Tough Forecast: Will There Be A Wind Storm Saturday?

11pm Friday…

The chance of strong wind in the Willamette Valley and Metro area Saturday has dramatically increased this evening, but it’s definitely not a “done deal”.  Here’s the latest:

  • Models have come together with MOST of them showing a surface low tracking north along the coastline quickly tomorrow afternoon.
  • Air rushes in the south side of the low as it moves north quickly, thus a gusty south wind behind it.
  • My latest thinking is wind gusts 40-50 mph possible from Portland down to Eugene.
  • Two models imply the wind could be significantly stronger in the central valley….gusts 60+.  If so, that would be the strongest Willamette Valley windstorm in years.
  • Prepare for power outages and some downed trees if either scenario occurs.
  • Whatever happens will be done after just 2-4 hours, then back to the usual showers and breezes through Sunday.
  • As of 11pm, there are no watches/warnings/advisories from the NWS and no media freak out.  It’s a bit weird.  We’ll see if that changes in the next 12 hours.

So what has changed?

This evening’s model runs have mostly all (ECMWF comes out in 20 minutes) converged on a low center tracking in the perfect path…right along the coastline and then inland over SW Washington.  That’s the GFS, NAM, and GEM.

They also don’t show the surface low “filling”, or pressure rising within the low, like they did this morning and on earlier runs. Plus the pressure is lower on the earlier runs.  What caught my eye this evening is the very strong wind field over us as the isobars line up with the Willamette Valley.  Take a look at the WRF-GFS sounding over Portland…50kts just off the surface up to around 70kts at 850mb (~4,500′)


We don’t often see the wind field at all elevations aligned directly south to north at the same time the pressure gradient at the surface jumps up from Eugene to Portland.  The WRF-GFS goes nuts, showing 55kt wind gusts (around 65 mph) in the central valley.  Other than earlier this week, I’ve never seen this model show such strong wind in that area.


The NAM is not quite as strong, although it still shows gusts around 50 mph in the valley.  Models still don’t show the low deepening as it moves north; that would be a major windstorm.

Hmmm, a few other hints.  moswind  The 00z GFS MOS (model output statistics) shows an unusually high south wind averaging 24 mph at 2pm as well.  We don’t see it go that high very often.  The Salem value is 34!  That’s average speed.

I should point out this may be a last-minute screwup in modeling.  Our RPM (not always a stellar performer) still has just a baggy-looking low pressure trough with wind gusts maybe 30 mph…snooze.

ECMWF UPDATE 11:15 PM  Whoa!  The Euro just came in with the exact same track and strength. It’s even faster (good if you want strong wind) and forecasts 18 millibars pressure gradient late afternoon from Eugene to Olympia.  That’s significant windstorm material.  It also forecasts 50kt (around 60mph) wind gusts in the valley. ecmwf_windstorm  So all major models are showing the same thing right now…confidence is even higher.

I’ll be up early tomorrow morning before the OMSI meeting (at 10am sharp!) checking things out.

Chief Meteorologist Mark Nelsen

35 Responses to Tough Forecast: Will There Be A Wind Storm Saturday?

  1. pappoose in scappoose says:

    809 AM PDT SAT OCT 25 2014

  2. runrain says:

    With the lull in the weather and all, I wonder if a lot of people are going to be caught offguard. Lots of folks may be heading out to pumpkin patches, mazes, etc. I even wonder if maybe they should reschedule the OMSI event today.I would imagine several people drive from some distance away to attend that.going to try to get my long run in and get home before the breezes hit!

    • dharmabum says:

      Even in our “modern tech society” it is always prudent to beware of our surroundings and possible weather eventualities. Odd that we have “smart phones” but sometimes “not so smart” people!

  3. W7ENK says:

    809 AM PDT SAT OCT 25 2014

  4. runrain says:

    Must have been the warm front that went through.looks like the National Weather Service is just going with a wind advisory. Wonder if they will upgrade that later.

  5. paulbeugene says:

    Looking at HRRR, 80m winds of 40-45 knots expected in Willamette Valley, starting in Eugene around 12-1pm, PDX by 3pm.

    Winds will not have much difficulty mixing down to surface.

    Best guess: Most locations in Willamette Valley with gusts to mid 50s.

    Pressure drops have not been all that impressive yet, on order of 0.5-1.0 mb/hr. The low tracking off to north quickly should give some decent pressure rises.

  6. alohabb says:

    Love the possibility of a good storm, but the BIG WINDS get me nervous

  7. Jason Hougak says:

    Winds have let up

    • Tyler Mode says:

      Had the same strange thing happen here in BG…

      Strange change in the weather this morning. Temp was 45 and shot up to 51 with my wind switching quickly from ENE to SW and gusting to 23 mph. Barometer also on the way up sharply.

      Now the winds are calm again and are back out of the ENE.

      Check out the graphs:

      Battle Ground Weather | Personal Weather Station: KWABATTL18 by | Weather Underground

    • Phil says:

      Skies are clearing quickly in Forest Grove. Almost like the eye of a hurricane.

  8. Jason Hougak says:

    Cascade foothills, getting a strong steady southwest wind. Woke up 10 minutes ago with limbs hitting roof.

  9. W7ENK says:

    322 AM PDT SAT OCT 25 2014

  10. schmit44 says:

    Follow the storm coverage on Facebook with Mark Nelsen and 873 other weather amateur/professionals. This group has been active since March 15 2011. Just ask to join if you’d like to participate.

  11. What? Nobody’s trying to troll people on this forum by insisting that there will be nothing more than 30 mph gusts tomorrow?

    I’m going to guess a peak near 50 mph for PDX tomorrow. Those calls for 60-65 just look a little, well, radical – but I guess it’s possible.

  12. paulbeugene says:

    Stuck in Seatac enroute from Kauai to Eugene. Put on flight that gets to EUG around 9:20, hopefully before winds arrive

  13. The Bad Forecaster says:

    Hi Mark

    The GFS model that Brian post’s on his Facebook group appears to be showing hints of three more “potential” wind events up until November 4th. I am probably thinking beyond where I should be but what do you think about those even though they are out in the long range too as late as the 4th.

    As for this Saturday I am watching satellite pictures closely on both the IR and WV imagery to see how well that potential windstorm stays together. I thoroughly believe if it stays packed together pretty well and skirts just offshore along the Oregon and Washington coast that many from about Eugene to maybe near Seattle will get some significant wind. How significant remains to be seen but I think 30 mph to a little higher would not be out of the question at least for gusts and as usual the strongest gusts would be over the water areas. It may be quite a interesting day out on the Narrows Bridge up here.

    The way things look tonight on all the models appear much like what I posted on Brian’s group two days ago at the 300 and 500 millibar levels as well as the surface on the UW WRF GFS. I was amazed at how well stacked the low was at all three levels.

    Hmm…I am really wondering if this is the windstorm season we have all been waiting for the last X number of years. All I know is that has been a while here and I still remember vividly sitting in this same spot at the computer watching the south facing window bow back and forth during the Hanukkah Eve storm which took the power down for a total of 4 days here which is quite rare for this area which is run by Tacoma Power. I was actually living about three miles south of here at the time and there was no power where my apartment was for 11 days. I was a Puget Sound Energy customer at that time.

    Lastly here… The soil is getting pretty well saturated in my area. Within the last 3 days I have had 2.25 inches of rain and to top that off it was the 13th day in a row here of measurable rainfall of 0.01 inches or more. My gardens here are a total mud bowl. If the winds get going really good I could see some trees coming down pretty easily and if there are other potential windstorms behind this potential one then many could possibly come down in part because so many leaves are still on the trees.

    Sorry for such a long post but I have not posted much in a while either. 🙂

  14. schmit44 says:

    10/24/2014 Oregon (All) Temperature Summary

    High:74 at Rome(4049 ft)
    Low: 56 at BROOKINGS(79 ft)

    High:39 at Mount Hood Meado(6601 ft)
    Low: 29 at Timberline Lodge (7001 ft ) & Mount Hood Meado (6601 ft )

    Largest Diurnal Change: 27 degrees
    BASQUE HILLS (72/45 ) (5080 ft )
    DANNER (70/43) (4225 ft)

    Heaviest Rainfall:
    0.66″ at EW4856 Brookings(1365ft)
    0.66″ at HEBOWX Mt. Hebo(3160ft)
    0.65″ at SOUTH FORK(2257ft)
    0.63″ at Astoria Regional(10ft)

  15. High Wind Watch for the Willamette Valley issued soon? Almost hard to rule against it at this point. Gusts 45-50mph is a safe and perhaps conservative call right now.

  16. Thanks for the update, Mark

    00z EC puts 55-60+mph gusts PDX – SLE

  17. Benjamin (West Salem) says:

    Anxiously awaiting the EURO……

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