8pm Wednesday…
I’ve got a short update to let you know what’s up weather-wise as we head into the busy Christmas Weekend. I’m planning on a longer post early afternoon tomorrow. Just about everything I mentioned yesterday evening is still valid. Here’s what I’m seeing right now:
- The next 4 days (Thursday through Sunday) we will be in the “showers and sun breaks” weather pattern. There are no “storms” headed for the lowlands west of the Cascades through Sunday (the 26th). But the airmass will be cooling each day, and by Christmas Day it’ll be cold enough for sticking snow at night even at the lowest elevations. During the daylight hours on Christmas Day, we’ll see mixed rain/snow showers, but sun breaks too. Most or all accumulation of snow that day should be in the higher hills around the metro area and mountains.
- By Christmas night (Saturday night), there’s a better chance snow showers stick all the way to sea level and I wouldn’t be surprised if many of us wake up to at least some “white” Sunday morning. More showers follow that day before we dry out a bit Monday.
- Just about all of our models are saying cold/dry Canadian arctic air gradually works south into the Pacific Northwest Monday through Wednesday next week. If that’s the case, the lower elevations will freeze up with daytime highs only in the 20s! Now that WILL be pipe-busting weather. Will it be something we haven’t seen in many years? Or just regular cold? TBD.
- If you see a snow total forecast or graphic showing “X” inches will fall in Portland in the next week, ignore it. We can’t forecast specific snow totals more than maybe 3 days ahead of time…at best. Especially in a showery pattern like what’s headed our way this weekend. We can say “it looks like many inches”, that’s reasonable. But anything specific 4-6 days ahead of time is silly.
At this point we don’t see a “snow storm” in the Portland metro area through Monday, but multiple chances (in showery form) for sticking snow from Christmas night through Monday. We’ll be keeping a close eye on the rest of next week though. Some models are trying to produce a “shut Portland down” type snowstorm Monday night & Tuesday. Yes, an “all hands on deck!” sort of event for Portland’s local TV stations. I have vacation scheduled for next week as do lots of other people…we will see.
Wondering about driving in the lowest elevations from Eugene to Longview? Just fine tomorrow, Friday, and daylight hours Christmas Day.

Key point…
YOU SHOULD BE COMFORTABLE DRIVING ON SNOW/ICE BEGINNING SATURDAY EVENING IF YOU PLAN TO HEAD OUT ON THE ROADS IN THE LOWLANDS
I’m not saying that will happen everywhere, but by sunset Saturday it’ll be cold enough for snow showers to drop sticking snow with accumulations anywhere, including the coastline.
Traveling elsewhere? Really tough through the Cascades from tonight through the weekend. I-5 through the Siskiyous could be treacherous at times. The Columbia River Gorge doesn’t look all frozen and messy Saturday, but some snow could accumulate at times Sunday as temps drop.

Coast Range highways will turn snowy for the first time Friday evening and that continues through the weekend, especially overnight hours.

That’s it for now, I’ll take a look at next Monday/Tuesday’s possible snow “event” on tomorrow’s blog post. Plus, we’ll see how cold we’re looking for the last few days of December. I’m on TV right now and will be through 11:30pm tonight. You can always find that at www.kptv.com/live
Chief Meteorologist Mark Nelsen
Dang sucks to see this is almost over before it even started. Maybe a day or two of cold weather with some snow in the air then back to 50s and drippy cloudy foggy days. Really sucks but this is our normal outcome. Merry Christmas all.
Models are looking warmer
This will be a short lived arctic blast like Tim is saying. Unfortunate.
For those looking ahead to “warming” trend by end of next week, it’s worth reminding that models frequently accelerate warming in these types of patterns. I’m not saying we’ll stay cold all the way through new years but wouldn’t surprise me if temps don’t warm as fast as models suggest they might.
I expect Timberline will have at least a 100” base by Jan 1st.
Nice. PDX broke 6” of rain today. Should finish above average for the month.
12z euro has us warming above freezing by next friday into the weekend.
Yes, of course it will warm up, but how in the h**l are you still being a Debbie downer and not mentioning the cool temps coming, it’s impossible to deny at this point.
Honest question– do you ever post anything of any remote relevance on here?
Posted this about 10 days ago
I see this same setup – but even further South and colder – forming on the Euro 00Z near the 1st. Which could indicate another Arctic hit moving towards the second week of January…
Posted this back in November
Dang I was close and it really does seem to be on a 2-week cycle 🤔 … maybe 2.5? Could be another coincidence, but it’s something to consider I guess
12Z Euro looks even better, but the death ridge over Alaska at the end will be a thing to watch. I wonder what the effects will be… shut out moisture to us for a very cold and very dry second half of January or allow very cold moisture to come in through the west from Siberia around the death ridge?
It’s somewhat ironic, but for the last 31 years (starting with 1990) I’ve seen more White Christmases here than in the years before then when I was growing up! 1990, 1996, 1998, 2007,2008 and probably 2021 will be. What is different in more recent times, is the lack of cold snowy days after Christmas. Perhaps this year will be like old times, but we’ll see…
It’s just amazing how we get a 100 days straight with rain and then once it gets cold enough for snow, the moisture finds a way to disappear.
NoSnow Tigard: FACT!
C’mon weather nerds! Give me more updates on models!
Snow totals are not as impressive, but like Mark mentioned, it’s very very difficult to predict this far out. Consider that we consistently get inaccurate rain totals even as it’s right on our coast, and you get the idea. Every 0.1in of rain is nearly equivalent to 1in of snow is Mark’s general rule, so hopefully we can squeeze out 2-4in between xmas night and Monday.
The pattern which I noticed coming from the gulf of Alaska 1-2 weeks ago which lead to the current arctic blast seems to be forming again at the end of next week and even more aggressively. My guess is even if we don’t score anything now, we’re going to see a very active January.
Thanks, fellow nerd! I needed that. 🙂
Guys looking good either way for next week. Brutal cold, snow totals unsure but even a little bit like couple inches will make it look like a winter wonderland and it won’t be melting. Of course the more the better and I prefer longevity of cold air rather than just a one off snow storm and it’s all gone the next day but that’s just me.
I’m worried. The Weather Channel is forecasting WAY less snow this morning than last night.
Although still flip flopping between more or less epic, especially compared to the last few winters here in Salem.
I would not worry about a forecasting office in Atlanta Georgia . It takes the true North West weather people here to get it right!!
I said if it still looked cold by the 12z GFS, I would buy my tickets. The 06z GFS and 12z GFS are very cold! Buying the train tickets right now, but I’m not boarding the train until the 00z.
Are they refundable on cancellation?
Yes, but any later than the 00z, you can’t get refunded.
No refund–JUST POUND SNOW
Is it theoretically possible to have the 48 states completely saturated in arctic air all at once? To where from San Diego to Bellingham to Key West and the tip top of Maine all to be dark blue? If so would that mean parts of Canada and Alaska would have to be warmer than average?
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I just looked at the 06Z GFS run (it’s not finished yet) and it’s looking a little better than the 00Z run. I think the GFS and Euro model had a little wobble last night. We’ll see how things progress with the models today (especially the Euro). I’ll bring my laptop to work and watch the models come in. Have a good day everyone 🤗😇❄🌨
cliff mass needs to be held responsible for showing single digits for lows in seattle when that’s not gonna happen shame on him..
Okay everyone is right you are at the very least a little annoying
if there was ever a warm biased version of Jesse you would be that guy, my friend. Always rooting for warm, while trolling at the same time.
Folks who have been here long enough will understand the “Jesse” reference.
Lol yeah I remember Jesse. And another guy named “South Wind”
Since we’re about to have a pretty harsh Dec cold episode descend into the region, I thought I would post a link to the missing Dec 2008 cold episode blog entries from Mark’s old hosting site, Storm Team 12.Type Pad. Unearthed them quite a while back. Starts with the first entry “The Train is Pulling into the Station”. It’s all good historical info. Many of the old replies to Mark’s entries are still there too.
https://web.archive.org/web/20090116040145/http://stormteam12.typepad.com/stormteam12/2008/12/the-train-is-pulling-into-the-station.html
That is awesome Mike. Oh atmospheric wrath, that’s SE Rob when he decides to say hello to us every now and again. I’m in there too, but not Mountain Man as you know me now. Thanks for the memories. I remember, as that approached, the models misfired and we almost lost hope for a minute, then it happened awesomely and was epic.
Great memories of those two weeks of epic winter weather! Thanks for tracking down and posting these memorable blog entries. I read the blog and comments daily back then but never posted comments myself.
Thanks for posting the link. I started checking out this blog in 2012, so I missed out on the activity in 2008. Fun to look back. I lived in Oregon City and we maxed out at 19″ on the ground in my location. Amazing white Christmas!
It will be cold next week but extended arctic blast now looking unlikely. At least we should get some snow when we come out of the cold air.
Cannot help but stare at the 00Z GEM-RDPS on how much arctic air there is from this polar vortex.
Can we just appreciate how it sags across almost the entire continent?!…..
https://ibb.co/cT4vMy8
It does span the entire continent I’m just having a tough time comprehending that much arctic air. Jeez
Well I guess everyone went to bed. Colder than normal by a lot, but dryer than normal is looking more and more likely too as this comes on. No point in talking to my self even if that’s what I do a lot of the time. Goodnight all. This is still going to be fun, we knew it would change a little, it’s going to change some more before everything is decided.
By the way Eric, I got on the lowlands train. The cold one. I’m not getting on the snow one quite yet. I just went through all the 00z models, that GFS is a little weird. But I’ll take the cold ticket, I’m still not buying a snow ticket… If I had to forecast, a few dustings seem likely at the lowest elevations, but I’m a believer in the cold now for sure and snow eventually. When the cold filters in, it’s just not organized like a front until/unless it gets further south where I can see something happens. A few more runs, we’ll see. We need the trough to kick up shortwave energy, it looks like it should, but then it doesn’t really. Lots of time for that to change though.
Tanis, you’re awesome. I’m a fan. Sorry I put my reply into a new post. I just was trying to say, be you. You’re always trying to hold back your enthusiasm in your presentations and it shows. Professionalism is best when you get just a little more excitement going and I can tell you have it, but your trying to hide it. Show your personality a little more. Mark has a personality, Rod Hill for example really has a lot of personality. Show me that your not just trying to be a reporter, you’ve got a bit more to give of you. I believe in you! You’re a very smart kid . Sorry that’s my reply you wanted, better late than never.
I’ll try my best. It’s fine that’s it’s in a new post. May take me a little while to break old habits. I think a lot of it is because I’m not really a confident person when it comes to my personality. A lot of it stems from complaints my freshman year in college for never having a girlfriend, exaggerating earlier problems. While I’ve gotten over the no girlfriend part (I’ll get one when it’s the right time), the low confidence and chronic shyness has not gone away.
Oh man okay, I wish we were buddies face to face, but in a public forum there’s not as much to say. Just try to be confident, force yourself to be, the more the better and it’ll grow on itself. I can tell you have it! Be like okay here we go, confident Tanis! I had to learn this when I was a young student and it’s hard at first. It’s hard at first, but it pays off, both with getting an awesome girlfriend and in your career.
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If it’s not cold enough to snow in portland metro then it’s not cold enough where i live so marks forecast is promising.
Super glad to be going to Christmas dinner at 4 one on Council Crest Drive.
Thank you for the update, Mark. I think we will see more snow than what you are thinking for Monday. Just my opinion.
Thanks for the update, Mark.
First!! Thanks Mark!