Quick Look Towards Early Next Week

We tied a record high today, broke a warm record low this morning, and will probably break a record high again tomorrow:

MarkWarm_PortlandRecords

Because of the warm weather, travelling conditions are excellent this weekend

MarkRoadConditions_I84_5_Passes

Enjoy the warmth because it’ll end quickly this coming weekend.

Maps/models have been interesting the past few days; fraught with forecasting peril.  The reason?  A split flow with most jet energy going to our south the next week but some northerly flow in the upper atmosphere too.  Over the past two days the emphasis has been on a shot of colder air Saturday-Monday moving down from the north and into the Pacific Northwest.  It doesn’t last long, because it appears the milder southern portion of the jet will take over again early next week.

There are two reasons the forecast is uncertain in this situation:

1. The interaction between moisture to the south and colder air to the north always raises the possibility of frozen precipitation, mainly in the Gorge, but at times models have shown it almost cold enough in the metro area.

2. Placement and timing of precipitation changes with model runs depending on how much energy from each part of the jet stream affects us most.

As of this evening, it looks like we’ll see a shot of the cold air arrive on Saturday.  This will be drier air so not much rain Saturday.  Then dry offshore flow kicks in for two days (Sunday and Monday).  Get ready for a couple of days of cold east wind.  High temps around 40 instead of 60!  On Sunday we’ll probably be dry, but then models are bringing moisture over the top of the cold air Monday.

Monday is the day I see a good chance for freezing rain and/or snow in the Gorge.  Here in the metro area it remains to be seen if it would be cold enough for freezing rain.  Definitely a marginal event, more so than what we saw a couple of weeks ago.  Plus we’ll see when/where the moisture shows up.  The evening ECMWF doesn’t even give us precipitation Monday!

Another reason to just relax and enjoy Thanksgiving!

I’m working Friday-Sunday and I’ll have a lot more time to see how things are shaping up.

Chief Meteorologist Mark Nelsen

179 Responses to Quick Look Towards Early Next Week

  1. GTS1K' says:

    49.6 to 43.1 last 10 min. or so…

  2. Deb says:

    People come on this site to read about the upcoming weather. I read it all the time, though rarely participate because I don’t know much about the weather. I’m learning a lot. I don’t come here to read people insulting others and you know who you are. Stick to the weather. I think that many people have a lot of hostility and maybe are unhappy and for unknown reasons they believe a nice friendly weather blog is an appropriate place to vent them. It’s not so please stop. Mark is so kind to come on here with his professional information. I don’t think this weather blog falls under his job description yet he shares so much with us. Rob is great, many others also share good, solid info-as much as is possible with this goofy Pacific NW weather. LOL! Looking forward to some interesting days ahead.

  3. Sapo says:

    NWS increased the chance of freezing rain Monday morning…Hopefully Mark will post on this blog tonight or tomorrow sometime, with an update.

  4. runrain says:

    I think this front was a lot more vigorous than anyone thought it would be.we’ve been getting pummeled with very heavy rain here in Happy Valley the last few hours and particularly the last hour, not to mention pretty strong winds. I’d say my trees loss three quarters of their leaves just today alone!

  5. David B. says:

    Been holding steady at 37 with light rain for the past few hours here on Bainbridge Island. I notice Paine Field (near Everett, WA and at 500 feet elevation) briefly reported snow this afternoon (then changed back to rain).

    Most Central Puget Sound stations are now in 30s, but Bellingham is still 41 as of last report. It’s got to be evaporative cooling. Bellingham has been dry since this morning, but it’s been raining most of the day here. And dew points are in the 30s pretty much everywhere.

  6. Boydo3 N. Albany says:

    Kind of a double punch coming with cold upper air sliding down from the NW and frigid surface winds howling in from the NE. Models sure don’t want to keep it around very long tho.

  7. Andrew (Beaverton) says:

    Went from 56 to 48 here in the last few minutes, that was a quick drop!

  8. Winter weather advisory up for Seattle

  9. Update: Northeast wind shift now at Omak about 1-2 hours ahead of the 00z/12z WRF forecast. Remarkable accuracy for a computer model. BLI-YWL -15.5mb, OMK-YKA -17.6mb

  10. Jake-(Gresham) says:

    If this second arctic air mass gets here I’m afraid it’s going to set the tone for me this winter. I’m already starting to adjust to the mindset that December will be like this too….. must resist…must….resist!

  11. Arctic front is between Agassiz and Chilliwack northeast of Bellingham. It’s also just north of Osoyoos and Oroville about to cross the Canadian border north of Omak. It appears to be right on schedule with the WRF.

  12. Diana says:

    Vancouver WA being hit with massive, torrential rains for the last 15 minutes! Exciting : ) But boy is my postman annoyed!

  13. Jason Hougak says:

    Can we please take it one event at a time… unless there is a major round 3 coming up I don’t want bad news!

  14. David B. says:

    OK now this is odd. NWS is reporting 44 degres in Bellingham, albeit with falling dew points and winds from the NE. It’s 38 and raining lightly here on Bainbridge Island right now.

    Must be evaporative cooling at work (wet bulb effect), since it’s raining here but dry in Bellingham.

    • runrain says:

      Odd, yes. And Great Falls is still at 54 deg. Meanwhile, Cut Bank is now down to 2 deg. Wonder if the arctic front is thinking of skipping a bit off to the east.

  15. paulbeugene says:

    Arctic air not at Abbotsford BC yet, as of 2PM.

    Head to Council Crest if you want to see flakes Saturday morning…at least a skiff

    Hope that the Euro weeklies are wrong. Chairlifts are going to get rusted stuck.

  16. Jeff NE Portland says:

    This is perfect; its when we don’t make it a big deal; that something awesome happens (snow) let’s keep it on this level.

    • David B. says:

      It’s not even December and Arctic Blast No. 2 is about to begin. Definitely beats month after month of model riding. I say this even though I’m moving on the 1st and the 2nd and the cold may complicate things.

  17. PurpleHaze says:

    My barometer is “doin” the plunge. 29.34. At about 12:45ish it was 2.40.

    Anybody else have falling air pressure readings?

  18. dharmabum says:

    The blasted weather channel is on — 24 hours of weather. We had something like that where I grew up. We called it a window.

  19. Jason Hougak says:

    Going to be a winter of rossby waves. Deep ups and downs in the jet stream. Yo-yo action packed winter.

  20. ….Tracking the Arctic air….
    Arctic front is just northeast of Bellingham between Agassiz and Hope, BC moving down the Fraser River valley. It has yet to cross the Canadian border into north-central Washington, but it’s close. It is now between Penticton and Osoyoos, BC (North of Omak). BLI-YWL gradient is now -13.9mb. OMK-YKA -15.5mb. 12z WRF forecasts the arctic front into Bellingham 4-6 PM and Omak by 3-5 PM. We’ll see if is still on schedule, faster, or delayed any.

  21. David B. says:

    At 7AM, Hope, BC was 8 °C, dew point 7. Currently -1, dewpoint -5. Fraser outflow has begun.

  22. runrain says:

    Bellingham’s wind just shifted to the east. Looks like Rob’s 12 PM to 1 PM prediction for arctic air coming into Bellingham is right on!

  23. Sapo says:

    This weekend weather looks pretty interesting. There’s a chance for higher elevations, or perhaps even us, if we’re lucky, to see a rain/snow mix tonight and early tomorrow morning. Tomorrow, probably just rain, but if there are a few scattered showers tomorrow evening, maybe around 6 or 7 pm, we should be around 31-33 and cold enough for snow. Sunday looks dry and cold but Monday morning is becoming increasingly more interesting…It looks like a close call for Portland for some freezing rain. I think the upper air temperatures will probably be too warm for snow in the metro area, except for a few pockets (like the last event we had this month), but if we manage to stay around 30-31 until sunrise Monday, we could get some freezing rain. The last WRF-GFS has us getting hit with precipitation Monday morning about 2-3 AM. If we could get that to shift even earlier, maybe 11 pm Sunday night, we could have something…That last part is a little bit of wish casting haha, but at least there’s some interesting weather to watch!

  24. Tyler Mode says:

    Monday morning is looking more and more interesting. GFS wants to bring the moisture up from the south and we should still have some cold air locally…

  25. Tyler Mode says:

    Meanwhile in Cutbank, Montana,

    Temp is down 27 degrees in less than an hour!

    WOW!

    http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=tfx&sid=KCTB&num=72&raw=0

  26. runrain says:

    Great Falls should be fun to watch today. They are at 50 deg now with 40 mph wind gusts. They are expected to drop to 10 below zero tonight!

  27. Tyler Mode says:

    Here comes the cold front. It has now passed Hoqiuam:

    http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=sew&sid=KHQM&num=72&raw=0

    Meanwhile here it’s windy and still mild. 53. It will be interesting to watch the temps fall this afternoon.

    Not holding out for any accumulating snow, but it would be cool even to see in the air again.

  28. dharmabum says:

    If you are the smartest person in this blog, you are in the wrong blog.

  29. Jason Hougak says:

    The blog is fun to read. All of us discussing weather but at the same time a real life soap opera. A lot is said that gives me laughs. There’s serious weather and the fun that goes on with it. I never thought I’d get tied into it but nobody I know has a passion for weather. Thanks for all the laughs! 🍻

  30. JohnD says:

    ‘Should be a fun few days coming up to be a weather follower–adding to the festiveness of the holiday–and football–weekend! Lots of variables. Who knows for sure how it will all sort out? I feel pretty optimistic overall. No doubt at the very least it will feel wintry for a few days beginning tonight. Monitoring the transition will be especially fun. There should be a rapid temperature fall at a certain point. ‘Still hoping for a burst of snow along with that.

  31. Jake-(Gresham) says:

    It’d be interesting if this ends up being something more than a glancing blow. I know we’re all used to cold arctic outbreaks busting in terms of producing snow but every once and a while they surprise us. I say this regard to a random 48hr window and suddenly you see all the weather men/women forecasting snow out of the blue when people turn on the tv (the best events because the whole town panics muhahaha!). I am cruel. I know. ^_^

  32. Arctic front is through Kamloops now. They dropped 18 degrees in 1 1/2 hours. BLI-YWL gradient approaching -10mb. OMK-YKA gradient turning northerly as arctic air heads towards Okanagan Valley. It isn’t to Vernon, Kelowna, or Penticton yet though. 00z WRF has the arctic front into Bellingham around 12 PM – 1 PM with a northeast wind shift occurring then and for Omak has the arctic front and northerly wind shift 2-4 PM today. Let’s see if that’s on track or if the cold surge is quicker or delayed any.

  33. schmit44 says:

    11/27/2014 Oregon (All) Temperature Summary

    Warmest:
    High:67 at EMIGRANT LAKE AT(2042 ft) & ECHO(683 ft)
    Low: 58 at DW2789 Milton Fr(1358 ft) & CW2627 Pendleton(1512 ft) & BROOKINGS(79 ft)

    Coldest:
    High:36 at Timberline Lodge(7001 ft)
    Low: 28 at DIMLKE (4726 ft )

    Largest Diurnal Change: 28 degrees
    UMATILLA (63/35 ) (270 ft )

    Heaviest Rainfall:
    1.72″ at FLYNN PRAIRIE(1543ft)
    1.66″ at BURNT RIDGE(2955ft)

  34. WEATHERDAN says:

    When posters like Rob have done their research I really enjoy this blog. And hey it’s okay to disagree. But when the trolls get involved it really spoils things for all of us. Rob I really admire your knowledge of the weather. Keep those blog posts coming. Thank you too to all of the posters who came to Rob’s defense. To those who like to troll here please stop. This blog is for an open exchange of opinions and reports dealing with items of climate and or meteorology. If you have an opposing forecast based on facts or research Henry I would like to see it. If not then find another place troll. Thank you. Oh by the way I hope you all had a great Thanksgiving. Be nice to see some snow on Sunday. Even just a little bit. Peace.

    • I appreciate this, but it’s just getting so old, and it’s quite frankly embarrassing that I have to put up with this time and time again, that I have to address this, or even if I do not and ignore it, others do. This is ongoing for 5 years now. 5 years! I don’t think it will ever stop to be honest. Hope you had a good Thanksgiving.

  35. To wishcast one has to make an actual forecast. I have merely analyzed the models (GFS/NAM/GEM/ECMWF/WTF) at face value exactly what is shown. What forecast would I make? Based on 00z WRF 4km Sounding we would not see frozen precip. However, there is a large T/TD spread(low dewpoints) with very cold, icy east wind, so we’ve learned from the past this can and has caused surprises before. I really do not see it personally. Let’s just see how cold we get, and how cold we remain if/when moisture arrives.

    One more thing. When we see cold air masses like this what almost always happens? In patterns like these Cold pool develops and PDX metro-east is in colder for much longer than modeled. I’d wager this happens 75-85% of the time, unless a low pressure system/frontal boundary moves north of PDX and through Columbia Basin, otherwise how do we scour out this arctic air mass Gorge/Columbia Basin. Something to keep in mind as that just happened back on November 10th – 19th.

  36. moosieman says:

    Its kind of ironic how BigBank Hank uses a holiday when Mark is not watching to spew his jealously. As a lurker I very much appreciate Rob and despise negative people like Hank. Happy Thanksgiving to all! All who are thankful that is…Let it snow!

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