High Winds, Cold Nights, & Another Dry Week

6pm Friday

For such a “boring” weather pattern the details for the weather geeks have been fascinating the past 24 hours.  Consider that:

  1. Temperatures soared into the 50s on Mt. Hood today…55 at Timberline Lodge!  In fact a few spots in the western Cascade foothills were in the 60s.
  2. Meanwhile, as expected, temperatures in the lowlands have continued to drop as cool air becomes established in the valleys & Gorge under an inversion.  Today was the coldest day so far this winter at PDX.  That’s right, you need to go UP at least a thousand feet to warm up!

3.  That’s due to the end of the mild downsloping wind off the Cascades.  Now all that air moving from east to west across the state has to squeeze through a very shallow layer under the inversion through the Gorge.  Check out the metro peak wind gusts…all areas west/south/north mainly calm…

4. Yet within the Gorge and far east metro the wind has continued to pick up.  The wind at Corbett has gusted above 70 mph every 10 minute period since 3pm…that’s unusually strong even for them.  The raging wind continues through the weekend.

I notice temperatures in the mountains will probably warm a few more degrees by Sunday as 850mb temps rise into the mid teens.  The strongest wind event I remember in the Gorge was when 850mb temps got up around +18 in January 2009.  That really squeezes the air down and speeds it up.  By the way, I drove by the Vista House wind sensor at midday.  It looks beat up, bent down and back a bit, which accounts for the “low” wind speed there the past two days.  Combine the wind and cooling airmass coming through the Gorge and it feels like mid-winter out there.  Here are the 6pm windchill values.

Ice has also begun to form on Gorge waterfalls.  It will be a great weekend to check out the wind, waves, and icy waterfalls in the Gorge.  I found this just on the road to Vista House at midday:

And the river will look like this pic from Kirk Mattila.

With such a dry airmass and our long winter nights, temperatures in calm areas have been plummeting.  Check out the mid 20s in many areas this morning.  Expect more of the same the next few days:


This general pattern continues through about Wednesday next week.  That will be our 10th dry day in Portland.  However it appears things will be changing after that time.  The most reliable model and its ensembles show onshore flow (and the end of the cold east wind) Thursday/Friday next week as the strong upper-level ridge flattens and systems go by to our north.  This happens to be the one pattern that can minimize or eliminate the threat for snow/freezing rain as we go back to milder weather.  We’ll see how it pans out, but we might be back to gray and drippy conditions later next Thursday or more likely Friday west of the Cascades.

Beyond that, models are in disagreement whether we go into a cooler/showery pattern with the big ridge moving farther west offshore, or stay in milder westerly flow with weak ridging.  The net effect doesn’t appear to be a return into a soaking wet November-like pattern.  Note the ensemble average precipitation from the ECMWF is only 1″ in the week leading up to Christmas.

So enjoy at least another 5 days of dry weather with sunshine, then most likely we’ll turn at least a little wet and much grayer late next week.

Chief Meteorologist Mark Nelsen

38 Responses to High Winds, Cold Nights, & Another Dry Week

  1. Adam in SE says:

    It was in the upper 60s on top of Saddle Mountain in the Coast Range today.

  2. Nahtalkin says:

    Epic December dry spell, but not in my observations over the years. Just for you youngsters, or those that can’t remember, or for the majority of residents living here now that have come from somewhere else.

  3. In a weird way, this weather pattern is extremely interesting. The top of Mary’s Peak (4137 ft) was nearly 70f today (with an overnight low of 53f). My back yard in Salem, bordered by a six-foot fence, has dropped to around 20f the last five nights. I have multiple thermometers to keep the readings honest. It is a perfect pattern to baseline radiational cooling effects for this time of year. No wind, no clouds, dry air, no influx of cooled or warmed air and I can expect 20 – 23f lows and highs in the low to mid 40s. It’s like the second or third week of July with December solar energy.

    Mary’s peak right now (10 Dec 4:10 pm) is 62 degrees with humidity at 6%. 6% is summer in Las Vegas humidity. Downright interesting.

    • This morning was insanely warm (well into the 60’s F) at or just under 2000 feet according to aircraft observations. No 70’s that I noticed but still an impressive distance in under 2000 feet (it was in the low to mid 30s at the surface).

  4. Ken in Wood Village says:

    Is it me or does that low look a little strong on the 20th? It seems to go right over us or just a little North. What do you weather geeks think?

  5. Ken in Wood Village says:

    00Z GFS looks very interesting 🙂

    • Joshua Downtown PDX says:

      06z GFS and 00z EURO are terrible. They go out to Christmas Day now. The ridge is sitting right on top of us. No white Christmas here. December will end up being a shockingly weather-less month. I feel very bad for Timberline, Meadows, etc. Thanksgiving was a bust, and Christmas will be too.

      • Ken in Wood Village says:

        I’m a little confused Joshua. I’m looking at the 06Z GFS and there is moisture that hits Oregon. I don’t see a lot of snow (for now) but you need to give these models a little time. I have seen the GFS start giving us more and more moisture over the past day. I’m just hoping the models will get better in the next few days. Christmas is still 2 weeks away. A lot can happen in that time. 🙂

        • Joshua Downtown PDX says:

          It is still a while from now. Things can change. I’m getting frustrated though. Are you looking at the operational or ensembles? The ensembles give a much more accurate idea of the big picture. Even two weeks out. Especially when different models agree.

        • Ken in Wood Village says:

          I’m not sure which one I’m looking at to tell you the truth. I’m still kind of new to looking at the models. I went to weather.cod.edu/forecast/
          then just click on the GFS model run. I do click on the surface products which is 2M temps then look at the Precip. Product and see what type of precip. is coming. Sorry, not sure if this will get to you because there wasn’t any reply under your comment.

        • Joshua Downtown PDX says:

          Ken, I like to use these two (amongst others). This is the only website I am aware of that gives so much EURO data/maps for free. The EURO has proven itself to be superior to the GFS and other models. http://wx.graphics/models/ecmwf/eps.php. http://wx.graphics/models/gefs/gefs.php.

        • Ken in Wood Village says:

          Thanks Joshua. It seems a little harder to understand than the other website that I use. I will try and figure out how to read what it says.

  6. It’s 60°F tonight… at 1800 feet (35°F here at the surface). Now that’s what I call an inversion.

  7. Nahtalkin says:

    If epic is mentioned in every other blog comment by some folks doesn’t that just make it kind of normal? Sure has been nice weather here recently and for that matter what a beautiful start to our winter. I used to ski also but rarely complained, back then we just accepted what Mother Nature gave us with appreciation. Our “new generation of folks expect weather to be delivered on demand from their precious little devices. I can’t help but think what a spoiled little group of folks we have become. If you disagree just read all the little pouting comments on this blog when they don’t get what they were wanting and are expecting.

    • Jake in Gresham says:

      I assume you’re an adult. You do realize, your complaining about kids complaining about not getting snow, right?

      This weather is interesting. If you don’t find that to be the case that perhaps find a new hobby? The fact that it’s snowing at the same latitude in Texas as Miami Florida while we sit dry and dusty is something to note. Sir.

  8. Today was our haziest one yet. Still made it up to 44°F after the fog broke up this afternoon. My thermometer said a low of 32°F, but I didn’t notice much if any ice this morning (in contrast to yesterday morning, which was quite icy).

    Now 38°F and falling. Expect the fog to re-form within the next hour or two.

  9. Ellen Wallace says:

    Weather Channel has high breaking down about the 18th – any thoughts?

  10. Jason Hougak says:

    06Z had -5 temps but generally cool temps and only 1″ precipitation in 16 days. The 12Z has -8C temps and 2.3″ precipitation in 16 days. GFS staying consistent in bringing in some colder air in the extended.

    • Joshua Downtown PDX says:

      12z GFS looks crappy to me. A secondary area of high pressure forms and moves in from the northwest. No snow for government camp for the next two weeks. Some for Timberline, but not a lot. Same with rain in the lowlands. Weak systems.

      • Jason Hougak says:

        Looks like snow potential down to the foothills to me but not a lot of precipitation. However it still beats not having any cold and precipitation.

    • Ken in Wood Village says:

      The one thing I do see that’s consistent is the GFS wants to give us colder air. It’s still two weeks away and the models will change a lot. Hopefully it will give us more precipitation.

      • Jake in Gresham says:

        Yeah, nothing significant though. Heads for us right over the Pacific ocean. Modified and so not that chilly. Meh, I think it’s safe to say a snowstorm (if it happens) now will be a January event. La Niña of the opposite coin from last year. THat’s for sure.

  11. Paul D says:

    Will be interesting to see if we get a deluge later in the month to get our rainfall to normal or we end up very dry for the month.

  12. Jason Hougak says:

    The 12Z GFS was a nice cold run, 18Z was an epic arctic blast, the 00Z is colder than the 12Z but wetter than the 18Z.

  13. Ken in Wood Village says:

    The 00Z GFS just came out. I know it doesn’t look like the 18Z but it still has a lot of colder air around us. That’s number two run with colder air. Let’s hope things keep going our way!!!

  14. Dave Brown says:

    Sorry for those folks in the gorge area. However, for the first time that I can remember having lived in the Venersborg area (north of Hockinson / east of Battle Ground) for 30 years, we have been mercifully spared that evil east wind. My trees and my nerves thank you. This is the kind of sunny, dry weather I can get into!!

  15. ocpaul says:

    I never enjoy 5 days of dry, sunny weather in December, unless temps are in the 20’s. Never.

  16. W7ENK says:

    Hey, 90 degrees or 20 degrees, you’ll never hear me complain about blue skies and sunshine!

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