Category Archives: “Cumulo-cirrus”

High cold ones, and lots of patterns in a complex sky

In particular, those Altocumulus clouds, “cold” Cirrocumulus (ones that transform to ice immediately),  and those “Altocumulocirrus” clouds combining  with  scenes of “regular” cirriform clouds.  Lots of interesting sights to have seen yesterday.  All these the result of marginal moisture aloft and strong winds, up around 100 mph at the highest Cirrus levels.

Let us begin as cloud maven folk by examining the late afternoon sounding launched from our Wildcat balloon launching machine at the University of Arizona, courtesy of IPS Meteostar:

The temperature and humidity profile obtained from a weather balloon launched at about 3:30 PM yesterday afternoon from the U of AZCats.
The temperature and humidity profile obtained from a weather balloon launched at about 3:30 PM yesterday afternoon from the U of AZCats with some suggested cloud levels.  The Altcoumulus level is in doubt. the others are pretty straight forward.  Notice how high those little Cu were yesterday afternoon, about 16,000 feet above sea level, or about  13,000 feet above Catalina, with bases at a cold -13°C or so.  No ice came out of those, though.  Likely droplets too small, or short-lived.
DSC_3122
6:45 PM. A very narrow line of Altocumulus castellanus and floccus virgae approaches Catalina.
DSC_3123
6:46 PM. Let us exercise our curiosity and examine this element in more detail below.
6:47 PM. Altocumulus floccus virgae. Another example of how the top of a storm, as here, can be composed of droplet cloud while the ice that forms in it falls out below. Here, the extreme dryness underneath the Altocu prevents long trails. The ice crystals wither so that they have almost no fallspeed soon after they have fallen out, leaving a flat bottom of tiny ice crystals.
6:47 PM. Altocumulus floccus virgae. Another example of how the top of a storm, as here, can be composed of droplet cloud while the ice that forms in it falls out below. Here, the extreme dryness underneath the Altocu prevents long trails. The ice crystals wither so that they have almost no fallspeed soon after they have fallen out, leaving a flat bottom of tiny ice crystals.  When you see tiny cloudlets like this spewing ice, you KNOW that the temperature has to be extremely low, and colder than -30° C (-22°C) would be a good starting guess.  Actually, guessing “-31.3° ” would be more impressive to your friends or neighbors….   It was a pretty scene, that’s for sure.
5:37 PM. Pretty iridescence occasionally erupted in newly formed Cirrocumulus, newly, as within seconds or in the last minute when the cloud droplets are extremely tiny, less than 10 microns in diameter. You don't see iridescence in clouds with droplets much larger than that.
5:37 PM. Pretty iridescence occasionally erupted in newly formed Cirrocumulus, newly, as within seconds or in the last minute when the cloud droplets are extremely tiny, less than 10 microns in diameter. You don’t see iridescence in clouds with droplets much larger than that.  And, it has to be pretty much overhead to get the best views.  Hope you saw those yesterday.
5:41 PM.
5:41 PM.
5:43 PM. ??????? These are little cloudlets of ice up at Cirrus levels, but it looks exaclty like a field of normal Altocumulus to the ordinary eye. "Altocumulocirrus"?
5:43 PM. ??????? These are little cloudlets of ice up at Cirrus levels, but it looks exaclty like a field of normal Altocumulus to the ordinary eye. “Altocumulocirrus”?  Without doubt this “ice” composition would be contested by other observers.  However, cloud-maven person’s interpretation should be used.  Now it is likely that the ice in these clouds first formed on what we deem as “cloud condensation nuclei”, and it might be likely that water saturation was reached.  But, if there was an instant of liquid, is certainly transitioned to ice in seconds since the temperatures at Cirrus levels were well below -40° C.   I don’t believe this was at the same level as the Altocu shown in the beginning of this writeup, yet it wasn’t as high as the highest Cirrus yesterday (up around the -50° C level).
6:07 PM. An example of how complicated the cloud scene was yesterday. The whitish clouds in rolls were icy cirriform clouds, and the delicated clouds were HIGHER Cirrocumulus and Cirrus. Cirrocumulus yesterday was indeed where most cloud schematics put it, at Cirrus levels, though probably half the time its in the mid-levels were Altocumulus clouds reside. So, with Altocumulus-like clouds at Cirrus levels and Cirrocu on top of Cirrus, it was really a crazy cloud day yesterday.
6:07 PM. An example of how complicated the cloud scene was yesterday. The whitish clouds in rolls were icy cirriform clouds, and the delicated clouds were HIGHER Cirrocumulus and Cirrus. Cirrocumulus yesterday was indeed where most cloud schematics put it, at Cirrus levels, though probably half the time its in the mid-levels were Altocumulus clouds reside. So, with Altocumulus-like clouds at Cirrus levels and Cirrocu on top of Cirrus, it was really a crazy cloud day yesterday.  At the very top of this photo were Altocu that were immediately ice clouds that might have comprised a separate third level of clouds.  Need a Lear jet to get there fast to resolve these many guesses.
5:07 PM. Jumping around in time.... These were some of the best scenes yesterday IMO, those oh-so-delicate patterns in those cold Cirrocumulus clouds, ones that transitioned to Cirrus clouds downwind.
5:07 PM. Jumping around in time here…. These were some of the best scenes yesterday IMO, those oh-so-delicate patterns in those cold Cirrocumulus clouds, ones that transitioned to Cirrus clouds downwind.
5:08 PM.
5:08 PM. Same patch Cirrocu.  Note Cirrus forming in the lower portion of this photo, once Cirrocu.  BTW, all power lines should be placed under ground.
2:29 PM. Amid some real Cumulus fractus was some Cirrus "cumulus mimicry" I've termed "Cumulo-cirrus". Can you spot the fakes at Cirrus levels? Its pretty hard.
2:29 PM. Amid some real Cumulus fractus was some Cirrus “cumulus mimicry” I’ve termed “Cumulo-cirrus”. Can you spot the fakes at Cirrus levels? Its pretty hard.
2:29 PM. OK, I give up. Here's a zoomed shot of Cumulus fractus mimicry by clouds at Cirrus levels. Might have been some droplets, too, before converting to ice.
2:29 PM. OK, I give up. Here’s a zoomed shot of Cumulus fractus mimicry by clouds at Cirrus levels. Might have been some droplets, too, before converting to ice.  These kinds of clouds suggest significant turbulence at this level, as would be in a regular Cumulus fractus cloud.

The weather way ahead

Still looking for that chance of rain before July….  haha

Troughy conditions will actually recur aloft over us over the next few weeks it seems, which means slight chances of rain, but periodic cold fronts passing by, mostly dry ones.  Best chance for rain still seems to be around the 20th, plus or minus a day or two, even though mod outputs have backed off that scene.  But, we have our spaghetti that tells us the models will likely bring back that threat around the 20th, even if some individual runs show nothing at all or only close calls.  We shall see if this interpretation has any credibility at all, won’t we?

Of note, Cal having big April in rain and snow after the gigantic January and February accumulations!  Looks like they’ll continue to get slugged by unusually strong storms, off and on, for another couple of weeks.  Water year totals are going to be truly gigantic.

The End

Catalina WY progress report; Cal WY update, too, since I grew up in Cal

I thought you’d like to see this:

As of the end of February 2017. We're pretty average, but it took some "heavy lifting" in December and January to get there.
As of the end of February 2017.  You can see were right about at the average for the Water Year,, but it took some “heavy lifting” in December and January to get there.

Doesn’t look promising for much rain here in Catalina in March, however.  No rain in sight through the next 10 days at least.

Let’s check our 7 inches with what’s happening upwind, say, in CALIFORNIA, and see if there’s been any drought relief there, through February,  via the CNRFC:

California water year totals through the end of February 2017. Note one station in the central Califorina coastal range is already over 100 inches!
California water year totals through the end of February 2017. Note one station in the central Califorina coastal range is already over 100 inches!  There are 20 stations already over 100 inches as can be seen from the table at right.  March looks to have substantial rains north of SFO, which will add appreciably to those highest totals.  Amazing!  You can go to the CNRFC and expand these interactive maps, btw.

As you are likely to know from many media stories last year, Cal was in a drought siege of five straight years,  with but got a little relief last year in the northern part thanks to help from  the giant Niño, one of the strongest ever.

Alas, it was one that failed to deliver as the big rain producer for the south half of Cal and the SW in general as was expected.

In case you’ve forgotten how bad things were in Cal, let us look back at what was being said, those horrific appearing drought maps,  and also how hopeful were were at the time  that the Big Niño would take a bit bite out of drought.  This is a really good article:

https://www.climate.gov/news-features/event-tracker/how-deep-precipitation-hole-california

Then, when the Big Niño faded away like maple syrup on a stack of buckwheat pancakes last spring and summer,  we were surely doomed for more dry years.  And, for a time, the dreaded cold tongue of water in the eastern equatorial region, the so-called, La Niña, started to develop, which would be no help at all for  a good rain season like a Big Niño is, usually.

The Niña faded away, too, to nothing as the winter went on, so we really didn’t have much going on in the tropical Pacific to help us figure out what kind of winter rainfall regime we were going to have om 2016-17.  Not having anything going on meant winter rainfall could go either way, a difficult to figure out situation for season forecasters.

In retrospect it is pretty astounding how big a signal must have been out there SOMEWHERE that this winter was going to be one for the history books on the West Coast in general, and in particular, for Californians.  Californians saw their drought chewed up and spit out in a single winter, including snow packs so high the height of some mountain peaks have been revised.  (I’m kidding.)

No one saw such an astounding winter coming.

This winter sure makes one think of the QBO (Quasi-biennenial Oscillation, one up there in the Stratosphere where there’s almost no air (haha, well, practically none)…  Did the QBO have a role in this astounding winter;  was there a delay in the effects of the Big Niño even without a bunch of convection in the eastern Pac tropics?  Doesn’t seem that could be right…

But, William “Bill” Lau, U of Maryland scientist,  reported some statistical evidence of  such a lag way back in ’88 due to a QBO connection of some kind and ENSO, no physical cause could be discerned, however,  not yet,  anyway.  Lau, 1988, is reprised below for readers who want to go deep:

Annual cycle, QBO, SO on global precip J Geophys Res 1988ocr

Sure has looked like the Big Niño WY we expected last year!

Some recent clouds; after all, this is CLOUD maven, not RAIN maven:

I’ve been kind of holding out on you.  I dropped my camera and busted it.  Its no fun taking pictures when you don’t have a real camera.  Still doesn’t work right, but take these anyway:

March 4th, afternoon. Hope you logged this; the rarely seen CIrrus castellanus (almost "congestus" in size) or, informally, "Cumulo-cirrus."
March 4th, afternoon. Hope you logged this; the rarely seen CIrrus castellanus (almost “congestus” in size) or, informally, “Cumulo-cirrus.”
Poppies are out, btw. Nice display on "Poppy Hils" just across and southwest of the Pima County Pistol Club, off Bowman.
Poppies are out, btw, in case you haven’t noticed. Nice display on “Poppy Hils” just across and southwest of the Pima County Pistol Club, off Bowman.
DSC_2499
March 4th, late afternoon. Nothing terrifically special in this tangle of Cirrus spissatus (“Cis spis” to cloud folk) but I thought it was just a really nice scene

Moving to the next day, Sunday, that REALLY windy day:

March 5, Sunday morning 6:13 AM. Altocumulus lenticularis alerts cloudwise folk to the possibility of windy conditions although it was already windy.
March 5, Sunday morning 6:13 AM. Altocumulus lenticularis alerts cloudwise folk to the possibility of windy conditions although it was already windy.
3:55 PM, March 5th. After a day of solid Altostratus overcast with underlying Cumulus and Stratocumulus, a layer of Altocumulus began to move in to add a little more interest to the sky.
3:55 PM, March 5th. After a day of solid Altostratus overcast with underlying Cumulus and Stratocumulus, a layer of Altocumulus began to move in to add a little more interest to the sky.
3:57 PM. Looking to the north revealed that some of the lower Cumulus/Stratocumulus complexes reached heights where ice could form. That smooth region on the bottom and right side of the cloud is a fall of ice from this cloud with a RW- (text for "light rainshower") if you like to text stuff) right below that. This is not a lot of ice and so you'd be thinking the cloud barely made that ice-forming temperature.
3:57 PM. Looking to the north revealed that some of the lower Cumulus/Stratocumulus complexes reached heights where ice could form. That smooth region on the bottom and right side of the cloud is a fall of ice from this cloud with a RW- (text for “light rainshower”) if you like to text stuff) right below that. This is not a lot of ice and so you’d be thinking the cloud barely made that ice-forming temperature.  CMP doesn’t think it was caused by an ice fallout from that higher layer, which sometimes can happen.  Let’s look at the most timely sounding, just to check.  From the real Cowboys at the University of Wyoming, this:
Ann 2017030600.72274.skewt.parc
The TUS sounding which I only now just saw, showing a vast separation between the lower Stratocumulus and the higher layers of Altocumlus and Altostratus on top. Note, too, that over TUS the tops of the lower cloud is not quite at -10°C the temperature we start to look for ice formation in AZ. However, our clouds were NW of that balloon sounding, and it would have been that tiny bit colder, and tops were also lifted some when they passed over the Tortolitas earlier, meaning that the tops of this complex were colder than -10° C (14° F) at some point.

Wow, too much information….after a hiatus in blogging I feel like that  Oroville Dam in California, metaphorically overflowing with too much hand-waving information.

6:03 PM, March 5. Its still real windy. Line of virga brought a few drops when it passed overhead at 6:30 PM.
6:03 PM, March 5. Its still real windy. Line of virga brought a few drops when it passed overhead at 6:30 PM.
6:04 PM. Nice dramatic shot toward Marana as the backside of the middle cloud layer approached allowing the sun to shine through.
6:04 PM. Nice dramatic shot toward Marana as the backside of the middle cloud layer approached allowing the sun to shine through.
6:09 PM. Virga getting closer. May have to park car outside to make sure I don't miss any drops!
6:09 PM. Virga getting closer. May have to park car outside to make sure I don’t miss any drops!
6:22 PM. SW-NE oriented virga strip about to pass overhead. Drops fell between 6:30 and 6:40 PM, but you had to be outside to notice, which you would have been as a proper CMJ eccentric.
6:22 PM. SW-NE oriented virga strip about to pass overhead. Drops fell between 6:30 and 6:40 PM, but you had to be outside to notice, which you would have been as a proper CMJ eccentric.  You would have WANTED that trace of rain report, maybe slackers would not have observed.
6:30 PM. Climax; the great sunset allowed by that backside clearing.
6:30 PM. Climax; the great sunset allowed by that backside clearing.

The End, at last!

A day with rare and regular clouds

Yesterday, whilst disappointingly dry, no rain fell here overnight was a day of rare cloud sightings, most of it involving the rarely seen, “Cumulo-cirrus1“, a cloud fakery situation where extremely cold (less that -40°Ç, -40° F)and clouds at Cirrus levels appear to be ordinary little Cumulus fractus clouds. I hope you weren’t fooled by those impersonators. You’d be pretty embarrassed at the next meeting when we go over yesterday…  Yesterday was, in essence, a test for you, and I hope you passed.

Along with the rare “Cumulo-cirrus” sightings, there were intricate patterns in Cirrocumulus clouds that may have caught you’re eye. However, with the wind aloft being so strong (around 90-100 mph at 18,000 feet) you didn’t have a lot of time to enjoy them.

Yesterday’s clouds

DSC_9554
10:01 AM.  These were the first “Cumulus” pretenders I saw yesterday, though I suppose the discerning eye might have called them “Altocumulus” as well.   When they first formed they look hard and rounded like they might have had cloud droplets.  But then within seconds, that brighter look caused by high concentrations of droplets or tiny ice crystals (sometimes called “germs” because they have no particular shape when just formed) fades as the concentrations decline rapidly due to evaporation and mixing with the dry environmental air around them.   Eventually, they become transparent.  Also notice that you don’t see trails come down out of them.  This is likely because the concentrations are so high that competition for moisture keeps all of the ice crystals so small they can’t really fall out.
10:01 AM. Zooming in.
10:01 AM. Zooming in.  The brighter ones have just formed.  The faded ones are the older ones heading for extinction.  Many more shots of “Cumulo-cirrus” to follow.  Got kind of carried away, as usual.
DSC_9557
10:18 AM. Another moist layer shot in, first showing up as Cirrocumulus, though this cloud was in the middle levels, not at Cirrus heights. The fine granulation makes it look higher than it really is. This was probably around 12, 000 feet above the ground, if that. One giveaway was the rapid movement of the cloud itself, and compared to the cirriform clouds above it. If they are near the same levels, they won’t move much at all relative to one another. Anyway, these patterns changed by the SECOND! It was amazing how quickly they devolved into something completely different.
DSC_9562
10:27 AM. A wid angle view of another incoming group of “Cumulo-cirrus.” The thinnest clouds are the ghostly remains of those clouds. The more compact and brighter ones are the youngest ones.
DSC_9565
10:27 AM. A closeup of a just formed globule. Everything around it was onece like that but now has the visual attributes of regular Cirrus.
DSC_9571
10:42 AM. One of the strangest cloud sights ever seen by yours truly, CMP. Here a layer of Cirrocumulus (note fine patterns lower center) passes rapidly underneath those globules of fake Cumulus clouds full of ice.

Explanatory figure below:

Ann DSC_9571

DSC_9597
11:22 AM.  Another patch of fake Cumulus fractus at Cirrus levels comes by.  Note the true Cirrus in the background, and was higher than the fake Cu fra.
DSC_9601
11:36 AM. Was beside myself seeing this! Just incredible!
DSC_9604
11:38 AM. Just two minutes later! Look what has happened to that puff ball of ice. The turbulence up there must have been tremendous.
DSC_9621
11:57 AM. Some real fakery here. Ordinary people would have said, “Oh, those are just little Cumulus fractus over our Catalinas.” But not you. You would have chided them in friendly, gentle way, telling them they were WAY too high for Cumulus clouds and are mainly composed of ice, not possible for low Cumulus fractus clouds.   You could have also pointed out that the cloud in the upper part of this photos were way below those Cumulus fakeries, and that they about to obscure them as this encroaching  layer slid underneath them.  Also, try not to be condescending, act superior like you know so much even though you do.  You might lose your friend if you do that.
11:53 AM. Another zoomed view of one of those icy puff balls, not long after it formed.
11:53 AM. Another zoomed view of one of those icy puff balls, not long after it formed.
DSC_9635
4:01 PM. Altocumulus opacus underneath a Cirrostratus layer. A great sunset was in the works with that opening to the southwest. Also notice, no ice or virga evident. Guess that the temperature at the tops of this layer, likely only a couple of hundred meters thick, is warmer than -10° C.
DSC_9647
5:31 PM. Altocumulus opacus at sunset. The height of this layer was about 8,000 feet above Catalina by the TUS sounding, top temperature about -5° C. “No virga, no cry,” as Bob Marley said.

The End

—————
1Though it fits, I made this cloud name up.  Probably would be Cirrus floccus, maybe Cirrus castellanus in the humped up cases.