SkyPix

A digital photographic storybook of clouds, weather and water by Roger Edwards.

Steam Devil Scene 3

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[Part 3 of 3]  A well-developed "steam devil" exhibits a smooth cloud tube mostly defining the vortex.  I say "mostly" because, as with actual tornadoes, the rotation likely extends outside the visible vortex, which just represents air cooled and moistened enough by lower pressure to condense before surrounding air.  Dust devils form similarly, but over hot land surfaces relative to air above.   … [Read more...]

Steam Devil Scene 2

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[Part 2 of 3]  Though the fog formation over the lake was continual, obvious vortices with condensation tubes showed up at quite irregular intervals.  How do "steam fog" vortices form?  Here was a flurry of them that appeared to be taking advantage of a narrow corridor of strong cyclonic horizontal shear, then the rotating air parcels formed a chimney-like column stretched aloft by the shallow but … [Read more...]

Steam Devil Scene 1

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[Part 1 of 3]  In early 2021, we had another nice outbreak of "steam fog" or sea fog on Lake Thunderbird, where bitterly cold air advected over the long axis of the much-warmer lake, eliciting moving fog.  Back then, embedded vortices were few and ragged.  This time, I managed to snag several.  Three of the best-defined appear in this series.  This one stretched and bent southward with height as … [Read more...]

Secondary Mesocyclone

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A large, complex supercell that had organized near Lampasas turned even harder rightward, churning south-southeastward along and west of US-281 past Burnet toward Marble Falls.  [Yes, I was chasing in the Hill Country in May, after doing so in April, and would again in June!]  Fortunately, I had left the crowds trying in vain to see inside the larger, nasty, rain-wrapped mesocyclone in trees and … [Read more...]

Lampasas Masses

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A previously disorganized but deep cluster of multicell storms west of Lampasas, in a very moist and favorably sheared environment, coalesced into a large supercell southwest of town, sporting a very wide base.  I knew this storm meant business when it turned hard right, while over the span of around 10 minutes, inflow picked up from a modest breeze of less than 10 kt to a stiff, steady, roaring … [Read more...]

Rotating but Nontornadic

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This behaved much like most wall clouds I've ever seen:  rotating moderately, perhaps briefly fast, with strong upward scud motion from the tail portion pointing to the forward flank.  Yet it failed to produce a tornado.  That was a good thing for some Hill Country acreage subdivisions in the area!  Despite a favorable environmental parameter space of CAPE, deep shear and low-level shear, this … [Read more...]