Bright Sunshine and Strong Wind

We saw our first strong Gorge wind of the season in the far east Metro area and Western Columbia River Gorge today.  The pressure gradient from Portland to The Dalles was up to -6.7 millibars at one point…pretty good for mid-October and just a sign of things to come as we get deeper into Fall.  Of course the big east wind season is in the winter, generally November to February, then it disappears quickly in early March.  The reason is the cooling of the continent while the ocean stays about the same temperature (a few degrees cooler).  Cooler land = heavier & cooler air overhead = high pressure.  Higher pressure east of the Cascades and lower pressure west means wind funnels through the only sea-level gap in the Cascades (the Gorge).  The wind then spreads out and slows rapidly, in most weather patterns, as it exits the Gorge.  Today was a prime example of a “gorge-only” wind event.  Sometimes the east wind also goes over the Cascades, bringing more widespread gusts to the entire Metro area.

Of course the result was a bright and warm Autumn day…temperatures into the lower 70s around town today.  I had more than one comment from the public that just loves this weather.  Cool and clear in the morning, warm and sunny in the afternoon.  The easterly wind also gave us great visibility too.

The wind goes away this evening…in fact the gradient is already down to around 2+ millibars.  We go to weak onshore flow tomorrow, so expect a drop in the temps as a front approaches, but still a real nice day, until we get some evening sprinkles.

The 7­­­­-10 Day Outlook still looks very boring for us weather weenies.  In general a ridge of high pressure or split flow through at least the middle of next week.  One change in the weather will be a cooler atmosphere Friday through Monday.  That plus relatively dry air and mostly clear skies at night could mean the first frost for outlying areas.  I mentioned this on Monday and it still seems likely even now.

Chief Meteorologist Mark Nelsen

61 Responses to Bright Sunshine and Strong Wind

  1. W7ENK says:

    Okay, so somethin’s blowin’ in, because the clouds are looking really dark, the wind is blowing at a good clip (maybe 20-ish) from all over the place, NW, W, S, ENE, etc… and leaves are swirling every which way in Oregon City.

    This is what I saw to the West from Milwaukie as I was leaving

    And once I arrived in OC about 15 minutes later

    Look at that wave! I’m sitting on my buddy’s front porch swing right now watching it overtake the clouds above and ahead of it. The wind is picking up and the temp is dropping fast, too!

    Are y’all sure there’s no chance of a thunderstorm this evening???

  2. 10-14-2010 Oregon Temperature Extremes

    Warmest:
    High 83 at Merlin, Hayes Hill & Prineville 4NW
    Low 64 at Red Mound

    Coolest:
    High 51 at Mt Hood Meadows (6600ft) Top
    Low 21 at Micro 3-FM (4N of LaPine)

    Largest Diurnal Change: 56 degrees
    Deschutes Portable (78/22)
    MICRO 3-FM (77/21)

  3. Yevpolo1990 says:

    One thing 18z shows is the low that moves from to the NE hours 170-190…a very interesting storm will be on horizon.

  4. Rob "Wrath" S.E. Portland says:

    18z shows something interesting off in la-la land….


  5. Mark’s new 7-day is fantastic:

  6. Kyle says:

    What’s the driest October for Portland and Salem?

  7. Yevpolo1990 says:


    What a big area of H pressure offshore!

  8. PaulB/Eugene says:

    Quick glance at models suggests overall tendency for west coast ridging through at least day 10. Frost 17/18 Oct looks less widespread than previously thought. No extreme cool or windstorms through day 10, probably through day 15. Cold air to remain bottled well to the N…

    • Mike (Orchards 255') says:

      Looks like the current pattern (main storm track to the north) we’ve been seeing for quite some time now, will continue into the foreseeable future.

  9. 40.5° and sunshine this morning.

  10. Snow-Zone/Monmouth-Elv200' says:

    42.1F and thick fog outside.

  11. PaulB/Eugene says:

    This should give us some perspective:

    Oct 13, 2009 Blog entry title:
    https://fox12weather.wordpress.com/2009/10/13/snow-wind-wet-season-begins/
    Excerpt:Whew! Sure feels like early winter out there. Snow came down a little lower than I expected this morning. I mentioned some snow or freezing rain possible in North Central Oregon or the Hood River Valley on the broadcasts last night. But the evaporative cooling (with dewpoints starting in the teens!) really did the trick. Snow stuck all the way to sea level briefly in the Gorge! The main band of precipitation is now out of the Gorge, so that should be it for snow.

    Oct 20, 2008: https://fox12weather.wordpress.com/2008/10/20/dry-outlook/

    Excerpt: The big story as I return from some vacation time this evening is the dry and mild looking weather maps over the next 7+ days. Hard to find much of any rainfall as we head towards the end of October. Yet this is the time of year that rainfall really starts to pickup. The last week of October and 1st week of November generally sees a tremendous increase in rainfall most years as we plunge quickly in the rainy season. November is only slightly drier than December, making it the 2nd wettest month of the year here in Portland. But basically November, December, and January are the 3 “big” months for rainfall. By February the heavy rains of late Fall through early winter are fading a bit, interspersed with a few dry spells, making it somewhat drier than the other 3 months.

    Not this year though…some sort of upper level ridging should sit near the West Coast over the next week or so. This will add to the very nice (boring for the wx geeks) Fall we’ve had so far. I didn’t do too much last week on my time off, but there was plenty of sunshine for hikes yard/garden work. Couldn’t ask for much more in mid October!

    • Washington Observer says:

      Hood River Weather’s blog post from a year ago. I was gone when this happened but I remember now my husband calling with the exclamation, “It snowed!”

      http://hoodriverweather.blogspot.com/2009_10_01_archive.html

    • Brian in Bellingham says:

      Excellent point, Paul. Not only October 2008, but also November. That was a fairly wet month, but quite warm. Seattle was 4 degrees warmer then normal, and two days set record highs. I remember being in the mountains the first weekend of December. Instead of seeing the skiers, there was bare ground.

      But I seem to remember December 2008 turned out ok.

    • Punxsutawney (aka HIOPHIL) at work by Sunset High elev ~280' says:

      The second half of Dec 2008 was something very-very special, and the first week of Jan ’09 as well, but the rest of that winter before and after was awful. If those record snows had missed us, and it was close for us in PDX, 2008-09 would rank right up there with one of the worst winters here in PDX of the last 10-15 years.

      But maybe that’s the price you have to pay for what we got that December.

  12. Yevpolo1990 says:

    All of this nice weather is going to really snap a big storm season

  13. Josh "The Snowman" From Everett, WA says:

    Everything is setting up perfect for this strong La Nina!!!

    Tranquil Octobers normally ensue and that is what we are getting, ha ha ha ha ha.

    Any of you analog-junkies have some food for thought for us based on how October has shaped up so far this year and how it pertains to Nov/Dec??

  14. Karl Bonner says:

    Just caught Mark on TV. I noticed that tomorrow’s forecast highs for the East Gorge are 68-69 while those down around Bend, Redmond and even Burns are in the 72-75 range! I’ve seen this happen before in the fall but not sure what the leading factor is. Would it be caused by the slightly higher sun angle further south, by an actually warmer air mass further south, or by a cloudless inversion in the Gorge and Low Desert (my term for the lower Columbia Basin)?

    • Mark Nelsen says:

      It’s the first sign of the cool season coming up. The sun has a harder and harder time warming the lowest elevations the next few weeks. Higher areas “mix out” into the warm air above first.

    • muxpux says:

      karl, im not saying you dont know this, but a lot of people tend to forget the east sides elevation. it isnt our elevation on the other side of the mountains. theres a reason its the “high desert”

      Bend: 3,625′
      Madras: 2,241′
      la pine: 4,235′
      Prineville: 2,860′
      Burns: 4,147′

    • muxpux says:

      and now that i re-read that, i guess the point of my post was to say, no fog=warmer temps. also, its a COMPLETELY different climate over there. think about areas around the mojave…

      diurnal swings can be insane there. its just how it is.

      wikipedia:

      Differences in Variation
      Diurnal temperature variations are greatest very near the earth’s surface. High desert areas typically have the greatest diurnal temperature variations. Low lying, humid areas typically have the least. This explains why an area like the Snake River Plain can have high temperatures of 38°C (100°F) during a summer day, and then have lows of 5-10°C (40-50°F). At the same time, Washington D.C., which is much more humid, has temperature variations of only 8°C (15°F). [1]

  15. W7ENK says:

    [Milwaukie] 10/13/2010
    75.7°F High
    45.7°F Low
    ENE 8.3 mph at 10:27a

    G’night! u_u

  16. 10-13-2010 Oregon Temperature Extremes

    Warmest:
    High 89 degrees at Illinois Valley
    Low 67 at Red Mound

    Coolest:
    High 55 at Eilertson Meadow
    Low 18 at MICRO 3-FM (4N of LaPine)

    Largest Diurnal Change: 62 degrees
    MICRO 3-FM (4N of LaPine) (80/18)

  17. W7ENK says:

    Just a note about the “Bright Sunshine” in the title…

    Technically, the sun is 0.02% dimmer than it is supposed to be. 😆

    http://science.nasa.gov/science-news/science-at-nasa/2009/01apr_deepsolarminimum/

  18. Karl Bonner says:

    Tomorrow, before any kind of west wind or cloud cover reaches the East Gorge, I’m going to cross the river and head just a couple miles west to where highway 14 gets steep mountain slopes rising immediately from the north side. I wonder if the combination of no wind and a steep south face will make for some impressive daytime heat?

    I’ve given up on the Catherine Creek spot because there aren’t enough steep south faces to crank out extra heat on a sunny day.

  19. High 74
    Low 37

    Very little wind.

  20. Tyler in Hazel Dell says:

    Mt. St. Helens is void of snow, so it wasn’t the focus of the pictures. Did hike down to Spirit Lake and it was gorgeous!

    http://weathercrazy.smugmug.com/Other/Mt-St-Helens-10132010/14183283_hK4du

    • Chuck on Mt Scott says:

      Nice pics. Thanks for sharing with us.

    • Washington Observer says:

      Thank you for the beautiful pictures. The colors are amazing and those old, stark gray snags add drama to it all.
      In about a week you should take the loop drive up the gorge, up through Glenwood, over to Goldendale and back down to Hwy 14. Our leaves are just starting to turn so I hope we don’t get rain any time soon.

  21. Karl Bonner says:

    A week ago I said:

    “I’m curious as to what kind of diurnal swings we can expect next week for places outside the Portland heat island. Will we see more of this contrasty pattern I love so much, or will the highs and lows get squished together a bit? What I’d REALLY like to see are two or three nights in the 35-40 range early next week, followed by some 70+ afternoons later in the week or next weekend.”

    Well the last two days my wishes were granted. Down into the mid 30s to low 40s by night, up to high 60s and low 70s by day. But there were tons of localized variations in temperature caused by the combination of calm air, low sun angle (shady north slopes), and evening cold air drainage.

    Leaves are finally starting to come through in The Dalles; apparently our foliage season often gets off to a late start since we quite often don’t see any significant cool weather until well into October, while Eugene can get some awfully chilly nights in September from time to time.

    • RobWaltemate says:

      I think that you would get big temp swings if there isn’t any wind and no clouds. That way the ground can emitt infrared heat out into space all night and cool off faster than if there are clouds, and unless the wind is from somewhere cold it will not help to cool off the nights either, or do I have this wrong?

      I bet the trees next to the Columbia river in the Gorge are always late to turn color for they are where the wind off the water can keep them above the temp that they need to change color.

      BUT if the wind blows them off…lol

    • Washington Observer says:

      I think the leaves are turning later this year Karl.
      Hunting season opens this weekend and we usually have good color by now.

  22. Rob "Wrath" S.E. Portland says:

    East winds 🙂 All I gotta say. Perfect October weather lulling us all to sleep before November rears its ugly head. Actually that would be ugly at all, rather welcomed.

  23. RobWaltemate says:

    Nice out today, darn it. A large gust of 11 mph. Low 40.4 high 66. right now its 55 DP 48.9

    • RobWaltemate says:

      Oh, and it was a West wind here North of Long Beach Wa, but I bet the wind on the Astoria bridge over the Columbia River was East, or even Chinook.

  24. 10-13-2010 at BG Lake

    High 68.1 Low: 39.9

  25. Mike (Orchards 255') says:

    ALL 33 miners are up!

    Perfect mid-October day…Currently 70° after a high of 73

  26. Tyler in Hazel Dell says:

    I was up at Mt. St. Helens and the winds were breezy, but I would say nothing over 20 mph at Windy Ridge. Falls colors are looking great up there though!

  27. Gregg-Formerly TTD, now in Bend says:

    Made it up to 77.4 this afternoon, after a low of 33.2. May see my first teens of the fall by Monday morning.

  28. W7ENK says:

    Not a breath of wind in Milwaukie…

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