Cirrus clouds – Page 5

Unusual patterns in afternoon Cirrus and Cirrocumulus clouds

Started out clear yesterday. Below, an example of that completely clear sky in case you missed it.

10:06 AM. Clear skies are evident. HOWEVER, note shallow smog plume exiting Tucson and flowing northwestward across Continental Ranch where Mark Albright, lives. — 10:06 AM. Clear skies are evident as we look in the general direction of Baja California. HOWEVER, note shallow smog plume exiting Tucson and flows northwestward across Continental Ranch over there by Twin Peaks where fellow University of Washington meteorologist, Mark Albright, lives.

I think it is interesting that Mark would chose to live as a snowbird in a smog plume rather than here in Catalina where that Tucson smog plume rarely strikes. Its pretty regular down there because the normal morning wind in Tucson is from the southeast and that wind shoves the urban smog over to Mark’s house on many cold mornings. Pretty funny, really.

Yesterday’s clouds

In the mid-afternoon, a stream of patchy Cirrus was beginning to creep over us. If you don’t believe me, you can see it in the University of Arizona time lapse film for yesterday.

And, in those leading Cirrus clouds were some spectacular, stupefying really, complex patterns of cloud formation and and holes in them, ones like CM had never seen before except maybe that one time in Durango back in the 1970s. Here are some examples of those odd that were up there:

3:14 PM overview of Cirrocumulus and Cirrus clouds with oddities.

3:14 PM Close up of previous cloud scene. Note all the weird stuff going on.

3:22 PM. More oddities. Going crazy trying to understand what the HECK is going on!

DSC_0052-1 — 3:23 PM. Close up of rectangular “fringe.”

Started to breath a sigh of relief when this melange of complexity moved off rapidly worrying that someone might call and ask me to explain it. So, when some Cirrus uncinus and/or the rarely seen Cirrus castellanus came by I started to relax, feel confident again. Here are some of those pretty shots of little, icy clouds trailing light snow showers, likely, to repeat again, crystals called bullet rosettes. The ones in the part of the cloud from which they spew are likely tiny prisms, side planes, and tiny solid columns, thick, but tiny hexagonal plates with little fall speed, so those hang up there, while the favored ones in the best tiny updrafts in these clouds that resemble tiny glacial Cumulus clouds grow from those kind germ crystals into bullet rosettes, complicated crystals with multiple tiny columns sticking out of them. If you would like to read all about the crystals that form in high icy clouds like these you should spend some time browsing this paper, co-authored by the great John Hallett^{1 I really like footnotes}–yes, of the Hallett and Mossop riming and splintering mechanism, discovered by them in 1974. Helped explain why there was a LOT of extra ice in clouds that shouldn’t have it.

Here’s one more weird scene in Cirrus before moving on to something explicable:

3:43 PM. Holes, plops of downward moving air amid the Cirrus/Cirrocumulus. But why so round?

Thankfully, here’s what transpired next at Cirrus levels:

4:02 PM. Cirrus uncinus (one with tufts or hooks at the top and long streamers of ice below them) followed the strangely patterned sky.

4:03 PM. Look at all the larger ice crystals pouring out these little guys! Its amazing. Notice how FINE those strands are. Airborne work we did indicated that the cores were only a 5-20 meters wide!

4:20 PM. Reminded me of ballet dancers the way the clouds and the streamers were arranged. — 4:20 PM. Reminded me of a ballet the way the clouds and the streamers were arranged around one another.

4:17 PM. Just a little before the dancing clouds came by, there toward the Gap was this CIrrus castellanus mimicry of a full grown Cumulonimbus cappillatus. Look, it even has a tiny anvil spreading out! How fun was that to see! — 4:17 PM. Just a little before the dancing clouds came by, there toward the Gap was this CIrrus castellanus mimicry of a full grown Cumulonimbus capillatus (tuft in center of photo). Look, it even has a tiny anvil spreading out, to use the word “tiny” for the 18th time! How fun was that to see!

Of course, with all the patchy Cirrus around we were guaranteed a nice sunset and it did not disappoint:

Today’s clouds

Heavy ice clouds, several kilometers thick at times. We call that kind of fray, often full sky-covering layer, Altostratus. Likely some Altocu around, too. Will look now and see if I see any of those latter ones. Oops, too dark.

With clouds kilometers thick, tops at Cirrus levels, you can expect to see virga, and the chance of a few “sprinkles-its-not-drizzle” later in the day. The whole progression of clouds can be seen from the U of AZ model output from last night in these forecast soundings for Tucson. As per usual, the bottoms get lower and lower as the day goes by, but are still up around 13, 000 feet above Catalina by around sunset. So, will be tough to get a drop to the ground before then. U of AZ mod thinks all measurable rain will be to the south of us. Oh, me.

BTW, and this is an embarrassment, it was asserted by this keyboard that rain would fall in November at the outset of the month. This is the last chance for that! Egad. But forgetting that possible gaffe, moving ahead anyway to what’s going to happen in December (of this year).

The storms way ahead, that is, ones in early December.

Those early December storms for us are coming and going in the WRF-GFS runs. But I am counting on rain here in early December myself due to an interpretation of those weird in so many ways, “spaghetti plots.” I think they’re showing, and continue to do so, significant troughs coming through the Southwest in early December.

The End

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¹Later after the referenced paper above, and this is quite interesting, the great Hallett was to claim that me and Pete Hobbs had embarrassed² the entire field of airborne researchers due to a paper published by us way back in 1983 (J. Hallett, 2008, communicated by him during his presentation at the Pete Hobbs Symposium Day of the American Meteorological Society, New Orleans.

²But it was a good embarrassment, not a bad one due to incompetence, I think.

About ice-in-clouds and APIPs (or high temperature contrails)

6:55 AM. A surnrise glow from receding CIrrus spissatus highlights Samaniego Ridge. Very pretty and dramatic.

8:19 AM. Forming uncinus, CIrrus that is. Note trails of precip beginnng to form under these tufts of Cirrus castellanus clouds.

9:06 AM. Jet contrails begin to show up in a Cirrocumulus cloud. You know what going to happen.... — 9:06 AM. Jet contrails begin to show up in a Cirrocumulus cloud composed of supercooled cloud droplets. You know what going to happen….something special for you to log in your cloud diary.

9:20 AM. Another patch of supercooled, very supercooled Cirrocumulus with evidence of a jet contrail. But, is the jet above or IN the Cirrocu? TIme will tell. — 9:20 AM. Another patch of supercooled, very supercooled for that matter, Cirrocumulus with evidence of a jet contrail. But, is the jet above or IN the Cirrocu? TIme will tell.

How cold were those Cc clouds? See below.

(Begin technical module)

The Tucson balloon sounding for 5 AM AST, November 19th with writing on it. — The Tucson balloon sounding¹ for 5 AM AST, November 19th with writing on it. The height of these clouds was slightly lower in the mid-afternoon, but (as Altomumulus then) were still about -23 C. As we know, cloud bottoms almost always get lower with passing time because the higher parts of cloud shields are moving faster.

In the mid- -20s C, around -15 F. Height, about 21,000 feet above the ground here in Catalina. Hope you got that estimate of cloud height right.

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Continuing…

9:21 AM. ANOTHER jet streaks by! This is going to be darn interesting, a rarity, like see a grey parrot in Catalina! — 9:21 AM. ANOTHER jet streaks by! This is going to be darn interesting, a rarity, like seeing a grey parrot in Catalina! The secret about what height the first jet was flying at is beginning to be revealed. Can you see what’s happening to that first contrail a little below the new one? This is a great test to see how far you’ve come as a CMJ (cloud maven junior)!

Here’s what happened in the Cirrocumulus cloud layer in yesterday’s special day, a pretty rare one, after the jets flew through it:

9:30 AM. OK, mystery's over. Even the average CMJ Joe can see that 1) the jets were IN the Cirrocumulus cloud, and more importantly, the aircraft contrails consist of ice. Yes, that's right, the passage of the aircraft has caused a phase change from liquid drops to ice crystals, a lot of them. — 9:30 AM. OK, mystery’s over. Even the average CMJ Joe can see that 1) the jets were IN the Cirrocumulus cloud, and more importantly, the aircraft contrails consist of ice. Yes, that’s right, the passage of the aircraft has caused a phase change from liquid drops to ice crystals, a lot of them.

9:47 AM. Now those contrails are looking like real and icy Cirrus clouds. In this case they're called "ice canals" but sometimes, when aircraft are ascending or descending and do this, they make round clear holes with ice in the middle, called "hole punch" clouds. — 9:47 AM. Now those contrails are looking like real and icy Cirrus clouds. In this case they’re called “ice canals” but sometimes, when aircraft are ascending or descending and do this, they make round clear holes with ice in the middle, called “hole punch” clouds.

Lessons to be learned from yesterday’s supercooled clouds and the aircraft interactions inside them:

Cloud seeding works! You CAN make a supercooled, non-precipitating cloud produce a little precipitation that would not otherwise have occurred.

But in those situations where the clouds, say, are topping the Catalinas, they are often quite thin, and whether there is an economically worthwhile amount of precip is not known. However, an experiment targeting those clouds would be the perfect “baseline” one in cloud seeding to establish how much we can wring out of non-precipitating clouds. Things become kind of a mess when even randomized seeding takes on already precipitating clouds.

“Overseeding”, as here in these clouds when aircraft produce prolific numbers of ice crystals in a small volume, it leads to tiny ice crystals with low fallspeeds. Sure, they fall out and leave a hole, but they virtually never reach the ground except in one a in billion cases when the very cold clouds are real low, practically on the ground.

The Wegener-Bergeron-Findeisen mechanism produces precipitation.

Alfred Wegener, 1911, and later Bergeron³ and Findeisen in the 1930s, came up with the hypothesis that adding ice to a supercooled cloud results in the growth of the ice crystal at the expense of the droplets. They’ll tend to evaporate while ice is being added to the crystal via deposition of water vapor that was once liquid. So, an awful lot, maybe most of the precipitation that falls on earth, involves “mixed phase” clouds. This process has also been called the “cold rain process.”

However, let us not forget the two other processes that produce precipitation, the all ice process (no liquid required–helps produce “powder snow”, and the all liquid process, where cloud drops collide and grow into raindrops–the biggest measured drops in the world (about 1 cm in diameter) have formed soley through this process. It is likely that most of the rain that falls in tropical locations like the Hawaiian Islands and in hurricanes is due to this process even when ice is present in the top part of storms.

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Later, we had some Altocumulus castellanus clouds with virga as the moist level lowered, though they were long gone before they could provide us with a nice sunset:

2:32 PM Bands of Altocumulus castellanus approach from the west. These clouds, while based at just about the same level as the Cirrocumulus clouds earlier in the day had three things going to produce so much ice, and really, convert to Cirrus clouds. The cloud bases were slightly warmer, meaning more water was available to the cloud, the tops were higher and colder, likely around -30 C (-22 F), and perhaps as importantly, the drops near the top of the Ac turrets were larger than those in the earlier Cc clouds. The larger the droplets, the higher the temperature that they freeze at. — 2:32 PM Bands of Altocumulus castellanus approach Oro Valley from the west. These clouds, while based at just about the same level as the Cirrocumulus clouds earlier in the day had three things going for them to produce so much ice (right side of photo–and really, convert to Cirrus clouds). The cloud bases were slightly warmer (the TUS sounding suggests, -22 C), meaning more water was available to the cloud, something that would impact the drop sizes in the turrets of the Altocumulus clouds (left side of photo); 2) the tops were higher than the Cc clouds (ones that were paper thin) and therefore, slightly colder (probably about -28 C) than those of the Cc clouds, and perhaps as importantly, the drops near the top of the Ac turrets before they converted to ice, were larger than those in the earlier Cc clouds. The larger the droplets, the higher the temperature at which they freeze. So, ice is more likely to form in a cloud with larger droplets in it than one with tiny droplets in it even though they are the same temperature. That might explain the difference ice-forming behavior of yesterday’s very thin Cc clouds which mostly had no ice (until an aircraft came along in them) and these prolific ice-producing Altocumulus clouds, ones that converted to all ice. Just educated guesses here.

Still looking for scattered very light showers in the vicinity tomorrow as a Mr. Troughy goes by.

The End.

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¹Through the oral history tradition I learned while viewing the Washington Husky meltdown² at AZ stadium on Saturday from a Mr. Mark Albright that the Tucson weather balloon launch site has been moved from Davis-Monthan Airbase to the University of Arizona campus next to their weather department.

²Late in the proceedings, with about 2 min left and the Huskies starting a play, and in the lead, CM was visibly moved to jump up and say, “Don’t hand the ball off!”, as a gift to Arizona fumble occurred simultaneously. But, being bifurcated in his loyalties now that CM is in Arizona and not with the University of Washington, he had to be somewhat “glad” that the Cats maintained their somewhat suspect but great win-loss record.

³From the Historic Moments in Weather collection:

Tor Bergeron and CM meet in Goleta. His head was gigantic! No wonder he was so smart. CM, not so much. — Your Catalina CM and Tor Bergeron meet for the first time in Goleta, CA, in 1968 at the headquarters of North American Weather Consultants. Yours for $2,100 dollars, today only. I remember thinking that his head was gigantic! No wonder he was so smart. CM, not so much.

Dull cool day and blog, book-ended by a nice sunrise and a nice sunset

Here we go…..some pretty, but also dull, photos, along with some novella-sized captions as mind wandered into the obtuse while writing them.

6:44 AM. Nice sunrise due to Altostratus/Cirrus ice clouds.

2:00 PM. Stratocumulus topped Samaniego Ridge most all day, but was too warm to have ice, and droplets too small to collide, stick together, and form misty drizzle. Misty drizzle? Could be a great name for a late night female vocalist. — 2:00 PM. Kind of a dull day yesterday, kind of like this blog. Stratocumulus (Sc) clouds topped Samaniego Ridge most of the day, below that gray Altostratus ice cloud layer. But those Sc clouds were too warm to have ice in them, and droplets were too small to collide, stick together, and form misty drizzle. Have to get to at least 30 microns in diameter before they stick to one another. Misty drizzle? Could be a great name for a late night female vocalist doing earthy songs like Earthy Kitt back in the ’50s. “Earthy” was much hotter than global warming.

3:29 PM. An Altostratus translucidus mostly ice-cloud with a dark patch of Altocumulus droplet cloud blocking the sun. If you look closely, you can see a that there's this Altotratus layer may be topped by a Altocumulus perlucidus droplet cloud layer. Yes, droplet clouds at the top of As where the temperature is lowest? Yep, happens all the time, up to about -30 --35 C. Been there, done that, in aircraft research. — 3:29 PM. An Altostratus translucidus to opacus, mostly ice-cloud with a dark patch of Altocumulus droplet cloud blocking the sun. If you look closely, (upper center) you can see a that there’s this Altotratus layer may be topped by a Altocumulus perlucidus droplet cloud layer. Yes, droplet clouds at the top of As where the temperature is lowest? Yep, this counter-intuitive finding happens all the time, up to about -30 C -35 C. Been there, measured that; in aircraft research. Ma Nature likes to form a drop and have it freeze before forming an ice crystal directly from the water vapor.

4:40 PM. — 4:40 PM, shot taken as we entered a local restaurant. You’ve got your two layers of Altocumulus, with some Altostratus translucidus above those, filling in the gaps. Gaps? Huh. I am reminded that I have a failed manuscript about “gaps”, these kind; *Cloud Seeding and the Journal Barriers to Faulty Claims: Closing the Gaps*., rejected by the Bull. Amer. Meteor. Soc. way back in ’99. It was an instruction manual, in a sense, about how to prevent all the bogus cloud seeding literature that got published in the 1960s through 1980s, and was not only published, but cited by our highest national panels and experts, like the National Academy of Sciences. Amazing, but true. I give examples. You can read about this chapter of science in Cotton and Pielke, 2007, “Human Impacts on Weather and Climate”, Cambridge U. Press, a highly recommended book. That cloud seeding distortion of cloud seeding science was due to many factors, of which perhaps the primary one was, “nobody ever got a job saying cloud seeding doesn’t work¹.” This was a great segue. Of course, we have similar stresses on those researchers looking for effects of global warming nee “climate change” now days. Nobody will ever get a job (a renewed grant) saying they can’t find evidence of global warming, “Can I have some more of that money to keep looking?” And beware the “Ides of March” if you criticize published work in that domain! Think of poor Judy C , a heroine to me, and how she’s been vilified for questioning climate things.

5:29 PM, took leave from Indian food there in R Vistoso for this. Its not just anyone who would excuse himself from dinner to do something other than visit the laboratory.

That’s about it. No use talking about the rain ahead again. Seems to be a couple chances between the 20th and the 30th.

The End

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¹You can make a cloud snow a little by seeding it with dry ice or silver iodide. This has been shown since the earliest days of experiments. Below, to demonstrate this, an aircraft inadvertently “seeded” this Altocumulus cloud layer. However, whether the small amount that falls out from previously non-precipitating clouds is economically viable is not known. Increasing precipitation due to seeding when the clouds are already snowing/raining has not been satisfactorily proven. As prize-winning stat man, Jerzy Neyman, U of Cal Berkeley Golden Bears Stat Lab would tell you, you need a randomized experiment and followed by a second one that confirms the original results, with measurements made by those who have no idea what days are seeded and evaluations done by those who have no vested interest in cloud seeding. Wow there’s a lot of boring information here. Getting a little worked up here, too.

Ice canal in supercooled Altocumulus clouds, bases -23 C, tops -25 C (from PIREPS). — Ice canal in supercooled Altocumulus clouds over Seattle, bases -23 C, tops -25 C (from PIREPS). Photo by the Arthur.

Continuing…..

Beginning where we left off in our last chapter….that rain foretold here by the (affectionately) US WRF-GOOFUS models back a few days ago for the 19-21st for us only remains a possibility if you’re Canadian:

Valid at 5 PM AST, November 19th. Rainy system strikes Cal, on doorstep to AZ. You got yer subtropical jet stream crashing into the coast over southern Cal, a nice low off SFO, and plenty of rain predicted as far south as Los Angeles.

Valid at the SAME TIME as the Canadian GEM model above, 5 PM AST on the 19th of November! This is a horrible prediction by our own best model, because it robs us of our rain! For rain here in the cool season, we have to have the jet stream over or to the south of us here in Arizona, and here the jet stream is over Oregon! There is no low off Frisco! No "Waterworld1" here — Valid at the SAME TIME as the Canadian GEM model above, 5 PM AST on the 19th of November! This is a horrible prediction by our own best model, because it robs us of our rain! For rain here in the cool season, we have to have the jet stream over or to the south of us here in Arizona, and here the jet stream is over Oregon! There is no low off Frisco, either! No “Waterworld1” here.

Areas of rain predicted for the 6 h preceding 5 PM AST November 19th by the US WRF-GOOFUS model. The low pressure center, rather than off Frisco, is way up there by Annette Island! Or is maybe that one inland in B C.

So, with “model divergence” like this, what’s a poor meteorologist to do? Well, here, at least, we go with the Smokers¹‘ version absolutely. Look for a chance of rain here in Catalina land on the 19th-21st window, as has been suggested here a few days ago, and for that reason alone we are “staying the course” as President’s like to say. We’re not here to give you necessarily the best forecast, but rather a consistent one. So, in conclusion, look for clouds and a chance of rain around the 20th. Furthermore, to maintain consistency and build confidence in the reader by avoiding the emotional distress caused by “fluctuating forecasts”, we might be forecasting rain right up until it doesn’t happen!

—–Temperature note, or “Egad!”———

Got an e-mail from local pal, Mark A., that the -27 F recorded in Wyoming a couple of days ago was the lowest temperature ever recorded in the State for the whole month of November! How could that be? It was only 12-13th of the month! Incredible. Weather, global warming or not, are truly amazing!

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Yesterday’s clouds

Here are a couple shots of the Cirrus clouds we had yesterday and thge day before, so the header is not accurate. Not much going on lately, but those Cirrus clouds did make the sky pretty at times before racing off toward the eastern horizon.

6:39 AM November 12th. Cirrus clouds add color to the morning sunrise.

9:46 AM. But which day? This is a surprise quiz for those aspiring to cloud mavenhood.

The End

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¹Movie buffs of course, recall the great Kevin Costner movie, “Waterworld” and know that the villainous “Smokers” in that movie were Costner’s subtle nod to Canadians who smoke a lot. Pretty funny, really. I can’t believe all the pop culture information you get here! Its pretty incredible.

¹I put in a second “1” footnote in case you missed the first one.

While waiting for S, the (NASA) Diary of the Great O

While waiting for the remnants of former H. Simon to pass over us during the next couple of days, bringing some rain, starting overnight, got distracted while looking to see how many rainfall measuring stations they have in Baja Cal, and found this about the Great O from NASA. Its a pretty fascinating read I thought, which you will also find fascinating. Sure, intense hurricane O’s floody remnants missed us here in Catalina/Tucson, but it did produce some prodigious rainfall on its path across Baja and points northeast from there into NM. NASA’s Tropical Rainfall Measuring Mission (TRMM) radar estimates that over the ocean off southwest Mexico that about 33 inches fell over a ten day period while O was meandering around down there with some other disturbances, probably raising sea level that bit. And up to 5 inches per hour was falling in rainbands as it entered Mexico from the Gulf of Cal! O was deemed the strongest hurricane (tied with 1967’s Olivia) to ever hit southern Baja since sat images became available.

You will also see reprised in the “Diary of O” the huge rainfall totals that were expected in the TUS area but rains that missed us, the sad part of the story for some folks, who we will not mention. But, as Carlos Santana said, “Those who do not know history, are doomed to repeat it.”

For that reason, in view of the prodigious rains predicted in southern AZ again, but to the west of us, I thought we should be prepared for disappointment by recalling O’s “terrible” miss for TUS.

Here are some graphics from our very fine U of AZ Weather Department’s Beowulf Cluster computer outputs from just last evening at 11 PM AST, ones that can be found here, in case you don’t believe me again, a seeming theme around here. First, when the computer model thinks it will start raining, Figure 1, and in Figure 2, the expected gigantic totals expected along and near the US border where we really shouldn’t go unless you 1) go in an armored vehicle of some kind, 2) make prior arrangements with the appropriate ruling Mexican drug cartel for that part of the US that you just want to visit some rain, nothing more:

Figure 1. Valid for 2 AM AST tonight. The leading edge of the rain has reached Catalina. You might want to stay up for that. That wet desert aroma as rain begins is so awesome!

Valid for 3 PM tomorrow afternoon. One small area around Organ Pipe National Park is forecast to exceed TEN inches by then! — Figure 2. Valid for 3 PM tomorrow afternoon. One small, mountainous area around Organ Pipe Cactus National Monument is forecast have more than TEN inches by then, likely slowing the amount of incoming drugs. Organ Pipe Cactus NM is a US national park that you are warned not to visit, or if you do, you might be shot or have some other untoward happenstance if you go hiking. So you probably shouldn’t drive down there to see this once in a century rain. How sad is THAT?

Right now, as of 4 AM AST on Thursday, this model thinks Catalina and vicinity will get less than half an inch. Be prepared for more, though, rather than less. Note the streamer of heavy precip associated with Simon in Figure 2. Well, recall that O’s heavy precip streamer was going to be right over us, but then shifted eastward in the models and in real life at the last minute. The above prediction would only have a bit of a “westward bias” (the real streamer is EAST of where its shown now) to give TUS and vicinity a memorable, drenching October rain. This is what occurred with O’s streamer of torrential rain which was expected to pass over TUS, but ended up a little east of us. So, anyway, given all the little uncertainties in model predictions at this point, the watchword here is “watch out” which is actually two words. The view from here, incorporating a positive rain bias as you know, is somewhere around an inch for Catalina. The grassy green is gone, most annuals in serious wilt or crispy now, but could an inch bring some green back? Clueless on that score.

Yesterday’s Clouds

6:06 AM. Nice Cirrus sunrise. — 6:06 AM. Nice Cirrus sunrise, maybe some Cirrocumulus at far right, and off on the left horizon.

5:05 PM. Altostratus translucidus with an Altocumulus layer on the horizon.

5:07 PM. A “classic” view of Altostratus translucidus (sun’s position can be discerned through it), and here, an all ice path to the sun. Liquid cloud elements would appear as dark flakes, or would obscure the sun’s position. Sounding indicated that this layer was 26 kft above the ground in Catalina!

The End.

Dial “O” for rain; Odile that is

Unless the younger folks watch Turner Classic Movies or something like that, they will be clueless about what ther the reference to “dialing” is in the title. Oh, well. Heck, who even remembers what a Walkman was these days?

The heavy cloud shield of TS Odile is moving in with some light, spotty rain hereabouts right now. It will be interesting to see if today’s rain amounts to anything. Seems it could be a very Seattle-like rain day with those heavy layer clouds over us (Nimbostratus/Altostratus) and intermittent very light rain all day. Boring! (Is “boring” with an exclamation mark an oxymoron of sorts?)

NWS is excited about Odile, as any meteorologist not having snow in his veins would be, and have posted some daily rainfall records for this week. Of course, we’ve already set some rainfall records for September; can it happen again? They seem to be concerned about that possibility. Many of those September records, as many of you will remember I am sure, were associated with tropical storm Norma that busted into Arizona in early September 1970 as you will see¹. Workman Creek got 11 inches in one day back then. You can read about Norma’s doings here and whether the NWS forecasts were adequate.

The meteorological situation was very different with Norma, and that may be why we precipophiliacs could be “disappointed” by rain amounts with Odile–Norma had help from the configuration aloft; Odile not so much. However, in the days following Odile’s passage, that upper level trigger does fall into place over southern Cal, and we’ll have to watch out for some big thunderstorms in the couple of days AFTER Odile goes by when that upper level trigger (trough) still has some tropical air to work with. So, some really “interesting” weather ahead, the kind of weather we’ve forgotten can happen here in the many droughty years we’ve had lately.

Here, just hoping for some nice steady rains, not just sprinkles, that add up to something significant like a half an inch or more, keeping the desert green that bit longer, and maybe, some good scattered thunderstorms for a few days after the big cloud shield of Mr. Odile fades away. That will pretty much do it for our summer rain season I’m afraid.

Now, since we don’t like to do work that can be done better by others, these ones and this one, for example, so on to yesterday’s pretty cloud pictures. (Can’t get over the thought I might be disappointed in Odile’s rain here, expectations not real high, so don’t want to express them and make you a little sad; keeping a lid on thoughts of a big Odile rain for Catalina, don’t want to get too manic, etc.) Will just lay back and enjoy it…whatever comes.

Yesterday’s clouds²

10:00 AM. Cumulus development looked promising in the mid-day hours, but none over the Cat Mountains produced ice. Was surprised that didn't happen. — 10:00 AM. Cumulus development looked promising in the mid-day hours, but none over the Cat Mountains produced ice. Was surprised that didn’t happen. Note glistening rocks dur to the recent rains.

: 11:59 AM. Towering Cumulus and Cumulonimbus clouds begin lining the International border. Warning: adult commentary included in photo, the kind you see every day on TEEVEE.

1:18 PM. High cloud shield from Odile’s advance creeps over Tucson from the south. Cumulonimbus clouds can be seen in the extreme distance.

4:06 PM. Cirrus and Altostratus have overspread the sky, and the darkening to the S-SW looks ominous in view of Odile’s approach after wrecking southern Baja.

Followed by a great sunset, one deserving of more than one example. No details, just enjoy.

The End

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¹The present Arthur was in Durango starting his first job as a weather forecaster for the great Colorado River Basin Pilot Project, a randomized cloud seeding experiment, when Norma’s remains hit and flooded the Animas River there. I was inside a vaudeville theater listening to the rain pound on the roof, the audience of that melodrama, too, distracted a time or two, and also being distracted by Durango school teacher, Janet James, whom I had taking a liking to. She was there that night, too, but not with me. Wonder what happened to her?

²Caution: one photo is annotated with adult humor.

Summer thunderama returns to Catalina for a day

Against the deepening blue skies over us as the sun continues its descent to overhead of the Equator, coming right up (September 22nd, AZ time), our late summer Cumulus and thunderheads become even more spectacular. You can see the whole cloud day here, courtesy of the University of Arizona, if you would like to avoid the tedium of examining photos and captions by yours truly.

I got very excited about a small thunderstorm that took shape almost overhead of Sutherland Heights, and you know what that means. Yes, too many photos of almost the same thing! See below. Captured it, too, BEFORE it even started to rain, or even thought about it. Produced a large number of cloud-to-ground strikes in the vicinity, too, more that you would expect from such a small storm. Also, if you could see them, you saw repeated split strikes, ones in the core of the rain, and at the same time a branch in clear air to the north, a mile or two quite a ways from the rain shaft. I had not seen that before happen over and over again. Samaniego Peak reported the only rain, 0.28 inches, in the ALERT Catalina Mountain gauges, like twice that in the core of the shaft.

Then, of course, we had a lot of LTG in the early evening and nighttime hours to the NE-S-SW as storms marched across Tucson, Marana and Oro Valley. Missed us, though. A place in Avra Valley got an inch.

That’s pretty much it for your cloud and weather day yesterday. Farther below, the details….

Mods see nothing for a couple of days, until Monday, when the moisture from now Hurricane Odile begins to work its way into AZ.

Yesterday’s clouds

10:30 AM. After a completely clear morning, Cu began to pop up around 9:30 AM. This size by 10:30 AM gave hope that the day would have full Cumulonimbus clouds later on.

DSC_0016-1 — 3:26 PM. Just a pretty scene. Note the contrast between the blue sky and the white glaciated top of this Cumulonimbus calvus. Note too, that there is only a faint rain shaft underneath (behind ridge top, that smoother area).

DSC_0022-1 — 3:48 PM. Here’s where you and me saw a lot of rain promise in this developing cloud base on our nearby mountains. Almost every cloud that had this much base or a bit more, eventually rained. Maybe it would explode into something really big with powerful winds! Well, “really big” didn’t happen, but it did do its job with nice, but small rain shaft a little later.

DSC_0036-1 — 4:01 PM. Excitement builds as base grows a little wider; rain excitement is now guaranteed. I can only imagine what you were thinking when you saw this, and how happy you were since it could lead to a nice rain on you. LTG and wind, just ahead.

Ann DSC_0038-2 — 4:05 PM. Bottom beginning to drop out now!

DSC_0039-2 — 4:06 PM. Graupel and/or large drop strand (center) just began to appear (look hard). This was taken just after the first cloud-to-ground strike near Samaniego Peak (center).

DSC_0045-1 — 4:11 PM. The gush reaches the ground amid frequent split cloud-to-ground LTG strikes, ones near or in the core, and repeated strikes a mile or two to the right in clear air.

4:17 PM. Our little rain shaft offered up a lot of wind, probably in the neighborhood of 50 mph, judging by the spread of the rain “plume” on the ground to the right. Some drops and gusty winds of 20-30 mph reached Sutherland Heights soon after this, making for an especially pleasant evening outside.

DSC_0089-2 — 5:42 PM. An isolated thunderstorm, rumbling to the west of the Tortolitas yesterday evening , offered up this dramatic shadow scene.Its remnant providing a sunset highlight.

DSC_0114-1 — 6:37 PM. The remains of the thunderstorm shown in the photo above provided a nice sunset highlight as they so often do.

Cloud stories, continued

Our last cloud chapter was rudely interrupted by drought, with the last “rain”, an embarrassing one, of just 0.01 inches here in Sutherland Heights a week ago. Areas around us, of course, got more.

6:40 AM. "Etched glass" Cirrus. — 6:40 AM. “Etched glass” Cirrus fibratus. The flocculent patches (center right) are newly formed ones in which the larger ice crystals that are falling out of the stranded regions, have not yet gotten big enough to fall out, but they will follow that same course.

7:08 AM. CIrrus radiatus, or at least the perspective makes it LOOK like its converging in the upwind direction. — 7:08 AM. CIrrus fibratus/uncinus radiatus, or at least the perspective makes it LOOK like its converging in the upwind direction. Had to pull off for this shot, it was SO NICE!

1:32 PM. Surprise of the day was seeing real Cumulus clouds forming over our Catalina Mountains underneath patchy Cirrus and Altocumulus clouds. — 1:32 PM. Surprise of the day was seeing real Cumulus (mediocris) clouds forming over our Catalina Mountains underneath patchy Cirrus and Altocumulus clouds. Note the rarely seen pileus cap cloud, indicating a good updraft.

1:32 PM. Close up of the rarely seen pileus cap cloud. Would really like to have been in it, and then feel the bump when the Cu top rises through it!

2:04 PM. Nice to see some unexpected shafting around, even if they were weak, indicating the tops were not terrifically high. With bases at the freezing level yesterday (14 kft above sea level), ice would not form until lower than normal temperatures, maybe around -15 C (5 F), but then would increase with each lower temperature. Here guessing were likely around -25 C, 25,000 feet or so above sea level due to the weakness of the shaft. Got a higher later. Very iffy discussion here, but that's what CMP thinks. — 2:04 PM. Nice to see some unexpected shafting around, even if they were weak, indicating the tops were not terrifically high. With bases at the freezing level yesterday (14 kft above sea level), ice would not form until lower than normal temperatures, maybe around -15 C (5 F), but then would increase with each lower temperature. Here guessing were likely around -25 C, 25,000 feet or so above sea level due to the weakness of the shaft. Got a higher later. Very iffy discussion here, but that’s what CMP thinks.

4:31 PM. Evening closed out with R--- ("triple minus"--hardly noticeable RAIN not drizzle, please) from mid-level clouds, Altocumulus being the lower, lumpy gray patches, and Altostratus Cumulonimbogenitus, being the one producing the sprinkles, not drizzle. — 4:31 PM. Evening closed out with R— (“triple minus”–hardly noticeable RAIN not drizzle, please) from mid-level clouds, Altocumulus being the lower, lumpy gray patches, and Altostratus Cumulonimbogenitus, being the one producing the sprinkles, not drizzle.

Today’s weather….

Well, its no fun telling folks what they already know, but will say it looks tentatively, relying on the U of AZ 11 PM AST run of last night, like a day similar to yesterday, except a cloudier morning, which I just saw was the case by looking outside right now at 5:49 AM. Cu develop, tops should get cold enough to produce ice-hence-rain and shafting. Hope its measurable today. Also, as you know, moisture levels increase over the next couple of days with substantial rains likely.

In a model curiosity, three consecutive runs of the US WRF-GFS model, beginning with the 5 AM AST, 11 AM AST, and 5 PM AST runs, all from yesterday, had the remains of tropical storm Norbert passing directly over San Diego with substantial rains there. What made it even more likely to happen was that the Canadian model run from yesterday’s 5 PM AST global data, ALSO had the remaining little center of Norbert passing over San Diego, Tuesday, September 9th! Amazing since Norbert is such a tiny feature in our models, at least by the time it gets near San Diego.

As reported here, a month or so ago, the newly discovered oscillation in ocean temperatures, called the “California Niño”, is helping to keep Norbert going longer as it trudges to the NNW just off the Baja coast. Water temperatures off Cal are warmer than usual this summer due to weak onshore flow for the past few months. When the flow is normal, it not only sculpts plants and trees along the Cal coast, but also causes upwelling of COLD water, horrible for beach goers.

Below, examples of wind sculpting¹:

Wind sculpted at Bodega — Bodega Bay, CA, just north of Frisco, that windy, foggy, “Stratus-ee”, and cold summer city. Note Stratus in the background hwew.rolling in off the cold offshore waters. No summer thunderstorms here! Imagine how awful it would be to live at this spot. Winters are pretty nice, though, often with frequent rains and wind….to balance things out some.

The End.

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¹When a realtor shows you property with scenes like these around it, you don’t want to buy there, even if its not windy that day. If you’re a realtor, you’d want to have bushes and trees like this trimmed up real good. hahaha.

Some recent clouds that have floated over Catalina, AZ

Many of you are starved to see some low clouds rather than a few Cirrus or Altocumulus clouds under a blazing sun, about 27 million degrees F in the core, only 10,000 F at the surface we call the “photosphere”, what we see up there. (And you think its hot in Arizona!)

So, I thought I would provide some relief in this time lapse video of the clouds of Seattle from yesterday, as provided by the University of Washington’s Weather Department. You’ll see some great Stratus, maybe some Stratocumulus, and later, little bulging Cumulus that rise up to as much as 5,000 feet (!) above the ground. Maybe some of your neighbors are temperature refugees in Seattle now, so it will be great to see what they are experiencing and logging in their cloud diaries. And, we’ll be checking this day when they get back, for sure.

The current dry spell begins to fade as the days go by now.. In the meantime, since this site is mainly for the display of pretty clouds and not of any other value, here are some shots from the past few days. Have left the captions for you to formulate in silence.

Best not to do too much with this caption.

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The End.

A day with Cirrocumulus, Cirrus and Cumulus; summer rain season looks to start on time

What a day, Mr. and Mrs. Catalina, except for that last second “header”:

7:57 AM. Cirrocumulus with exceptionally fine granulation (left center). You might feel a little chop if you were flying in it, but it would be hardly anything. More chop, lower right, where you have something akin to ocean waves rolling along from left to right.

8:04 AM. Pretty Cirrus fibratus (strands are pretty straight in Ci fib).

4:47 PM. Pretty scene over the S-Brooke population complex. — 4:47 PM. Pretty Cu humilis and fractus scene near the S-Brooke population complex.

5:05 PM. Nice shadow bounding the Catalinas, — 5:05 PM. Cu hum and fractus over the Catalinas, Nice shadow bounds the mountains I thought.

The weather way ahead, 10 days and beyond; dreaming green pixels

Rain showing up around these parts beginning overnight on July 3rd-4th, kind of a normal time for a summer rain season onset. This from last evening’s global model crunch. Prior model runs have been dry, so it could be bogus, of course. But, its a hopeful sign. Rains every day after that in this run. Below, the titillating start as rendered by IPS MeteoStar:

Valid at 5 AM AST July 4th. Green areas show those ones where the model has calculated some rain in the prior 12 h.

Valid at 5 PM AST July 8th. Raining all over Arizona by this time. How great would that be? Com'on model! — Valid at 5 PM AST July 8th. Raining all over Arizona by this time. How great would that be? Com’on model! Don’t let me down! A feel a really old song coming on about being let down.

Let’s look at some spaghetti and see if the “solution” above has any credibility at all:

Valid at 5 PM July 4th. Note gaps in red lines in northern Arizona and NM. Errorful mod runs are therefore pretty confident the necessary ridge of high pressure aloft WILL be centered to the north of us. So, there is a fair amount of confidence from spaghetti that the summer rain season will start pretty much on time. — Valid at 5 PM July 4th. Note gaps in red lines in Arizona and NM. Errorful mod runs (deliberately so, recall) are therefore pretty confident the necessary ridge of high pressure aloft WILL be centered just to the north of us at this time, extruding all the way from the central Atlantic. So, there is a fair amount of confidence from spaghetti that the summer rain season will start pretty much on time. What’s also supportive is the bulge in the jet stream to the north in southern Canada, as indicated by the bunching of those bluish lines. Pac NW looks cool and rainy with this pattern, BTW. You can enjoy more spaghetti here.

So, right or wrong, you heard it here first because I got up early; summer rain season looks to start on time.

The End.

Yesterday’s clouds

Today’s clouds

The storms way ahead, that is, ones in early December.

Yesterday’s clouds

The End

Yesterday’s Clouds

Yesterday’s clouds2

The End

Yesterday’s clouds

The End.

The weather way ahead, 10 days and beyond; dreaming green pixels

Yesterday’s clouds²