Pretty skies, but no castellanus (again)

Apparently the castellanus formations went over during the nighttime hours when we couldn’t see them…

But it was a fabulous day again of interesting high and middle cloud flecks anyway.   Below, a reprise of yesterday’s clouds starting with that delicate patch of Cirrus passing over the Catalina Mountains with its tiny fibers of Cirrus uncinus embedded in it.  I have also included two sinister crossing contrails.  Who knows what evil lurks there?  Perhaps they’re marking a target of some kind, or filling out a questionnaire with crosses instead of check marks.  Oh, well.

Later, as the sheet clouds of various Cirrus, Cirrostratus, and even Altostratus with virga cleared off, we got into some scattered lenticulars, some of to the distant north, and with our usual friend downwind of the Catalinas, shown in the last two shots.  It was able to hang on for several hours, right past sunset.

Again, for the whole day’s cloud excitement, a great place to go is to our very own U of AZ Wildcat time lapse movie.  In the late afternoon of this movie, you can see some great Altocumulus lenticularis clouds hovering over and downwind of the Catalina Mountains, occasionally shooting upwind as the air moistens in the humped up airflow, and you can get a sense of how little the air is pushed up in lenticular clouds from this movie.

(Once again the caption function has quit in WP before I got to some of these.  My apologies.)

The weather ahead

Gee, “dusty cold snap” is beginning to look more like “muddy waters” as the later model runs dip the jet stream farther and farther south over us on the 14th and 15th.  Check this forecast of the precip hereabouts from the U of WA’s WRF-GFS model run from last night, showing a bit of rain HERE Saturday morning (colored areas of map).  Sure hope so. Terribly cold air with this, too, for mid-April.  Likely some low temperature records will be set in the State somewhere for this time of year with this.

The End.

Tiny Cirrus uncinus, top center, Cirrocumulus top right with,oh, maybe Cirrus fibratus (has linear fibers) lower left.
Cirrus uncinus.
Altocumulus lenticularis.


Altocumulus lenticularis continues in place as sun goes down

By Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.