Is It Going To Snow In the Lowlands? No

9pm Sunday…

The most useful indicator for snow chances the Portland Metro Area the next few days will be the web site  This is one of my favorite sites; which 364.5 days of the year displays this:



Looking for a day off work or school Tuesday…it’s pretty unlikely that’s going to happen.  The colder models have slowly been coming around to the slightly warmer ECMWF and GEM models for Monday night and Tuesday so…

  • Steady rain develops in western Oregon/Washington Monday evening.
  • It turns to cold showers daybreak Tuesday morning
  • Sticking snow at that time reaches the lowest point around 1,500′.  That’s the top of the Coast Range summits, Welches area, and the very top of Bald Peak possibly.
  • Anywhere else in the hills could see a “sloppy mix” of snow/rain showers around daybreak but no accumulation with temps above freezing.
  • The rest of us just see a few light & chilly showers tapering off through the day with mainly dry conditions by Tuesday afternoon
  • Traffic in the lower elevations will not be affected by snow this week; continue with your usual and customary Thanksgiving Preps!

I do expect 5-10″ in the Cascade passes by Tuesday midday, which means snowy driving through at least midday Wednesday.  Then the snow will gradually work off the roadways.

Why am I so negative about low elevation snow?  Model 850mb temps have ever so slowly risen to around -4 to -5 with the precipitation Tuesday morning.  That’s not lowland snow material.  We need -7 with onshore flow, and it doesn’t help that our ocean is running several degrees above normal.  The air will be coming in off that ocean Monday night and Tuesday morning.  I notice the WRF-GFS maps are looking less and less snowy…this evenings’s run:


and our RPM evening run:


Beyond that we should just be dry and chilly (but sunny) Wednesday through most of the holiday weekend…very nice.

Chief Meteorologist Mark Nelsen


35 Responses to Is It Going To Snow In the Lowlands? No

  1. Boydo3 N. Albany says:

    Does this not look like the dreaded SPLIT FLOW….

  2. WEATHERDAN says:

    40 and drizzle this afternoon. Ties New Years Day as coldest of 2015. 38 days left in 2015 and so far no sub 40 highs. No Arctic air for us in 7 day NWS forecast which takes us out to the end of the month. But still mighty cool. Low 40,s during the day and mid 20,s at night. Lots of sunshine though. Peace.

    • Even Bellingham and Vancouver BC aren’t forecast to have highs much colder than 40 for this event. And they’re typically the most affected by the cold outflow of any coastal cities. An arctic blast this event definitely is not.

      The wrinkle is what happens after the outflow winds subside and the high pressure kicks in. If fog and stratus form, the lowlands are going to end up having significantly different weather than forecast.

      And it’s often tricky to forecast if such conditions will develop (and once they develop, if they will persist). So I for one am taking that “long sunny stretch” forecast with a grain of salt.

  3. muxpux (Longview) says:

    Not even 2 days ago the weeks highs were barely 40, now they are upper 40’s. Why does this always happen? Lol

    • Boring Oregon says:

      Well, today is actually colder for me. Currently 41.9 and it’s been holding steady like that for awhile.

  4. jimbo says:

    Feels like snow. Looks like snow. Dang it all

  5. What about tomorrow in the Gorge? I think the fake cold is deep enough for snow if warm air doesn’t slip in above.

  6. WEATHERDAN says:

    Just too d*** cold out this morning. 26 today. Our coldest so far. Looking forward to the sunshine Wednesday-Sunday. 44-47 during the day and 24-27 at night. Weather pattern starting to resemble 76-77. Does not bode well for mountain snow. Some lowland snow would have been nice but at least we get some holiday sunshine. And who knows maybe we get some snow later on. Peace.

    • Intresting to see you comparing this present situation with 76-77. It did get cool and frosty back in late November 1976, as I recall also. Anyway, right now it’s overcast here with some very light rainfall and 40F. I don’t think we’ll have much precipitation at all out of this system. I’m more concerned about ice on the roads tomorrow.

  7. runrain says:

    Does anyone have an idea of how strong the east winds will be when they set up again by the end of the week? Just wondering if the winds will be similar to what we just saw in PDX or stronger. Thx

  8. W7ENK says:

    Glad I laid down and covered my avocado tree last night, it was a frosty 28.0 when I left the house this morning! It’s going inside tonight, probably to stay through the long weekend, at least. My banana tree looked like it fared pretty well, though it’s somewhat sheltered under some other trees. I’ll take a closer look when I get home. The pepper plants that I chose to leave out were all sparkly, I’m curious to see how a frost affects them. This frost should also bring down the last of the leaves on my cherry trees. Winter is here.

    A cold walk this morning from the train down the 11 blocks to my office, and slick in some spots, too. This new commute definitely has its share of disadvantages.

    As for over the weekend, I didn’t lose the East wind until last evening, so my temperature never dropped below 40/41 on Friday/Saturday nights. That makes this morning my first official freeze of the season. My last freezing overnight temperature was 29.3 back on March 5th, making this year’s growing season 263 days.

  9. runrain says:

    Awfully bright and sunny out there. Hard to believe there could be precip before the end of the day.

  10. says:

    Mark, ANY chance of valley snow this Winter????

    Ann Merklin Salem, OR

    • High Desert Mat says:

      100% chance. 15% probability.

      Meanwhile I’m expecting 3-6″ tomorrow. Highs dont get above freezing til about Saturday or Sunday.

  11. Fogversion is here. But with a storm coming in by tonight, it won’t last.

  12. Jason Hougak says:

    The RPM has no snow north of Bend for Redmond or Madras but NWS has them under a Winter Storm Watch, 3-7″. I guess we’ll have to all just wait and see.

  13. I’m not seeing snow in the forecast here now as well. It’s a bit of a disappointment, I ‘ll admit, but it’s more important that we get snow up on the hills rather than down in the city. Oh well, it’s going to be perfect weather for Christmas shopping! 🙂

  14. Paul D says:

    I’m a bit confused by the green “NO”. What are you trying to tell us, Mark? 🙂

  15. schmit44 says:

    11/22/2015 Oregon (All) Temperature Summary

    High:60 at EW4856 Brookings(1365 ft)
    Low: 48 at BURNT RIDGE(2955 ft) & RED MOUND(1753 ft) & BUCKHORN SPRINGS(2780 ft) & SQUAW PEAK(4964 ft)

    High:25 at CW5984 Pilot Roc(1749 ft)
    Low: 1 at North Powder (I- (3272 ft )

    Largest Diurnal Change: 42 degrees
    FOSTER FLAT (49/7 ) (5000 ft )

  16. W7ENK says:

    Was anyone actually saying it was going to snow down here in the lowlands? I’ve been busy this weekend, so I haven’t been paying attention…

  17. paulbeugene says:

    It’s going to be the nicest Thanksgiving weekend we have had weather wise here in a long time. Doesn’t look like there will be much fog.
    Any snow that falls in the Cascades in next 48-60 hours may be all that falls at pass elevation for the next 10-15 days. Ensemble model runs show lack of significant precipitation from Wednesday through the following Wednesday, then some sort of warm advection pattern may set in after that with high snow levels. That gets us through the first week of December.

    • paulbeugene says:

      not nicest for me, just for the general population. Personally would rather have high of 28 with 5 inches of snow on the ground in Eugene, with a base of 84 inches at Mt Bachelor.

      The ski areas desperately need enough snow to fall to have decent business running over winter break. That is four weeks away. With this week and much of the following week seemingly already spoken for, it is making me a bit nervous.

    • Boydo3 N. Albany says:

      Not just the ski areas (which I totally agree with since I’m a skier) but the mountain snow pack in general. Granted it’s still WAY early, but if we get another weak snow pack this winter the entire NW will be dealing with big water supply issues next year.

    • Sifton says:

      Imo I doubt it, at least for Portland metro that is. Even if it’s another dry winter snow wise in the mountains our spring rains never seem to fail = danger averted. +1 also for Clark County as we have aquifers thank god instead of nasty Bull Run & duck ponds they call open air reservoirs (wasn’t caps supposed to be in the works?) & don’t have to rely on snowpack as much. Alas it IS the N.W., we always get our water sooner or later. For now….

    • Dave in South Salem (500') says:

      Bachelor looks to be getting a good dump of snow out of this storm. Hopefully enough to get them going with a little snow making to round it out. The key will be the temperatures following this storm…

  18. MasterNate says:


  19. timbers15 says:

    Always first! And no snow yet, but winter hasn’t started yet. Plenty of time left. Happy Thanksgiving everyone!

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