Will There Be A Windstorm Monday?

8:15pm Sunday…

The short answer is…possibly.  If anything does happen, it’ll happen  between 11am-1pm.

Here’s what’s going on:

  • A deep area of low pressure will track almost straight west to east just to the north of us tomorrow.  From around Willapa Bay on the Washington coast late morning to around Pullman on the Idaho border by late afternoon.
  • Central pressure should be around 985 millibars, plus or minus 5 mb.
  • Theoretically there should be a strong rush of wind up the valley as the isobars align east/west at midday when the low passes by north of us.
  • It’s moving very quickly, so it’ll occur quickly and leave quickly.

You can see the WRF-GFS forecast for Noon:

slp.20.0000

One would think that this could produce 50-65 mph gusts in the northern Willamette Valley with this setup.  But there are some problems with that:

  1. We have very few situations in the past where the low pressure takes this west-east path, so not many past examples to learn from.
  2. Last time we saw a track like this we were totally “burned” overforecasting windspeeds…December 17, 2012  That low was even deeper, but farther north.
  3. There are other examples where the same track has given us wind gusts to 60 mph.  Early January 1990 is one good example.
  4. Almost all models are producing very weak wind fields in the very lowest part of the atmosphere (where we live).  Interesting don’t you think?  Are they all wrong, or are human forecasters going to lose on this one again like in 2012?  Our RPM would say gusts only 30-40 mph…just windy for a few hours like we’ve seen 15 times this month already!
  5. This is likely due to the low level southerly pressure gradient being southerly like in a typical windstorm, but all wind from just a few thousand feet on up is straight westerly at that time.  The two don’t line up like last winter’s 3 windstorms where the surface low travelled almost south to north.  We won’t see strong wind from above mixing down.

You can see the sounding from the WRF-GFS for 1pm…notice all westerly except right at the surface?

kpdx.21.0000.snd

Now I am still on vacation…and I hopefully don’t have have VACATION-BIAS* (see below) right now, but…

THIS IS WHAT I WOULD FORECAST

PORTLAND METRO & WILLAMETTE VALLEY:  Southerly wind 20-30 mph with gusts 40-50 mph between 11am-1pm.  Then dying off.  Similar to what we saw about 10 days ago.  Plenty of power outages, but not a huge wind storm.  I know this is way below the NWS forecast of 65 mph gusts, we’ll see how that works out.  For betting purposes…I bet no higher than a 46 mph gust at PDX.

COLUMBIA RIVER GORGE:  This is a spot that just about has a guarantee of seeing some high winds…not sure why there isn’t a high wind warning out from Multnomah Falls to Carson area.  SW wind 30-40 with gusts 60-70 mph suddenly arrive around Noon-1pm.  It’s a similar event to the damaging wind about a month ago.  Wind gusts 50-60 mph possible from Hood River all the way out to Arlington/Hermiston.  This could be a big windstorm all across North Central Oregon too.

Alright…we’ll see what happens now.

Chief Meteorologist Mark Nelsen

* VACATION-BIAS DEFINITION:  When forecaster hopes that nothing exciting happens when on vacation in a warm place so he/she doesn’t miss it.  Thus he/she forecasts less exciting weather than he/she would otherwise.

226 Responses to Will There Be A Windstorm Monday?

  1. Mendy says:

    What about for the Corbett area will we see snow?

  2. sw says:

    Odd’s of a “true” arctic outbreak this year?

  3. paulbeugene says:

    Storm underperformed in terms of what I guessed would be peak gusts, by a bit, with the zippy anemometer at PDX bailing me out with a 55mph gust. Or should I say I underperformed in coming up with gust forecast. At least I’m glad I didn’t say 70 or 80 something or whatever. I haven’t heard of any injuries but maybe I’m not paying attention. Was skiing at Skibowl today, was not expecting to have enough mild air wrap up ahead of the storm such that it was raining and mid to upper 30s around noon.

    Now onto the next subject….will it be a Skiffy Christmas or not.

    • paulbeugene says:

      in terms of lowland snow accumulations, am not thrilled to see models spitting out 1-2 inch snow fall on the Willamette Valley floor (see 18z NAM 4km from this afternoon), while modeled 850mb temps are in the neighborhood of -3 to -4C, without any sustained, intense precipitation rates. Should wait and see if there are model trends in the “white” direction, but at this point I am not buying into lowland snowfall prior to Christmas.

  4. JackFrost says:

    Was the windstorm suppose to bust like this or did it take a wrong turn and went north to Seattle and caused grief there?

    I though the wish o cast was for 60-70 mph winds with Rob’s eyes popping out at the charts something about 18mb gradients or whatever.? Maybe I was seeing things.

  5. boninepaul says:

    Interesting storm where I was south of Wilsonville. Impressive gusts that were sustained. Neighbor on Greeley has a big fir on his house. Not a good thing. I peaked at 53mph at my house. Thats on my roof.

  6. Sapo says:

    Looks like areas around 2k feet could get quite a bit of snow around Christmas (or Wednesday/Thursday).

    Just something to mention, 6z-18z GFS today are in agreement (and trending colder) that a week from today (next Monday) there could be a potential for some snow or freezing rain. It’s far out but thought I’d mention it.

  7. Lance says:

    Let the wishcasting begin!!!!

  8. W7ENK says:

    Lots of reports of snow sticking down to some very low elevations, a couple at sea level in Puget Sound basin today.

    • Mostly at/above 500 feet, with the odd exception here and there in the stronger showers. Nothing here Downtown at work. It’s a marginal event, probably a precursor for Christmas or Christmas Eve.

  9. mothernature007 says:

    Thank you. We just started a little bit of snow also 🙂

  10. Sapo says:

    Potential interesting weather Christmas Eve/Christmas but chances aren’t great…
    GFS is still undecided about whether we will get precipitation at all between Thursday and Saturday, and if we do, if we’ll be cold enough for snow. NAM is much warmer than the GFS and gives us lots of mid-30s rain on Thursday. The SREF indicates a chance of snow Thursday morning, small, brief shot of snow for Portland Metro (likely under an inch).

    Oh yeah, the WRF-GFS isn’t good either. We’ll see what tonight’s 00z runs show.

    • Boydo3 N. Albany says:

      12Z Euro is probably cold enough for some snowflakes also. But it looks pretty dry…

    • As ever is our issue. Cold enough but no moisture; wet enough but too warm.

      Wah wah. I still think some folks will see a few flakes overnight Xmas Eve.

    • Sapo says:

      Yep, we’ll see how the models handle it, worst case scenario we’re warm with no precip or we get some chilly rain, best case scenario we get an inch or two Christmas Eve morning, my guess is it will be somewhere in between.

  11. Jeff--Garden Home250 says:

    Seems like impacts were pretty localized. Just seemed like a breezy day here in Garden Home/outer SW Portland. A little bit of debris, but no branches down and no power issues at all. My sister in Gresham lost power.

  12. W7ENK says:

    No more wind to really speak of now. TriMet says Orange Line MAX not running South of SE 17th “due to police activity.” No mention of any power failures on their system, and let’s hope it stays that way. Not sure how I’m getting back to my car at this point, though. They have one hour to get their act together!!

  13. jimbo says:

    Hope everyone is okay. Now can we concentrate on Thursday/ Friday weather?

  14. Thinking we are over 55 miles a hour. Where would we check this?

  15. W7ENK says:

    Wind has really let up now.

  16. Jon SE/PDX says:

    So weird. I’m in inner SE near the river and didn’t notice a thing. Been outside off and on for the last 3 hours

    • Aleta-West Gresham says:

      When I left Gresham at noon the wind was whipping around pretty good but i noticed a pretty good drop off by the time I reached Tigard. There were a few gusts there around 1:15 that rocked the car but not bad at all. I’m wondering if this was more and east side event? Now all we need is some snow and we’ll of had about everything this month!

    • Ann says:

      In Sellwood there were some pretty impressive gusts. And it’s garbage day- every single (empty) can has blown over and some were carried a ways down the street.

  17. PDXJL says:

    PDX is operating the Crosswind runway still for most flights.

  18. Jeff says:

    55 mph gust measured at PDX Airport at 1:51 pm.

  19. runrain says:

    HWW verifies for NWS. PDX just gusted 55 mph!

  20. EY (Oak Grove) says:

    It seems the storm has decided to surface and make an appearance. As such, I think we should give it a proper, lasting and fitting name…

    Today’s date is 12-21. But, depending on your date method, it’s 21-12. The storm is moving fast, sort of like it’s in a Rush or something…

    Rush 21-12.

    That’s the name of today’s storm.

    • Sifton says:

      How did The Trees fair at your place? I got fir crap everywhere here!

    • EY (Oak Grove) says:

      The problem with the maples is that the oaks are just too lofty. Because of this, not only do they grab up all the light, but they’re more likely to get blown over.

      The word’s out on how the firs feel about the whole situation.

    • s says:

      It NEVER fails I tell ya, I clean out the gutters & within a week we get a significant wind event!
      Kinda like when Mark leaves on 1 of his numerous vacations & the ‘S’ hits the fan in whatever season we’re in.
      Oh well, gettin my rake & ladder out……..AGAIN!!
      Guess that’s why they call me The Working Man

    • Sifton says:

      Gettin out my ladder n rake…….AGAIN!
      Guess that’s why they call me The Workin Man.

  21. kcteach says:

    Neighbor just came over and we took a look at a 30′ cedar between our houses. Tree has been leaning towards his house lately, but he noticed that the root ball was moving in the wind. Had a plan to at least take off the top but it was just too windy. We have it tied off to keep it upright for now.

  22. Longview 400 ft says:

    I have a maple snap in two, another break as well, we are OK, yard is littered with branches, power was off for a few minutes.

  23. Shawn says:

    Kind of a small event for Hillsboro, didnt really notice much close to Intel.

  24. Anonymous says:

    What a borind event. Didnt last nearly long enough in Hillsboro, 😦 and I had to work through it so missed most of it.

  25. W7ENK says:

    Little power blips in downtown now. Did you notice that Runrain??

    It takes a lot to do that, usually something major going down or transferring up the hill…

  26. W7ENK says:

    Pretty windy out there now. The river looks angry, almost whitecaps, but not quite.

  27. We have had a few power bumps on Swan Island. Hopefully that is all we get.

  28. Longview 300' says:

    Huge fir just came down two houses down, heavy winds up here Columbia heights now! Police on scanner adviseing people to stay in doors.

  29. W7ENK says:

    Total outages approaching 33,000.

    11,700+ in Multnomah County
    13,800+ in Clackamas County

  30. Longview 300' says:

    Extreme wind now, 80 foot alder just came down in our backyard, no house damage. Heavy rain and wind racing through, branches cracking and flying!

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