No Sign of Lowland Snow Next 10 Days

9:30pm Tuesday…

These first 10 days of December have been mild; quite a turnaround from that cold Thanksgiving week.

web_PDXTemp_13days

Of course we’ve been on the dry side since early October too.  Both Oregon/Washington saw a dry fall.  Take a look at the precipitation percent of normal for the past 60 days

anomimage

I do see three wet days ahead.  A Pacific system moves inland tomorrow afternoon followed by lots of post-frontal showers in the colder airmass Thursday and Friday.  There are hints we could see vigorous showers Thursday with maybe hail or thunder.  Then I see another somewhat “splitty” jet stream setup this weekend and part of next week.  That’s a return to weak systems.  You can see the upper-level system heading into California on Tuesday

gfs_tuesday

All models advertise strong southwesterly flow of some sort later NEXT week (about 10 days out).  The GFS 500 millibar heights and anomaly for Friday the 20th…

gfs_fri20th

What I don’t see, at least during the next 10 days, is any setup for lowland snow or a freeze.  I’m sure not going to bother putting on my snow tires for now.  Maybe next week.

Snow levels will vary between 2,000-6,000′ in the next 10 days.  Probably lowest this weekend.  Notice not a single one of 51 ECMWF ensemble members produces snow in Portland through Christmas Eve either!  Leading up to the Thanksgiving cold spell there were multiple ensemble members hinting that we might see some snow fun.  But you see nothing here.

ecmwf-ensemble-KPDX-indiv_snow_24-5979200

I’ve also been noticing the consistency in those ensembles for 850mb temps (temp in Celsius around 4,000′) through the next two weeks.  Not a single member down below -6; that’s when I start getting interested in lowland snow setups.

tseries_850t_000-360_Portland

The last time we saw snow in December was Christmas Eve 2017.  You may remember a couple hours of light snow, followed by a bunch of freezing rain.  It was a “Silver Christmas Morning” in 2017.

December Snow PDX 2017

To summarize

  1. There’s no sign of lowland snow or a hard freeze in the next 10 days, possibly longer
  2. That means we’ll make it at least 2/3rds of the way through December without snow
  3. We can’t see much beyond that point, although there are no hints of anything a little farther out.  It’s too early to know if we’ll be close to snow or ice for Christmas Week

Chief Meteorologist Mark Nelsen

35 Responses to No Sign of Lowland Snow Next 10 Days

  1. Joshua Lake Oswego says:

    Are we going to talk about the 00z ECMWF operational??? 6” of rain in less than 72 hours. Fire hose pointed right at us. I know this likely won’t happen, but it could…

    • Tanis Leach says:

      4.6 inches now in the 12z run of the Euro. Above the 90% for ensembles though.

    • Paul D says:

      Thursday went from “dry” to “heavy rain & windy”.

      I’m betting Thursday will be a washout because it’s my anniversary and the wife & I have outdoor plans that evening.

  2. Mr Realist says:

    So many searching for excitement, good luck.

  3. Joshua Lake Oswego says:

    Potential flooding issues mid-late next week. GFS operational has put PDX under the gun for the last couple of runs. My bet is that the bullseye will shift further south as originally forecasted, and we will be left with garden variety rain. Something to watch.

  4. Paul Sorensen says:

    What a waste of short days, of low angle sun.

  5. WEATHERDAN says:

    From around the 23rd to about the end of December we appear to be very dry and just on the outside of a very cold air mass. This gives us sunny and chilly conditions. Highs of 40-45 and lows of 20-25 but little or no precipitation. So at least it will feel like Christmas and we will escape the gloom. Now if the high retrogrades about 100 miles or so we might see a different scenario. Otherwise… . Merry Christmas and Peace.

    • Kyle says:

      With the warm(er) ocean over the coast that’s going to block it from ‘retrograding’ anywhere. That sucker is going to remain ‘stuck’ for some time until we have more weak westerlies take over.

    • Kyle says:

      The ‘warm’ coast is several degrees above normal. I’ve told the reasons why and gave links but nobody wants to know so good bye.

  6. W7ENK says:

    Another day, another day off because of another medical appointment…

    Went from 0.18″ to 0.60″ in about 12 minutes around 1 o’clock this afternoon. Rainfall was pretty intense. Didn’t hear any thunder in Milwaukie, but that’s not to say there wasn’t any to be heard, my catch-up on a certain TV show might have drowned it out… 😕

  7. Roland Derksen says:

    Nothing exciting here today- just a lot of rain (about 1.2 inches at 2pm and counting) i’m looking forward to some sunshine on the weekend.

  8. runrain says:

    Thunder and lightning in Happy Valley. Torrential rain.

  9. Tanis Leach says:

    Well today just got interesting. The coast is under a marginal chance for severe weather, and the storm prediction center has the valley in thunderstorm range but not the cascades. Also a 2% chance of tornadoes on the coast. From what I understand, that’s the same chance when the Manzinita tornado hit.

  10. Jake in Gresham says:

    Went for a bit of a hike this morning and got a few cool shots in the fog (Wahkeena to Multnomah fall loop):

    https://imgur.com/a/YaIfIdp

    All the snow and ice has melted away and the weather was super wet. The moss really stands out on the rocks near the water.

  11. WEATHERDAN says:

    Did see a little of hope about 10 days out. GFS meteogram shows lowering heights but pretty dry over Western 1/3 of Conus. 520 for PDX. Marginal I admit, but better than today. Hope it develops. Peace and Merry Christmas.

  12. Roland Derksen says:

    I agree- it’s been dark and gloomy recently. These low overcast skies really make the night come on quickly in the afternoon. Well, maybe this dull December will be followed by an interesting January. (just a wishful hope 🙂

  13. W7ENK says:

    We’re currently in the “No Man’s Land” of mid-Winter darkness, right now — the ~3-week period of darkest days between the earliest sunset (Dec 9) and the latest sunrise (Jan 2), centered on the Solstice (Dec 21).

    https://sunrise-sunset.org/us/portland-or/2019/12
    https://sunrise-sunset.org/us/portland-or/2020/1

    IMHO, this is the absolute worst time for clouds and rain. At least if there was snow on the ground, the reflected light would brighten things up a bit. But as others have lamented, this is awful!!

  14. Evan -- Cedar Mill says:

    Weather = 🤮 right now.

  15. Mr Realist says:

    Preach it, that is a wonderful service!!!!

  16. Don Santos says:

    Thanks mark! Keep on trucking!

  17. W7ENK says:

    Oh wow. In training (work) for 2 days, unable to get onto this blog. Take a down weekend to myself (slept so hard!), followed by a sick day and then a day off for a Dr. appointment… and now I see I’m up an inch and a half of rain, but down 20 bucks…

    Poor timing? Or just further evidence that the universe hates me, I suppose. 😥

    Still raining, BTW.

    🎵🎶And it shows no signs of stopping…🎶🎵

%d bloggers like this: