2017: First Week Looks Cold

9:30pm Monday…

The astute FOX12 viewer will notice a sudden drop in the high temperature Monday…the 2nd of January.   And your weather app is looking quite chilly for next week too isn’t it?   Well it’s looking like we’re going to turn quite cold next week once again.

Models all show a similar pattern developing Sunday through sometime later next week…an upper-level ridge builds over Alaska.


That forces a cold airmass to dive down through western Canada and into the Pacific Northwest late Sunday through next week.  In general, the pattern is the same on all models.  As a result I’m quite confident we’re headed for a very cool first week of January 2017!

But will it just be cool like earlier this month?  Or could it be a real arctic blast, one we haven’t seen in 3 years (since December 2013).  That’s a good question and I don’t have an answer for you yet.

For reference, I’d consider a widespread Pacific Northwest arctic blast one in which 850mb temps drop down to at least -12 (celsius) over Portland/Salem.  The last 5 times that has happened?

December 2013:  -14
November 2010:  -12
December 2009:  -12
December 1998:  -18
December 1990:  -22 (coldest 850mb temp on Salem sounding record)

You can see a true widespread Pacific Northwest outbreak of deep arctic air is quite rare.  It’s like the weather geeks (including me) are reaching for that “big one” each winter, but most winters will end in disappointment.

It could possibly happen next week.  The ECMWF model run from this morning was that cold, but other members of its ensembles were not.  Same thing with the GFS model.   Check out the ECMWF ensemble chart from this morning:


Quite a variety of solutions by next Tuesday/Wednesday, but in general it looks cool. Check out the ensemble forecast temps from the same morning run:


A pretty clear signal for a chilly week ahead…starting Monday.  It was interesting to note that only about 1/2 of those ensemble members showed 2″ or more snow over Portland in the next 8 days, but that number jumped to 46 of 51 members by the 12th day.  The point is that once real cold weather arrives, moisture will likely interact with it at some point.  Especially since the pattern seems to stay cold for a while.  Look at the 1st and 2nd week of last night’s ECMWF monthly run.




That’s a cold pattern with the upper-high remaining over Alaska and downstream troughing over us.

This evening’s GFS run is not nearly as cold as the ECMWF for next week; it looks more like what we saw earlier in December.  But I’m sure there will be lots of twists and turns the next few days on the models.

Stay tuned..

Chief Meteorologist Mark Nelsen

63 Responses to 2017: First Week Looks Cold

  1. JJ78259 says:

    Gotta luv Global Cooling! 82 and sunny today in San Antonio!

  2. High Desert Mat says:

    Come on Mark, new post with thoughts please.

  3. Tyler Mode in Battle Ground says:

    I’ve recorded more days below freezing this December than the entire winter of 2013-2014…19 so far this month. 18 during December, January and February of that winter.

  4. Hmmm… super-mild November, cold (but not epically so) December with some mild arctic outflow events, and now a possibly big arctic blast for January. Starting to sound more and more like an analogue to 1950. Here’s what January 1950 was like (mostly reports conditions in Seattle but it does mention the Columbia River mostly freezing in the Portland area):


    Probably won’t get that cold this time, of course, but it does make one wonder if the coming cold spell might at least be a repeat of December 2008. Time will tell.

  5. Jason Hougak says:

  6. Sapo says:

    Well the Euro has remained cold, 12z just as cold as ever today with highs in the 20s for PDX this week. GFS had backed off as of yesterday, but it came around today and operational&ensembles have both had major improvements. GEM has been fairly consistent and very cold. Point is, we’ll probably see high temperatures in the 20s for a few days at least, and probably won’t get above freezing (starting Monday) for around 5-7 days, maybe more.

    A reload in the 11-15 day range is certainly possible, and our 500mb pattern looks to be pretty solid for a prolonged arctic blast/cold spell. We could see a historically cold January!

    Moisture is the only question here. We should see some moisture associated with the arrival of cold air on Sunday..Models are still up in the air about moisture amounts, low track, etc. but it appears that we could see anything from rain to 2-3″ of snow. It depends how quickly we cool off once the moisture arrives, and how much moisture there is. I think most everyone will see some snow at the back end of precip, question is how much. On and off models have been showing some sort of system in the Wed-Fri timeframe, way too far out to know specifics but there are definitely chances of snow with this event.

    • Jason Hougak says:

      Yeah Sapo looking exciting.

    • Jake-(Gresham) says:

      Agreed! Heck, the models that have run since; we’re looking at 0F to -15F East of the Cascades. Most of Oregon is going to be frozen solid if this all plays out!

    • Sapo says:

      Yeah Jake lows could be in the single digits even here if we have snow cover!

    • Sapo says:

      Wow 18z GFS was insane…GFS back to looking amazing, I hope the 00z runs continue the trend of cold and snow.

      18z GFS keeps us in the cold for around/maybe more than two weeks, complete with 1-2″ Sunday, 2-4″ Thursday, and something like 5 or 6″ on Saturday. Then on Wednesday (Jan 11 so like 14 days out) another 3-5″..Probably close to 12″ total on that run, maybe more.

      The trend is looking good! Hope to see the 00z runs keep it up, I’d like to see a stronger low on Jan 4..we’ll see

    • Sapo says:

      It’s not just the GFS showing snow though as 36 of 51 12z euro members show 6″ plus by the end of the run.

    • Anon says:

      Updates are excellent Sapo thanks!

    • HAWKEYES23 says:

      To many members on board= MAJOR BUTTHURT BUST

    • Dave in South Salem (500') says:

      I predict 34 degree rain followed up by dry cold air. Enjoy it!

    • JohnD says:

      Have been without media until now today. Thanks for your astute input Sapo–as always. Fun stuff ahead!

  7. Max in Fairview says:

    Better start preparing for long episode of cold not seen in January for years.

  8. pappoose in scappoose says:

    Public Information Statement
    National Weather Service Portland OR
    603 AM PST WED DEC 28 2016

    …Snowfall totals for the Cascades…


  9. Alohabb says:

    Models show one thing, it’s gonna be dang cold for a while. Snow is still uncertain

  10. Doug Steiner says:

    The “Portland MB temp” is the worst graph I have seen you. All the black lines are completely indistinguishable from each other. Also this new format the same as news channel 8 is BS!

  11. Leeateea says:

    Bring on the cold and hopefully snow!Were having our Christmas party with the in-laws on the 6th,maybe it will be a white one!

  12. Jake-(Gresham) says:

    So as others have stated the Euro was impressive. It puts -13C spilling over Washington and Oregon all the way out well over the Ocean. That’s 8.6F folks.


    If we factor the gorge for PDX that puts us at 5.6F ( my personal rule of thumb is subtract 3 degrees because the models do a poor job in that regard which is critical for our complex climate).

    The downer is the GFS is now completing its run and it appears to back the cold off at the 850mb. That is a real negative. One positive note is the 700mb is extremely impressive:


    But again, the difference is night and day however to the 850mb which shows the air of that depth largely trapped behind the Rockies (so no chance at even getting to the Cascades):


    The good news is it’s still early in the ballgame and the cold air doesn’t seem to be moving to the East spilling over the Great Plains and Great Lakes. In short, both the GFS and Euro models are only disagreeing on severity The bad news is the devils in the details.

    If we get both accuracy and precision (i.e. consolidation) tomorrow among the models where they’re both saying the exact same thing I will say it’s time to grab some popcorn, and some hot beverage.

    As for the low pressure system on dates 1/2 ~ 1/3. It seems to have stayed in similar location for both models coming in around Astoria.

    If it stalls there or greatly strengthens coming down North from British Columbia over the Pacific briefly West of the Washington Coast we could have some serious weather.

    For those who have been here a along time. These variables are quite the norm. to riding the train. I think it’s all too often to see the GFS or Euro having the cold ‘just’ North in British Columbia:


    That is overall the equivalent of a polar vortex for us at -34F temperatures. What is has to get over is some of the highest elevation in regards to the Rockies. That’s grizzly bear country. If you click the next slide the GFS easily shows it moving into Eastern Oregon. That is not a normal run, quite aggressive (I will say that).

    But again!

    The models underestimate the mountain ranges and cold air sinks like stone. We currently are looking still looking at dice toss. Not even a coin toss for a major snowstorm. My personal thoughts.

    • GTS1K' says:

      Thorough and logical analysis, Jake.

      There is room for hope….and despair. Such is the nature of the PNW – PDX-style.

      On a brighter note, despite the “models”, Hillary will never be our president.

      Could that be a sign????

    • Diana F. says:

      Awesome post Jake, and I really like the 3 degree subtraction! You’ve given me a lot to contemplate, and plenty of food-for-google thought! Thanks for the links.

      Of course, I am praying to the snow gods in addition to analyzing the science. cya eh?

    • Scooter says:

      TMI son, you are looking for information that fits your desires. As you grow wiser you will take the weather as it comes and enjoy each and every day, life is short

    • Scooter says:

      Gt boy, we’ll check back with you in a few years and see how you and your ‘Trumpeter’ are doing. It never ceases to amaze me how you PWT think a billionaire is going to be covering your backside. Wow!

    • GTS1K' says:

      Scooter, old man, You are only whining because, politcally, you didn’t get that which fits your desires. As you grow wiser you will take the election results as they come and enjoy each and every day, life is short

    • Jake-(Gresham) says:

      You’re very welcome Diana. 🙂

      You guys need to stop talking about politics! Bahumbug!

      This just made my day. Thanks guys. 😛

  13. JohnD says:

    It seems like the Blog would be WAY more active at this point! Maybe the “events” that we already had quelled the emotions of some folks(?) LOTS of fun ahead!

    • Diana F. says:

      I would have thought so too, JohhD. Perhaps some are tired of the “end result” of most of our storm and snow watches……weather casting isn’t for babies!

    • gidrons says:

      The other weather sites are a lot more active. Maybe people migrated to them.

  14. Jason Hougak says:

    18Z GFS showing a massive storm Sat. January 7th into the 8th. Far out but precipitation over an inch and cold temps which would be a serious winter event.

  15. Mark,my neighbores and myself live in housing right on the Depoe Bay beach with not well heated homes. Can you let us know if we will be below 32 and how long. We will need to buy heaters. Thank you. We don’t want to freeze.

    • Alohabb says:

      Get ahold of your PUD and look into the ductless incentives. You may qualify for lots of different options.

  16. WEATHERDAN says:

    This Winter starting to remind me of 1968-1969. We had a cool December with some snow but no frigid weather until December 30th. Then it was pretty much cold and snowy until early February. Looking more and more like a repeat. This from somebody that many have accused of a warm bias. Enjoy the cold and snow. Peace to all and a Happy New Year.

    • ‘Twould be fun it it were to happen but I’m making no predictions.

      HNY to you too, Dan.

    • Diana F. says:

      Cliff Mass
      “The latest weather.com forecast (which is generally excellent) is going for cold and sunny early next week as the cold, arctic air spreads south. Is there a chance of snow as the cold air moves in? The answer is yes…but the uncertainties are too large to speculate on that now”.

    • Roland Derksen says:

      Yeah, I recall 68-69 as well. Intresting to compare your description of December 1968 as having “no frigid weather”- up here it sure was cold right after Christmas that month. Got down to 0 degrees Fahrenheit on the 29th, if I recall correctly. The Fraser river froze over and and a federal icebreaker ship had to be used to break up the ice there. That’s the last time that happened!

  17. Diana F. says:

    A little too much time on Weather.com today! Last one I promise, but who knew snowflakes were so stunning?? I certainly didn’t.


  18. Diana F. says:

    ………and not so much……………well……I guess if we HAD TOO….

  19. Jason Hougak says:

    ⚠️️12Z ECMWF is impressive

    • Scooter says:

      Ya, just like reading a cheap novel, a lot of meat and no gravy.

    • GTS1K' says:

      …Reading a cheap novel is like meat with no gravy???

      Well, I’ll defer to the expert as to cheap novels. However, the comparison offered seems inapt at best. Sounds like the ramblings of someone who ate and, more specifically,drank too much this last weekend….

      Whatever you say, there, Skoot. And lay off the “gravy”, would you?

      It’s for your own good.

      I’m only here to help…..

  20. Dave in South Salem (500') says:

    Its the perfect time of year too. Lots of cold air up north and low sun angle to moderate it on its way down. But as usual for us, it depends on the position of the highs vs the low as it moves down off our coast. I’ve seen these patterns turn to where the low stops about Bellingham and moves inland.

  21. Roland Derksen says:

    Looking forward to a “real ” January for the first time since 2009.

  22. Scooter says:

    Look’n like a ‘plumbers paradise’ coming up following the ‘body shop bounty’ & the ‘tow truck treat’ earlier in the month. Remember to prepare now so you don’t complain later.

  23. Jake-(Gresham) says:

    Looking at the long range models. I believe the weather system coming in Sunday may well bring precipitation into Monday. As of now the models are calculating that the arctic air will not be coming down South over the ocean nor slip too far into the East:

    1) The next model runs will really show if there’s any consolidation (i.e. agreement) worth noting. If things start shifting East (which is the high probability looking at the polar vortex that wants to very much develop over the Great Lakes). May only see things fall apart with cold rain West of the Cascades.

    2) If the models don’t solidly agree on the low coming in on Sunday to significantly strengthen and the cold staying with the current streamline trajectory on the 850mb levels, then it’s well over. I.e. no chance of a large snowstorm. Everything has to hold from here on out.

    • Jake-(Gresham) says:

      Overall, my thoughts are 50% for proper arctic air arrival and 20% percent chance of precipitation arrival in amount for a snowstorm. Taking everything else into account the overall percentage is 25% in my eyes.

      So we’re in the ballpark, but right now current range is only in the models. Once things get into the reality scope is when things will get interesting. Next 24hrs are when the real numbers start coming in (i.e. model runs closer to the actual dates).

  24. “However this is starting to look like it could be the start of quite a significant winter weather event for the Pacific Northwest starting late New Years Eve or on New Years Day (one that has not been seen since December 2008).”


    • HAWKEYES23 says:

      Probably 4 good days of cold with no moisture, than as we are all eagerly awaiting the hope of something frozen to fall during a transition event the south winds come and screw it all up 😦

  25. …here in Cove, all roads are closed, a couple new inches of snow overnight with major blowing and drifting snow….and it continues to snow…

  26. Jason Hougak says:

    6Z GFS not as fridgid but a lot more precipitation through the run. The 00Z ECMWF run looks good with for the cold air plunge into the PNW. Cold air even extende out over the Pacific Ocean.

  27. Paul D says:

    School starts again on January 3, or will it? This is going to get interesting!

  28. Diana F. says:

    Welcome Back Mark! Hope you got enough sun because it’s time to bring on the cold!

  29. Jason Hougak says:

    Last cold snowy January Mark… it’s been awhile!

  30. JJ78259 says:

    Global Cooling is finally hitting home! Today is my last day on Paradise Island Bahamas we had Weather Dan Weather for the whole 6 days just beautiful!

  31. Tyler Mode in Battle Ground says:

    Nice dusting of snow here in Battle Ground. Maybe 1/4″ so far. Temp dropped to 33.

    • Diana F. says:

      I saw that on my weather app…so I checked the traffic cams in BG because it sounded so odd! Couldn’t really see much on the cams…nice to know it happened!

    • Tyler Mode in Battle Ground says:

      Ya, wasn’t much on the roads, just the grass, cars and roofs etc.

  32. Hood Canal Effect spillover didn’t happen for me. Just cold rain tonight. But looks like more snow chances are coming up.

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