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. Garron at work in Aloha says:

    HAPPY NEW YEAR 2012!!!!!

    I’m celebrating by doing inventory at work!!!! YEA! Someone’s gotta do it.

  2. PDX Weather Nut says:

    Interesting stuff. We had a very brief period of sunshine here this morning. It’s been very grey and damp the last few hours. I hope the pattern does change towards colder and wetter weather!

  3. Runrain says:

    Home tomorrow, but what an insanely nice day in Phoenix today with mid-70’s and almost no wind. Strange seeing everyone out in shorts and tshirts in the park playing basketball, volleyball, frisbee, etc. at the end of December. There have been air quality problems the past couple of days.

  4. Wendy-Silver Lake says:

    Does anyone have a radar link that will show things further north than Battle Ground and further south than Centralia. I can’t get Wunderground to work and the one on 12 only goes as far north as Battle Ground.

    Thanx!

  5. Just had a light shower pass through. Temp warmed from 34 to 35 and there were a few flakes, but certainly nothing major. 🙂

  6. Nathan Marx says:

    I hope it snows in a couple of weeks because im bored of having no snow this year. please respond im a 12 year old boy who likes the snow.

  7. PaulB/Eugene says:

    00Z GFS not to bad…consistency is key…neg anomalies over SW Canada…pos over G of AK…even saw the 570 line cross over Kenai Peninsula in AK…pieces falling into place even though the operation did not scream arctic blast otherwise…with initial trough digging a bit offshore and holding the main blob of cold N. The good news it looks as if someone finally read the instructions on how to turn the SW/NW Canadian Freezer on…now just need to leave the door ajar. Palms beware…especially in zones 3a and 3b..you know who I am shouting out to

  8. AdamInAumsville says:

    Wow!

    Did anyone else see that Eugene has had 4.67″ of rain in the last 72 hours? I have had about 3″ at my place and I thought that was a lot.

  9. Things are already icing up out here and it’s 36.7 degrees. Tomorrow morning could be interesting for those driving.

    An intense squall came through around 4:45 this afternoon. Winds went from 5 mph up to a peak wind gust of 29 mph from the WNW along with a temp drop from 43 to 38 in 15 minutes. By 5:15 the wind was from the west at just 3 mph.

    Today was my wettest day for the month with 0.62″ of rain.

  10. Danny in Troutdale says:

    I want some snow (cries)

  11. so now the NWS says no snow for me. Did not get to see Mark….what was his verdict??

    down to 33.4

  12. Jacoby (SE Gresham) says:

    Nice little squall just moved through.
    Even heard a nice clap of thunder.

    • Hal in Aims says:

      nice graupel shower here……..entensified right over us…..temp dropped two degrees in about 10 minutes…….all white now….35.9

    • IceCold says:

      We were at white-out conditions with the wind, sleet, snow, and hail. The thunder and lightening were impressive. It reminded me of 2008 for about 5 minutes…..then it suddenly ended.

  13. Derek Hodges says:

    Just got plastered here on the portland/gresham border with some very heavy precip. Heavy sleet/snow/rain mix. Everything was coated with the sleet. 🙂

  14. Wow! -31.2 at Govt Camp LOL

    http://www.tripcheck.com/popups/WSDetails.asp?
    SCANStation=68013

    34.8 barometer 30.40

  15. Big Nel says:

    Damascus 37.6, chill in the air

  16. hmmmm barometer going up……temp 37.9 no precip

  17. ORE6
    MP 20
    ORE6, 19 miles West of Glenwood
    Unconfirmed
    Crash/Hazard

    Lanes Affected: (Westbound) 1 Lane (Eastbound) 1 Lane
    Comments: An unconfirmed report of a landslide has been received, use caution.

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