Rain Arrives, In the Valley and Cascades Too

Here are the rainfall totals so far today…for all of us it’s the heaviest we’ve seen the whole month.  And this map only tells part of the story

In the mountains, both west and east of the Willamette Valley, the precipitation has been far heavier. Lee’s Camp, along Highway 6 in the Coast Range, has seen 4.90″ as of 11pm. And the snow earlier today in the Cascades has changed to all rain.  Timberline Lodge’s total today (so far) is 2.40″, most of that as rain.  In the past 4 hours more than 1″ has fallen…not good for the thin snowpack.  Timberline has cancelled their night skiing both tonight and tomorrow night due to the conditions.

The heavy rain continues in the mountains tomorrow as a new slug of moisture arrives and sits over us most of the day.  Thursday the band moves farther south, then late Thursday night and early Friday we get one last cold front moving through.  There is good news for skiers though!  The trend the last few model runs today has been for a sharper upper-level trough coming behind that last cold front Friday.  850mb temps drop to -5 to -7 by Friday afternoon and evening.  The precipitation will be tapering off, but the transition to colder air plus leftover moisture could leave 6-10″ new snow before we finally dry out.

It was a challenging long-range forecast this afternoon due to  the GFS and ECMWF differences.  The ECMWF was totally dry Saturday through the middle of next week with a strong upper-level ridge developing overhead.  The GFS was weaker with ridging and showed a few rainy systems coming through.  Luckily we gambled on the ECMWF and now the 00z GFS has turned much drier.

Wind this evening turned out even weaker than I expected, no gusts to 40 mph here in the metro area and now the gradient is weakening.

A look at the VERY long range (10+ day maps) shows no sign of cooler than average weather.  Here’s the new 00z GFS ensemble 850mb chart.

Above average for the next 8 days or so, then closer to normal beyond that.  The 00z ECMWF has ridging of some sort over us through the next 10 days.

Chief Meteorologist Mark Nelsen

32 Responses to Rain Arrives, In the Valley and Cascades Too

  1. Jeremy KF7NGT says:

    1.08″ 24 hrs in SLE.

  2. Looks like the east winds might ramp up around New Years Day….

    Sub-tropical 52.3°….0.19″ rain today…0.52″ yesterday.

  3. Muxpux (Castle Rock 175') says:

    2.26″ in the last 36 hours here. 1.85″ in 24.

  4. Emily Waldman says:

    It has been very windy & rainy up Longview all night! But, is it true it might S-N-O-W in the valley Friday & Sat! Thundersnow maybe? Just the thought of a dusting! Oh My! I thought I might not get snow before my birthday which is Sunday the 1st!

    • W7ENK says:

      For those that live above 1,000 feet, maybe. It won’t be much though, as moisture will be running out as the cooler air arrives… same old song and dance.

      Good luck you you, and Happy Birthday! 🙂

    • Derek Hodges says:

      No guarantees but look a little closer Erik. The numbers do support borderlin snow to the valley floor if we actually can get any moisture Saturday morning. MM5 models show a little bit so its not out of the question, but certainly more likely that nothing happens.

    • Derek Hodges says:

      That, and there appears to be some kind of focus just offshore saturday morning. Its not even a real low pressure but the isolines do dip south along them which normally indicates a front. In this case maybe just a weak wave or something but hey, lets not give up hope just yet.

    • pappoose in scappoose says:

      Before I forget (I have a good memory…but it’s short).

    • W7ENK says:

      If you take the models at face value, sure. But, running them through my reality filter, I see SL ~1,000 feet, and as always, moisture is running out immediately after the front passes. That secondary little “bump” is so weak, it probably won’t squeeze out any additional moisture, and even so, the Coast Range usually gobbles that up anyway. Flow will be NW-ly behind the front, but the airmass won’t be the chapped lips/bleeding knuckles kind of dry, so SOWT won’t come into play because there’s nothing to suck the moisture up out of the ocean. Best one could hope for would be a heavier shower to push the SL down to the surface, and we all know how that goes around here.

      Purely based on past history, is all.

      Would I love to see it? Absolutely! 🙂
      Will it pan out? Most likely not. 😦

    • Garron Beaverton says:

      My guess is that the coastal range will eat up any moisture we do see by Sat. morning. Those pesky left over showers usually get hung there and the forecasting tools we have are not quite sufficient enough to read the topography of the valley and mountain and gorge effects we receive like a human can to decipher what we can expect. They usually over estimate the moisture that reaches us, but we can always hope!!!! HAPPY BIRTHDAY, AND HOPEFUL SNOW DAY as well!!!!

  5. o.c.paul says:

    “Waiter, oh WAITER! This is NOT what I ordered. I ordered the ‘Frigid Siberian Arctic Outbreak with The Overriding NW Low on the side’. So, take this back, this is not what I ordered!”

    • Jethro says:

      Yeah, sorry… I’m the one who ordered 54 and rainy with a side of south wind. Guess the chef decided to send out a round for everyone…

  6. gidrons says:

    GFS 12z operational has arctic paydirt in lala land

  7. David B says:

    LOTS of wind up here in Seattle overnight. Of course, I’m currently living in a hilltop neighborhood, so I tend to catch the wind where I am.

  8. Even if my lows are 50 degrees the rest of the year, my average for December will still be below 32 degrees.

    Looks like I will have 20 days below 32 this month, which I think is the most I’ve ever seen in any one month.

  9. gidrons says:

    Looks to me like I will get a little snow Friday night, in the hills above Scappoose

    • pappoose in scappoose says:

      Coming attractions, perhaps.
      A drive to find snow, with the dog in tow. He really likes to play in the snow!

    • gidrons says:

      It looks like the precip tapers off just as the cold air arrives — it will likely be only a dusting.

    • pappoose in scappoose says:

      Doesn’t take much for me and the dog to have fun. Could get lucky. Thunder snow anyone? Graupel perhaps?

      National Weather Service Portland or
      620 am PST Wednesday Dec 28 2011

      To throw more fun into the mix on Friday…some pretty cold temperatures aloft warrant the addition of a slight chance of thunderstorms for the coastal waters and coast. If you believe NAM bufr soundings…we have
      a chance in the interior. And with snow levels getting down to as low as 1000 feet or so…maybe we could get a snow shower in The West Hills. Kmd

  10. W7ENK says:

    Rain — well, if it wasn’t for the fact that I’ve more than tripled my monthly rainfall in the past 24 hours, then it really wasn’t all that impressive. Only 0.50″ since this all started, ~36 hours.

    Wind — I had one gust that made me take notice, and my station clocked it S G17.0 … pretty lame. Any more wind coming?

    So, a ridge returns, huh? Lemme guess, this one will hold through most of January, our chances for arctic air will be pushed back ’til at least Valentine’s Day, and the ski season is pretty much over with? That explains why all the winter gear at my friendly neighborhood “One-Stop-Shopping” store is already on clearance…

    • PDX Weather Nut says:

      It seems like a repeat of last “winter” so far. 😦

    • boringlarry says:

      … wouldn’t surprise me if winter stuff is on clearance to make room for Easter displays!… 🙂

    • W7ENK says:

      Not really a repeat of last winter, last winter was far more eventful!

      @Larry, I fully expect to see shorts, tank tops and swim gear out by the end of next week! That baffles me… and then it’s gone by the 4th of July? I guess I’ll never understand the retail world.

  11. I ended up with 0.54″ of rain yesterday. So far today my low is just 50.1 and it’s 52.3 now. Peak wind of 20 mph and just 0.02″ of rain.

    I’ve only seen two other Decembers with max low temps above 50.

  12. Garron at work in Aloha says:

    Thanks again Mark. I always like to see the spagetti chart, and also the estimated rainfall charts are appreciated. Well, at least it will be dry this weekend so I can work on the tree parts that fell all over the yard! Nice and warm out this morning too!

  13. *BoringOregon* says:

    3rd-Lot’s of rain and wind !!! I miss the sun 😦

  14. December 27th stats

    0.49″ of rain and a max gust of 33mph at my place – http://classic.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KORPORTL110

    0.25″ of rain and a max gust of 33.7mph at my parents – http://classic.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KORHAPPY4

  15. bgb41 says:

    12/27/2011 Oregon (All) Temperature Summary

    Warmest:
    High:61 at CW9205 Lexington(1558 ft)
    Low: 47 at DW8735 Yachats(92 ft) & DW4535 Cannon Be(23 ft) & OCNSID Oceanside(22 ft)

    Coldest:
    High:29 at HARL BUTTE(6071 ft)
    Low: 17 at Rome (4049 ft )

    Largest Diurnal Change: 31 degrees
    Rome (48/17 ) (4049 ft )

    Heaviest Rainfall:
    5.11″ at DW0237 Lees Camp(699ft)
    3.93″ at SOUTH FORK(2257ft)
    3.60″ at SADDLE MOUNTAIN(3250ft)

  16. Karl Bonner says:

    Second! Looks like we have a LOT of rain ahead. Currently nearly 0.20″ for the day in The Dalles.

  17. Wendy-Silver Lake says:

    Thanks for the update, I was wondering what was up with the lack of wind!

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