Today: 317 Years Since Last Subduction Zone Quake

8am Thursday…

The weather is quite slow again today with areas of morning fog/clouds leading to at least partly cloudy conditions this afternoon.  A little more easterly flow Friday through Sunday SHOULD give us more sunshine.  We’ll see how that works.  The next chance for a real soaking isn’t going to be until February!  That would be next Wednesday of course.

As of Wednesday, January is the 5th coldest month on record here in Portland.  We still have 6 relatively mild days to go, but we could easily end up with the coldest month since 1990 here in Portland and one of the top 10 coldest months!


On another note, today is the anniversary of the last great Cascadia Subduction Zone earthquake.  It was in the evening, January 26th, 1700.  Geologists tell us it was likely at least a 9.0 magnitude quake just offshore.

How do geologists know?

If you have some time take a look at this info on the Orphan Tsunami of 1700 .  I think it’s fascinating reading, but of course I find almost anything scientific to be fascinating.  It’s a paper written by Brian Atwater  and others about the clues to a massive West Coast earthquake, summarized in the graphic below


Some have theorized the massive Bonneville Landslide and the resulting “Bridge of the Gods” in the central Columbia River Gorge could have been triggered/formed by the big quake, but it appears maybe it is too old for that to be the case.  Great reading again just on the Wikipedia link.

Enjoy the weekend!

Chief Meteorologist Mark Nelsen

40 Responses to Today: 317 Years Since Last Subduction Zone Quake

  1. Jake-(Gresham near Nadaka Nature Park) says:

    I’m thinking this trends colder in the next 24 hours. Either the La Niña is making me biased or I’m seeing the Euro is trending more South than before. Maybe both. One thing is for certain. Both the GFS and Euro have put us in the ballgame. Euro more so.

    The GFS has us in Wintry mix territory as Mark’s forecast shows but the Euro is eluding to potentially more. My money is on the Euro.

    • Jake-(Gresham near Nadaka Nature Park) says:

      Borderline between days of snow or just a few days of cold rain:

      Come on, show me the powder!!!

    • boydo3 N Albany says:

      Not seeing it. Looks more like a short event for the gorge maybe. There won’t be a cold enough air mass on the east side.

    • Anonymous says:

      Look at the long range models such as the GFS and then scale back from there. I know you’re versed in this. Trajectories right now sway the system South going from long range to short range. It all will depend on consolidation though. That I do concede.

    • Jake-(Gresham near Nadaka Nature Park) says:

      Look at the long range models and then go to mid and then short range. I know you’re versed in this. Following this line of observation the trajectory of the weather system is trending Southward. I do concede that consolidation is the key but my excitement is toward it not being there just yet for the impossibility!

    • boydo3 N Albany says:


  2. Can we put a fork in this one? Every long range forecast I’ve seen Weather Bell, NWS, Euro etc. leads me to believe this winter pretty much done for the west.

  3. Roland Derksen says:

    Not much moisture with today’s system coming through: After a nice red sunrise, we saw increasing clouds and light rain beginning around 10:45 am. That lasted for about an hour and a half. Since then, some clearing skies and a nice peek at the setting sun. January 2017 looks like it will have a well below normal total of precipitation.

  4. JohnD says:

    Really interesting developments in the upstream weather. We “could” be in line for another Portland event mid week. We’ll see how it plays out. We all know that nothing is for certain until it is on our doorstep! Also, I can’t believe how somber the blog is this morning with all the potential in the wings!

    • Garron 1/3 of a mile from Hillsboro Airport says:

      You and me both! I read the Area Forecast Discussion, and said, wwwwwhhhhhhhhaaaaaaaaaaaaaaaaaaaaaaaaaat? Next Wed, and maybe colder beyond late weekend, WEATHER GASM! Steve Pierce, where are you???

    • JJ78259 says:

      That the issue people are probably a little tired of the cold weather of a typical northwest winter. After the first and second event of an La Niña season is great but if you remember 2011 not much to look forward to till July. Just got the old Mustang waxed and detailed ready for a Cruze in the warm sun! Going to hit some golf balls with friends at Top Golf.

    • marinersfan85 says:

      With as little cold and snow We get. I never tire of it regardless. Who knows when we’ll see snow again.

  5. JJ78259 says:

    San Antonio weather next week all mid seventy’s that is nice to see! Perfect Spring weather! Weather Dan would like it!

  6. GTS1K' says:

    Change in the weather?

  7. CorbettTez says:

    Winds out here in Corbett are gusting up over 60mph at times. Hadn’t heard it was going to be getting that strong again this weekend. Anyone know how long this is supposed to last? Wondering if some calmer weather is in our near future for some much needed property clean up after the ice storms. Thanks!

  8. Sapo says:

    Well the 12z NAM, GFS, and ECMWF were all pretty cold/improving for next week if you want snow. GFS gave us 4-5″, Euro just a trace but there is definitely improvement. It’s something to keep an eye on at least.

    • JohnD says:

      Thanks for your input–as always. The afternoon NWS AFD sure seems to corroborate. We’ll see how the trends finally consolidate over the next few days–one way or another. With the various other similar scenarios already this winter, it definitely seems possible!

  9. Registered Nerd says:

    Now 12z is back to potential snow around the 2nd/3rd, models swinging back and forth. Is the vast temp difference between runs due to where the low comes onshore?

    • Boring 550' says:

      As far as I know the low placement means everything. If I’m correct, you don’t want the low going north of Tillamook if you want snow here.

  10. JohnD says:

    It seems like overall weather features–and attendant models–were hinting at something conducive for some low elevation action–but have since backed down. Too bad. But at least we got to enjoy some great winter weather in earlier weeks. Only a couple weeks or so left in the prime time zone–or maybe a little onger this year, given La Niña, along with what we have already experienced. Not quite ready to fork it yet.

  11. esmewwax says:

    Power is out at Vista House. (At 4:50). Computer will not get turned back on until morning. Hence no more wind info….dang it.

  12. Jake-(Gresham near Nadaka Nature Park) says:

    Morning, hey guys. Thought I’d give a shout out to this website / app. Really great:

    Android app (was not able to find it for IOS):

  13. Tyler Mode in Battle Ground says:

    Has anyone noticed the rather high pressure? Not record breaking, but the highest in some time! 30.63″ at my house.

  14. Ash Qelon says:

    Bored down at the studio and have to reinvent an old
    “shop worn” article with “new lines”.
    Post some food recipes or perhaps how to change spark plugs in a lawnmower.
    Try something new, it won’t kill you..

    • muxpux (Longview) says:

      This is a weather blog. He says at the beginning the weather is slow, but he knows if he leaves the group without direction they get restless. There is talk of a possible winter event around the first, in sure there will be a post soon enough about that. But for today, let’s talk about the anniversary of a huge earthquake.

    • Ash Qelon says:

      I’m glad for that faux put.
      have a nice day.

    • Scooter says:

      It’s frosty cold this morning so we’re having French toast this morning but I don’t have the recipe handy……Actually thinking about the lawnmower is weather related and a very good time to get the thing ready to go now and a person won’t be waiting 6 weeks for the shop backlog this spring when the grass is wildly growing.

    • GTS1K' says:

      Sounds like someone had their allotment of cafe’ already – toast notwtthstanding….

  15. Gee, thanks Mark for reminding us that a 317-year ticking time bomb is lurking beneath us, nearly overdue to detonate! :O

    The first half of February sure looks interesting, btw…

  16. WEATHERDAN says:

    Felt today like Winter was over but maybe not. Meteogram showing snow in PDX next Wednesday and Thursday. We shall see. 37 at 8:00PM. Peace.

  17. JohnD says:

    I will unabashedly date myself in confirming that I was born in Albany, Oregon on February 10, 1950. The great winter of 1950 had finally abated a few days before that date. The story goes that my Mom was understandably challenged during that time–as many were–and as we all can relate to amid our own recent storms of 2017.

    We have been in Portland for many years now but I always closely follow the Mid Valley especially due to ones historical roots.

    In 1950 b-t-w, 55 inches of snow fell in January in Albany. It is fun looking at pictures from back then in the old photo albums.

  18. Ellen Wallace says:

    Great book on the subject called Cascadia’s Fault by Jerry Thompson. Very good read. Amazon carries it.

  19. GTS1K' says:

    Funny, I would have sworn it was 316 years ago….

    Oh, well …… who’s counting?

  20. Jake-(Gresham near Nadaka Nature Park) says:

    Sigh, ordered the Ambient Weather station model WS-1400-IP off Amazon. After 3 weeks waiting for it to come because of inclement weather. Opened the box to find a very beat up box of a WS-0900-IP weather station.


    It looks nothing like the WS-1400-IP on-the-box! How can they do this!


    Prints out return label.



  21. Roland Derksen says:

    Quite a sobering anniversary(regarding the earthquake). I hope it gets longer. I don’t want to experience anything like it Anyway, I’m surprised in your list of coldest Januarys you didn’t include 1993.

  22. JERAT416 says:

    Great information Mark! I’m enjoying this weather and the break from ice and snow. Have a great weekend everyone (early)!

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