December 09, 2011

Amazing Fog Pictures and Inversions

 Special Eclipse Forecast: I got up at 5 AM...and saw the eclipse begin...

Last night we developed a very strong inversion and a shallow fog layer that has now mainly burnt off.  At daybreak many land areas around the Sound had fog, while large areas of the Sound were clear.

Here is an extraordinary picture sent to me by Tracee Geernaert at a location on Salmon Bay, looking to the north.  You see those wave-like structures---reminiscent of breaking waves on a beach?   Stunning.  Those are examples of Kelvin-Helmholtz Instability (KHI) waves that are produced when there a very large change in wind with height over a layer of the atmosphere that is stable.

These are also called billow clouds.  Here are a few more examples:

Such clouds can be associated with substantial turbulence as they roll up and break.   Often quite turbulent to fly through.   A few years ago I was sitting in a window seat on an aircraft and saw those clouds ahead of us.  I told the person next to me that it would be a good idea to put on her seatbelt.  She laughed at me.  A few minutes later we hit moderate turbulence.  She wasn't laughing anymore.

Some beautiful shots this morning of the sun and shallow fog from the Queen Anne and Space Needle cams:

 Last night warm air moved in aloft and offshore flow increased.  As result the inversion aloft really cranked up.  Here is the temperature structure at 8:30 AM this morning over the Puget Sound region:
Around 30F near the surface, but in the mid-50s above 2500ft.  Very strong inversion!  Want to hear something amazing? The temperature right now (1 PM) at Mowich snotel site west of Mt. Rainier, at an elevation of 3150 ft, is 62F!  And it is 50F at Paradise on Mt. Rainer (5500ft).  Can you imagine?  You could be hiking in bright sun in 60F temperature right now!

Let me end with an extraordinary shot this morning  of the fog from Peter Benda's house at 1100 ft in Bellevue


  1. Nice segment on KPLU this morning -- amazing inversion, and I wasn't aware of the record-making high pressure a week ago. Glad to see outside that it's clearing up. And great pix of the K-H clouds -- I've seen those up at about 35,000 ft when flying across country. Very cool.

  2. When I left my house in Bellevue this morning it was cold, but not frozen. While riding over Capital Hill, there was ice on the cars, and frost on the ground. Totally fogged my glasses.

    Bellevue is just a few hundred feet higher than Capital hill.

  3. I am planning to try Newport Hills Golf course road ( 150th?) for viewing tomorrow.

    DeLeo Wall on Cougar is my second choice.

  4. Cliff,

    On your eclipse blog you might also mention the upcoming solar eclipse of August 21, 2017. See

    I saw the one in February 1979 with perfect viewing conditions. Portland was rained out. Several groups headed to Goldendale and some to Stonehenge. We headed just south of the Dalles onto the tops of some hills and found ourselves in the rainshadow of Mt. Hood. Goldendale, I recall, was cloudy. Fo formed at Stonehenge But where we were we could see everything including the Moire-like diffraction bands. Conditions in 2017 should be much better than in 1979 and it may not be too early to start thinking about hotel reservations down in Bend, etc. This eclipse will be viewable across the entire country.

  5. That's a crazy inversion! Is it going to be like that on Saturday? Good day to go hiking up high?

  6. Just for the record, the elevation of Mowich Lake is 4929'. I've hiked from there many times and knew it wasn't so low as 3150'.

    Great photos on today's post, Cliff!

    9:00PM, and it's now showing 29F here in Olympia, just a couple of blocks away from Budd Inlet and within view of the Capitol.

  7. I saw the moon at 3AM. Nice and bright. But now (6:33AM) its like pea soup outside - so no eclipse! Lousy fog!

  8. By Mount Vernon it was clear until about 3:30 and then the fog/low clouds moved in and temp raised from 25 to 33. At about 5 though we loaded into the car and went to Arlington where it was clear and we got to see the moon about half until thirty minutes after totality where the moon sunk into the low clouds.

  9. Drat! Beautiful, clear skies as late (early?) as 3 am, but socked in with clouds and fog just a couple of hours later. Alas, no eclipse for those of us on up at the Canadian border.

  10. Beautifully clear from 5:00 until 5:45... from a small bite out of the moon until just a thin wedge was left. Then the clouds covered it. So how high would we have to have gone to get above those clouds? Is there such a place that's drivable with a good west view? I thought about Paradise, but I'm pretty sure the gate at Longmire is locked until the snowplows finish in late morning now.

  11. We saw the start here in Sequim but as the moon set slowly it dropped out of the "Sequim hole" while directly overhead the stars stayed visible.

  12. was the Mowitch Snotel site, not Mowich lake...sorry...fixed the blog...cliff

  13. aperarKen:
    One more point on relative humidity: molds start growing at about 60% RH, so if you have a really tight house (like ours) you need a dehumidifier! Otherwise you can develop a real health problem.
    Molds grow at low temperatures, 28 F to 30F for some types, 40F for most molds while bacteria start growing about 50F. Many dehumidifiers don't work below 55F, so if you have a cold tight house you can really have problems. Heat may be the biggest help with molds here in the PNW.


    same thing in Alabama today


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