Huh, Sounds familiar. Well, 50 shades of gray is a theme here at cloud-maven.com. Those various shades brought 0.02 inches of rain this morning to The Heights. Here are yesterday’s 50 shades:
7:58 AM. Massive ice cloud advances on Catalina from the Tropics.
This Altostratus invasion covered the sky within about 15 minutes, and that was it for sun, except some “filtered sun” at times (when this layer is called Altostratus translucidus (the sun’s position can be seen). Its an all ice or mostly ice cloud.
10:58 AM. Altostratus creates a pleasant gray sky.1:26 PM. Lower droplet clouds began to appear, high-based Stratocumulus. The globules are too large to be Altocumulus, though these were based at about 7,000 feet above Catalina, or a little above the height of Ms. Lemmon.1:26 PM. A UFO appears to be soaring toward Catalina with some kind with a trailing spider web. Other lenticular can be seen, this one was truly out of this world. But, from where? What world?1:41 PM. More lenticulars; more shades of gray.3:36 PM. Altostratus is now transitioning to Nimbostratus with lower bases as steady, but very light rain, moves in toward Twin Peaks. What you’re looking at here is mostly virga, and, as the relative humidity increases below virga bases, the virga is able to drop to lower elevations. The humidity is increasing due to gradually rising air that is accompanying an upper level trough. Got pretty wind about this time, too, before calming down. Not sure what that was from except maybe virga falling into very dry air ahead of the rain.3:42 PM. Classic look of Altostratus translucidus. “Opacus” (too thick to see the sun), just ahead. Those darkest areas near the sun are droplet clouds. Most of the scene is ice cloud.4:16 PM. Finally, as very light rain began to fall, we now see the most perfect view of Nimbostratus you’ll ever see. I hope you took plenty of shots of this scene cloud maven juniors! (Nimbostratus, the deep, deep cloud producing steady rain and snow is almost ALWAYS partly or totally obscured by lower Stratocumulus clouds so you can’t really see it. But, not here!
The weather ahead
Pretty much a sure-thing rain (we, unprofessionally forecast at least a 90-100% chance of measurable rain then) will move in late on the 16th or on the 17th. Should be a significant, vegetation-boosting rain, too–by that I mean at least a quarter of an inch–unlike this rain this morning. It looks,. too, like a second rain might move in a day or two after that one. Quite strong support in the ensembles (“spaghetti plots”) for that to happen, too. How great would that be? Very great, of course.
After that, the models are showing even more troughs affecting AZ, but the ensembles aren’t sure about it. Neither am I (CMP).
I was thinking how great yesterday was for you. Started out with a spectacular sunrise (lasted just a couple of minutes), and then you could watch for pretty much the WHOLE day, orographically-formed Altocumulus opacus and castellanus transition to ice crystal clouds (in this case, Altostratus with virga and some mammatus) right before your eyes!
Sunrise:
7:16 AM. Flecks of Altocumulus clouds below Altostratus.
After sunrise….this odd scene below of an extended Altocu lenticular cloud:
7:33 AM.12:24 PM. Altocumulus opacius shedding ice as they moved westward across Oro Valley.3:01 PM. Altocumulus castellanus forming just upwind of the Catalinas, moving toward the west (to the left in this photo). No ice is falling out yet, though tiny ice crystals are likely starting to form.3:01 PM. Looking farther downstream from the prior photo. Some ice is beginning to show up and fall out (center and left side of photo).3:02 PM. Looking still farther downwind, those Altocumulus clouds are mostly glaciated, that is, mostly consist of ice. This transition has taken about 10 minutes of travel downwind. The sounding near this time, indicated that tops a little downwind of the U of AZ campus release site, were about -27°C (-17°F). However, tops were likely rising some small amount in this region downwind of the Catalinas, and so were almost surely, even a little colder than that.4:33 PM. Nice example of what some of the Altocumulus castellanus looked like yesterday. That tallest turret will fall back. Its partner is just to the right, one that was previously as high, but fell back, its load of ice crystals drifing down. Some of the ice in the taller one is still being held up there until it, too, collapses. A error in aircraft sampling can occur if you don’t realize that tops have collapsed from lower temperatures, such as when collecting ice concentrations in the collapses one. You could easily assign a cloud top temperature that was too high; would not reflect the temperature at which they really formed.
Well, on some days, there were Altocumulus clouds, too, helping to blot the sun. Altocumulus clouds are mostly or all liquid clouds, if you care, which I doubt. But then you are here, wasting time on this web site about clouds, so maybe you do care!
But, to conitnue the title’s theme, what a remarkable streak here in the “Atacama Desert” of Arizona where it has been said that it has never rained. It certainly hasn’t rained here in recent memory. And, will we have a truly dismal wildflower display? Could be, due to the absence of fall rains that are so important in producing good displays.
And while there has been a pattern change, as there always is sooner or later, the conditions for rain just will not develop. We are now in a “warm in the West, cold in the East” pattern of jet stream flow, that the atmosphere seems to like; gets stuck in it for days to weeks at a time. A big ridge of high pressure will be deflecting the jet stream into Alaska and to where its toasty warm in “Utqiaġvik” (formerly Barrow; new name not pronounceable by non-native peoples–haha, just kidding, but what does that dot mean above the letter “g”?!) with lots of precip for them. Then that jet shoots down into the Rockies and upper Mid-West bringing masses of Arctic air and snow (the formerly warm air gets modified like mad when sitting on snow and ice–yes, there is still some ice and snow in Arctic regions, contrary to some popular beliefs). But, what about in 50 years? That is the question…
No rain shows up for southern Arizona for two more weeks in the models. Oh, me.
The only thing that will be fun in the next two weeks is looking at the hourly reports for Mount Washington, New Hampshire over the next two weeks, and see how cold and windy it gets. Do you know that once (1989) it was -44°C (-47°F) at Mt. Washington with winds of, oh, I dunno, 100 mph or so? Wind chill probably was around -500°F….. The craziest thing about that long ago ob was that they were reporting “icing”, liquid cloud drops hitting and freezing. But, how could they be liquid at -44°C?
Well, its been reported, strangely believe it, as we like to say here, that liquid drops have survived to between -40°F and -50°C by motorcycle-riding, atmospheric scientist, Kenneth Sassen, when he was at the University of Utah. Utah is located north of Arizona. Ken, if I may, thought it was due to sulfur in the droplets associated with volcanic aerosols, so it wasn’t “real” water, but rather the kind of water geoengineers want to inject to cool old mom earth. Maybe, if true, that icing report at Mt. Washington wasn’t “real” water, either, but polluted water from cities and factories to the NW where the wind came from….
BTW, when you get bored some more with our own weather, the obs for KMWN can be found here. You’ll be glad you’re in Arizona when you look at them. Well, you’ll be glad you’re anywhere but THERE! Maybe some geoengineers should spend some time up there instead of proposing crackpotty schemes that would change our sky color. I demand, as persons of the 1960s would, of course, that the people of earth be allowed to vote on such schemes BEFORE they are implemented!
Oh, yeah, about clouds…..after all, this is supposed to be, “cloud-maven” country…
3:36 PM yesterday. Once again, Altostratus translucidus (too gray to be Cirrus) has blotted the sun. The bottom of this layer was about 20,000 feet above Catalina, according to the balloon sounding yesterday afternoon.5:36 PM. Sunset was painterly, not bad.
The End, for now. Have some other chores to plug away on.
Hope you saw them and recorded them in your cloud and weather diary. I’m thinking that at the next Cloud Maven Junior meeting we should devote a lot of time to this issue. It was a rare day yesterday that the WHOLE day had that phenomenon occurring as aircraft penetrated those clouds, usually on ascent or descent. Sharp descents/ascents produce holes. See the sequence below if you don’t believe me (ppt from a recent talk):
Yesterday’s clouds: lots and lots of aircraft-produced ice
(btw, see note below about pop-up ads in this blog, ones that started to appear after downloading latest WP software)
6:44 AM. Altocumulus at sunrise. As we say so many times here in old AZzy, “So pretty.”Also at 6:44 AM. From a smartphone, color not so great, though not bad either.U of AZ Wildcats balloon sounding, launched at about 3:30 AM yesterday. Those Altcumulus clouds were way up there for Altocu, 22,000 feet above Catalina, 25,000 feet above sea level.because they were so high, were so cold, AND were composed of supercooled liquid water, they ripe for aircraft to create ice going through them, likely on climb out and descent from TUS and perhaps PHX as well, Davis-Monthan. What was unusual, was that it was happening most all day as the clouds filled in some. They remained liquid, high, and cold.7:23 AM. Wasn’t long before aircraft made their presence known in this cold, cold layer.6:54 AM. I should point out that a colder topped Altostratus layer was present to the N. Its not represented well in the TUS sounding. That layer was all or mostly all ice (the rosy colored segment of this photo).7:37 AM. An unperturbed view of Altocumulus perlucidus (“Mackerel sky”). Are there any mackerel left? Also, from a cloud viewing standpoint, these are much higher than one would guess. The fact that aircraft were making ice in them is a clue that they were higher than we would normally think of a “middle-level” cloud. I like patterns like this. I thought you would like to know that about me.9:03 AM. Slicing and dicing. An aircraft has left a contrail through a Altocumulus line . What’s really unusual here is the ice contrail so far outside the liquid water cloud. It is thought that hole-punch and ice canals are limited to regions where there are liquid droplets, and so this is quite an anomaly, one that suggests the humidity was almost 100% with respect to water outside the cloud boundaries. Also, can you just make out the partial 22° halo, indicating very simple ice crystals like columns and plates? Streamers of tiny ice crystals are also evident, trailing to the right, below the contrail? This shows that the wind decreased rapidly with height just below the flight level, but was still from the southwest to west.9:24 AM. Coming at you, another ice-canal has formed SW-W of Catalina, a favored locale for the formation of these canals on days like this.9:40 AM. What’s left of it is almost to Catalina. Note streamers of ice. Below, a close up of a couple.9:40 AM. The intensity and narrowness of these streamers point to an artificial origin. So, even if you didn’t see the canal, and here, some of the clouds are reforming at the top of the streamer, you would make a good guess that this was not natural ice. Sometimes the canals can fill back in if the air is in overall ascent at cloud level.9:57 AM. Here’s what those contrails in Altocumulus look like as they first appear. Can you spot’em? There are two.1:45 PM. Another aircraft-produced ice event as the Altocumulus increased and became thicker, making detection of these events less obvious. Sometimes a canal clearing is very muted.4:12 PM. Aircraft-induced hole punch cloud with ice below the hole. Can you spot it? See close up below.4:12 PM. Close-up of that hole punch, ice mostly below the Altocumulus layer.4:35 PM. That hole punch cloud 35 min later. The long trail indicates high humidity well below the Altocumulus layer in which it appeared.The 3:30 PM balloon sounding from the U of AZ. A study in ambiguity.The day ended with an unusually bright sun dawg, mock sun, or parhelia. So bright it did, again, suggest a plume of ice from a prior aircraft passage through extra cold Altocu or Cirrocu clouds. But, just wild speculation here. Hope you don’t mind.5:41 PM. Nice sunset, but one strongly impacted by clearing from aircraft-produced holes and lines of ice, the ice now mostly gone.
The End
——————About those nuisance ads—————
Note to me and the two other people that drop by my cloud or “clod” blogulations: The embedded pop-up ads are due to a WP third party plug-in that needs to be repaired. It will likely happen today.
After consultations about ads…
Oddly, those pop-ups and blue highlighting and double underlining do not seem to be present outside of my personal view of my own blog, this according to hoster, “godaddy.” Even using a different browser other than FIrefox does not show them as I have just verified.
Been busy as a briefly unretired science worker (gave a stressful talk at a university last week) and thought maybe a lot of usual drop ins to this site might not anymore. So, in the title for today, am reaching out to a new demographic: persons interested in congealed soil matter. They might later, after stopping by, discover a new interest; that in clouds, pretty ones. Most of the cheap tricks I try like this don’t have any effect, though. Oh, well.
Let us go forward after backing up:
November 3rd
8:01 November 3rd. OK, I’m way behind! Flock of Cirrus uncinus overruns Catalina and environs.8:02 AM. Looking SW from Catalina. So pretty with the deep blue skies we have at this time of year due to sun’s lower angle in the sky.9:16 AM. Look how different, even unreal, that flock of Cirrus looked when leaving us. Looking NE toward the Charouleau Gap.
But the Cirrus kept coming and more odd sights were seen:
10:06 AM. Two levels of Cirrus can be seen. This vertical white patch is likely a few thousand feet lower than the crossing faint strands center and right side, which are likely above 30,000 feet above the ground. The heavier Cirrus (spissatus) in the distance is also lower than the strands.
Heavier Cirrus, increasing and lowering to Altostratus finished off the day as a heavy shield of middle and upper clouds raced toward southern Arizona from the Pacific:
3:08 PM. Cirrus spissatus here, too splotchy in coverage to be Altostratus. Nice subtle lighting effect on the Catalinas…
“Due to time constraints, we move ahead in the action…”
November 4th
7:27 AM. Classic A row of Altocumulus floccus and castellanus underlie an Altostratus layer. Where the bases have disappeared, at right, are termed “floccus”, if you care.8:00 AM. Altostratus, some lower Altocumulus castellanus with graniteen boulders and a coupla saguaros.8:59 AM. Bird collective watches in hopes that the darkening, lowering Altostratus layer (with some Altocumulus) will bring rain. It didn’t. “Dang”, we say here.4:51 PM. All of the higher layers were gone, leaving only a lowest, but thin scattered to broken Stratocumulus clouds. 🙁 All in all, it was a good day for hiking and other outdoor activities.
Sunday, November 5th:
6:01 AM. Flock of CIrrus uncinus and spissatus again advances on Catalina.6:21 AM. a closer view. Here they seem to be uncinus with fibratus. Stratocumulus clouds were topping the Catalinas, too, indicating more humidity than we have been seeing most of the past few weeks.8:38 AM. I thought this was an especially spectacular scene, this lattice of Cirrus racing toward us. Hope you did, too.
4:26 PM. Perhaps the brightest example of iridescence I have ever seen! Just spectacular for a few seconds in this patch of Cirrocumulus. Iridescence is caused by diffraction around the tiny of droplets, less than 10 microns in diameter, as are present when a cloud just forms.
5:09 PM. Seeing this scene of Altocumulus, you KNEW you were in for a superb sunset. It didn’t disappoint.5:39 PM.5:40 PM. There is no virga here.5:44 PM. Super!
The weather just ahead
The Wildcat Weather Department model is foretelling perhaps a measurable rain event between this afternoon and tomorrow morning at 7 AM! Heavier rain is foretold to be south of us, but just a slight error would mean something more substantial. Hoping for error! A sky covering Altostratus layer is just about assured with a lowering tendency as the day goes on. Should see some Altocu , too, a day a lot like last Saturday.
Now, that’s pretty funny. We specialize here in too much said! Its a niche thing. Of course, not enough can be said about our past July. Take a look:
This, of course, was a new July rainfall record for Catalina/Sutherland Heights going back to 1977, anyway. Had to adjust vertical axis of this chart, too. Formerly, it stopped at only FOUR inches! The moon lore was right! It’s interesting how the ancient lore of early peoples that I made up a month ago was more accurate than the Climate Prediction Center’s prediction of an equal chance of above or below normal rain in southern Arizona while something incredible was on the doorstep! Kind of like last winter in the whole West where record amounts of snow and rain piled up over a huge region, and that, too, was also unforeseen “going in.” Think how horrible it would be if those predictions were always right. Sure, billions could be saved by such accurate outlooks, but then the element of surprise would be gone. How bad would that be?
After the paucity of rain in the preceding five months, and with June carrying into around July 10th this year with its blazing heat and no clouds, all that rain that followed with thunderations day after day, the attendant rain-cooled “breezes” to 50 mph on occasions, blowing stuff all around everywhere, were sure welcomed (?). (Another case of innovative punctuation to emphasize a point, whatever it is.)
Let us begin today by examining the greenth of the 2017 summer on our Catalina Mountains so far, thanks to July’s copious rains. Hah! The climate really has changed. Looking into growing bananas now…Now for some cloud photos from yesterday:
9:40 AM. Like most of our summer days, it begins with mid-level layers of Altocumulus, in this case shown here, “translucidus” variety (rather thin, it is.) It was up around 13,000 feet above the ground, if you care.11:07 AM. As the Altocumulus clouds thinned, burned off, the rise of the Cumulus begins, here a gigantic one spurts upward telling you that there are going to be some blasters yesterday. Very exciting to see this. I can feel your heartbeat as you, too saw it.11:51 AM. Wasn’t long before giant Cumulonimbus clouds were dumping over there on the town of Oracle. Nice town it is, btw. However, these clouds weren’t much electrified, telling you that the updrafts weren’t particularly strong yet, even though tops here were probably pushing around 30 kft.11:52 AM. Cumulus congestus, and Cumulonimbus calvus start unloading over there toward I don’t know where exactly, but its just on the other side of the Tortolita Mountains. You’ve probably noticed how clear the sky has been, completely free of haze. That’s good for rain production, since the cleaner conditions are the larger the drops can be in the clouds because there are fewer of them compared to clouds forming on hazy days. Nat King Cole sang about summer haze as early as 1963, so we know that haze is not a new thing, like CO2 is. You won’t find people singing about CO2 in ’63!11:58 AM. The three amigos…. A slight rain shower can be seen in the slight haze in front of the mountains below the center Cumulus. Tops of these spindily Cu leaned way out again due to weak updrafts and and stronger winds aloft from the S. Since rain forms in the upper portions, it fell a little away from the mountains in these weaker Cumulus.12:02 PM. Dump truck, fully unloading! Not messing around anymore here. With cloud bases running around 15°C (59°F) there was a ton of water up there. Well, thousands of tons.12:06 PM. I know what you’re thinking: “Oh, look, a baby dump. Isn’t it cute!” Suggests an abnormally narrow turret poked to far higher altitudes that those around it.12:24 PM. More Cumulus congestus clouds joined the fray and this became a major 2 inches or more producing system over on the Tortolita Mountains.1:01 PM. Now the outflow surge can be seen on the left, pushing new Cumulus turrets above it. This was about the peak of it, as it gradually wound down. Its certain that flash flooding occurred with at least 2 inches having fallen in the core.
Well, the day closed on a disappointing note as Cumulonimbus debris clouds overspread the sky, killing new convection.
5:45 PM. Altostratus “cumulonimbogenitus.” The day went quietly into the night.
The weather way ahead
Looks like below average rain for August. :(, as we say. Hoping for error here. Average August rainfall here in Catalina/Sutherland Heights is 3.16 inches.
Haven’t had much to say, brain pretty empty again after the big review of the NAS 2003 review which really needed reviewing and commenting on real bad….
(More “late homework” in the offing.)
———————-
Nice sunset last night; we have had a series of pretty nice ones over the past few days.
April 26th. Sunrise over the Charouleau Gap.Orangy mountains highlighted by a gap in the Altostratus layer that allowed the setting sun to shine through.7:04 PM. There was some turreting in this line of Altostratus that passed over, and because of those deeper tops, indicating stronger, if still slight updrafts, larger snow particles developed and produced this line of heavier virga underneath it.7:10 PM.A contrail that’s more than about ten minutes old, now, after the new Int. Cloud Atlas has been released, termed, Cirrus anthrogenitus, maybe castellanus in this case, too.
From IPS MeteoStar, this interesting map for tomorrow morning.
The orangy colors denote the strongest winds in “Jetty Jetstream”, and as you know, the colder, low clouds, ones capable of reaching the temperatures where ice forms, are contained within that ring of strongest winds at this level (500 mb). So, while the models I have looked at so far have no rain here, I think there’s a pretty good chance of a rogue shower tomorrow morning anyway. At least there should be some nice Stratocumulus/Cumulus tomorrow and some will have ice in them. As you know, it’ll be awful windy today, too, maybe 40 mph or so in brief gusts here in The Heights of Sutherland.
Also will be looking for some nice lenticulars since “Jetty” will be right over us, but a little toward the warm side where lenticulars mostly occur.
Map valid for tomorrow morning at 5 AM AST.
In the meantime, spaghetti suggests a big trough in our area again about nine days from now. The later ACTUAL model outputs don’t show much of anything. What’s up with that? I’m hanging with spaghetti that later model runs will indicate a strong trough, and at LEAST another pulse of cooler air, and another minor chance of rain as we are going to see today and especially tomorrow as when become within the “ring of winds” aloft. Didn’t Johnny Cash sing something about that? Maybe it was Wall of Voodoo…
Below, some spaghetti for you showing a big trough over Arizona and the Great Basin which is not much reflected in the actual models, as noted. But, just watch my friend, how those model outputs will change to reflect a bigger trough about this time!
In case you don’t believe me that over an inch fell, this digital record from Sutherland Heights with writing on it:
Your last 24 h of rain in the Sutherland Heights, Catalina, Arizona, USA. Total resets at midnight.
Probably a little more to come, too. Got some blow damage, I’m sure. Will be looking for roof shingles around the yard today.
12:45 AM. Your radar and IR satellite imagery for our blast last night from IPS MeteoStar . That tiny red region near Catalina represents hail and/or extremely heavy rain.
And, as everyone knows from their favorite TEEVEE weatherperson, “New Storm to Pound SE Arizonans!” Begins Monday night, Tuesday AM. May have snow in it as it ends.
Your know, its no fun telling people what they already know, so lets look ahead beyond the normal forecast period of great accuracy, beyond not seven days, not eight, but beyond TEN days!
First, we set the stage with a ten day look ahead (from last evening) in a NOAA spaghetti factory plot:
Valid for 5 PM, Monday, January 30th. If you’ve not seen this, you’ll be screaming “warm in the West, and damn Cold in the East.” Its a common pattern often associated with some of the driest years in the West when it recurs over and over again during a winter.
This plot indicates that the pattern of a towering, storm-blocking ridge is certain along the West Coast by ten days–will be developing for a day or three before this, That ridge represents an extrusion of warm air aloft over the entire West Coast extending all the way into Alaska. The couple of red lines in and south of AZ are due to the change of a minor, likely dry, cutoff low in our area about this time (plus or minus a day).
In other words, this plot suggests a warmer, dry period develops over AZ, and storms are shunted from the Pacific Ocean, located west of the West Coast, all the way to Anchorage and vicinity, They will be welcoming a warm up in weather up thataway at some point in this pattern.
Is that it, then, for the AZ winter precip? It could happen. Just one more storm after the current one fades away today?
Hint: Sometimes anticyclone ridges like the one in the plot above get too big for their britches, and fall away, or, break off like a balloon from a tether, and a warm blob of air aloft sits at higher latitudes, often floating off to the northwest.
The exciting ramification of this latter scenario is that in the “soft underbelly” of the “blocking anticyclone” (as in American football), the jet stream throws something of a screen pass, goes underneath the belly of the blocking high, and races in toward the West Coast at lower latitudes. Having done so, such a break through pattern (“Break on through to the Other Side”) results in heavy rains in Cal and the Southwest.
Izzat what’s going to happen?
Let us look farther ahead, unprofessionally, really, and see if there is evidence in spaghetti for such a development and you already know that there must be because it would explain why I am writing so much here. Below, the EXCITING spaghetti plot strongly indicating break through flow breaking on through to the other side, i.e., the West Coast, from the lower latitudes of the Pacific:
Valid on Thursday, February 2, at 5 PM AST. Flow from the lower latitudes of the Pac will, in fact, break on through to the other side, as told in song by the Doors1. Who knows what they were talking about but here we’re talking about a jet stream….
Well, we’ll see in a coupla weeks if CMP knows what he is talking about.. I think this is going to happen, resembles what’s happening now, and weather patterns like to repeat, more so within the same winter. However, how much precip comes with this pattern will be determined by how much flow breaks on through to the other side….
Yesterday’s clouds
Let us begin our look at yesterday’s clouds by looking back three days ago before the Big Storm. We had a nice sunrise. Here it is in case you missed it:
7:21 AM. Altostratus sunrise. Virga is highlighted showing the precipitating nature of Altostratus. Amount of virga can vary.7:31 AM. Same kind of view, different colors.7:40 AM. Highlight on the Tortolitas. This is why you carry your camera at all times.9:04 AM. Pretty much solid gray after that nice sunrise for the rest of the day with cloud bases lowering and raising. Early on, cloud bases were well above 10,000 feet; i. e;, above Mt. Lemmo, and would be called, “Altostratus opacus.” The virga is very muted, and there are embedded droplet clouds as well as a droplet cloud layer (Altocumulus) encroaching on the right. Estimated ceiling here: 12,000 overcast.” (Pronounced, “one-two thousand overcast” if you want to make your friends think that maybe you were a pilot at some time in your life.)12:58 PM. Clouds began to appear on Samaniego Ridge as the moist air above us lowered steadily. However, due to lowering cloud tops, the ice in the higher overcast layer was gone. Here there are two layers above the scruff of Stratus fractus (I would call it) on the ridge. The lower one looks like its a Stratocumulus, and the higher one a solid layer of “Altocumulus opacus.” Its already rained some, and we were in between storm bands.2:48 PM. Looked like the Altocumulus opacus (stratiformis, if you want to be exactly correct) was breaking up just enough for a sun break. But no; it kept filling in as it headed this way from the southwest. No ice, or virga evident, so tops are pretty warm, probably warmer than -10° C (23° F) would be a good guess. Hah! Just now looked at the TUS sounding and tops were indicated to be at -11° C, still very marginal for ice (absent drizzle drops in clouds, which causes ice to form at much higher temperatures, but you already knew that.)4:24 PM. Small openings allowed a few highlights to show up on the Catalinas underneath that Altocumulus opacus layer. And clouds were still topping Ms. Mt. Lemmon, indicating a good flow of low level moisture was still in progress.
Moving forward to only two days ago, the day preceding the nighttime blast: a cold, windy day with low overcast skies all day, shallow, drizzle-producing clouds, something we don’t see a lot of here in Arizona.
8:08 AM, January 20th, 2017, btw. “Gray skies, nothin’ but gray skies, from now on”, by Irving B. Stratus fractus underlies an overcast of Stratocumulus. Some light rain is falling toward Romero Pass on the right.8:10 AM. A really special shot. Stratus with drizzle, shown here, is a very difficult photographic capture. I can feel how enthralled you are with this scene toward Oro Valley. You know, I do this for YOU. Look how uniform the gray is! It just takes your breath away!9:44 AM. Before long, drier air down low moved in, eradicating our beautiful Stratus layer, leaving only holdouts (Stratus fractus) along the Catalina foothills below the heavy layer of Stratocumulus.10:20 AM. The wind had now shown up, and these ragged, shredded shallow Stratocumulus shedding drizzle or very light rain showers stormed across the Catalina Mountains. This was quite remarkable sight, since such shallow clouds as these are more often seen in clean maritime locations like Hawaii. Scenes like this suggest that the cloud droplet concentrations were very low, and that there were larger than normal cloud condensation nuclei on which the drops could form, getting a head start in the sizes needed to produce collisions with coalescene (larger than 30 microns in diameter (about one third to one half a human hair in diameter, for perspective.)
3:12 PM. Lower, drier air moved in, eradicating the Stratocumulus and revealing the rarely seen Nimbostratus precip-producing layer. This layer, considered a mid-level cloud, is usually obscured by, you guessed it, Stratocumulus clouds.
By the end of the day, the clouds had lowered again, and we were about to have a very interesting night!
5:01 PM.
The End
———————- 1Remember how great we hippie relics thought that first Doors album was? Later, the Doors, and that era were to be made fun of by 80s punk and humor group, The Dead Milkman in “Bitchin’ Comaro.” (Its worth a listen.)
4:17 PM. Line of spreading out Altostratus translucidus. Many of you might have added, “radiatus” to that cloud name. “Clearly” it is widening as it passes over.
4:00 PM AST. That line of ice cloud looks pretty straight doesn’t it? Imagine how wide a cloud would have to spread, after seeing that Altostratus photo, to REALLY be radiating, spreading out!
As Einstein wrote, “Things are not always as they seem.”
Q. E. D.
Now, for the snow report
…from the Lake Tahoe area (after all, we made a BIG DEAL out of the incredible NWS, Reno, forecast in the prior blogulation):
0822 AM HEAVY SNOW NORTHSTAR 39.28N 120.12W
01/11/2017 M42.0 INCH PLACER CA PUBLIC
NORTHSTAR AT TAHOE REPORTED 42 INCHES OF NEW SNOWFALL IN THE LAST 24 HOURS. 48 HOUR TOTAL OF 78 INCHES AND A 7 DAY TOTAL OF 122 INCHES1.
1This note passed along to the Arthur by Mark Albright.
Looks like a bite has been taken out of the Cal drought this water year, a drought it was said would take years to end! Folsom Lake, near “Sacramenta”, Cal, has risen 30 feet in the past 30 days! Oh, my.
Now for some more of them cloud pictures…
Been holding out as other chores fill up the day:
7:19 AM, Jan 10. Pretty Altocumulus, some Cirrus above.Also 7:19 AM, Jan 10th. Time seems to be standing still, as we look a a cloudlet spewing heavy virga.7:22 AM, Jan 10th, time moving ahead again. Close up of that Altocumulus cloud with virga. Top must have been turreted, colder maybe a half hour or hour before this photo to have so much ice compared to its brethren. That’s the learning part of this sequence. Doesn’t look like an artifact from an aircraft because there is droplet cloud at the top, and not just a clear spot, which usually happens when an aircraft makes ice in a “supercooled” droplet cloud.5:14 PM, Jan 10th. THought this was a neat scene, Cirrus uncinus, the long trail of ice crystals falling behind, the overhead view.12:57 PM, Jan 8th. Makes you want to cry… This Cirrus spissatus is trying so HARD to be a precipitator all the way to the ground, and doesn’t know that those bottom ice crystals are evaporating 25,000 feet above it.
The weather just ahead
U of AZ latest mod output (from 11 PM AST last night) has a substantial rain on the doorstep. Starts here in Catalina Saturday afternoon with projected totals over half an inch nu mid-day Sunday. Check it out:
Totals valid at 11 AM AST, Sunday, Jan. 15th.
HECK, this storm wasn’t even predicted 10=12 days ago! The major weather change was indicated about the 20th, plus or minus a day. Those storms, indicated in the NOAA “spaghetti” plots more than 12 days ago, are still in the pipeline after we have a brief “recovery” from the “surprise” storm about to arrive on Saturday! Yay.
This sequence of storms is so great for the AZ water situation, too, as well as giving it to Cal good again around the 20th as well. No doubt, as the humans we are, the peoples of Cal will be complaining about TOO MUCH WATER!
This will lead to apathy about water issues, you can bet on it! See the well-known “cloud seeding cartoon” about drought and apathy posted so many decades ago in a journal article on cloud seeding by editorial nemesis1, Bernard A. Silverman, J. Appl. Meteor., termed the “Hydro-illogic Cycle”:
Published in 1978, but was around in the cloud seeding culture for many years before that. Used without permission. hahaha I believe it was drawn by the founder of Atmospherics, Inc., Tom Henderson’s daughter. Atmospherics, Incorporated performed numerous cloud seeding operations in the US and around the world beginning in the early 1950s. Yours truly worked for them on several occasions in the early 1970s as a “radar meteorologist” directing seeding aircraft. Later, I became a published critic, mostly with Prof. Peter V. Hobbs, of a number of cloud seeding projects.
The End
——————————- 1Nothing yours truly submitted during the era of BAS as Editor of the J. Appl. Meteor. “got in”, including the benchmark paper reporting that our own aircraft was creating ice in clouds at temperatures as high as -8° C. Three sole-authored papers critical of cloud seeding that I submitted were rejected in 1983 alone! All or parts of them were published years later.
The paper on our aircraft, submitted originally in 1981, was rejected twice before being accepted and published in 1983. The effect was confirmed in experiments conducted in the Mono Lakes area in 1991, by the president of Atmospherics, Inc. mentioned above! Aircraft produced ice particles at unexpectedly high temperatures is a now well-known phenomenon that researchers have to be aware of when re-sampling the same cloud with an aircraft at below freezing temperatures.
Soap box: It really is the editor of journals that determines whether you’re going to get in or not. They know, or should know, those who are going to keep you out or not, those with axes to grind, and those who are more objective. However, let me say this, I like Bernie. Has a great sense of humor. Below, Bernard A. Silverman. You can see the twinkle in his eye:
Bernard A. Silverman, publisher of the journal article containing the “Hydro-illogic Cycle” cartoon at the Cape Town, SA, 2006 WMO award ceremony for achievements in weather modification. He acknowledged in that 1978 article that he was a cloud seeding advocate.
What a day for cloud maven juniors and me, too, watching the Altostratus opacus (but sometimes “translucidus” cuz you could see where the sun was) become Altocumulus! It happens pretty often and is the result of lowering, and warming of the cloud tops, but I need to generate some excitement on an otherwise somewhat dull day.
What else is happened as tops warmed? Good-bye virgae (“virga”, in plain speak), except in a couple of locations that raised the question, “Was it hers (Mother Nature’s) or ours (aircraft effects)?”
The TUS balloon sounding through all that Altostratus opacus virgae. Launched at about 3:30 AM. The top temperature is so cold (-60° C, -76° F) we don’t even want to know here in Arizona that such temperatures are possible. So, you can imagine all the ice that might form in a moist layer of air. The bottom is even cold at nearly -15° C, there were the temperature jumps out to the right. This is a situation we call “overrunning”, where warmer air is going over a colder air mass. This cloud was about 22,000 feet thick, 7 km at this point.
The slight spread between the two lines illustrates the classic representation of what we measure when the balloon passes through an all ice crystal/snowflake cloud like this version of Altostratus was yesterday morning. The humidity element on the balloon measures the humidity relative to liquid water, not ice, so there will be some spread between the dew point temperature (line on the left) and the temperature (line on the right) when the balloon ascends through an ice cloud. Saturation with respect to ice is indicated here in that deep “overrunning” layer, something also likely to happen tomorrow to the writer’s “company” fubball team tomorrow.
And here’s the TUS sounding launched yesterday afternoon when we only had Altocumulus opacus clouds, just as dark as Altostratus opacus, but much thinner. Tops around -10° for the most part, but there may have been some turrets to around -20° C. The balloon almost certainly passed between clouds, did not go exactly through a Altocumulus cloudlet. Don’t worry if you can’t make out the actual temperatures on the lines sloping up to the right, just take my word for everything I say. You can easily see how much it dried out in the middle and upper cloud regions between the morning sounding and this one.
Yesterday’s clouds and the transition
8:29 AM. Altostratus opacus virgae (has some downward pendants of ice and snowflakes coming out of it). The TUS radar had some sprinkles showing up here and there.8:29 AM. Altostratus opacus virgae (has some downward pendants of ice and snowflakes coming out of it). The TUS radar had some sprinkles showing up here and there. If this seems familiar, the caption is identical with the prior one. Redundancy is one of the niches we practice here, mostly in cloud photos of the same thing.
Now let’s look over here:
8:29 AM. The same.9:19 AM. “Thin spots in overcast”: we used to say that a lot in our human weather reports of ages gone by. Here the thin spot makes this Altostratus translucidus.. While there is an irregular look to this Altostratus due to virga hanging down, there is no indication of liquid water elements, ones that would show up as sharply-outlined darker elements. While this is hours later than that morning TUS sounding, it is likely that in spite of this thin spot, the Altostratus layer was still many kilometers (thousands of feet thick). Ice crystals and snowflakes are far less numerous than droplets in liquid clouds, and, therefore clouds composed of ice are more transparent given equal depths. Compare the visibility in a dense fog with being in a light snowfall.9:38 AM. Example of a some sharply-outlined liquid clouds embedded in the Altostratus layer have formed. The growth of ice crystals and snowflakes is enhanced in liquid clouds because they represent regions where it is saturated with respect to WATER, and highly supersaturated with respect to ice (the relative humidity with respect to ice is well over 100%). Also, if the droplets in these clouds are large enough (larger than about 15 microns in diameter) they can be collected by the falling ice and snow, adding to their mass of those, causing them to fall faster.10:29 AM. Had numerous, dramatic outbreaks of mammatus around this time, probably representing the fall back of turrets on top of the Altostratus as this time. We will say no more about mammatus since the author has tended toward the prurient to break up the tedium in past notations about” mammatus.” This might be viewed as an upside down look at the cloud tops at this point, BEFORE they collapsed and dropped below the main bottom of this layer. At the top (rumpled area), regions of a liquid cloud layer are beginning to appear, a sure sign that tops are receding.11:55 AM. Moving along,looking upwind across the Oro Valley. Still looks composed mostly of ice (Altostratus opacus virgae here), but liquid clouds are on the far horizon.1:21 PM. Altocumulus opacus rules. The deep icy cloud is all gone by now. No virga. Notice, too, in spite of being less than a kilometer thick, this cloud looks as gray as the Altostratus that was many kilometers thick. The droplet concentrations in a liquid cloud such as this might be 200, 000 per liter, while the ice concentrations in that Altostratus cloud were likely in the 10s per liter. The smaller particles in Altocumulus clouds, average perhaps only 15-20 microns in diameter also are able to reflect far more sunlight back into space, and less sunlight reaches the bottom making it darker. In contrast, the (ice) particles in the Altostratus would be hundreds of microns to millimeters in diameter (i.e., precip-sized).2:22 PM. Looking around at these cold Altocumulus clouds, generally not showing virga, you begin to wonder if those areas you do see have been the result of an aircraft passage, as here in that little spot of virga.2:28 PM. Some breaks in the overcast allowed some nice scenes to fall upon our mountains. Here, the Charouleau Gap is highlighted.
From the global ingest of data at 11 PM AST last evening. Indicates that green Catalina will be in the half inch to three quarters of an inch between now and New Year’s Day afternoon. Comes in two segments, the first overnight tonight, and then another starts New Year’s Eve. Seems reasonable. Probably not quite reasonable is the red on the Cat Mountains, indicating 3-4 inches accumulation during this time, probably a bit overdone. Both storms are rather small in size, so the amount of rain depicted in these model runs has varied a lot. But, they seem to be settling on something decent. Seems the least we’ll end up with has to be more than a third of an inch, worst case scenario. See Bob and the NWS for a good look at these incoming events. We’re mostly about clouds here.
Undercutting flow from the tropical Pacific is on schedule. So, a good chance for major rains along the southern portions of the West Coast in a few days, with a pretty good chance they’ll leak into Arizony.
