FAKE WEATHER: No, It’s Not Going To Snow In Portland Next Week

3pm Friday

I’m on a day off, but was just summoned by a coworker wondering whether it’s going to “snow next week in Portland”  due to something read in a local newspaper.  I immediately came running in out of the warmest temperature we’ve seen this late in October in 42 years to see what’s up.  I checked all the models.

Nothing says SNOW to sea level, or below 1,500′ elevation for that matter.

Here’s what happened:

  • There are maybe 4 longer-range models that we regularly look at run at least twice each day.
  • Each of those 4 models have 15-50 different “ensemble” members that run just slightly different.  That way we can get an idea which models are doing best.
  • We call that “ensemble forecasting”.  There are literally HUNDREDS of different computer model forecasts for a week from now.
  • From now until mid-March, there’s always a chance that SEVERAL (OR EVEN 50!) OF THOSE HUNDREDS OF DIFFERENT ENSEMBLE MEMBERS COULD SHOW A COLD/SNOWY PATTERN over us while most models/ensemble members don’t.

So if you use a weather app…it has to make a decision which model to use.  Then that automated forecast ends up on your app, without any human input!

I see the same app that focused on one cold overnight model (snow close to sea level), has now corrected itself and looks like this for next weekend, which is probably still colder than what we’ll actually see:


The National Weather Service sure hasn’t forecast snow to sea level (they only forecast 7 days out anyway), and neither has any TV station in Portland.  As of this afternoon no model shows a snowy pattern late next week, just the very cool pattern I mentioned in my previous blog posting.  For the foreseeable future, humans are still needed to interpret computer modeling of our atmosphere.

A far more disturbing issue is the rise of, yes, FAKE WEATHER across the Internet.    Sorry to use the term, but it’s true.  Weather dis-information spreads at the speed of SHARE, FOLLOW, & LIKE.  Scary for forecasters…it gets discussed quite a bit by meteorologists across the USA.

I ‘m disappointed that this time the weather “disinformation” came from what I would typically consider a very solid local source of information, the biggest newspaper in Oregon.  Not quite Clickbait…but close.  You better stick with FOX12; you know as a weather geek I sure won’t leave you wondering about snow the next few months!

Well, back to the sunshine!  Enjoy a few more days of fantastic weather.  73 in Portland at 3pm.   Wow, only twice in Portland airport weather record history have we made it to 73 on the 27th of October or later in the Fall.  Just once in 1975 we hit 73 and then a 75 in 1944.

By the way, this might be a good time to mention the yearly WINTER WEATHER FORECAST CONFERENCE is tomorrow at OMSI.  There will be a recap of last winter, plus a few outlooks for this winter.  It’s always fun if you are into weather…details:

Mark OMSI Forecast Meeting Promo


Chief Meteorologist Mark Nelsen



37 Responses to FAKE WEATHER: No, It’s Not Going To Snow In Portland Next Week

  1. JERAT416 says:

    Looks like a 20+ degree cool down next weekend compared to last. Not at all off but shows us the rainy season is about upon is

  2. WEATHERDAN says:

    Autumn leaves look nice this year. Sorry to see the nice weather go, but go it will. Next two weeks look cool but not too wet. A nice Northwesterly flow will keep the atmospheric river at bay. Peace.

  3. Alohabb says:

    By the way, anyone in the Aloha area here a loud explosion about 2am today? It shot me out of bed at 198th and Farm, but police dispatched to investigate off at 185th and TV. No explanation can be found, but it was loud.

  4. Alohabb says:

    Geesh it’s windier now than it was for the wind advisory we had a week or so ago. It was 41 going to bed and 57 now. Seriously gusty out there.

  5. Jason Hougak says:

    Active start to November about to come in. Enjoy these last 2 nice October days to come. Hopefully the hammers coming down and winter 2017-18 will be one for the weather history books!!!

  6. Joshua Downtown PDX says:

    The new 7 day is more like it. The one from earlier today showed 56 for a high on Saturday and Sunday. Not happening.

  7. Nahtalkin says:

    Since we are talking about the upcoming winter weather, let’s talk about the “Road Salt Debate” again. Sure it’s easy to talk about the easy quick fix to road problems and transportation when the inclement weather strikes, but there are other long term consequences to this cheap quick fix.

    Bear with me while I present these consequences: As a long time owner of 3 Chevy trucks that I like to keep well maintained and in original condition (the undercarriage of these trucks look like new i.e. no rust or corrosion of any kind, very nice and easy to work on), now go to YouTube and look at almost any repair video for brakes, shocks etc. and you will see what road salts do to a vehicle….it is not pretty nor easy to remove rusty corroded bolts, not to mention safety and loss of investment.

    • Jason Hougak says:

      No Salt and I’d prefer no gravel but I know that won’t happen.
      Owner of classic 1985 Fj60 landcruiser with no rust and I plan to try to keep it that way!!!

    • Mark Nelsen says:

      I think very few are advocating for regular salting of our mountain roads. But I seriously doubt 2 days per average winter on major freeways or highways in the lowlands is going to have any effect on either autos or the environment. I’m tired of the constant spraying of that other chemical that goes on all winter long and seems to have little/no effect during ice/snow storms. What is the regular usage of that doing to our streams?

    • Salt, sand, etc. won’t do a lot of good for drivers that have no clue how to drive in adverse conditions.

      • JERAT416 says:

        Exactly, instead of them saying salt is bad, they need to show the spray stuff works and is safe. Occasional salt beats constant useless spray.

    • Boring 550' says:

      At the very least, salt should be used when we get freezing rain, especially in the gorge.

  8. In celebration of this spectacular final warm day of 2017, I biked from Scappoose to Hillsboro. Climbing Rocky Point Road was definitely an ordeal, but the rest of ride through North Plains and to Hillsboro was downhill or flat.

  9. John Fairplay says:

    So you’re saying there’s a chance!

  10. JohnD says:

    ‘Really enjoyed the weather conference at OMSI foday. Fun stuff. ‘Have been several times over the years. I would assume that a number of Mark’s blog posters were also there. The thought occurred that next year we should provide ourselves with “name tags”. It would be fun to see/meet fellow poster/compadres!

    • JohnD says:

      My novice takeaway: Another mild La Niña/ENSO neutral season is upon us. Not necessarily a duplicate of last year; but many characteristics are similar. Odds favor an active winter with at least “some” valley snow/cold possible–if not “likely”!

    • muxpux (Longview) says:

      I was there, got a coffee cup! Lol

    • Jason Hougak says:

      That’s only for weather geeks😆

    • pappoose in scappoose says:

      I did a name tag there once.

  11. Jason Hougak says:

    GFS is really bringing in cold weather in the extended. Each model run is colder with more precipitation.

  12. W7ENK says:

    Just in case anyone was wondering…

  13. Jason Hougak says:

    I’d say mid-late October is just awesome in the PNW. The mountains are topped with fresh snow and the color contrast of the evergreens and deciduous trees is amazing. I worked in so many cool locations this week and just took in it all both on the drive and at the jobs. Sure does put that nasty early August until Mid September to shame!

  14. High Desert Mat says:

    Weather. It’s nor here nor there. Its everywhere. Maybe it’s not and we’re the ines that are gone. Lee, Lee? I’m lost

  15. Jason Hougak says:

    Pendleton NWS has colder weather late next week into weekend with snow potential to valley floors. I’ll be hunting Elk so will thoughly enjoy it. There’s nothing like following a blood trail in white snow!

  16. Jason Hougak says:

    “It was me!”😆

  17. Roland Derksen says:

    Maybe it’ll snow at my place on November 11th??

  18. marinersfan85 says:

    Whats going to happen over my house?

  19. Slavik Lungu says:

    Well since we’re on the topic of snow, what’re the chances for a white Christmas?

    Yes, I know, I still haven’t had my Thanksgiving turkey.

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