Welcome to one of the great cloud blogs of our time today, great as in volume, not in eloquence or anything like that.
6:16 AM. Pink castellanus, Altocumulus castellanus. Note the “micro-cumulonimbus” turret complete with a little anvil that’s shearing off to the left (center left). So now what? Should we have a cloud called an Altocumulonimbus? Maybe so, since on this morning, clusters of Altocumulus grew into major true Cumulonimbus clouds with rain and lightning in Arizona yesterday morning. Its a pretty common thing having thunderstorms and Altocumulus castellanus and floccus based at the same level at the same time.6:21 AM. Looking pretty much at the same scene but a little farther to the north where a dissipated Cumulonimbus can be seen (on the right) formed at the same level of the Ac cas, in case you didn’t believe me that that could happen.6:43 AM. Rainbow and corral, horse poop in foreground. Yours today for only $1800. Shows that aforementioned Cumulonimbus was producing rain to the ground. Was the first rainbow event of the day.12:08 PM. While Ac cas and small Cumulonimbus clouds dominated the sky all morning, heating finally started to launch boundary layer clouds fueled by that heating. With lower than normal temperatures aloft due to an upper level trough, watch out! Here we go!12:13 PM. Hardly had the thought to “watch out” crossed my mind, when I looked up toward Winkelman and Mammoth areas and saw that it was too late to “watch out” as this gargantuan Cumulonimbus had already exploded up thataway.1:23 PM. A large Cumulonimbus erupts upwind of Catalina. Will it make it? Because this is a fall circulation pattern with a tough in the westerlies affecting us, the clouds are moving more rapidly than usual and from the southwest, not from the eastern semicircle, our as during our normal “summer rain regime.” Remember, the “monsoon” is in India and all around there.2:21 PM. OK, its an hour later, that distant Cb didn’t make it but this one upwind looks more promising. Why? Because its got a protruding Cumulus base on the left side suggesting it will keep developing. Same on the right side. Without those re-inforcements to the updraft of this complex, it would die, all or most of the rain fall out before it got here. Let’s see what happens.2:31 PM. Starts to look disappointing again, but hope arises in the distance. See caption-sized note on photo.2:43 PM. I could feel your excitement here as the farther out base developed, broadened, new shafts started to appear in the distance from that complex of firm-looking bases. I was excited too. Maybe we’d get half an inch out of this group!2:44 PM. In the meantime, nice lighting on the Catalinas and moderate Cumulus pass by in a hurry. Thought for today: “Mountains: the canvases on which clouds paint.”3:03 PM. Heart has sunk by this time, as did yours. New cloud bases (on the left side) driven by outflow winds is causing this thunderstorm to propagating to the right of the wind flow and so the part of this that appeared to be directly upwind of us, and looked so good, was now raining out because there was no new cloud forming to keep it going in a steady state way So, no half inch after all except maybe down there. Oh, me. Nice scene, though.4:21 PM. Break in the action. This Cumulus congestus cloud person seems happy, thumb is pointing up. Not so much here as upwind clouds have dwindled.5:13 PM. THen, just after it looked like it was over, and cloud maven person left his post, all HECK broke loose as a powerful thunderstorm roared out of the Tortolita Mountains and off toward Oracle and points north. The shaft that fell out has produced a small arcus cloud, that lower scruff ahead of it. That was to be our hope. A blast out of the north from this monster that could trigger overhead new cloud developments!
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5:15 PM. Unnecessary close up of this monster.5:20 PM. Another look at the dramatic sideswiping storm. Looks more like a shot from Kansas or OK.5:20 PM. In the meantime a blast of north wind from the giant cell north of us has hit Sutherland Heights and is pushing up a great looking base that is creeping TOWARD us!5:21 PM. Its only a minute later, but its such a great, dramatic scene its worth checking again.5:23 PM. That great cloud base just north of Sutherland Heights is starting to unload, but it hasn’t progressed farther south. Hmmmm.5:29 PM. The north wind was accompanied by a scruff of clouds that topped Samananiego Peak. But what’s wrong here? Look at the poor “quality” of the cloud base over and just east of us now, full of light and dark areas, not a solid blob of darkness as we saw just to the north of us. So, this is going to do nothing here.5:31 PM. That low cloud continues to race south, and with the sun breaking through, produced a pretty scene if a depressing one due to the lack of a “good” big, dark base.5:32 PM. That large, dark cloud base has receded to the north while scud clouds still stream south. Dang.5:39 PM. That great Kansas-looking storm is disappearing now behind Pusch Ridge with only the middle portion of the cloud left to precipitate (once have a great bottom, one that disappeared as the shove upward went to the east. So, its still thick and low enough on the right side to produce a burst of moderate rain, but will it get here?5:45 PM. Remarkably heavy rain still falls out of clouds that now appear to be only residual Altocumulus/Altostratus (cumulonimbogenitus, of course). And, if you saw this scene, you could anticipate being in somebody’s rainbow when the sunlight got to you, and that you were going to see something special in that regard VERY soon.5:47 PM. Yes, but two minutes later, the sunlight reached Sutherland Heights causing this rainbow spectacle.5:48 PM. Another look at this spectacle. There appears to be a pinkish red drop, maybe a part of the rainbow I have to be in for others to the west of me! Real evidence maybe of being in a rainbow when your in the rain and the sun is shining! Never have seen a pink drop before.5:49 PM. Let’s look and see if there is another end to this rainbow… Yes! There it is toward Charouleau Gap.5:50 PM. Close up of a rainbow to see what it looks like a little better.6:44 PM.6:43 PM. Stratocumulus of the evening.
A humorous final note: Here are two model runs only 6 h apart from last evening. The first one, from 5 PM AST global data, valid on the 26th, brings that Mexican Pacific hurricane back into AZ/NM as that strong low drops down into Cal! How crazy izzat?
The second panel was the model output from just 6 h later for about the same time. No trough nowhere near Cal as is shown in the first panel, and our powerful hurricane stays well offshore. Still, it was an intriguing glitch of a magnitude you hardly ever see.
Also, I am also posting way below a new (!) not-previously-published. but rather rejected- by-important-scientists-a-long-time-ago-manuscript FYI!
Very exciting! (Hah!)
Its published now, though, isn’t it???!!!
“Online.”
Its about science and how it works, and how it has failed; examples given. I put it down toward the bottom of a normal blog because I am shy.
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Clouds from a few days ago, August 26th, now that the “choke point” in uploading photos to Word Press has been, at least temporarily ameliorated.
Here’s the sequence as a great cloud bottom drifted toward us from Pusch Ridge on the afternoon of the 26th. If you saw this coming, you should have been clearing channels around the house for excessive water flow. I forgot to.
Unloaded 0.45 inches at this site. 1.69 inches up on there on ol’ lady Lemmon. We sure needed this dump! Below, one of the great cloud bottoms of our time, that of a Cumulus congestus cloud, filled, as we say here, with rainy portent (maybe hail, too):
1:44 PM, August 26th. Note just a tinge of shading on the right side. First drops, the biggest ones, or even hail stones are just coming out.1:48 PM. Cloud beginning to bust open with rain now; updraft collapsing over there. Now its a Cumulonimbus.1:53 PM. Nice shafting over there, but will the cloud base overhead now split open over us?1:54 PM. Looks really good almost overhead toward Saddlebrooke! Just don’t unload after you go by! Note scruff of lower cloud (called, “pannus”) caused the the outflows of storms to the SW of Catalina. Not long enough really to be a “arcus” cloud, but clouds like this are almost always associated with a shift in the winds that helps build clouds overhead by acting like a micro-cold front, the rain-cooled air lifting the warmer, humid air ahead of it, and some of that warmer air being cooled to its condensation point producing these lower shelves of cloud.2:07 PM. The height of the storm, the visibility down to a hundred yards or two is all. This particular intense period hardly lasted a couple of minutes before it let up noticeably.
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Pedagogical or possibly, pedantic (boring) module
Update alert for the posting of new (!) not-published rejected items by this Arthur:
(the original title, submitted first in 1997), final rejection in 1999 (Bull. Amer. Meteor. Soc.)
The reviewers, Harold O., Danny R., and someone named “Anonymous Reviewer B”, guessed as, “”B”, for “Bernie S.”
Those in the cloud seeding culture don’t need the names spelled out. Harold O. is part of the “old guard” cloud seeding culture, while Danny R. is part of the new cloud seeding guard, one that has gone on to be a science superstar since his early work at the Hebrew University of Jerusalem under the leader of the Israeli cloud seeding experiments. He did some work there on the clouds of the Mediterranean and satellite interpretations of them (available in Hebrew only the last time I checked).
While Danny R was there during the time of the reporting of the benchmark Israeli 2 randomized experiment by the leader of the experiment (1976-1986) he himself was not involved in those (ultimately flawed) analyses. Later, he participated in the unraveling of the 2nd experiment with Israeli statistician, K. Ruben Gabriel in 1990, J. Appl. Meteor. Half of the 2nd experiment’s results had been previously omitted, an omission which produced an apparent, unambiguous “confirmatory” success of the Israeli 1 experiment, for the short of it.
The 1990 development in Israel, in essence a retraction of what everyone thought was an unambiguous cloud seeding success, plus the fall of the equally important, earlier benchmark randomized experiments in Colorado, at one time also claimed to have proved cloud seeding by the National Academy of Sciences (Malone et al 1973), were the primary reasons for composing the piece being posted today. You may also know that your very own Catalina “cloud-maven” was in Israel in 1986 for 11 weeks, in doubt of those “hard-to-rain” clouds that were being described by the leader of those experiments, resulting in “Rain from Clouds with Tops Warmer than -10° C in Israel”, (1988, Quart J. Roy. Meteor. Soc.). This was to some degree the first crack in those experiments. (Of course, I would say that!)
How could such glowing, but ultimately critically flawed journal papers appear ultimately involving hundreds of journal pages? What went wrong with peer reviews?
I attempt in this piece to describe in this piece how science is supposed to work, and these pretty amazing chapters of science in cloud seeding, and offered some possible solutions.
At one time, Prof. Peter V. Hobbs, named to write up a status piece on Clouds-Climate for the World Meteorological Organization (WMO) in 2003 or so, was going to use the “rise and fall” of the Colorado and Israeli experiments in this piece I have just posted. He was going to demonstrate how we scientists can think we have proved something, but upon closer inspection, find that we have not proved at all!
Peter Hobbs was concerned that the then many unknowns about clouds were not being treated properly in climate models (being parameterized too crudely), and therefore those parameterizations of clouds in climate models could lead to erroneous conclusions concerning the amount of global warming that might be ahead.
In his take on this MS, and that “rise and fall” section in particular, Peter, who was not one to dole out compliments very often said of it, “This is pretty good.” Peter had not reviewed it beforehand.
Ultimately, Peter contracted pancreatic cancer and was unable to submit his status summary to the WMO.
As well as some shots of that violent blast that hit the CDO HS and the area around Concordia Ave. One ALERT gauge reported 1.34 inches! Nice. The uprooting of trees wasn’t so nice, however.
Sutherland Heights whiffed again on rain, except for that little sprinkle just after 8 PM, sad to say.
4:37 PM. What a great looking pileus of Cumulus congestus with a little pileus veil at the very tippy top. This is heading toward being a Cumulonimbus calvus (remember, “calvus” means “bald”), the most ephemeral stage of Cumulonimbus. This stage doesn’t last long since its when the cloud droplets are disappearing because of the rapid formation of high ice particle concentrations inside the turret. Remember, ice and water don’t stay together long; water disappears, evaporates due to mixing of environment air around the turret, all that ice sucking the life out of those poor droplets since water vapor molecules love ice more than being inside a droplet when ice is around and they escape to the nearest ice particle, which then gets fatter and fatter, cannibalizing those droplets in a sense.
4:52 PM. Jumbo Cumulus congestus has congealed into a complex of Cumulonimbus clouds, riding the north wind that was about to sweep into the Sutherland Heights later in the evening.6:32 PM. WIth the gush of north winds, Stratocumulus and Cumulus bases quickly covered the sky, some piling higher into Cumulonimbus clouds.6:55 PM. Northerly wind and associated line of Cumulus above it grow into Cumulonimbus clouds. Very pretty scene. But tops not doing much here, so big dump not likely without something changing, which did! The older wispy turret above the larger rain shaft is already sinking back. The new shaft is coming out of the youngest, firmest looking turret.6:55 PM. Zoomed view of the top of turret where the new rain shaft is coming out. That bubble on the right side is just starting to show its ice externally, though grauple (soft hail) and/or hail were already hidden inside it as evidenced by that new thin rain shaft. Notice the younger turret behind it is higher, and therefore colder, and must also be full of precip. Watch out below! It doesn’t show the “softness” as the droplets evaporate in the presence of ice likely because its still on its way up, and condensation onto drops is faster than removal of vapor by ice. Watch out below, #2.6:57 PM. In the meantime, the Catalinas reap a nice sunset shower.7:08 PM. That new turret is now unloading around Ina and Oracle. Very exciting and a pretty scene, too, with the glow of the sunset. This storm was to go on for another hour.7:23 PM. Slightly out of focus, but you can see one of the MANY strokes of lightning that accompanied this tremendous downpour.
AZ mod (from 5 PM data last evening) thinks we have a chance for an afternoon dump today, Thursday.
7:21 PM, August 13th. A sky so full of portent that evening after a clear day. This our last chance for rain for quite awhile, but Sutherland Heights and Catalina whiffed on this incoming complex of thunderstorms. But, we had a fabulous light show from a cell that developed almost overhead, pf Sutherland Heights as dark fell, but a little to the SE, dumping heavy rains in the Romero Canyon/Pusch Ridge area.7:16 PM., August 13th. A very dramatic looking shelf cloud (Stratocumulus) spread across and otherwise completely clear sky that evening providing a great sunset photo op. Northerly winds of 25-35 mph and a temperature drop of about 10 degrees accompanied this scene.6:57 PM. The churning, roiling motion of this turret was remarkable, almost like time-lapse there was so much of it. That easily seen churning was evidence of how unstable the atmosphere was on this day. It was unusually cool for summer at 20, 000 feet or so above us. leading to a strong drop in temperature from the 100 F or so at the ground. So, as the warmer air that clouds represent relative to their surroundings, made them more buoyant than usual as they climbed upward; a hotter than usual hot air balloon, if you will, one that goes up faster. Stronger updrafts are thought to lead to more lightning compared with Cumulonimbus clouds having weak updrafts.3:57 PM, August 13th. Even slender clouds could shoot up and reach the “glaciation level” where the tops became comprised of only ice crystals, and sent long plumes of ice out from the parent cloud. The long trail of ice shows how much the wind increased with height at the top of this cloud. As that evening’s storm approached, all of the anvils from the many Cumulonimbus clouds that were approaching were mostly kept from view so that you couldn’t see them. This cloud also poses a naming enigma. Its got an ice plume, a very little rain fell out on the left side where Pusch Ridge begins, but no shaft is visible. It can hardly be called just a “Cumulus” cloud, and yet the more accurate label, “Cumulonimbus” with all of its attributes, makes one a little uncomfortable due to the lack of a visible shaft.
The End (of the cloud discussion)
New “not pubbed” item:
I’ve added RViewpoint_10-24-06_submitted date Aug 31, 2006_final, something that’s been sitting around for years! Spent a lot of time writing it, but ultimately deemed it a hopeless task that it would be published in the Bulletin of the American Meteor. Soc. under then current leadership in the weather modification domain of that journal, and ultimately never bothered to submit it. I was sick of the conflict, for one thing. Haven’t read this piece in years, either, but just wanted to do SOMETHING with it so here it is on this blog.
A longer piece, “Cloud Seeding and the Journal Barriers to Faulty Claims: Closing the Gaps“, also worked on again in spare time at home, for about two years, with the final rejection in 1999 under pretty much the same Bulletin editorial leadership. In this MS, I had a chance to get in, but the specific reviewer whose demands the Editor said I had to meet, insisted that I indicate in the manuscript that the lead scientists in the faulty published reports I wrote about “did the best they could under the circumstances” in the two early benchmark experiments, those in Colorado and Israel. I knew from direct personal experience that wasn’t true; I couldn’t write such a bogus statement that might have made the difference in “getting in.” So two years of on and off effort went down the drain. Sometime soon I will add this second futile effort to the “not pubbed” list! I have a number of those….. It didn’t help either that the two leading scientists whose work I questioned were also the two most beloved scientists in this field.
As with all but one of these pubs (Hobbs and Rangno 1978) in the domain of weather modification, they were done at home, outside of grant funding work while I was at the University of Washington in the Cloud and Aerosol Research Group. And, as I sometimes alert audiences to, working at home on stuff year after year. thousands of hours involved, could be considered a “crackpot alert”. Well, I think of myself as a “good crackpot.” haha.
Surfaris. Except it wasn’t funny. This song begins with a mocking laugh. Well, maybe “mocking” is correct.
Used 90 min of video on an “incoming” yesterday, thinking we’d get shafted pretty good as a thin line of heavy Cumulus congestus transitioning to Cumulonimbus passed over, maybe a quarter or more of an inch from both warm rain and ice processes1 in a line of clouds produced by the winds resulting from a strong fall of rain from a cell just north of Biosphere2. I am sure you were thinking the same thing and are profoundly disappointed today, not only by that one, but also by that Big Bopper that formed in the late afternoon around the same spot to the north-northeast of us.
10:33 AM. Icy topped cell has unloaded N of the Biosphere2 and a line of heavy Cumulus have formed above the outflowing wind boundary, creating a line of rain headed this way!10:49 AM. Outflow winds pushing nice, fat Cu up, and its getting closer raising hopes.11:16 AM. Good rain shafting moves into Saddlebrooke. I can feel the huge drops! MIght even be an all warm rain process shower, too, Wind shift almost here, though it is taking its time, I begin to think.11?39 AM. Shaft thinning by the second! Dammitall. Wind shift, rain drops still not here! This is now looking horrible. Cloud base above wind shift narrowing, falling apart, too. This could be the worst day of my life.11:58 AM. Rain, wind and wind have quit. Shaft is transparent, Code 1 maybe, easily seen through. 0.04 inches registered by Davis Vantage Pro Mark IV super-duper personal weather station.
Wished I’d copied that Wundermap of precip amounts at personal weather stations, but here they are, to reinforce the concept of a “wipeout“:
Wind blast here out of this event? Oh, maybe 12 mph.
What started out as a happy day turned sad in a hurry.
And this wasn’t the only “wipeout“! A worse one happened in the late afternoon that was far more excruciating; pain unbearable. A real explosion into gigantic Cumulonimbus occurred in a broken line, again in the area north of Saddlebrooke. It appeared one had produced a huge outflow for a time–probably was up toward the Biosphere2.
Some background. Here’s how it all started with a gargantuan line of Cumulonimbus and Cumulus congestus clouds in familiar broken line from just north of the Tortolitas to our northwest to north of Oracle to the northeast shown in the photos below, all taken at 3:43 PM. CMP wasn’t looking when this eruption of activity suddenly occurred, and seemed to happen elsewhere as well. May have been that afternoon temperatures just reached that higher point to send these big boys up there.
3:47 PM. Looking toward Tucson as this embarrassing formation arose, Cumulonimbus calvus erectus. This tall, slender cloud was incredible because it showed how great the instability was on this day. Fat clouds we know can rise up to become huge purveyors of rain, but narrow ones like this need a lot instability, lots of humidity around the growing turret so that it doesn’t evaporate, and a good updraft so that it doesn’t take to long to reach 30-35 kft level, as estimated here. So, it was real demonstration of the type of air mass we had this day.3:55 PM. Crushing rains are now dropping out of those behemoths to the N-NE. Surely a blast of wind will come shooting south toward us!
After feeding a horse on another property, I am racing back home to experience “The Blast”, and the rain in its full glory. I stopped to grab this photo, heart pounding.
4:12 PM. “Holy Criminy!” Look at this thing, and I can just now begin to see the arcus cloud forming (just to left of where dirt road disappears) on the nose of the winds coming at us! This will be incredible!4:24 PM. There she is! Arcus rolls toward Catalina pumping clouds up above it, though, you know, those clouds above the arcus don’t look as big as maybe they should. Some doubt begins to creep in.
The arcus cloud and the once proud Cumulonimbus cloud and its incredible rain shaft wiped out, the bottom of it vaporized if that’s possible by rainout, the wind push out of it unable to reach Catalina, in spite of an auspicious start. I now insert a picture of a horse, Zeus, to keep your interest up, maybe raise your spirits after such a debilitating cloud stories as are found here today. Animals, such as dogs, miniature horses and donkeys, are often used in psycho rehab units, especially for depressed persons, such as you are right now after reading this. So, I am really doing this horse insertion for my reader, whom I have depressed royally today:
Zeus, a Paint breed horse, 16.2 hands tall, eating. Has a pleasant disposition overall.6:09 PM. Some people no doubt had two or more inches fall on them from those storms north of us, and the day ended cool, humid and overcast due to multiple layers of clouds from Cu, Ac, and As from anvils, with isolated showers as shown here toward the SSW toward Tucson. It was nice to be outside, swatting gnats and such a minor nuisance.
The End (for August 3rd–falling behind more and more!)
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1As a cloud maven junior person, of course, you know what I am talkin’ about when I mention “warm rain” and “ice processes.”
Some apocalyptic cloud scenes can be Cumulus that explode suddenly into Cumulonimbus, and Cumulonimbus clouds with their foreboding (unless you live in a desert) rain shafts, and their predecessor shelf clouds like “swirly dark Stratocumulus”, and arcus clouds, the latter, a lower line of clouds just above and a little behind the wind shift at the ground, usually just ahead of the main rain shaft. While we didn’t get to see an arcus cloud yesterday, we had some dramatic swlrly dark Stratocumulus clouds to scare us. I say “swirly” because if you looked up yesterday evening as they passed over, you would have seen rotation in them.
These can combine, as they did yesterday, to make you think someone might drop out of the clouds and fix the world1. See those scary photos below, way below as it turns out.
This monster collection of Cumulonimbus clouds (“mesoscale convective system” or MCS in weather lingo) with swirly shelf clouds preceding it barged over Catalina later yesterday afternoon after it appeared that not much was going to happen all day. Heck, there wasn’t even a decent Cumulus over the Catalinas until after 2 PM!
The result of this system slamming Catalina was the usual strong preceding winds roaring down from Charouleau Gap way and points north or northeast. The winds were not as damaging as three days earlier.
Then the rain! So nice! Got 0.55 inches of rain here in Sutherland Heights, an inch and half on Samaniego Ridge, and 1.65 inches on Ms. Lemmon.
Worth watching is the U of AZ weather departments time lapse video, especially beginning at 2 min 50 s into it. That’s when the big group of Cbs begins to make its presence known from the east. What is interesting, and what I have not seen before, is that you will see the tops of a thunderhead farther west, that icy part up around 30,000 to 40,000 feet, shoved backwards (back toward the west) by outflow at the tops of the huge incoming system. Very dramatic.
Yesterday’s clouds
1:30 PM. Yawn. Its 103 F, dewpoint 60 F. Baby Cu begin dotting the Catalina Mountains.2:14 PM. Cumulus congestus finally arises within the local cloudscape. Looks like the top is high enough to convert to ice.
Detour: detecting ice in clouds….some practice shots
As the burgeoning cloud maven junior person you, of course, know how important the appearance of ice in our clouds is. You got ice; you got precipitation, which is snow up there, soft hail, hail, frozen drops.
2:19 PM. The declining right side of this cloud has ice in it, but its hard to detect for most observers. Only the BEST of the cloud-mavens could scream out, “there it is!”, before its more obvious to the less gifted CMJPs.2:22 PM. Well, too easy now to see that there’s ice in those little fingers extruding out from the body of the cloud; evaporation of the cloud drops has left the slower evaporating ice “naked” so-to-speak. It also in the higher turret, and would be termed a “calvus” topped Cu, properly, Cumulonimbus calvus, though not much fell out of this one, close to Saddlebrooke.3:31 PM. In the meantime while I wasn’t looking, Mt. Lemmon erupted sending a plume of cloud droplets, higher up, ice, skyward to at least 35,000 feet ASL. Indicated a phenomenal amount of instability afternoon, instability that was about to be realized in a line of mammoth Cumulonimbi.3:49 PM. “Eruption” just about over. Notice how skinny the root is now, AND that the top of the stem of convection is now only about half as high as in the first shot. Like a wild fire plume that has cooled off, the plume height goes down. Still formed ice on the right side, as you SHOULD be able to see. You should also be guessing that those were likely warmer habit crystals, like needles and sheaths. I did, if that’s any help.4:38 PM. Another cloud jack (Cumulonimbus eruption indicating a whole lotta instability), tops probably far above 40,000 feet. A lower portin of the anvil drifts southward toward Catalina. This one was dumping somewhere near the Biosphere 2 landmark. Note that anvil, lower right. That was our incoming major complex of Cum5:17 PM. WOW! This was magnificent, and just one of the many large Cumulonimbus clouds racing toward the Catalina Mountains. This is the one that in the video, the crown of it can be seen forcing the air over us in the opposite direction. Still, it was not certain at this time these storms would make it here. And, this is looking ESE, while the storm movement was from the ENE.5:25 PM. The “Menace of Charouleau Gap”. Many of our worst storms roll in from the ENE, toward Charouleau Gap, and many who have lived here will tell you and this is the archetypical seen for those storms. A sudden blackening of the sky beyond Charouleau Gap. These darker clouds are rarely the ons producing the storms, but are riding a strong NE wind surging toward Catalina, about to produce some mayhem. The winds always arrive before the rain. And, as a few days ago, there are times when ONLY the wind arrives, there is not enough instability aloft to allow the storms to drift past higher terrain without falling apart. On this day, they will make it.5:48 PM. I am going to work this scene over because it is associated with one of the more spectacular storm sequences here in Catalina, one that comes up usually a few times every summer. The anvil outflow aloft is thickening and lowering, and the outrider shallow Stratocumulus are racing out and along the Catalina Mountains. Things are changing incredibly fast and the NE wind is about to hit.6:05 PM. Walking the dogs to beat the rain, The NE wind has hit, the power line wires are howling. The sky continues to darken and look ominous, but….no rain shafts have come over the mountains, a cause for concern.6:21 PM. The shallow clouds ahead of the rain area continue to spread down and out from the Catalinas. A small opening in the clouds allows this dramatic highlight. I like highlights.6:22 PM. Let’s look a little closer at this spectacular highlight. Wow! This is just as good as a bolt of lightning.6:33 PM. Maybe time to get the Good Book out, cram for the finals…. This was really quite the sight, considering it had been so sunny just a couple of hours before. Again, these are fairly shallow clouds riding the outflow winds, now gusting 35-45 mph in Sutherland Heights. The mottled bases here indicate that there is no organized wide updraft to launch them into deep Cumulonimbus clouds at this moment, anyway.6:34 PM. Finally, a major new rain shaft emerges over Samaniego Ridge, upstream of Catalina!6:35 PM. Looks like more and more people are dropping off Word Press as these files are going in pretty easy now.Here, the apocalyptic cloud formation rolls down and out across Oro Valley, with heavy rain just to the left.6:43 PM. A rare sight, wind driven rain streaming off the tops of the foothills of the Catalinas. The winds were likely hurricane force (>64 knots, 74 mph) to do this. Samaniego Peak received 1.50 inches during this storm.7:21 PM. Sunset in Catalina, July 29th. The sun does not have a sharp disk, is rather blurry, because the light from the sun is being scattered by large particles like rain drops which bend the light so that we can’t see the disk’s outline. When its smog, the particles are of the order of micrometers and a sharp disk will be seen because the sunlight is not bent around large particles. I think Einstein said that…7:21 PM. Orange and rainy as sunset procedes as usual.
Only the largest hailstones up there can make it to the ground as such here in Arizona due to our high summertime freezing levels. The rest melt into raindrops, some of which are large enough to reach the ground. Those downpours that suddenly emit from cloud bases were always hail or graupel (soft hail) aloft.
Sometimes in deep stratiform clouds attached to clusters of Cumulonimbus clouds, and with especially moist air from the base of the stratiform layer to the ground, clusters of ice crystals we call snowflakes make it to the ground without evaporating as steady light or very light rain.
Last night as our storm was coming to an end, it is likely that THOSE drops were once snowflakes rather than soft hail or graupel.
The End (finally)
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1Huh. Maybe that wouldn’t be a bad thing. I am very concerned about microplastics (particles 5 millimeters and smaller) in our oceans, resulting from the breakup of larger plastic items we’ve been throwing in the oceans for decades. Seems those tiny particles are getting into everything, including the fish out there! It would be great if someone could get rid of them.
Lot of great scenes on the 18th, but, ultimately with hopes raised for appreciable measurable rain in Catalina, it was a disappointing day. Nice temperatures, though, for May if you’re a temperature person. Only a sprinkle fell (4:15 PM), and if you weren’t outside walking the dogs you would NEVER have noticed it.
Here is your full cloud day1, as presented by the University of Arizona Weather Department. Its pretty dramatic; lot of crossing winds, as you will see, and an almost volcanic eruption in the first Cumulonimbus cloud that developed near the Catalina Mountains.
That blow up was indicative of an remarkable amount of instability over us yesterday morning, one that allowed really thin and narrow clouds to climb thousands of feet upward without evaporating. Usually the air is dry enough above and around skinny clouds that even when its pretty moist, they can’t go very far without the drier air getting in and wrecking them (a process called, “entrainment”). Here are a few scenes from your cloud day yesterday.
5:45 AM. Gorgeous grouping of Altocumulus castellanus and floccus. They’re coming at you. (If you thinking of soft orchestral music here, you may be remembering well-known orchestra leader, Andre Castellanus.7:37 AM. Here a castellanus turret rises five to six thousand feet above its base. Had never seen one this skinny and THAT tall before. Was really pumped about the mid-level instability at this time. It wouldn’t last. The great height is indicated by the luminosity of the top,Also at 7:37 AM, another amazinging tall turret rises up from quiescent bases, ones not connected to ground currents. The bouoyancy in these clouds is due to the heat released when moist air condenses (latent heat of condensation). When the temperature drops rapidly with increasing height, that bit of heat released is enough to allow weak updrafts to rise great distances, sometimes becoming Cumulonimbus clouds and thunderstorms. These clouds, due to their size, would no longer be considered just Altocumulus andre castellanus, but rather Cumulus congestus. Here’s where our cloud naming system falters some. Later, a couple of these grouping did become small Cumulonimbus clouds with RW- (light rain showers).7:11 AM. The great height of these tops was also indicated by the formation of ice, that faint veil around the edges. Stood outside for a few minutes, thinking I might experience some drops, but didn’t.7:38 AM. The top of this Cumulus congestus has just reached the level where ice will form in the top.10:22 AM. Cumulus congestus clouds began their transitions to Cumulonimbus clouds early and often over and downwind from the Catalinas. Can you spot the glaciating turret in the middle, background? Pretty good skill level if you can.10:23 AM. Here’s a close up of that turret in rapid transition to ice. It was this kind of phenomenon that led Hobbs and Rangno and Rangno and Hobbs to reject the Hallett-Mossop theory of riming-splintering as THE major factor in ice production in Cumulus to Cumulonimbus transitions like these. The high concentrations of ice particles happened faster than could be explained by riming and splintering, or so it was thought. Still think that, but am in the minority, though there have been reports of inexplicable, fast ice development like that Stith et al paper (with Heysmfield!) in 2004 that for a time appeared to put the “icing on the career cake.” Incredible ice concentrations were found in updrafts of tropical Cu for which there was no explanation! That finding hasn’t been replicated by others, casting doubt on the whole damn paper! “Dammitall”, to cuss that bit.11:04 AM. Nice Cumulonimbus capillatus incus (has anvil) pounds up toward Oracle way. Tops are not that high, maybe less than 25 kft.3:41 PM. The air aloft began to warm and an inversion capped most of the convection causing the tops of Cumulus clouds to spread out and create a cloudy mid to late afternoon. Nice, if you’re working outside in mid-May. Since the tops were colder than -10 °C (14 °F) the ice-forming levels, some slight amounts of ice virga and sprinkles came out of these splotches of Stratocumulus clouds. One passed through the Sutherland Heights, but if you weren’t outside you would never have known it!4:38 PM. Isolated rain shafts indicate some top bulges are reached well beyond the ice-forming level. Note grass fire in the distance.7:22 PM. Pretty nice sunset due to multi-level clouds, some Stratocumulus, Altocumulus, and a distant Cumulonimbus anvil.
More troughiness and winds ahead during the next week as has been foretold in our models, and reinforced by weather “spaghetti” plots, after our brief warm up today. No rain here, though. Seems now like rain can only occur at the very end of the month where weaker upper troughs coming out of the Pac appear to be able to reach down and fetch some tropical air.
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1Its gone now because I couldn’t finish yesterday. Went off to Benson for horse training with Zeus.
Back to weather and yesterday’s microburst with three minutes of sheets of unbelievably heavy rain with rice-sized hail, 50-60 mph gusts, blazed across Sutherland Heights between 4:06 PM and 4:13 PM. It was a memorably violent storm, comparable in those worst 2 minutes or so to anything we see in the summer, and it was completely un-predicted for Catalina the day before (0% chance of rain here) though showers WERE predicted for the higher terrain of eastern AZ yesterday). For the full story, see Bob M’s excellent discussion. For just clouds and stuff, here is OK.
Looks like the Sutherland Heights got the most of anyone anywhere near here. No reporting station in the Pima County ALERT system in Catalina or in the Catalina Mountains got measurable rain, that’s how local our storm was. Rarely if ever do you see that happen.
Stuff blew everywhere and I felt lucky not to lose some branches of trees in the yard. Here’s yesterday’s cloud diary. First the background about what was happening, the TUS balloon sounding of the atmosphere:
The TUS sounding at 5 PM AST (launched around 3:30 PM). Classic inverted sounding associated with downbursts. Cloud bases are at 0 °C (32 °F) at 14 kft above sea level, or about 11,000 feet above us in Catalinaland. Lots of turning of the wind, too, helpful for stronger storms. So, rain and hail had a long ways to fall, cool the air, drag it down and blast the surface.9:43 AM. Castellanus of the morning. Patch Cirrus on top. Recall that in my cloud chart it says when you see this cloud, it might rain within 6 to 196 h. Pretty accurate yesterday since it rained about 7 h later here.2:11 PM. Cumulus were reaching mediocris stage around here while off to the horizon, Cumulonimbus tops could be seen over the higher terrain of the Mogollon Rim.2:11 PM. However, a single Cumulus congestus just past the Tortolita Mountains was transitioning into a little Cumulonimbus. Precip is fall out of that lofted flat side of the cloud to the left of the main base. What a surprise to see that! But it was clearly too small to do anything.
3:00 PM. However, those cloud over there kept shooting up turrets, becoming larger and larger until we had us a full blowed Cumulonimbus and something in the way of a rain shaft (Code 2, transparent, except for that one strand–almost certainly a hail or graupel shaft).3:54 PM. While CMP had to be inside for an hour, this surprise happened just to our SW, with rain falling on this side of Pusch Ridge! Wow, WHAT an interesting day this is turning out to be! Not only was there rain, but thunder! Didn’t think it would get here, well, maybe a sprinkle is all.4:02 PM. The rain shaft had gotten denser, and there are tendrils of heavier precip. Thunder is a remarkable every minute. Didn’t look vigorous enough for that kind of electrication rate. What’s really promising now is that darker round blob in the upper right hand corner of the photo indicating new cloud growth. That raining part of the cloud would hardly make it here even if it came right at us, given the light winds up there; needs to be replaced by new cloud growth. Was thinking now, “Gee, it might measure!” No thought of wind yet since that shaft looked kind of weak..4:04 PM.4:04 PM. Looked down on Catalina to see this remarkable site, a surface dust plume racing through town, rain just behind it! At this point you could see that it was going to blast the Sutherland Heights, so was a pretty exciting moment, and the rain was certainly going to be measurable if the gauge didn’t blow over!4:04 PM. Another view of this shaft just before the wind came roaring over the hill in the foreground. From the incredible but very short-lived torrential rain, Sutherland Heights must have gotten one of those narrow strands, but again it would not be one of those you see there, but something dropping out almost on top of us.4:06 PM. Here it comes, just over the hill. You can see the surface dust plume advancing north into Catalina where no rain fell!4:06 PM. Here’s something you rarely see, dust blowing off the little hills above the Sutherland Wash, Baby Jesus Trail area. Rain was just starting here.4:09 PM. Just about the peak of the rain shaft. Horsey retiree Jake shows that the wind si blowing away from the corral. The visibility is relatively high in this extremely heavy rain because the shaft was so tiny.4:09 PM. Just seconds later the shaft had moved a few blocks away and down the hill (whitish area running from left to right). Note expanse of blue sky in the background, too.4:13 PM. Storm is virtually over and here you can see the amount of water that came of the roof, and some wind damage (cushion out of place). Some cushions went down the hill.4:43 PM. The day ended peacefully enough with more Cumulus and distant Cumulonimbus clouds around. Great sunset scene of clouds over the Catalinas, but was enjoying live classic rock music at a friend’s house with some 50 others; no camera.
Too dry today for rain. Next chance for rain around the 17-19th as that bigger (but maybe drier) cold trough settles in. Temps will be nice, though. Lots of intermittent trough action indicated in 06 Z mod run through the rest of May, so May should continue to be pretty interesting and likely devoid of never-ending heat month as sometimes happens here. This scenario pretty well supported in those crazy NOAA spaghetti (or Lorenz) plots.
The End
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Photos not loading in WordPress now, so quiting here, dammitall! Must go on to other chores now. Not happy!
OK, photos finally went in. Happy now, though too many photos as usual.
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1I doubt that happened…. Really, this was a song about people who don’t like to go to work, kind of anti-capitalist which is ironic because it was that system that allowed the boys to make their millions (billions if they had invested wisely into Microsoft in the early 1980s) and gone on to help the world with their billions like Bill and Melinda.
Yesterday was another great humilis day for you, with quite a phase twist at the end. I am sure most of you out there saw the surprising final touch to a warm day with high-based shallow Cumulus.
11:52 AM.11:52 AM. Cumulus humilis and fractus over the Catalinas, in case you think I was hiding bigger clouds that might have been over the mountains.5:15 PM. 95 and 25, temperature and dewpoint. What is the height of the cloud bases above ground level given a 70 degree F difference? Hint: divide difference by 5 and that’s the hieight above the ground in thousands of feet. So they were way up there at about 17,000 feet above ground level!
Let’s see how close that using that old estimator technique was yesterday by examining the Tucson sounding for 5 PM AST (launched around 3:30 PM, goes up about 1,000 feet a minute). From the Wyoming Cowboys, this:
Wow! LCLP was 515 millibars, just about exactly at 17,000 feet. Also, look how darn cold bases were, almost -10 °C or 14 ° F, tops around -14 °C or just 7 °F, and yet we see no ice…yet.
6:06 PM. Which way is the wind blowing at cloud level? Ans: at you. Nice cloud street streaming off the Catalinas over Catalina. Clouds not looking so much like Cumulus humilis anymore but rather more like Altocumulus opacus. No signs of any ice…yet.6:09 PM. Hint of ice in this photo of clouds far downwind of the Catalinas (looking north over Saddlebrook and beyond. Can you find it?6:52 PM. By this time, there was ice EVERYWHERE! It was an amazing transition from cloud lurking up there with no sign of ice, to ice in almost every cloud. Have hardly ever seen such a dramatic transformation in clouds that seem to be unable to produce ice most of the day. What happened? I don’t know. But will guess. These clouds, part of a moisture slug moving around the big trough coming in, were actually being lifted in time so that minute by minute they were getting a little colder until ice concentrations suddenly onset. Ice seems to depend on droplet sizes (the larger ones freeze at higher temperatures, AND temperature, the same size drop will freeze as the temperature falls. In clouds like this, the largest droplet sizes were likely the same before and after the transition to ice, so one would guess that the temperature at which they would freeze was reached as the tops rose due to a layer being lifted, not because some tops were higher and colder. The transition was too widespread and affected small clouds as well as the larger groupings. Well, lotta handwaving here, but it was an amazing change that transpired last evening.7:07 PM. Noticeable virga is now dropping out of those clouds, ice concentrations probably up to a few to tens per liter!7:07 PM. Looking toward the Charouleau Gap. Icy looking cloud over there, too. What is going on?7:08 PM. Nice sunset, though. Ice barely visible at right.
While waiting for some rain in the days ahead, not backing off that in any way, though models generally have not had any (bad models!), will pass along a horse prank that happened.
Two days in the morning, as I went to fill “Zeus” water tank in the dawn hours, there was something dark at the bottom of it. I thought maybe some poor little animal or bird had drowned in his tank that night. I reached down, and found it was my State Park baseball cap! I had left it on the top of a panel, maybe above the water tank, wasn’t sure, so it likely blew off the panel into the water tank. But then again, I wasn’t sure that Zeus hadn’t put it in there on purpose.
But that was a crazy thought.
As a test, yesterday morning I decided to put the cap back on top of the end of a horse corral panel, but much farther away where it could not possible fall into the tank, just in case Zeus was telling me what he thought of me by dunking my cap.
9:41 AM May 4th.
Here’s what I found when I came back in the afternoon to feed Zeus:The same scene as the prior morning!
0.02 inches of it, anyway, as the core of the jet stream at 18,000 feet or so passed by Catalina yesterday afternoon. Keep your eye on the orange and reddish streak in these progs from IPS MeteoStar yesterday morning beginning at 5 AM AST and how it slides over us as the clouds began to ice up:5 AM yesterday. Jet at this level races across central AZ. 11 AM yesterday. Maximum winds getting closer! Tiny Cumulus clouds begin to appear over the Catalinas and on the west to north horizon.
11:40 AM.
The jet separates deep cold air on the left side, looking downwind, and deep warm air on the south side. The deep warm air prevents Cumulus clouds from getting very deep due to inversions and stable layers where the temperature does not change much with increasing height, or even rises. The temperature at 500 millibars or 18,000 feet above sea level dropped from -17.7 °C to -21.1° C over TUS yesterday between 5 AM and 5 PM, while the temperature about which ice begins to form in our clouds dropped about 400 meters during that time. With the temperatures at the ground rising into the mid-70s as the colder air moved over us, Cumulus clouds deepened, reaching the ice-forming level between 1 and 2 PM.
Also with patterns like this, the cyclonic rotation (vorticity) in the air above us is increasing like mad, and that leads to a gentle upglide motion in the atmosphere, one that also helps cool the air aloft and usually produces sheets of clouds like Cirrus, Altostratus, Altocumulus and NImbostratus. But yesterday the air was too dry for sheet clouds to form.
First ice was noted just after 1 PM. Can you find it?
1:11 PM. Looking N toward the Charouleau Gap. Tiny puff of ice ejects from a Cumulus humilis cloud based at about 8 thousand feet above ground level. Bases were running about -5 °C
2:31 PM. Cumulus and Stratocumulus clouds launched off Pusch Ridge and the Tucson Mountains stream toward Catalina. The sky begins to fill in rapidly.3:44 PM.3:49 PM.3:57 PM. A horse eating as it clouds up.4:33 PM.5:09 PM. Light rain falls in Catalina/Sutherland Heights.6:04 PM. RW- (light rain showers) continue in Oro Valley.
5 PM yesterday. Just passed! B y this time, Sutherland Heights had 0.02 inches as the tops of Cumulus and Stratocumulus complexes continued to cool and ascend. The sounding from TUS at 5 PM AST (launched about 3:30 PM AST) indicated the coldest tops had reached -20 °C or so, plenty cold enough for ice, virga, and light rain showers. Too bad the bases were so high since we could have had some real rain if they had been lower.
But, we were “lucky” to get that. Even the great U of AZ model had no rain anywhere near us late yesterday afternoon when it fell! THAT does not happen very often.
Looking ahead….today:
Nice Cu, ice, too.
Farther out:
Substantial rains, maybe half an inch or so, still on tap between May 6th-8th as previously foretold here. Yay! May averages 0.38 inches here in Catalina. More rain likely after that episode, too. So an above normal May in rain is pretty much in the bag now. Could be an especially great May, too.
The same scene as the prior morning!
5 AM yesterday. Jet at this level races across central AZ.
11 AM yesterday. Maximum winds getting closer! Tiny Cumulus clouds begin to appear over the Catalinas and on the west to north horizon.
