1st East Wind “Event” Of the Season This Weekend

9pm Thursday…

You’ve probably noticed; we have entered a remarkable period of mid-October sunshine!  Today was totally sunny except for some spots of brief low clouds and/or fog.  The next 6 days should be mainly cloud-free, or just plain sunny as you can see in our 7 Day Forecast (which you can always find here)

7 Day Forecast Graphic 2017

The reason is a strong upper-level ridge shifting from the eastern Pacific directly over the Pacific Northwest.  It’s going to stick around for quite a long time.  Here’s the forecast from GEFS (GFS ensemble system) for Monday.  Lines are upper-level heights, colors are the anomaly (red = above normal, blue = below).

gefs_mon_am

Then next Wednesday from the EPS (ECMWF ensemble prediction system)

eps_wed_am

The ridge appears to be strongest at that time.  Looking farther ahead is stretching the limits of weather forecast models, but most interesting is that they all show a similar setup through Day 10…NEXT weekend from the EPS.  Not quite as extreme, but warmer and drier than normal.

eps_sun_21st_10days

So it appears that we are in a long (7-10 day) stretch of unusually dry and warm weather in the Pacific Northwest.

But there is a wrinkle to this forecast…not all of you will be able to enjoy the sunny & warm weather as much because of…the wind.

We’re quickly approaching the cool season (November-March) and that means “East Wind Season” too.  Fall and Spring feature the seasonal oscillation from westerly Gorge wind to easterly wind.  In this case surface high pressure drops down the back side of the upper-level high Saturday through the middle of next week.  Strong high pressure east of the Cascades will give us quite a strong pressure difference across the Cascades.  You can see it on the WRF-GFS surface map for Sunday morning.

wrf_sundayam

That’s 7 millibars easterly gradient from the lower Columbia Basin (near The Dalles) to Portland both Sunday and Monday mornings.  That’s a very strong east wind for October.   Plus, from Saturday afternoon through early Monday it will also be a “downslope” wind.  The layer of easterly flow is deep enough to move right over the Cascades and down into the valleys.

What does that mean for us?

Much of the metro area will be very windy Saturday afternoon through early Monday.  Expect gusts 20-35 mph in the windier spots with gusts at the west end of the Gorge in the 40-55 mph range.  Probably a few scattered power outages as well…under sunny & blue skies.

Of course Crown Point will be a bit stronger…maybe gusts 60-65 mph for the first time this season.  Those highs in the upper 60s will feel quite a bit cooler out there in that wind!

You can see this on the WRF-GFS time/height cross-section over Portland.  Time goes from right to left.  Starting at 5am today (right side) and ending 5pm Sunday on the left.  You see a few 50 kt speeds around 2,500′ over Portland Saturday night and Sunday AM.  That’s impressive even for winter!

kpdx.th

The pressure gradient will drop off a bit Tuesday & Wednesday confining wind to the Gorge.  At that point temperatures will likely peak here in Portland as the wind backs off.  We should reach mid-upper 70s on those days.

Enjoy the sunshine Friday and into the weekend, but be ready for things to blow around a bit too!

Chief Meteorologist Mark Nelsen

31 Responses to 1st East Wind “Event” Of the Season This Weekend

  1. Ken in Wood Village says:

    I’m up at Crown Point enjoying the sunny and windy day. Not as windy as I like it to be but it will do. Been in the wind for awhile and my hands are a little cold. There are a lot of people here. Took awhile to find a parking spot but it was worth it 🤗🌬😉

  2. Ken in Wood Village says:

    I’m really liking the 00Z Euro. The 06Z GFS is a little similar but wants to build a High Pressure in front of the Low so can’t come into the PNW. The 00Z Euro though, is great. It brings the front into our area and a massive Low stays in the Eastern Pacific. Looking good…I hope 🙂

  3. Just checked the River Gage for the Cowlitz River, it is at 10.7 feet deep . WOW!
    https://water.weather.gov/ahps2/hydrograph.php?wfo=pqr&gage=kelw1

  4. On the side note, have any of you seen how low the Cowlitz River is? we have sand bars where I haven’t seen sand bars before, and I have only seen smaller boats out there instead of the lager boats.

    Perhaps Mark could check to see what its level is and see if were nearing a record low?

  5. Any one else get their first frost?

  6. Kyle says:

    October is usually when our “storm doors” open up and we get either a deluge of rain or sometimes one end of the month gets it. Not the last few years.
    There has been a lot of minor but permanent changes to the earth MSM won’t cover or cover so very little to the point you have to go to obscure places to get it archived.

  7. Kyle says:

    Now that the rain has been taken away long range for the last few days not a SINGLE spray line across the sky. I wonder where all the “normal” jet traffic has gone. 🙂 ? You know normal jet traffic ALWAYS leaves spray lines that grow and block out the sun.

  8. Ken in Wood Village says:

    Well, the 18Z and the 00Z GFS is interesting. I know it’s a long ways out but maybe we could hope for it.

  9. M Perry says:

    Where’s that east wind? Shouldn’t it be here by now? We are interested up at Vista House (<:

  10. Ken in Wood Village says:

    I’m seeing a trend on both models but it’s a long ways off and the only thing is we have seen this before but then the High pressure builds back up. Let’s just hope this time the High backs off and let’s in the systems.

  11. JERAT416 says:

    How is there an “east wind season”? We get east wind anytime April-September which warms us up. We get it November-March and it cools is down. It’s here now in October so someone please explain how it’s confined to a season.

    • Ken in Wood Village says:

      I’m not an expert but I agree with you. We do get east wind during the summer time but it’s more rare. When we get east wind during the summer time we normally get really warm. When we get it during the fall/winter time we normally get cooler temps because the high that is over on the east side normally is a cold or artic high. We get more east wind during the fall/winter time because the weather pattern is more active.

      I hope that helps a little bit 🙂

      • Muxpux (Castle Rock) says:

        It’s not necessarily seasonal, but I think what he’s referring to is the “cool” east wind.

        In the warmer months, the strong east winds aren’t as disrupting as they are just winds…. in the cooler months, that wind also makes things MUCH cooler.

  12. Roland Derksen says:

    Sorry to be of the minority opinion, but I like this weather. This October might end up being one of the driest in years, but that doesn’t mean November will be the same. I recall October 2006, and what happened afterwards… and if I’m correct, wasn’t that winter season supposed to have an El Nino? Sure didn’t seem like it at the time. Anyway we’ll see what transpires.

    • Gene says:

      I don’t think you’re in the minority, actually (maybe a minority among this blog’s commenters, but not among most people in the area). Today especially is such a glorious day — sunny, warm, no wind . . . a great day to be outside, to be out and about. But for the small minority who doesn’t like this weather, don’t fret — the fall/winter rains will be coming soon!

  13. Jason Hougak says:

    There 2 sides to every coin…
    I love this weather especially after getting some much needed rain.

  14. W7ENK says:

    Glorious sunshine, and temperatures below 80!
    Absolutely zero reason for anyone to complain. 🙂

  15. Paul D says:

    Hey Mark! Why can’t that awesome 7-day graphic be on the KPTV weather page like it used to be? Also, the numbers don’t agree with the 7-day forecast on the KPTV weather page.

  16. Joshua Lake Oswego says:

    2018… The year without a spring or autumn. Summer began in April and appears that it won’t end until at least November. Yes, we had a few days of troughiness and cool, damp weather recently, but the overall pattern since April has been very warm and very dry.

    Looking ahead, the ridge might flatten in about two weeks allowing some zonal flow and precipitation. That’s a best-case scenario at this point.

    • Paul D says:

      That’s a very accurate summary of the year! I started mowing my lawn the first week of February. That’s the earliest I’ve ever started mowing! I don’t like it when that happens – it makes me grumpy because I like having the time off from yard work. I wonder how late into the year the grass will be growing this year…

    • Ken in Wood Village says:

      Sums up what has been going on. Every time I see the models I just get more depressed. I wish the weather pattern would change. A high pressure staying over the East Coast and a low over the West Coast…lol. I could dream…lol

  17. Tanis Leach says:

    Wind won’t bother me down in Corvallis. At least not as much.

  18. boydo3 says:

    Looking forward to this spell of spectacular weather down here on the south coast.

  19. Ken in Wood Village says:

    Well, I’ll be enjoying a little time at Crown Point. Just wish we could get into our rainy season. First

    • Paul D says:

      Rainy season? What is this “rainy season” you refer to? 🙂

      • Ken in Wood Village says:

        I feel like I’m in California with no rain most of the year. I like to have some rainy and cooler conditions. I remember when fall started and we started having cooler and rainier days. Now a days it’s no rain and always sunny. I use to work swing shifts and loved it when it was cloudy a lot and I would be able to sleep in but not anymore.

        • Kyle says:

          October is usually when our “storm doors” open up and we get either a deluge of rain or sometimes one end of the month gets it. Not the last few years.

          There has been a lot of minor but permanent changes to the earth MSM won’t cover or cover so very little to the point you have to go to obscure places to get it archived.

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