Willamette Valley Tuesday afternoon/evening with heaviest precipitation from Salem south and west. That’s because the precipitation band is moving away from the main storm center and weakening. There are hints that MAYBE the west side of the Willamette Valley up against the Coast Range could score snow to relatively low elevations…maybe.

This model and the ECMWF produce about .20-.30″ liquid precipitation. But temperatures remain above freezing through the Valley on both. GRAF gives hints the far westside of Willamette Valley might get something. But nothing for most of us…like today

The WRF-GFS says forget it as well; all the sticking snow is right up against the east side of the Coast Range. Total snow ending at 4pm Tuesday…It could be quite a snow dump up in the Coast Range!

ECMWF tries a little harder, but temperatures are 33-38 degrees through the entire “event”.

Luckily we’ve got another day to see if models warm up a few degrees as they did this time around. There WILL be an gusty east wind blowing through the Gorge, but there’s no cold air source eastside as I mentioned. So that doesn’t help us. Models are insisting dewpoints drop down into the 20s Tuesday just ahead of the precipitation too; allowing the 40-42 degree midday temps to drop down close to freezing a few hours later with evaporative cooling. I’m a bit skeptical.

Beyond Tuesday, snow levels lift a bit. It appears Wednesday through next weekend they will be in the 1,500′-3,000′ range. No sign of rain in the Cascades and it’s going to stay cool in the valleys.

I will have some time to blog again tomorrow evening, sometime after 5-6pm. Hopefully things become a bit more clear at that time. That should allow us to either swing toward NO SNOW in the valley (most likely) or SOME OF US WILL GET A LITTLE TUESDAY P.M.

Chief Meteorologist Mark Nelsen

35 Responses to A Cool Week Ahead; Snow Level Low Again Tuesday Evening

  1. JohnD says:

    Actually Andrew—and I do-btw-recognize you to be a sensible, nice person—with formidable weather view; but I NEVER diminish weather expectations or reactions large or small. What is important to some may not be to others. Etc. All relative. My wife is from Massachusetts and I do get it. I’m a hiker—mtns too. In the lower stretches, you see the novice folk. Up high, the tending Herculean. All relative and all good. So too with weather—forecasts and outcomes. ‘Hope I’m not mis-understanding your point.

  2. Joshua Lake Oswego says:

    Haha. I read it and cringed. Imagine being from Buffalo and reading that statement.

  3. Andrew says:

    you know it’s been a lame winter when a Special Weather Statement from NWS feels like a blizzard warning. It’s actually a pretty comical read. Describes a 1-3 hour period of light non-sticking snow. Anyone who reads my comments knows I’m a fairly positive, glass half full kind of guy when it comes to snow chances, and even if I find that pretty hilarious. What’s the next level down from this, a predicted total snow flake count? Well I’ll be damned if we don’t maybe get a fourth hour out of this thing!

    • Larry says:

      Yeah, like, who cares? As long as the snow doesn’t stick I don’t see the need to issue a SWS. Then again they expect snow to stick down to ‘500, so it makes sense.

  4. Chad says:

    I hope you guys all have clean windows for tomorrow when you spend the day and evening licking them 😂😂😂

    May be a flake or two in the air 😜

    • Larry says:

      Thank you!!! I know my tongue will be very dirty after, but whatever it takes to chase winter, right?

  5. runrain says:

    James Taylor must have had Northern California in mind when he wrote “I’ve seen fire and I’ve seen rain, I’ve seen sunny days I thought would never end”.

  6. runrain says:

    Adding insult to injury: it’s snowing in Scottsdale, Arizona at this hour…

    • W7ENK says:

      Yeah, but aren’t they roughly a mile high?

      • JohnD says:

        My wife has a cousin in Payson, AZ @ 5,000’ in the middle of the state. Elevation notwithstanding, most years they stay mainly mild and dry with high temps averaging in the 50’s. They do get a little snow now and then—but not nearly as much as notorious Flagstaff to the north, for example.
        Today they are having a huge weather anomaly there—and in the surround. Two day snow totals may exceed 2 feet. Pretty bizarre.

      • runrain says:

        About 1,500 feet on the north side of Scottsdale, Carefree, and Cave Creek. They were getting graupel in the actual valley around Peoria, which the excited Arizonans thought was snow.

        • runrain says:

          Carefree/Cave Creek is up around 2,400’ feet, actually.

        • W7ENK says:

          Ah, my bad. I was thinking Prescott. They’re up North toward Flagstaff at right about 5,500′. Flagstaff is closer to 7,000′, but you’re right, Scottsdale is a suburb of Phoenix.

          Pres-SCOTTs-dale… 🤦🏼‍♂️ Is there anyone named Scott in this blog that I can blame?!? lol

          Oh, and FWIW, a little local pronunciation guide: Prescott is pronounced “PRESS-kit.”

  7. Ken in Sheridan 330 feet says:

    Light dusting of snow in last half hour out here in West Valley. 35-36 degrees ……. sticking to surfaces

  8. Andrew says:

    EURO really seems to want some light snow tomorrow. No more than an inch or so but very consistent across members on the ensemble. I share Mark’s skepticism. EURO was overly bullish on snow the first time around. I think our chances of seeing flakes in air might be higher tomorrow but think it’s another elevation event.

    There does appear to be slightly more snow cover now east of cascades. Spotty and shallow but more than we’ve seen throughout most the winter. Perhaps that helps with cold?? That’s a big reach. Clearly no pool of arctic air in columbia basin, the more ideal setup.

    • Joshua Lake Oswego says:

      Still insistent on the 12z. Best chances for decent accumulations is the western metro area as Mark talked about. The coast could even get in on the action.

      • W7ENK says:

        See, that’s what baffles me the most about these marginal setups. How the hell does it snow on the beach when they’re immediately adjacent to the planet’s largest heat sink, but even with cool dry continental air blasting into Milwaukie through the Gorge, we still end up with 37 degree rain… or 38 now, to account for GW.

        • Andrew says:

          Issue of course is that air just isn’t very cool so the best shots of “snow” are based solely on strength of precipitation…but I share the frustration. For what it’s worth EURO always liked tomorrow-Wednesday over Sunday and as Mark points out, the model (somewhat mysteriously) wants to generate a slightly colder offshore influence. I’ll believe it when I see it.

      • Andrew says:

        I noticed that. Just based on strength of precip i’m assuming?

  9. W7ENK says:

    An absolutely GLORIOUS day! NOT!!!

  10. Whatevertheweather says:

    A dusting (1/2″) for me here in the foothills above Washougal tonight. About 450′ elevation. Snowed pretty good for about an hour. Ended shortly after it started to accumulate. 33°

    • Anonymous says:

      You must be up river a bit towards the Merc to have snow at 450′ in this situation. That’s a crazy climate area, I know it well. About MP 6 to Salmon Falls and up Canyon Creek, snow level can go way under the the forecast or any of the surrounding area.

  11. Mountain Man says:

    Thank you for the update Mark Nelsen 👍

  12. Mountain Man says:

    Alright, so I have a whole inch and a quarter, half of that fell between 4 and 5, the rest just gradually, and now just a flurry. Underachiever for how it fell all day and melted on contact, but overall about what I expected. On to the next one!
    And was someone trying to get under my skin in the last post comments or thinking I’m someone else? That was confusing? Whatever, if you don’t want me to comment, I can go somewhere else. I have been Mountain Man since 2007 here after when I was West Linn 550’ before I moved. I try to bring some knowledge, and just felt like this place was kinda dying so I increased commenting. I can go away if not wanted.

    • Gene says:

      Stay — the more knowledgeable old-timers commenting here, the better — especially during a lame winter such as this one!

    • runrain says:

      I’m one of the old timers and I appreciate your input Mountain Man. And Jason and Tanis and Rob and Erik and all of you that contribute constructively. The noise is just that – noise. Always going to get, always going to ignore it!

  13. Andy says:

    Down to 34 here in Albany at 9:15 pm…stars are shining. If it keeps this up it will be icy by morning….maybe a snow flurry later? Seems to be colder than the forecast.

  14. W7ENK says:

    Quite the amazing day here under The Dome™️.

    Temperature, humidity, and the cups on my anemometer haven’t budged since midnight.

    §
    Looking forward to another day like this on Tuesday/Wednesday

    • Anonymous says:

      WOW

    • Joshua Lake Oswego says:

      Got up to 41 here in the dome within the dome. Stuck at 39 now. I like to look at Weather Underground and see if I can find a single station in the metro area warmer than mine. I usually find one or two out of many dozens.

      • W7ENK says:

        Sorry, but Lake O is definitely NOT “under The Dome™️.”

        You may be just across the river from The Dome™️, but you’re not under The Dome™️.

        • Anonymous says:

          Right LakeO gets more and the Dome doesn’t, it’s almost like the 1/4 to 1/3 mile wide river kills everything. It’s actually true, I am a believer in that little banana belt of the metro area.

        • Joshua Lake Oswego says:

          Haha. I’m telling you that my part of Lake Oswego is in the dome. I am about as far south and west as you can be in Lake Oswego. Every time you post stats from your place, mine is warmer and drier.

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