Altocumulus clouds, Cumulonimbus clouds, Cumulus clouds, Definitions, The weather ahead, The weather WAY ahead (10 days or more), Virga

Examples of virga; the model rain ahead

7:20 AM.
7:20 AM.  Altostratus with pouches of virga
7:23 AM.
7:23 AM.  Ditto.  Ac len is the fine line cloud upper center.
7:27 AM.
7:27 AM.  Ditto, pretty much.
7:30 AM.
7:30 AM.  Nice lighting (not lightning) for just a few seconds.
8:19 AM. Altocumulus trailing snow/virga.
8:19 AM. Altocumulus trailing snow/virga.  Tops, though the coldest part of the cloud, are composed of mostly of droplets at temperatures far below freezing.  A few ice crystals form and drop out leaving the supercooled droplet cloud mostly intact.

 

12:55 PM. Just about the first boundary layer cloud, this a Cumulus fractus fragment. Hope you recorded this event in your cloud diary. Its pretty mandatory to note developments like this if you want to move on to the next level of cloud-mavenhood.
12:55 PM. Just about the first boundary layer cloud, this a Cumulus fractus fragment. Hope you recorded this event in your cloud diary. Its pretty mandatory to note developments like this if you want to move on to the next level of cloud-mavenhood.

 

3:03 PM. Those boundary layer clouds, Cumulus ones, were reaching their maximum depth about this time. This would be a Cumulus mediocris, estimated depth 2500 feet or so.
3:03 PM. Those boundary layer clouds, Cumulus ones, were reaching their maximum depth about this time. This would be a Cumulus mediocris, estimated depth 2500 feet or so.
5:14 PM. Whilst clouds locally never got beyond the "mediocre" stage, or produced ice under them, to the north where the air was colder aloft, Cumulus clouds were able to grow taller and become Cumulonimbus capillatus incus (the last term just meaning it has a flat anvil.
5:14 PM. Whilst clouds locally never got beyond the “mediocre” stage, or produced ice under them, to the north where the air was colder aloft, Cumulus clouds were able to grow taller and become Cumulonimbus capillatus (hairy looking with ice)  incus (the last term just meaning it has a flat anvil, a flat head.)

 

5:47 PM. This post sunset shot shows layers of smog at the same level where some flat clouds have formed. The smog is so visible because the air is ALMOST saturated near those clouds at their level, and some of the smog particles (hygorscopic ones) have deliquesced, have gotten much larger by absorbing water vapor, or might even be haze droplets ("smoglets"). It therefore, by definition, cannot be a "pretty sunset."
5:47 PM. This post sunset shot shows layers/lines of smog at the same level where some flat Cumulus remains are. The smog is so visible because the air is ALMOST saturated near those clouds at their level, and some of the smog particles (hygroscopic ones) have deliquesced, have gotten much larger by absorbing water vapor, or might even be haze droplets where water has condensed on them  (“smoglets”). It therefore, by definition, cannot be a “pretty sunset.”

 The model rain ahead;  two episodes

The low that plunks down off the coast of Baja this weekend from southern California,  circles around out there for a couple of days,  before deciding to move back over southern California with clouds and rain.  If it was a song, it would be The Wanderer.  Yes, that fits.  Its expected to scoop up a generous helping of middle and high clouds from the deep tropics as extra baggage.   The “extra baggage” (model predicted rain) arrives here late on the 26th (Monday) and continues off and on through Tuesday night.  The first clouds, of course, high ones like Cirrus, will begin arriving a day ahead of the actual rain, on Sunday.

It is virtually certain that there will be some high-based Cumulonimbus clouds and thunderstorms in these masses from the tropics, though maybe not here.  Most of the rain is projected for eastern California and western Arizona where rain is really needed–and how great is that?

However, we should be in for a quarter inch or so, anyway.  Last time I guessed limits on a storm, even the lower limit of 10% chance of less than 0.05 inches wasn’t even realized.  Pretty pathetic forecast.  But, moving forward and forgetting past errors, this one seems to have a similar range of possibilities, the least amount 0.05 inches, the most, 0.50 inches.  The chance of measurable rain here in Catalina in this first 36 h storm period  is probably, from this typewriter, about 80%.

“But wait!  There’s more!”  “Maybe!”

A second system floats in right after that and from Jan 29th through early in Feb, and more welcomed showers are possible.

You can check out these prognostications in a more professional way  at IPS MeteoStar, this link to the latest model run from 11 PM AST last evening.

The End

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1Who can forget Dion and the Belmonts?