Sequence in C; Cirrus spissatus

Some nice CIrrus spissatus and the rare Cirrus castellanus yesterday (something I say a lot here in old AZy).   Here is half hour sequence of a patch of heavily precipitating Cirrus spissatus,  kind of a cloud oxymoron.  I thought it was pretty spectacular even if you don’t care one wit about it.  (Hahaha,  “wit” instead of “whit.”)

Those Cirrus clouds were up at about 35,000 feet above sea level, at around -50 C (-58 F), but snowing like mad.   Don’t let folks tell you its too cold to snow; usually happens that way because here on the surface there’s a high pressure over you, the sky is clear, to wit; a fair weather pattern, and that’s why its not snowing here on the earth when its -58 F, except maybe when there’s a ice haze called “diamond dust“, tiny ice crystals floating/glinting in the air.)


8:48 AM. Cirrus spissatus on the left with the little snowstorm trailing off to the left will pass overhead of Basha’s parking lot there on Oracle in about half an hour, a prediction made in hindsight.
9:07 AM

9:07 AM.  Taken while not driving down Equestrian Trail Road to Basha’s supermarket.
9:21 AM.  Basha's parking lot.
9:21 AM. Basha’s parking lot.  Snow, composed of single crystals, not flakes or what we called “aggregates” because they don’t stick together at such low temperatures, pours out of this really cold cloud.  The single crystals in the trail would be bullet rosettes, a complex looking crystal consisting of hexagonal columns that stick out from a center point. How much snow falls out?  Just a dusting.  You could blow it away off any surface.  When flying through these icy clouds toward the top where the crystals are simpler, there are sparkles and glints when the sun hits the crystals just right.  Very pretty.


The day ended up with lower Cirrus and few Altocumulus clouds with virga as the dry air aloft moved in, providing the clear western horizon that allowed the sun to highlight our clouds.  That great sunset, as much as I could see anyway being “on the road” here:

5:37 PM.  Heavy Cirrus with Altocumulus on the right.
5:37 PM. Heavy Cirrus (spissatus) or Altostratus patch, either name OK, with Altocumulus on the far right horizon.

The weather ahead

Mods still showing rain in the area on Sunday the 17th pretty consistently now. And as we saw from the “errorful” NOAA spaghetti maps yesterday, a trough with cooler weather, clouds and scattered precip is pretty much in the bag for that time period (16th-18th). Can only hope that we get something measurable here. But, even without rain, those days will be pretty ones with Cumulus clouds around.