The Long Range Outlook

Lots of moisture surging inland again this evening for one last bout of valley rain and heavy mountain rain.  The snow level has climbed back up to around 7,000′, forcing Timberline to shutdown night skiing for a 3rd night in a row.  Somehow Mt. Hood Meadows and SkiBowl are stubbornly hanging on to a very wet night.

The good news is the big dump of snow that will be here in just about 8 hours.  Much colder air behind tonight’s cold front moves into the Cascades around daybreak, lowering the sticking snow level down to around 3,000′.  Models are showing strong westerly wind at ridgetop elevations all day tomorrow along with plenty of moisture for heavy snowfall.  Maybe a foot to 18″.  It’ll be a real powdery snow too by tomorrow evening as temps fall.

The snow level eventually drops to around 1,500′ or even a bit lower late Friday evening as the coldest air pours inland, but by then the showers will probably be all gone (sounds familiar doesn’t it?).  Nevertheless, some of you in the hills above 1,000′ will probably wake up to a dusting Saturday morning.

We get some gusty east wind New Year’s Eve and Day.  Beyond that, the weather still looks real dead through most or all of the first week of 2012.  The reason is the stubborn upper-level ridging re-asserting itself over the west coast of North America once again.  This weakens Pacific storms and gives us warmer than average temperatures (at least in higher elevations).  What little precipitation we get next week may fall as rain once again in the Cascade passes.

Beyond next week, there are signs of a change.  All models show the ridge shifting to the west within a few days of January 10th.  Yes, it’s 2 weeks away, but we’ve seen several model runs now showing SOME sort of change after 10 days or so.  Check out these maps (click for a better view):

First the 12z GFS 850mb temp ensemble chart. It goes out to around 16 days.. 

The 12z ECMWF…

Note they both show a downward trend in the latter half of the period. Today the 4 week ECMWF came out as well. It’s run twice a week out to 4 weeks. Here are the weekly 500 millibar height anomalies. Orange/red areas are higher than average heights (ridging), blue areas lower than average (troughing).


Notice the current ridging over the west coast shifts well to the west from the two week mark onward. This doesn’t give us any detail of course, it’s just the weekly average. But having a trough nearby would spell much cooler weather than we’ve been seeing. This would also be far more typical of a La Nina winter.

Chief Meteorologist Mark Nelsen

123 Responses to The Long Range Outlook

  1. alohabb says:

    Should be a fun night..temps dropped quick to 39 and with that recent heavy rain shower…could be a slippery night! Mostly clear here now so this should be fun!

  2. marcus5day says:

    Temps failling fast in BG. 42 at 4pm down to 39 at 4:45

  3. Brian in Bellingham says:

    Find a common enemy or a common goal. If none available, they need to be seperated.

  4. cherie in vernonia says:

    US26, Intersection with Mount Hood Highway ORE35 MP 57

    The highway is closed at US 26 due to a crash on Oregon 35 7 miles north of US 26. Use alternate routes

  5. pappoose in scappoose says:

    SPLAT ALERT!!! Just had a shower pass through…passed the splat on the skylight test!…or was that a flock of birds. No…that wouldn’t have melted. Hahaah!

  6. Longview - 400 ft says:

    Temperature dropping!!

    For most of the day 44.2 now in the last 20 minutes down to 39.7 currently.
    Frost is a sure thing tonight!!!!

    • Wendy-Silver Lake says:

      Here too. We’ve been at 42 all day, now at 38 and it’s dropping fairly quickly. Heading into Vancouver tonight, hopefully it won’t be too bad on the way home.

    • Longview - 400 ft says:

      Please let us know when you return and your temp. A chilly night is in store for us.

  7. WEATHERDAN says:

    It looks like we may see this pattern of cold air stick around for awhile. From the graphics Mark posted it looks like below average temps all of January after about the 10th. Other sources are forecasting below average temps continuing through March. If this does indeed pan out, which it may not, this would be the coldest winter since 85-86. Now if this does occur I hope we have a nice average spring and a warm summer of 2012. Something for everyone. Happy New Year.

  8. W7ENK says:

    At 321 o’clock, the rain has stopped, the clouds are breaking up, the sun is shining through a bit, and the temperature is down to 42 degrees.

  9. Wendy-Silver Lake says:

    Snow/hail mix!!!

  10. alohabb says:

    So no warnigs in Metro area from NWS , but city of Portland puts out warning for black ice and frost tonight?

  11. PaulO says:

    18z GFS – the trend continues…

  12. Brad says:

    No snow for you…come back, one year!

  13. josh says:

    watching the temperature drop was 45 here 30 mins ago now 41

  14. Kyle says:

    2.3 inches of rain yesterday evening and steady rain all night/morning.

    I bet another good 2 inches came out of this.

    • W7ENK says:

      Right, but… The GFS (above) also has the cold at days 11-12, so they’re pretty much in agreement in that way. Granted, there’s still A LOT of real estate to traverse before we get there, so…

      I guess I’m just getting excited. I don’t want to watch this one flop like all the others…

    • W7ENK says:

      ^^ Not sure why that posted here…

  15. W7ENK says:

    I really hope this doesn’t jinx it, but I thought I’d share with all of the the glory that is today’s 12z…


    • W7ENK says:

      The best part is, the cold air in La-la Land isn’t necessarily staying out there, just out of reach. This time, it’s sliding forward with each consecutive run, getting 12 hours closer to reality every 12 hours!

      Me likey!!! 🙂

    • W7ENK says:

      Aaaaand… The ECMWF is coming around, too. It’s still a long ways out, but this is the best we’ve seen in a very long time!

      Things are definitely beginning to fall into place… Let’s just see if we can get it to hold together long enough to bring it all the way inside hour 60, then we can fire off the sirens! 😆

    • Mark Nelsen says:

      Not to bring you down, but out to 10 days the 12z ECMWF is still real mild. Better after that hopefully.

    • W7ENK says:

      Right, but… The GFS (above) also has the cold at days 11-12, so they’re pretty much in agreement in that way. Granted, there’s still A LOT of real estate to traverse before we get there, so…

      I guess I’m just getting excited. I don’t want to watch this one flop like all the others… 😕

    • PaulB/Eugene says:

      12z extended holds arctic N of BC/WA border through 360

    • W7ENK says:


      C’mon guys, I’m trying my best here…

      At any rate, things are changing, and there’s a ton of chatter behind the curtain! It’s encouraging, to say the least.

  16. alohabb says:

    accuweather saying freezing rain on the 10th, then rain/snow on 12th with snow on 13th of january

  17. Christian Marx says:

    I am so excited that we might actually get back into a fun winter. If the models are right on the cold air, do you think this will lead for some Portland metro area snow?

  18. Anyone remember this exciting day 43 years ago? (Dec 30 1968)

    High of 14 and a low of 8!!

    That was the beginning of the winter to remember…1968-1969.

    • vinnybob says:

      My favorite winter 68-69. My high here in Beaverton was 8 with drifts that went up to the roof of a school by my house. ( 10 ft.).

    • Punxsutawney (aka HIOPHIL) at work by Sunset High elev ~280 says:

      The whole period from Aug 1968 to Jan 1969 was something really incredible, snow in the cascades in mid-late August, above to well above average rainfall each month, and snow and cold in late December through January. Huge snows in Eugene.

      And all during a mild El-Nino to boot.

  19. pappoose in scappoose says:

    Happy, Happy. Timberline Lodge

    Weather 12/30/2011 11:00 AM Temperature 27 °F Wind Speed
    7 mph Wind Direction N

  20. pappoose in scappoose says:

    This wind animation page is a quick way to check temp trends at various locations/elevations.

  21. PaulB/Eugene says:

    72 h total precip at Timberline Lodge around 14″ liquid. Impressive.

    Will get some much needed snow next 24h….although not nearly enough to make up for recent losses.

    Long range:

    Models seem to be converging on idea of west coast toughing by end of second week. I would like to see higher 500mb heights over AK before getting too excited about arctic blasts but certainly things look better than a few days ago (although GFS 00Z last night was a bummer run). PDS ESRL GFS ensemble keeps vortex over AK with trough extending SE toward the PacNW…good for ski areas…during second week.

    Remember…564dm heights over Anchorage…can start to sniff the arctic air…but 570dm plus over ANC equals bingo for arctic blast. If arctic air is forecast by long range models but do not have high enough heights over AK…I get suspicious that the arctic dome of cold is not big enough to overcome terrain effects that models may not resolve…and what happens is the cold air gets “taken away” as we get inside day 5 and it either splits and goes E of divide or is simply a transient sharp open wave that gives us a whole lotta nothing. Don’t take this as a hard and fast rule…exceptions exist historically.

  22. pappoose in scappoose says:

    Ken (S. Salem). Looks like the area of increased activity you pointed out yesterday, is coming ashore!

  23. At least some consistency with the models, even at 10 days out. Maybe we can have a repeat of the 2008 model accuracy?

    • Ryan (Walnut Grove) says:

      Or last years model consistency of an epic even only to be quashed within 48 hours of the event by all models. ;-P

  24. Wendy-Silver Lake says:

    Bright blue skies here this morning (well there are a couple of clouds, but not much). Is the rain finally over, or is there more coming for today?

    • Jethro (Canby ~187') says:

      The steady rain is done for you now (cold front is still passing through just south of PDX), but there should still be plenty of cold showers later in the day.

    • Wendy-Silver Lake says:

      That’s good news. I do pretty good with showers missing me, depending on what direction they come. I wanted to finally get my lights and decorations down from outside, so it sounds like it’s a good day for that.

  25. pappoose in scappoose says:

    Sounds like body-bracing potential here:

    National Weather Service Portland or
    337 am PST Friday Dec 30 2011

    The surface flow will turn offshore on Saturday then
    strengthen Saturday night and Sunday bringing increasingly strong
    east wins to The Gorge and other gap and passes in the Cascades. The Cross Mountain pressure gradient will peak between 8 and 10 mb on Sunday. Ruthford

  26. pappoose in scappoose says:


    Must keep close watch on any Stray Albino Donkeys roaming about today!

  27. Ryan (Walnut Grove) says:

    00Z and 06Z GFS stopped the trend of a major shift by mid-month.

    • I wouldn’t say it stopped the trend. They just shifted the coldest air farther east. The 12Z however brings it back toward us. Variations in the details are going to change frequently until we get closer but this is now 9 consecutive runs of the GFS that is advertising varying degrees of potentilal for us. And I might add has not pushed the timing back. We’re still looking at 1/10 or 1/11.

    • Ryan (Walnut Grove) says:

      Well I posted that before the 12Z was out… A shift east in my book is pretty much a trend stopper. As most cold developments that far out shift east and PDX gets nothing.

      Glad to see the 12Z brought it back but having successive runs showing everything going east is enough to throw up a yellow flag going forward.

      A nice development in the long term is The Dalles gets a little colder as does Pendleton… Makes the Gorge more of a player when the winds shift off shore. Still not a significant of cold air in the basin though.

    • Yeah, I was getting a little nervous looking at the 00Z and 06Z too. Glad to see the trend is back in our favor per the 12Z

  28. My high today was 53 at 1 this morning…headed down. Already down to 46 degrees. Already snowing at Government Camp too.

  29. pappoose in scappoose says:

    Should be a interesting show here today. If we can just keep the vandals off the tower!

  30. Kyle says:

    When will the temps start to drop below 40F again?

    Sorry if it looked offensive or weird but I have a spirit attacking my PC making all me look bad and I will stop at nothing to get revenge at it.

  31. bgb41 says:

    12/29/2011 Oregon (All) Temperature Summary

    High:60 at DW0069 Ferndale( 840 ft) & Hermiston
    Low: 51 at DW6842 Gold Beac(449 ft) & CW5925 Coos Bay(49 ft) & BANDON(79 ft) & NERRS MET SITE A(10 ft) & DW5808 Portland(256 ft)

    High:30 at ALAKES Haines(7979 ft)
    Low: 20 at ALAKES Haines (7979 ft )

    Largest Diurnal Change: 19 degrees
    CW8140 Spray (56/37 ) (1772 ft )
    POWELL BUTTE (53/34) (3199 ft)
    W7DJH Prineville (52/33) (3586 ft)
    CW1893 Prinevill (52/33) (3251 ft)

    Heaviest Rainfall:
    5.82″ at RED MOUND(1753ft)
    3.25″ at GOODWIN PEAK(1800ft)
    3.24″ at QUAIL PRAIRIE LO(3183ft)

  32. 12-29-11 stats

    I finished with 0.82″ of rain and a max gust of 22mph today! –

    My parents finished with 0.59″ of rain and a max gust of 23.2mph today –

  33. Karl Bonner says:

    Let’s get some regression and some good ol’ chilly La Niña showers in here, with the signature 1000-3000 foot snow levels, so that we pack up lots of snow in the Cascades and plenty of moisture in the ground at the low elevations.

    And while we’re at it, some kind of weak arctic event that brings a little bit of snow to the I-5 corridor and temps down to 15-22 degrees for lows on the coldest nights. That would spell low teens for The Dalles since we’re typically 5-10 degrees colder during arctic blasts.

    I can deal with low teens. Especially now that we’ve had enough “fake cold” during the low-dewpoint parts of the December dry spell, with about half a dozen nights in the 18-24 range. That helped pull everything into a solid winter dormancy, making marginal plants a bit hardier than if the same temps occurred near the beginning of the season.

    What I’m not too happy about are low temps down around 0-5F, especially if accompanied by moderate wind and high temps in the 15-20 range. Alas, the frustrating reality is that The Dalles gets clobbered with a freeze of this magnitude from time to time, probably about once every 3-5 years. And below 0F about once every 5-10 years. However, we haven’t gone below 0F since February 1996, nearly 16 years ago (that was right before the epic flooding event). And truly brutal cold is exceedingly rare here: we haven’t seen negative double digits F here in over half a century – January 1957. The numbers from that cold snap, however, are downright terrifying: FOUR consecutive nights in the negative teens, and six consecutive nights below 0F – and worst of all, a daytime high of 0F on January 29, 1957!

    • pappoose in scappoose says:

      Hahaah! One man’s loss is another man’s gain! Some brutal/terrifying cold in The Dalles, could translate into a special delivery of said fright fest, through the gorge, into the land of gravelly plains! Needless to say, I’d welcome this horrifying event with lotsa grins. (sounds overdue)

    • o.c.paul says:

      Yes, we’ll gladly take all the extra cold you can spare. Send it on a screaming East wind!

  34. Derek Hodges says:

    Moderate steady rain still going and not stopping anytime soon. Very encouraging signs in the longer range.

  35. Kirk( Sandpoint Idaho) says:

    Finally something to get excited about

  36. Sean (Canby) says:

    Sounds like its time to get the chaps on…

  37. Absolute monsoon out there. 0.70″ since 6am. I dump the gauge at 6am every morning. Tomorrow will be the 3rd day in a row with over an inch.

  38. W7ENK says:

    Careful now, we wouldn’t want another January 2011 repeat!

    I’m sure many of you remember this?

    • Wasn’t that when we all jumped off the cliff? Larry was grilling some great burgers and kegs of micro brews were being lowered down by the pickup load. 🙂 My hunch is different this year. We’re just a month off as opposed to two months off last winter. This also means we may see the rains end by May instead of late June.

    • weather lurker says:

      Hahaha. That is awesome and accurate.

  39. boringlarry says:

    …been stuck at 42.3 since noon, and have quietly picked up another .51 of sky juice…

  40. Ben (Beaverton 775 ft.) says:

    Bring it on!

  41. Tyler Mode says:

    Warming quickly now. Up to 50.8 with 0.29″.

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