Big Hump Clouds

View of Mt. Baker from Skyline Divide Trail. Oh, and a wee contrail cloud.
  An open weekend and a spectacular weather forecast lured 3/4 of my family up to Mt. Baker to hike and catch a glimpse of the alpine wildflowers in bloom. We hadn't been keeping up with the news, but thought we smelled forest-fire smoke in the air as we left Olympia Saturday morning. It was a distinctive smell we had come to know quite well from our five years in Southern California.
   The skies around us were blue, but hazier than they normally are this time of year. I put forth the idea it might be the snow sublimating--changing from solid ice/snow to vapor--and then condensing. I had spent the past few weeks writing about water molecules, condensation nuclei, and scattering; my answer to everything was water's molecular structure.   
Haze? Smog? Volcanic dust? We were clueless.
 And there was a bit of brownish-pinkish tinge to the haze. We thought it might be smog. But we couldn't imagine the source--Bellingham? Seattle? Abbotsford, B.C.? 
   On our hikes to Artist's Point and along the Skyline Ridge Trail, we didn't see any big billow clouds from a forest fire on the horizon. These clouds, known as pyrocumulus (pyro=fire) clouds, look like strange forms of cumulus congestus clouds. Here is how they work: the heat of the wildfire creates a thermal (rising parcel of warm air) that is loaded with bits of ash and other particles that serve as condensation nuclei. When the rising, smoky warm air rises high enough, it cools, and the water molecules in the air condense and create a cloud. 
   Pyrocumulus are often easy to spot because they are the only clouds visible on a an otherwise blue-sky day and they do not rise and float above the horizon the way a "normal" cloud does; the base of a pyrocumulus stays attached to its source--the fire. However, it is often difficult to distinguish the border between the billowing smoke and the billowing cloud.
    What I am writing about but did not see was The Big Hump fire--a 1,150-acre Olympic wildfire that started on Thursday, September 8th along the Duckabush River just west of Brinnon. (It's been named Big Hump after a point on a hiking trail nearby).
Mt. Shuksan from the trail.
    Meanwhile, we were on top of the world. None of the other hikers we passed or chatted with mentioned the fire. We were all too enraptured with the scenery, which did not include the sky (mostly because there were no real clouds in it--only that mysterious haze). We are all admiring the alpine meadows at our feet and the snow-capped peaks of Mt. Baker, Mt. Shuksan, and every ridge in between. I was glad there were no clouds to distract me.       
The reward for an hour-long ascent on the Skyline Divide Trail
 It was at this idyllic spot (above) that I overheard a tourist say to on of his friends, "Now I feel I have been to America." I smiled, happy for him, and grateful to be alive and on that mountaintop.
The Accidental Naturalist cooling off on a former cloud.
 Hikers: A detailed description and more photos of the hike can be found here: Skyline Divide Trail