Cool & Dry November Weather On The Way

Highlights This Evening

  • One more warm day tomorrow with temps well into the 60s
  • Enjoy it, I don’t see any more of the warm stuff on the way; last mid 60s until February?
  • Much cooler the rest of the week and into the weekend
  • Not much rain between now and Sunday!
  • First Frost is possible even in urban areas Friday or Saturday morning.

I was sick the last half of last week, plus the weather has been dead, so not much to talk about anyway.  But finally some interesting weather coming up over the next 7-10 days…hopefully.

5 out of the last 9 days we’ve tied or broken record warm low temps.  We won’t today since we’re already down to 54 at 9pm and it’ll be lower before midnight.  That’s a long stretch of warm nights!  Yesterday Salem and Eugene were into the 70s for record highs too.  It’s been nice to be outside with no jacket in November, but now it’s going to cool off.

The Big Picture
It appears a longwave upper-level ridge is going to be taking up residence out around 160W  off/on the next 10 days or so, which means a trough located most of the time along or off the West Coast.  There is amazing model agreement on this general plan in fact through the 10-14 day period.  Here are the 500mb height anomaly (all ensembles) maps from the 00z GFS, 12z GEM, & 12z ECMWF for 10 days from now: 

They all look pretty much the same don’t they?

Here’s the brand new 00z GFS model 850mb ensemble chart, very good agreement on below average 850mb temps through the next 9 days:

This means cooler than average weather returns.  We are just about into the time of year (mid November through early March) when “cooler than average” means real chilly.  So it’s going to be quite a change the next few days going from well above normal temps to a few degrees below normal.  And it goes without saying that after about November 15th, we watch very closely to see if that perfect snow or cold pattern will show up.  You usually want the ridge a little bit closer for an “arctic outbreak”, but with the ridge a little farther away, it can be a great snow pattern for the foothills and Cascades.  Right now nothing looks too interesting on the maps for the next week.  We have a first cold upper trough moving down over us Wednesday-Saturday.  We don’t get dry offshore flow, but even so it might be a cold enough atmosphere (-5 deg @850mb) that we get clearing and finally get a frost in the city (or at my house, I still haven’t been below 36…cheated…).  With an upper-level trough digging so sharply over us Wednesday and Thursday, the main precip action is farther south.  In fact the rain we have in the forecast for Thursday may never make it into NW Oregon east of the Coast Range as that system heads into California.

What about skiing? 
Very little moisture means little/no snow through Saturday, so no skiing for this 2nd weekend in November.  But with a cold trough over us next week, a couple wet storms could get some areas open for the weekend before Thanksgiving?  Think positive, but I definitely don’t see an early start to the ski season though this year (well before Thanksgiving).

Lower Elevation Snow?
This is the general pattern in which we would expect to see snow at least down to 2,000′, in fact I thought that would happen Thursday/Friday, but now just about all the moisture is farther south.   As of this evening, I don’t see anything on the maps through the next 7-8 days which would bring snow any lower than that.

Here’s what is NOT in the plan for the next 7-10 days:

  • Warm and Wet weather (we had enough of that for 3 weeks)
  • A Windstorm Pattern

Chief Meteorologist Mark Nelsen

44 Responses to Cool & Dry November Weather On The Way

  1. bgb41 says:

    ‎2012 Yearly Summary for Portland Airport. First 6 days of November running a staggering +8.3 degrees above normal.

  2. bgb41 says:

    ‎12z GFSx @ Hillsboro .. Potentially 5 nights in a row at or below freezing starting tonight.

  3. paulbeugene says:

    Looks like the coolest weather in the next two weeks most likely will be the second half of this week…I had thought previously that temps could dip into the mid/upper 20s later this week at night, but it looks more like 30-35. As for the following week…models have really backed off on the idea of a second, potentially colder trough over PacNW…with increasing heights over SW USA and trough over the NE G of AK…looks like things will get wetter as we get to days 7-14.
    Skiing outlook: problem this week is cold enough to snow in mountains but not enough precipitation. The following week it ends up being wetter but not cold enough for snow in passes/ski areas.

    CFSv2 weekly run from this morning has fairly mild temps for much of the country for middle to latter part of November..with cold temps in AK, NW Canada.
    The ESRL MRF reforecast model is sticking to idea of ridge over G of AK and trough over western No Am…for next week. This is odd model out.

    As for seasonal/monthly forecast….CFSv2 forecast anomalies based on most recent conditions (10/26-11/5) show markedly colder temps for Canada, AK in Dec, Jan than previously forecast…with neg anomalies in Dec for Washington and now even for Jan (near the Canadian border).

    The JAMSTEC (Japanese) long range model output from Oct 1 showed cold over NW 1/3 of USA….won’t get to see Nov 1 output until next week.

    I am not sure what the Euro long range has in store for us.

    Bottom line…no skiing at Meadows until at least last week of November. No arctic air in our region in next 2 weeks. No windstorms in sight.

    Blog should be a more interesting read as we get into December.

  4. Karl Bonner says:

    If we’re now to the point where “cooler than average” means really chilly, when do we get to the point where “warmer than average” means springlike? Valentine’s Day?

  5. Aimers says:

    Question for all of you amazing weather gurus…My elderly mother is driving to Seaside Saturday morning, how is the weather going to be in the coast range along hwy 26? I noticed talk about the snow level being around 2,000 feet, but will we need to worry about ice? Thanks!!

  6. W7ENK says:

    I like how this one is all wiggly! :mrgreen:

  7. SnowedIn - North Plains says:

    For anybody that’s interested in learning about how to read models/learning about the different types of troughs and ridges and weather patterns and such, here’s a website that has really helped me in the past:

    • W7ENK says:

      Are there any websites out there that will help people master the basics of the Eengrish Ranguidge? Like splelllinge ant punktewayshins??

    • SnowedIn - North Plains says:

      Are you implying that I’ve used incorrect grammar??

    • Chris s says:

      SnowedIn, I believe he is referring to a few posts below by a person, which are just painful to read.

    • SnowedIn - North Plains says:

      Hehe, I was being sarcastic 😆 I ughree, some peeples no understranded dah basick conseptes uv duh Eengrish Ranguidge.

    • W7ENK says:


      I’ll not point fingers or name names. :mrgreen:

      I wonder if Mark could add a spelling and grammar filter to the blog? Like, if three or more words fail either filter, it gets caught for moderation. Mark could then designate an articulate co-moderator (like myself) to read, correct and approve anything that hits the net…?

      Or not.

    • Sifton says:

      Whoa, I thought you already WERE the moderator W7ENK!!

    • W7ENK says:

      Hahaha! 😆

      Naah, just the resident Grammar Nazi!

  8. pappoose in scappoose says:

    Thursday sounds like fun! Bring on the graupel!

    National Weather Service Portland or
    155 am PST Tuesday Nov 6 2012

    Isolated thunder will become more possible Wednesday night/Thursday as the main upper low and cold core aloft moves into the or/Washington coastal waters. The best instability will be near the coast Wednesday night due to the relatively warmer ocean waters. 00z NAM reflects this by keeping negative lifted indices offshore. Better chance inland Thursday as the upper low moves over Oregon…along with -30 to -32 degree c 500 mb
    temperatures according to the 00z NAM. With freezing levels expected to be below 4000 feet by Thursday morning…any heavier convective showers will probably come with small hail. Snow levels will be below 3000 feet by Thursday…but with little to no organization to precipitation there should only be spotty snow accumulations. Likens

  9. lynnadele says:

    And yes i love the wather . Sice i was little. When i was my school whnt to omsi it was on wwather. And not leave that spot…..

    • Chris s says:

      Please tell me you are either in first grade or this is a joke. Otherwise, your posts are downright scary. !!!

  10. lynnadele says:

    I was liking this wather. Just right for someone have to the city bus’s not cold ant to hot…..

  11. bgb41 says:

    11/5/2012 Oregon (All) Temperature Summary

    High:84 at RED MOUND(1753 ft)
    Low: 66 at RED MOUND(1753 ft)

    High:49 at HOWARD Mt Howard(8150 ft)
    Low: 27 at Lakeview, Lake C (4734 ft ) & DANNER (4225 ft ) & CRANE PRAIRIE (5500 ft )

    Largest Diurnal Change: 45 degrees
    CHRISTMAS VALLEY (73/28 ) (4360 ft )

    Heaviest Rainfall:
    0.40″ at NORTH FORK(3120ft)
    0.30″ at SEINE CREEK(2000ft)
    0.29″ at CW2664 Corbett(659ft)
    0.25″ at CW2654 Corbett(1050ft)

  12. Where was that sun today? 600-800” elev. seems to be the magic number to get outta the funk. And what’s the deal with changing the forecast to clouds and sprinkles tomorrow? I got leaves to rake and grass to mow! Come on, dang it. I’m bored as hell and I’m not gonna take it any more! 😉

    • Mark Nelsen says:

      The fog/low clouds hung on a long time Salem to Eugene, all day long spells of gray aren’t far away!

    • Sifton says:

      I think you mean ‘today’. Well into the 60’s my ***!!

    • Muxpux (Castle Rock 175') says:

      I work in landscaping, and kept waiting for te clouds to break today, thank goodness we got all the mowing, edging and leaf pickup done before the “heavy” drizzle started. Got a 1acre lot to mow tomorrow in lacenter and a 100×75′ lot in se Portland, hopefully it isn’t too dang wet. It’s coming down pretty good up here

      • Mark Nelsen says:

        Yeah, that was annoying. Strong inversion and little/no south wind to mix out the low clouds. I thought we’d see SOME mixing for those mid 60s…big X for today.

    • Sifton says:

      Boy your right about that heavy drizzle. Me & the mutt got caught last week in the rain, no biggie. But tonight in about the same amount of time outside as last week, we got SOAKED!

  13. karlbonner1982 says:

    I like your comment on “no mid 60s until February,” as opposed to “no mid 60s until March.” I can see that Mark has the same False Spring Fever I’m horribly guilty of!

  14. W7ENK says:

    I guess it’s a welcome change… as long as the sun makes an appearance?

  15. Thanks for the update, Mark. 500mb/850mb Ensembles edging cooler and cooler. As I posted in the previous thread it is becoming apparent a ridge will be out in the Pacific from 150-160 W. A block may develop near 160-170W. Very cold air will be just to our north in British Columbia ready and waiting to be tapped. What isn’t determined is where the block develops. Depending on where everything lines up in the Pacific we could see a rare November cold snap(Arctic air?) before Thanksgiving. In my opinion of course….

  16. Reb says:

    Brilliant! I can finally start bringing out my peacoats! 🙂 this is the weather I wait for all year. However, I am missing the wind storms we usually get out here in Troutdale. :/

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