Sunday, July 20, 2014

the smoke ascending, it seem to reach the sky

The clouds of smoke over the wildfires to the south of us are making their own weather.  Heat from the fire drives convection currents upwards, making the classic "caulflower" shapes in the smoke (same as cumulous clouds, except dirtier).

("I saw the smoke ascending, it seemed to reach the sky/
.. till all my strength had left me, and all my courage too" are lines from Texas Rangers, performed by Tex Ritter among others, lyrics have been attributed to Richard Shindell or .  Though in the case of wild fires, the conclusion "you'd better stay at home" will only help if your home is someplace green and humid, far away.  Wild fires and the extreme weather that's increased their ferocity in recent years are far more implacable than the fiercest warrior; wars are avoidable, but even if we gave up all our combustion-driven toys and spark-producing tools, we'd still be facing lightning-lit fires across these Western landscapes in dry summer weather.)

Smoke column with lenticular cloud
In this image you can see a "lenticular cloud," sometimes called a mountain cloud or lens cloud, the little bent wisp above the main cloud.  This type of cloud is formed when air is forced upward (usually as it passes over a mountain rainge), causing little droplets of water or crystals of ice to form in the bands of air.  I believe it's because the air gets chilled, and the pressure drops, as it's forced upward - if there was almost enough moisture to make a cloud, and you change the conditions to make it a little easier to form a cloud, then you get a little cloud where those conditions are different.  You will often see similar lens-clouds hovering over mountains like UFOs.
This is looking south from the parking lot at the grocery store.  I ran into our current fire chief, and he said he thought those kinds of clouds only formed way high up in the atmosphere - meaning this smoke column is getting really tall.

Smoke column with drift smoke
Still seeing the smoke column growing this evening, over larger hills, on my way home.  There are also bands of 'drift smoke,' which has cooled enough to sink but is not ready to fall out of the sky yet, lower down.  Drifting smoke can stay in the air for days or weeks, making it hard to see what's going on with the fire (or anything else), and making a lot of people nervous so the fire department gets more false alerts.

(Of course, fire fighters would much rather get a false alert than sit on our hands while you wait for the fire to get big enough to be sure.... but it would be even better for everyone if we had some nice, gentle rain to wash the smoke out of the sky, leaving us a clear field of view and better chances of controlling any remaining fires.)

While all this is going on, our little rural fire department is sending a truck or two to help with the efforts on the big fires.  I'm babysitting Karen's goats, while she's off running with the fire crews.  Lots of goat milk!  Lots of curious noses!