Mainly Calm Weather Heading into December

9pm Sunday

Thanksgiving Weekend is wrapping up now with lots of you at home relaxing, getting ready to head back to work tomorrow.   I had some leftovers here at work…very nice.

Last week was quite warm, which cancelled out the cold first half of the month.  You can see the Pacific Northwest is running about average temp-wise so far this month.  The nation as a whole has been warmer than average:

Skiing has been shutdown on Mt. Hood now due to the washout through Thanksgiving Day.  Timberline just announced they won’t open again until Friday and Meadows/Skibowl are on hold as well, waiting for more snow this week.  The good news is that there IS some snow coming for the Cascades this week, 2-3″ fell this evening, and another 10-20″ is likely by next Sunday.  Here’s the ECMWF snowfall forecast:

Along with the 12-20″ (very dense & solid) base already on the ground that should allow some basic ski runs to open next weekend at both Timberline and Meadows.  Skibowl might be tougher since some of the snow falling this week won’t get below 5,000’…we’ll see.

In the lowlands it’s been a wet November once again but not crazy “flooding wet”.  In general it hasn’t been stormy this month like we sometimes see.

The rain this week should be relatively light.  I see one weak cold front coming through Tuesday, then another on Thursday afternoon/evening.  Other than leftover showers Friday and Saturday, that’s it for the next 7-10 days.   In fact the Friday/Saturday showers aren’t more than just showers because the main energy with that cold system dives south into California instead of heading into the Pacific Northwest.

If I don’t sound real enthused about the upcoming weather it’s because I’m not.  The pattern over the next 10+ days signals a very slow start to “meteorological winter” which begins on December 1st.    There DOES appear to be a change in the pattern about 8-10 days out.  A strong upper-level ridge builds right over us or just to the west, blocking storms and giving us mainly dry weather for NEXT week.  For now there is excellent agreement on this basic feature…look at the forecast GEM, & ECMWF ensemble averages of 500 millibar height 10 days from now…on Wednesday the 6th.


Then the GFS & ECMWF 5 days later…this is two weeks away…

They all look the same!  That’s some unusual model agreement that about 8 days from now the pattern will change.  It’ll feature an upper level ridge in the West (dry & mild) and cold troughing in the Eastern USA.  This is more likely a chilly east wind pattern for us, depending on the orientation of the upper-level ridge.   I will mention this in the 12 Day Trend…a graphic I use from time to time in the 2nd half of the 10pm show.


By the way, note this isn’t a 12 day FORECAST, but a general trend.  In fact I’d rather not have those “40s” on there or specific clouds for each day, so don’t read too much into that.  I like the text part best.

Regardless, it’s obvious the early part of December will not feature much active weather.  Weather Geeks:  Get your Christmas shopping and chores done now…who knows what is around the corner in mid/late December!  As I recall some seasons that started out slow suddenly saw the weather action pick up after early December (2008).  I think 2007 was pretty quiet too early on, followed by tons of foothill snow.

Chief Meteorologist Mark Nelsen



24 Responses to Mainly Calm Weather Heading into December

  1. WEATHERDAN says:

    December looking cooler and drier. Also maybe some cold air by December 12th. We shall see. Peace.

  2. Roland Derksen says:

    I wish that future trend was starting today: I’ve seen heavy rain this morning. Looks like this November will have more than 10 inches now for me- might even be more than last year’s.

  3. JJ78259 says:

    Definitely Calm weather in San Antonio today 82 and sunny 🌞 great day to swing the clubs!

  4. W7ENK says:

    Cold rain season is upon us.

  5. Nahtalkin says:

    Tracy sure is doing a good job at the weather desk, I especially like that she slows future cast down to shorter intervals so a person has better chance to see what is in store for a specific time period of the day. Thanks!

  6. Ace in Wood Village says:

    I wanted to ask about the Volcano in Bali. I would think that will affect the weather around the world? Also, do the weather models factor that into what will happen in the future?

    • Tyler Mode in Battle Ground says:

      Only large volcanic eruptions tend to have an influence on world weather. The last good example was Pinatubo in 1992. I do believe now that once a large eruption occurs, weather models can take that into account.

    • Andy says:

      It is more of a long term affect. Event size also plays a part in global affect.

  7. JERAT416 says:

    Thankfully this isn’t near as bad as 2002. I took some pictures up at Timberline which looked more like August would, and this was in the first week of December. That year there had been some snow in November which had all but melted. There were patches a foot or more deep in north facing areas in shadows but otherwise it was like late summer. I’ll gladly offer pictures as proof but I am not sure how to post any here.

  8. Roland Derksen says:

    I don’t mind a dry start to December. I ‘ve seen enough rain for the last 2 weeks to make me want to see a dry spell.

  9. JohnD says:

    Oh no–a death ridge on the horizon! Oh well at least typically that should translate to sunny skies, breezy east wind and fake cold (or at least cool) temperatures. And who knows after that? Maybe a pattern transforming retrograde just in time to deliver some goods by Christmas. Here’s to wishful thinking!

  10. Jason Hougak says:

    Went up for our traditional family Cascade Christmas Tree Hunt. The bonus for the mild rainy weather last week was being able to get up above 4-5K without a snowmobile. We had 8-12″ on the ground with a rain/ snow mix this afternoon. Went to our super secret spot that has a hidden cabin with wood stove. Had a beef stew in our cast iron Dutch oven over bed of coals while we searched. Got a nice Pacific Silver Fir for ourselves and a beauty for our church. Our friends we took were a bit nervous about wheeling in but we made it and had the best time we’ve had. Looking forward to tons of snow in the foothills and some epic skiing. I will be meeting up with the Timberline mantenance crew Wednesday. They want to be able to make snow and need pumps to move the water from ponds to the slope side snow machines. Pretty awesome for sure.

  11. ocpaul says:

    I really, really hate this 8-10 day trend. I really do.

    • Nahtalkin says:

      180 degrees from you, I really, really love this long range trend. I really do! So many time in my life we have had a cool dry spell in December where we have frosty cold mornings with sunny afternoons, perfect weather for doing some farm chores. So folks like me say there is hot weather and then just right! Never ever say it’s too cold.

    • pappoose in scappoose says:

      Couldn’t agree with you more, Nahtalkin. Under 50 degrees and dry is perfect weather to get out on the property and get to work. Love the Winter for that.

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