August 01, 2010

Stratus, Fires, and the Answer

Update: 1:30 pm...It really appears that some kind of haze/smoke layer is over western WA...with yellow/orange/red coloration of the sun and sky. From the eastern wa and British Columbia fires? In fact, checking on the situation, I think the overwhelming proportion of the smoke is from the many fires in British Columbia. In fact, here is a graphic for vertically integrated smoke for 10 PM from the National Weather Service. It really appears the origin is in BC.The MODIS picture today really shows the smoke over us (see picture above).

Here is wonderful video of the smoke (

Normally I show pictures from the National Weather Service geostationary weather satellites, stationed at around 35,000 km above the surface...that is what you normally see on TV and on the web. But sometimes I turn to the NASA MODIS imagery, which provides much more resolution, but which is only available a few times a day. Above is an example from yesterday. See the low clouds over western Washington--but now you can note the details. You can also view the lines of convection...thunderstorms...on the eastern slopes of the Cascades and the relatively clear skies over the crest and western slopes (where I was hiking yesterday!)

Here are some MODIS images the day can see the Stehekin fire very well...particularly in the close up.
What about today (Sunday). Here is the latest visible image (not MODIS). Lots of clouds in the west, but with a few breaks around Centralia. Looks like some kind of smoke layer over the west...could the smoke from some of the fires have made it over the Cascades and from British Columbia?
The marine layer is deeper this morning, even pushing up to the pass (see image)

Expect a slow burn-out this afternoon. I wish I could tell you I expect a major change in the situation, but I don't. We are locked in this pattern, with no change in sight.

Now, let me answer a question that has come up time and time again. For many cyclists in the Seattle area that live north of the city, they face headwinds in the morning and headwinds in the evening. How could this be?

The reason: the winds are often near calm in the morning, or in the situation we are in, southerly. During the day the clouds break and the land heats up. This creates a big sea breeze circulation, known as the Sound Breeze, that brings northerly flow during the afternoon (more water to the north of Seattle than south). My book has a lot more about this.

A message for boaters:

Please help researchers evaluate how to communicate weather forecast information.
 The survey will take you only 20 minutes to complete.
 Survey data will be used to improve weather forecast products designed for boaters.
 If you own a boat and would like to participate, please click on the link below. Thank you.


  1. I got my first alert on my Public Alert radio this morning! (A thunderstorm advisory)

  2. The sun seems to be tending to orange. My porch where the sun is hitting it has an orange cast.

    Has the world ended?

  3. Why is the color of the light so different today? For example, the shadows are blue and the light on the sidewalk is orange/yellow.

  4. Why is the color of the light so different today? For example, the shadows are blue and the light on the sidewalk is orange/yellow.

  5. After growing up in LA I can note the color of sunshine through smoke almost instinctively and noted this at 1:10 as I was riding the water taxi. I am surprised at the volume of smoke -- The Stehekin fire was reported at 5,000 acres, big but not that big (compare the two MODIS pictures). So maybe the fire got larger? And of course, Cliff had already posted...Thanks Cliff.

  6. I assume the haze is filtering the yellow out of the sun light, thus a more orange glow and blue shadows. Kinda funky. Since I don't remember seeing this before, I have to assume it's some oddity--like fire smoke--in the atmosphere.

  7. I noticed the same thing and am seeing comments from people on

    I took this picture at Redmond Watershed Park at noon. There were many areas in the park glowing in salmon / golden hues.

  8. Yes, there was an odd almost autumnal tint to the light today. I hope it's not a sign of Aug-tober!

    Maybe it's from the fires burning in E. Washington?

  9. I'm a fire weasther forecaster working in BC. I remember back in 2003 how impressed I was with the NASA MODIS images of wild fires in the BC Southern Interior. I was wondering where you access these photos in real time. They would be great to use in my briefings to fire crews.

    BTW we met quite a few years ago at one the Seattle conferences

    Rob Pigott

  10. I was curious about this myself, so i took a picture, and twittered it. The sun is definitely red orange, a lot more than shows in my picture:

  11. Thanks for the helpful post re: light quality and the haze today - it almost felt like we had filtered stage lights spotlighting our day! I remembered back to the summer of 1994 (?) when we had the same, but much more so, around the Lake Wenatchee area from wildfires.

  12. Check your boater survey form. It won't accept my answer to 2.2 and allow me to continue.

  13. The sun was blood red in a yellow sky just before sunset. Very apocalyptic.

  14. I figured we'd get a great orange sunset from the smoke. Nice crepuscular rays, too! Thanks for posting the video, Cliff.

  15. My girlfriend and I are so glad to know that we're not the only ones who noticed the weird light! Like some nuclear blast happened somewhere. Tho the light in the house, on the floors and bedspread was quite beautiful.

  16. I heard from a friend the northern lights may be visible from the Cascades around August 12th. Is this a given or do certain things need to happen?

  17. Cliff, coronal mass ejections headed our way, are we in for a show of the aurorae in Seattle tonight???? I know it's SPACE weather, but still!


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

Thunderstorms Return to the Northwest

 Thunderstorms have been relatively rare this summer, but today will see some boomers over the Cascades and eastern Washington. In fact, the...