Oh what a weird and dark and admittedly apocalyptic time, this is turning out to be!  I’m going to save the monster wildfire scenario for another day, when things are calmed down a little more.

Needless to say, many of us know someone who has evacuated or lost their home because of these fires.  The loss is horrendous: nearly a million acres of Oregon’s majestic forests no longer exist.  Towns like Detroit and Phoenix (near Ashland) are all but wiped out.

The conflagration began Monday evening and continued into Thursday, before east wind died out.  That slowed the tremendous growth of the fires.  It also meant that the smoke would linger over the Pacific Northwest, for many days to come.

And linger it has.  Air qualities over Portland the last 2 days have been in the 300-600 range for most neighborhoods.  That’s historically hazardous.  All of this material in the atmosphere is blocking solar energy during the day…while still allowing infrared energy to escape into space at night.  The result has been a dramatic cooling of the lowlands the past 3 days.  It’s basically the same as a “volcanic winter” or “nuclear winter,” just on a less global scale.

Check out this sounding graph for near Salem on the afternoon of Sunday, September 6..before the east wind and smoke arrived.  Notice the red temperature curve moves pretty steadily from upper left to lower right.  Except for a slightly stagnant layer up around the 850-900 level, the atmosphere is fairly well mixed.

Now here’s the same sounding for the afternoon of Friday the 11th:

The curve is completely bent back below 800mb, or about 6,500′ elevation.  This is much more like the sounding from a foggy wintertime inversion.  In many cases the surface temp didn’t even make it to 73; my neighborhood was in the low 60s during the day both Friday and Saturday.

Weather models do a terrible job picking up on smoke cooling effects like this. We were originally slated to be about 90 degrees those days, not 63.  The wintry inversion also means surface high pressure is stronger than expected, which tends to make it harder for onshore flow to push the smoke away.

Nonetheless we should begin to improve somewhat by Monday as our first rain of the fall approaches!

Stay indoors today! -Karl