A Warm December ends With a Cold New Year’s Eve

5pm Sunday…

We had a nice cold front pass through the region Saturday evening, leaving us with scattered showers and sunbreaks today.    Tonight skies begin to clear out as we get into a cool northeast flow for a couple days.  This isn’t an “east wind comes blasting in with bitter cold temps” sort of setup.  It’s just back to normal temps or even a little below (especially at night) for most of us.  That’s something we haven’t seen much of the past 2-3 weeks.  Since early October we’ve been in a mild/warm weather pattern much of the time.  This December will likely end up in the top 10 warmest at PDX.  As of the 29th, it’s the warmest since 1979, but that will change with cooler temps this evening and Monday.

Month Climate Temps Calendar

We have caught up on rain, making it just about average for December.  Snowpack has been slowly improving the past week as well.  Now over 50% throughout Oregon with much of Eastern Oregon right at average.  Very nice! Considering I can hardly see movement on Hwy 26 @ Timberline Road on the ODOT camera at 5pm, I’m guessing that a LOT of you are enjoying the snow?


One thing we’ve been missing?  Those of us in the east wind areas missed the cold nights in early December, meaning some parts of Portland central/east metro have barely seen a frost!  PDX has hit 32 four different times, and will likely do it either tomorrow morning or by midnight tomorrow night once again

Mark Warm Low Temps

That’s quite unusual, even for that relatively urbanized location at the airport.  All the rest of us in the western valleys have been down into at least the mid-upper 20s.

Mark Warm Low Temps2

You can see that most Decembers we get at least down into the mid-upper 20s at some point at PDX

December Coldest Night Each Year


We are 1/2 of the way through our “storm & cold” season and I think it’s fair to say it’s been a real dud so far.  It shouldn’t be a surprise in this El Nino winter; these are sometimes quite boring for the geeks like me.  Yes, I know it’s not officially an El Nino, but most likely it will be considered one once we look back on it.  It’s especially disappointing considering it’s our second consecutive cool season (so far) with not much exciting weather.  You may recall that last year was a real dud from November through mid-February, except for that Christmas ice/snow.

What’s ahead?

It’s very clear that we’re back into a ridgy/split-flow pattern for the next 7-10 days.  Little or no storminess, just occasional wet weather systems.  Temperatures will likely be milder than normal for at least the first week of January.  The 18z GFS shows 3 systems splitting as they move towards the coastline: this Friday, Wednesday the 9th, and Friday the 11th.

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The ECMWF model is a little more consolidated the next 10 days, but still “weak” looking.



Chief Meteorologist Mark Nelsen


36 Responses to A Warm December ends With a Cold New Year’s Eve

  1. My total December precipitation was 7.92″, all rain. Low of 30˚F overnight after a low of 31˚F on New Year’s Day.

    • Roland Derksen says:

      My total December precipitation:13.17 inches. Just a brief light fall of sleet here before noon, before the monsoons return.

    • Yeah, it was interesting when some of that Precip turned to ICE!

      thankfully it effected roads in higher elevations. But sure was interesting to see.
      Just glad we had no driving to do, drunks plus ice…no thanks.

  2. Diana F. says:

    Brrrr. Starting to rethink the open window while I sleep thing. I knew something was up when the cat took refuge underneath 2 down comforters that were rolled up in an open closet (by that open window!).
    It’s 30 degrees at 10am in East Vancouver…….!!

  3. Jason Hougak says:

    It’s been below freezing here all year. Time for some snow!

  4. Kyle says:

    Also only cities of your state would be allowed no ‘regional 24 hours’ except in the Plains states. Canada already ceased weather info by 1940 making Canada ‘vanish’ off the charts.

  5. Kyle says:

    FYI in 1941 at this time all weather information ceased as Uncle Sam felt it was too dangerous to allow the knowledge to leak since our storms travel west to east.

    The US Weather Bureau would not publish a general forecast again until at least 1943 with modified versions ONLY during an event and totals the night before but nothing before that or thereafter.

    Also no wind speed would be allowed even during the event. Only 24 hour temp totals and precip to the nearest .10 of an inch would be allowed.

    A Chicago reporter somewhere in all this was given a civilian award for an important game that was shrouded in dense fog to the point the reporter couldn’t see what was going on but he never once used any weather terms thru the whole game thus keeping the forecast classified.

  6. Joshua Lake Oswego says:

    I don’t want to jinx it… but I think we might go below freezing tonight, ladies and gents. Happy New Year!

  7. Ken in Wood Village says:

    I want to wish all the weather geeks a Happy New Year. Let’s hope the new year will bring more weather action to the PNW.

    The 00Z GFS looks better to me for the short term and a little in the long term too. I did notice something. If you look over in the East part of Russia, the temps start to fall over the long term. I was seeing temps in around -50 Celsius (-60F). It looks like they maybe getting into their cold time of the year.

    I also see a small Omega High at the end of the run. Not sure if that will happen but if it did, then we would start seeing more cold storms coming into the PNW with low snow levels and a lot of snow up in the mountains.

    For once, I actually like this run. I just hope the GFS keeps this up.

  8. Anonymous says:

    Plenty of frost in Eugene, just not much precip. Fourth driest year on record. Climate Prediction Center has Oregon continuing in drought through at least March.

  9. Lurkyloo says:

    Happy frosty New Year, folks! Hope you all stay safe this evening. Cheers to an interesting weather year in 2019!

  10. 31°F and frosty this morning. Expect something similar tomorrow morning.

  11. tim says:

    Another scorching summer is on the way, the cpc is showing blowtorch for the westcoast in 2019 agian.

  12. W7ENK says:



    It’s not going to snow in the lowlands this Winter. Wake me up when the warm sunshine returns.

    • JohnD says:

      ‘Not going to throw in the towel on Dec. 31; but at this point it sure doesn’t look promising for any low elevation winter weather this year. Frustrating too because so long as we are in the statistical winter weather window, we still have a chance. “You say there’s a chance?!”

      • Roland Derksen says:

        I was afraid of this. Well, anyway, today has sunshine, and we had our first frost since Dec.7th (27.5F minimum). Snowpack looks good now, but January can be a long month. Just hope it’s not as wet and mild as last time.

  13. Lurkyloo says:

    I’ve only seen 1 frost this entire season — so odd.

  14. K says:

    What a sad winter. Pathetic, truly pathetic.

  15. Ken in Wood Village says:

    Thanx for the update Mark. I will wait until the next Euro comes out to say something about what I see in the forecast.

  16. Paul D says:

    Another dud winter…. 😦

    • W7ENK says:

      So, I’m guessing the last two weren’t enough for you? Or have you simply forgotten?

      • Tanis Leach says:

        Except for 2 events, 2018 was a dud. 2017 defiantly wasn’t. Check out the Oregon AMS winter weather forcast review 2017-2018 powerpoint for my source (I dropped one if the interesting events).

  17. alohabb says:

    Summer, the door is open. Please come back.

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