Warmest Day Of December & Low Mountain Snowpack

7pm Friday

What a warm day!  Temperatures reached well into the 50s west of the Cascades with even some lower 60s showing up south of Eugene.  Central Oregon got into the warm weather act with low 60s in Redmond and Bend.

Todays Observed Highs OrWa 2017

Today we have been in the warm sector between a warm front that passed overhead last night and an approaching cold front.  The gusty southerly wind brought in the warm air.  The wind has remained light easterly in the Gorge, keeping temperatures in the 30s there.  This warming winter wind after a cold spell actually does have a name; although it’s rarely used anymore.  It’s the original “Chinook Wind” before that name was more commonly used to refer to westerly warming wind off the east slopes of the Rockies.  We should use it more often just to annoy those folks in Denver.

At 7pm the cold front is moving into the western valleys of Oregon and Washington, evidenced by falling dewpoints and temperatures at Astoria.  A surface low pressure area is moving across NW Washington and will move into Eastern Washington the next few hours.  This reverses the pressure difference across the Cascades, leading to a gusty WEST wind through the Gorge.  The WRF-GFS forecasts 4-6 millibars by 10pm!  That means you’ll make a quick jump to 50-55 degrees in The Dalles sometime between 9-11pm.

Unfortunately for the mountains and ski areas, it has been pouring all day long.  The snow base dropped by about 10 inches at Timberline due to the warm rain.   Radar and models show this is not the type of system where we get lots of cold showers behind the front tonight.  In fact we only expect a dusting to 3″ at the ski areas by midday tomorrow.  The fresh snow just before and during Christmas was great; salvaging what could have been a really rough Christmas Break.  But all signs point to a continuing pattern of weak and warmer than normal systems for the next 7-10 days.  Take a look at the latest snowpack numbers…only about 50% of normal for the end of December:

Snowpack Oregon Plus Facts

Snowpack Oregon Plus Facts2

We’ve seen this in the past, but generally not in La Nina winters.  I’m not sure what’s going on this year since we keep seeing ridging popping up over or just west/northwest of us.  You may also notice the lack of stormy weather.  How often (since October) have we seen this gusty south wind and a strong frontal system?  Not much…this winter is reminding me of the La Nina of 2000-2001 which turned into quite a dud for the region.  That year we had one ice event in mid-December too which brought freezing rain to the metro area.  Other than that it was a mainly quiet winter.  We’ll see, there’s still a good 6 weeks in which we could get a widespread snow/ice event in the lowlands and of course we can get a wet morning snowfall all the way into March.  And this weekend should be just fine with much colder temps firming up the snowpack tonight

Snow Report

In the short-term, we have a nice weekend ahead with mainly dry weather.  Sunday and Monday we’re back into the chilly east wind pattern.  Your New Year’s Eve will be chilly and breezy (or very windy if you live in east metro) but dry and comfortably cool

New Years Eve Fcst

Chief Meteorologist Mark Nelsen

31 Responses to Warmest Day Of December & Low Mountain Snowpack

  1. Nahtalkin says:

    I’ve seen it all now, today on the noon news Pete the story teller say’s take a look at this…..a frozen tee shirt…amazing, something to tell the grandkids about someday!

  2. Jason Hougak says:

    This current weather is the reason I wouldn’t like to be a weatherman. The summers here are so boring and now are our winters.

    • It’s another one of those useless “winter” ridges that can’t even manage to get decently cold and wintry at the surface. Surface temps are actually forecast to rise through the week. Bah, humbug.

      • Though I still can’t be too grumpy about any winter that delivers a white Christmas to the lowlands.

        • Nahtalkin says:

          So folks are never happy with reality……it wasn’t long ago I was reading about “Epic Winter Snowfall and skiing” but now that’s long gone……back to crying.

  3. Dennis Widmer says:

    Hey Mark, the 7 day graphic is missing Tuesday.

  4. Ken in Wood Village says:

    Well, that kind of sucks a big one. I went to this website


    and all I get is the East Coast 😦

    • Joshua Downtown PDX says:

      Sign up here. https://weathermodels.com. Free for the next month or so. Otherwise, this site will always be free… https://weather.us. Not all the same maps, but EMCWF data is available.

      • Ken in Wood Village says:

        Thank you Joshua, I have the second website already but the first is interesting. I will see about signing up for it. With the website I posted, I was just wondering why they just have the East Coast. It use to have different tabs of different areas of the U.S. Maybe the last run didn’t download right. Hopefully when the next one comes out it will download all the way.

  5. Roland Derksen says:

    Nice way to end 2017: sunny skies and cool temperature this afternoon (in the 30’s). December 2017 was a weird one for me; near normal precipitation(8.19 inches) but 5 days made up 87.3% of that amount.

  6. Andy says:

    This pattern looks like it continues out into mid January. Maybe a change after that? If this continues it will be interesting to see what the experts say who forecasted cold wet winter. I guess the NW is like a grab bag…you never know what your getting.

    • JohnD says:

      Yep. Everyone makes their best “educated” forecasts and in the end reliability is typically at risk–for understandable reasons–as you allude. Likely why Mark chooses to be the initial presenter at the annual OMSI winter weather conferences–talking about the prior season instead of the coming one. Definitely frustrating though for those of us impassioned about active winter weather–when it all is going seemingly everywhere but here!

    • Jake in Gresham says:

      Got my weather station setup today. Yeah, no record breaking snowstorm this Winter. I jinxed the crap out of that now. 😛

  7. Jason Hougak says:

    Alaska looks to continue to stay much warmer than normal.

  8. Ken in Wood Village says:

    Like I said before, it’s a never ending story with the high pressure over the west coast. It’s a real buzz kill for this winter. It’s almost like being in a El Niño winter than an La Niña one. I will put the fork into this winter but I will probably eat crow if for some reason this weather pattern finally changes. I really don’t see it changing anytime soon tho. 😦

  9. JohnD says:

    Simply an odd, odd season–at least so far. ‘Can’t quite recall anything completely comparable–although I am sure there has been. We’ll see what lies ahead. But with the persistent current features, things don’t seem too optimistic. OTHERWISE, Happy 2018 fellow bloggers!

  10. WEATHERDAN says:

    Reaching for the fork, almost there. Peace.

    • Jason Hougak says:

      Go for it Dan!

    • WEATHERDAN says:

      Our Winter is Forked. I wanted some snow this Winter but with this pattern I think we all end up disappointed. This pattern is very similar to 2014 and 2015. I really worry about the mountains. Here’s hoping for snow. Peace.

  11. Roland Derksen says:

    Some welcome sunshine here today, after an all day cold rain yesterday(with some snow briefly after 8pm). Local mountains are snow packed. This La Nina winter may not be like last year’s in some ways, but there’s lots of snow where it should be.

    • You’re right on the edge of the cold air (as you probably know). Major ice storm in the eastern Fraser Valley, and the southern interior of BC is snowy and frigid. But the outflow is weak so it’s not getting very far. It’s in the 40s here; pretty normal.

  12. “Other than that it was a mainly quiet winter. We’ll see, there’s still a good 6 weeks in which we could get a widespread snow/ice event in the lowlands and of course we can get a wet morning snowfall all the way into March.”

    Heeeeyyyy…didn’t Portland just have a genuine snow/ice storm on Christmas Eve? How often does that happen?!? Quit whining Mhork!!! 😉

  13. Jason Hougak says:

    56″ base quickly cut down to 44″ currently on Timberline telemetry. I wonder if Slush Bowl is even going to operate this year? Very strange weather indeed. Can’t wait for another strong NW flow out of the Gulf of Alaska again… one can only dream😴💤💤💤💤

  14. Ken in Wood Village says:

    Mark, I think you need to change your year. You put “20001” I don’t think we have reached that year yet…LOL. Another thing, and I said something about it on the last post. Unless we get ridging along the East coast of the U.S. we won’t get anything here. That High keeps on wanting to build on the West coast all the time. I haven’t seen this type of ridging in a “La Nina” year forever. I’m afraid the ski resorts are not going to have a epic snow season 😦 It’s really sad to tell you the truth. 😦

  15. Nahtalkin says:

    2nd thought is I really like all the quick changes between warm rain and cold, dry and sunny weather. (not so much east wind where I am).

  16. Nahtalkin says:

    1st of all I must say what a beautiful warm day after all the cold weather and snow.

%d bloggers like this: