Virga – Page 2 – Cloud-maven

Rare “Geo-Astro-Meteo Conjunction” captured on film!

Well, it used to be film….

Blobs of sprinkle clouds pummeled Catalina yesterday beginning soon after 12 Noon and ending only after 7 PM when an extraordinarily rare “Geo-Astro Meteo Conjunction” (GAMC) was observed due the conjunction of a rainbow, a moonrise exactly over Mt Lemmon, and the top of Mt. Lemmon itself visible through rain. The GAMC “trifecta” scene, is thought to occur only once every several hundred years. The duration of yesterday’s scene was about 3 minutes, the cloud with the rainbow having produced a sprinkle here just prior to the rare scene. Only more rare than the GAMC is a sunrise exactly over the crest of Mt. Lemmon with a rainbow in the direction of the sun.

Three sprinkle periods were recorded yesterday, the longest between 5:43 and 5:45 PM. The others occurred at 12:28-12:29 PM, and 7:26 to 7:27 PM. The rain brought June’s monthly total to a trace, ending the prospect of a completely rainless month.

No accidents were reported due to excited motorists reveling in the “rain” on their windshields, having attention diverted from driving. Local meteorologists explained that higher dewpoints than expected allowed a few drops to reach the ground instead of evaporating completely from the high-level virga that had been forecast earlier. The higher dewpoints allowed cloud bases from which the virga fell, to be 100 millibars, or about 4,000 feet, lower than computer models had predicted. The meteorologists blamed a lack of data far upwind of Catalina for the forecast gaffe.

Below, a rare GAMC, one that you will like not see in your lifetime if you did not see it yesterday:

7:28:26: A Trifecta scene is observed toward Mt. Lemmon (the rounded hump below the moon). This scene can only occur with the rain and sun in proper positions to produce an arc of a rainbow over Mt Lemmon, but the rain must be light enough so that neither the moon nor Mt. Lemmon are obscured in any way. Yours, today only, for $1,000,000. — 7:28:26: A truly rare GMAC scene develops toward Mt. Lemmon (the subtle, rounded hump below the moon). This scene can only occur with the rain and sun in proper positions to produce an arc of a rainbow framing Mt. Lemmon, but the rain must be light enough so that neither the moon nor Mt. Lemmon are obscured in any way. Yours, today only, for $1,000,000.

Moving on…..yesterday’s clouds

6:33 AM. Pretty Altocumulus, fatter version of "perlucidus." Didn't look to be as interesting a day as it turned out to be. This layer was about 12,000 feet above the ground. — 6:33 AM. Pretty Altocumulus, fatter version of “perlucidus.” Didn’t look to be as interesting a day as it turned out to be. This layer was about 12,000 feet above the ground.

12:38 PM. Some Cumulus begin forming underneath the sprinkle clouds (ice visible on the bottoms of the Altocumulus clouds on the left. — 12:38 PM. Some Cumulus begin forming underneath the sprinkle clouds (ice/virga visible on the bottoms of the Altocumulus clouds on the left–that made the bottom smooth.)

1:17 PM. Gorgeous example of Altocumulus castellanus (no ice/virga). — 1:17 PM. Gorgeous example of Altocumulus castellanus and floccu (no ice/virga).

5:30 PM. Cloud complex of the day, loaded with sprinkles, CMJs were predicting that sprinkles, and ONLY sprinkles, were about 5-10 min away.

5:46 PM. Following the sprinkle, eyes should almost automatically turn to the east for a some rainbow eye candy.

7:37 PM. The pretty cloud day closed out with a satisfying sunset.

The weather ahead

Today looks like it will be pretty much like yesterday, lots of mid-level clouds cold enough for virga, as you can see out there right now (just after sunrise), supplemented by afternoon Cumulus. Altogether another pretty day with reasonable temperatures held down by clouds and virga around. We’re on the edge of this mid-level moist plume coming up out of the Tropics, BTW. Rain is foretold by the quite wonderful U of AZ Beowulf Cluster calculator to only fall in the SE corner of the State today. This from last evening’s 11 PM AST data.

The later model runs have had potent Hurricane Crissy’s moist plume missing us to the east now, so don’t really want to talk about it. Winds in Cristina now 145 mph sustained as it rapidly intensified from yesterday’s 75 mph. Should mean good surf along the west coast of Mexico and a certain south-facing southern California beach haunt of CMP, called, “Zuma Beach”, where the acclaimed dramatic series, “Baywatch” was first filmed.

The End.

Icy up top

You won’t find such small Cumulus so full of it as they were yesterday very often. But with cloud bottoms and tops as cold as -15 C (5 F) and -25 C (-13 F), respectively, it was bound to happen. Cloud bottoms were located at 16,000 feet Above Sea Level (ASL), or about 13,000 feet above the ground above Catalina. That was a LONG way for a melted snowflake to fall, though it did appear that some sprinkles may have reached the ground toward Tucson town later yesterday afternoon and during the early evening. I was driving down into Tucson to see friends play in a band¹ at the appropriately named, “Nimbus² Brewery” and saw those clouds up pretty close as I went.

Here’s the late afternoon sounding for yesterday, providing the backdrop for those icy clouds, as rendered by the Cowboys of Wyoming³:

The temperature and dewpoint profile above Tucson, measured between about 3:30 PM and 4 PM AST yesterday afternoon. The balloon making these measurements rises about 1,000 feet a minute.

Here’s your cloud diary for yesterday, starting with a shot of some wildflowers taken while being bored waiting for the icy Cumulus mentioned yesterday to develop:

9:53 AM. By 9:52 AM, boredom had turned to worry, "Where were the Cumulus?!!", until 9:53 AM when I saw this and could relax, have a cup of coffee or something, lay around worry free. — 9:53 AM. By 9:52 AM, boredom had turned to worry; “Where were the Cumulus clouds?!! Was I going to be wrong again?”, until one minute later, 9:53 AM, when I saw this one and could relax, have a cup of coffee or something, lay around pretty worry free. You might need a telescope to see that Cumulus cloud…

11:48 AM. Almost 2 h later, the Cumulus are piling up toward Saddlebrook. Feeling great now, though we don't have any ice showing yet. Recall that even these little guys are about -15 C (5 F) at their bases. maybe a little warmer because the bases get higher (colder) as the afternoon wears on. — 11:48 AM. Almost 2 h later, the Cumulus are really piling up toward Saddlebrook. Feeling great now, though we don’t have any ice showing yet. Recall that even these little guys are about -15 C (5 F) at their bases, maybe a little warmer because the bases get higher (colder) as the afternoon wears on.

3:19 PM. Pretty typical of the afternoon hours; tremendous amounts of ice originating in Cumulus clouds maybe but 2,000 feet thick at this time. — 3:19 PM. Pretty typical of the afternoon hours; tremendous amounts of ice (frizzy areas) originating in Cumulus clouds maybe but 2,000 feet thick at this time.

4:23 PM. Cumulus really piling up over Saddlebrook now, quickly converting from droplet clouds to ice clouds. — 4:23 PM. Cumulus really piling up over Saddlebrook now, the larger ones quickly converting from droplet clouds to ice clouds.

6:18 PM. Looking S along Oracle Road at some pretty heavy virga. A drop or two may gotten to the ground below that one puff (all snow at this point up there). Clouds likely got to 3 or 4 K thick here. From the "Not taken while driving" (because that would be crazy) collection though at first glance it looks like it. — 6:18 PM. Looking S along Oracle Road at some pretty heavy virga. A drop or two may gotten to the ground below that one puff (all snow at this point up there). Clouds likely got to 3 or 4 K thick here. From the “Not taken while driving” (because that would be crazy) collection though at first glance it does look like it.

6:35 PM. That heavy virga made for some nice sunset scenes, though this is not one of them.

The clouds ahead

Not much weather ahead besides excessive warmth, but, a nice surge of middle and high clouds this coming Friday and Saturday (12th and 13th), maybe some sprinkles.

The End.

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¹Randy Prentice Band, perhaps the most eclectic collection of folks that has ever been in a rock band, featuring famous photographer, Randy Prentice on lead guitar and vocals, and African grey parrot and Pima County residential appraising expert, Dr. Diana May, on bass and vocals. Paul Daniels drums away and also sings; probably has a Ph. D., too.

²“Nimbus”, which means rain, is not a cloud of itself but is an appendage applied to clouds, like Cumulonimbus, or Nimbostratus. Why would a weatherman go anywhere else?

³Shouldn’t WE be the “Cowboys”, as in University of Arizona Cowboys? Don’t we have more of them, at least folks who ride horses than Wyoming, a state where hardly anybody lives, but they’re quite happy anyway^a for some reason? And is the moniker we have now, one that refers to feral cats that great?

I can’t believe how many footnotes I’ve put in already and I’m only on the first 10 lines or so! Better slowdown, go easy on the readers, though those many footnotes do give the “piece” an ersatz academic aura.

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^aOBJECTIVE HAPPINESS BY STATE 001 I inserted this once before a long time ago, but thought you should read it again. Folks in WY are happier than folks in AZ, it says. See state listings.

Clouds ‘n’ ice galore, a trace of rain, and thunder, too!

Rained, too, between 3:42 PM and 3:47 PM, actually 273 seconds, if you had your stopwatch out. It was great. I ran around trying to get wet, but couldn’t do it.

3:44 PM. Rain drops, and don't forget to recycle stuff. And, of course, the admonishment that this is NOT drizzle. — 3:44 PM. Proof that rain drops did fall yesterday afternoon. Don’t forget to recycle stuff and also don’t forget that this kind of rain is NOT “drizzle”¹. Drizzle are fine close together drops that almost float in the air. Tough to bicycle in drizzle if you wear glasses, in fact, I would say its impossible even if you’re wearing a baseball cap and helmet on top of it because the drizzle blows underneath the cap and onto your glasses so you can’t see anything right away. Rain drops fall too fast for this to happen. This from personal experience in Seattle. Always wear a helmet when bicycling.

10:23 AM. Altocumulus clouds formed rapidly over and downwind of Mt. Lemmon. — 10:23 AM. After a completely clear morning, Altocumulus clouds formed rapidly over and downwind of Mt. Lemmon. Before long, most were shedding ice.

11:45 AM. Distant Cumulus cloud forms just underneath some Altocumulus clouds. Here's where you KNOW that the day is going to be pretty good as far as convection and virga go because these clouds were so cold, and its late March when the sun is strong. — 11:45 AM. Distant Cumulus cloud forms just underneath some Altocumulus clouds. Here’s where you KNOW that the day is going to be pretty good as far as convection and virga go because these clouds were so cold, and its late March when the sun is strong.

1:51 PM. Two hours later the sky was full of glaciating Cumulus clouds, and isolated heavy virga trails, ones heavy enough to reach the ground with a few drops. Looking SW over Oro Valley and toward Marana.

2:31 PM. Thunder was heard just a minute prior to this photo, The thunderstorm was just to the west of the Tortolita Mountains. — 2:31 PM. Thunder was heard just a minute prior to this photo, The storm was just west of the Tortolita Mountains.

3:29 PM. Part of the cloud mass that brought the sprinkles (coded as RW--) to Catalina. — 3:29 PM. Part of the cloud mass that brought the sprinkles (coded as RW–) to Catalina. Probably measured below that little streamer, dead center. The virga hanging well below solid young cloud bases told you that those bases were far below the freezing level yesterday. How cold? Sounding indicates that the bottoms of the Cumulus clouds were about -12 C (10 F). The higher tops were colder than -30 C (-22 F)

6:36 PM. Residual Altocumulus cumulogentus with a little ice on the side (left). — 6:36 PM. Residual Altocumulus cumulogenitus containing a lot of ice if you look closely..

Today’s clouds

Still enough moisture for very shallow Cu fractus, Cu humilis, hold the ice (tops too warm). Skies will also be overrun with Cirrus, maybe verging on Altostratus, as part of low and trough barging into northern California today.Will get nice and breezy this afternoon, as the low zips on into the Great Basin and makes its presence known here. Instantaneous puffs might reach 40 mph this afternoon. No rain possible with this system, darn.

However, deeper Sc and Cu with ice in them should be visible up toward the NW-NE horizon today since a little rain and snow is expected on the M-Rim today, this from the U of AZ super mod’s 06 Z (11 PM AST) run, here.

The End.

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¹Here’s the interesting story behind getting THREE public service messages in a single caption/photo: I wanted to both better serve my public by getting some public service messages out there while at the SAME time, documenting some weather singularity, in this case, one of the rare rain events in the Catalina winter of 2013-14. Suddenly, in the midst of the rain I was dancing in, I noticed some shiny drops on the lid of the recycle bin, and things just “came together” you might say for a remarkable photo.

Snowy day (overhead)

Cloud tops in those deeper Cu reached -30 C (-22 F) yesterday, plenty cold enough for lots of ice, with a few scattered very light showers reaching the ground, even a few drops here in Sutherland Heights a little before 5 PM, qualifying for a day with a trace of rain. Imagine! Rain! What izzat?

Here is that day below (if you want the short version, go to the U of AZ time lapse film department, online here).

Day Summary: Sunny with Altocumulus castellanus/floccus virgae in the early morning, then in the late morning, Cumulus humilis and mediocris, the latter with virga; Cu grew into shallow, but very cold Cumulonimbus capillatus (lots of “hair”-ice), with virga and RWU (rain showers of unknown intensity) in a couple of spots. Sunny again in mid-afternoon, but Cumulus re-developed in mid-late afternoon with more virga and some Cu reaching the shallow Cb stage with sprinkles here and there.

That’s it, in kind of a jumbled form. Hope you logged all these clouds and changes yesterday.

9:55 AM. Altocumulus castellanus/floccus virgae

11:06 AM. Cu developed rapidly over and downwind of the Catalinas. Lots of ice at far left, indicating how cold those clouds were, likely around -20 C (-4 F) at cloud top by this time. Bases, too, below freezing by this time.

11:10 AM. A classic, gorgeous example of Ac castellanus and floccus (the latter has no base, just a turret). No ice visible here.

2:07 PM. Cold Cumulus and Stratocumulus filled in as trough apex was about to pass overhead (wind shift line, one you can see in the movie linked to above).

2:08 PM. Rain showers reach the ground toward Marana whose city limit is pretty much everything you see in this photo I think…

4:00 PM. Clearing developed for awhile in the mid-afternoon, but then Cu were quickly reforming. Lots of ice again in this one at left, the oldest portion of the cloud where droplets are evaporating, but the ice becomes visible because it doesn’t evaporate as fast as the droplets do. BTW, air flows THROUGH the cloud, youngest portions on the upwind side, oldest portions downwind. You want to know that if you’re flying around with a research aircraft because if you’re only targeting the young portions, you’re not going to find the “correct” amount of ice that developed in that cloud. Some researchers apparently did this and reported in journals anomalously low ice particle concentrations for the cloud top temperatures that they sampled. For the sake of courtesy, I will not mention their names. But this is why at Washington, we always found a LOT of ice because C-M /we knew where to go!¹

4:31 PM. This was probably the deepest cloud of the day, and there is some suggestion of soft hail (“graupel”) falling out as would be an indicator of some higher liquid water contents before it converted completely to ice. Graupel comes from ice crystals or snowflakes that have bumped into a lot of supercooled cloud droplets that then freeze instantly on the crystal, helping it fall faster and collide with more droplets on the way down, a process called “”riming.” Pilots know full well about riming.

6:24 PM. Nice sunset color in clouds and on the mountains.

Don’t see any weather ahead that I like, and so not talkin’ about that today.

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¹One of the many pioneering innovations here at “cloud-maven” is the novella-sized figure caption.

Rain to fall in Catalina, March 1st and/or 2nd!

Very happy to post this breaking future news here on February 24th. Close rain call on the 27th, too, as the first of two significant troughs with their low pressure centers march into California, bringing a drought break there of some consequence. Likely an inch or two in the coastal areas south of SFO (“Frisco”; rhymes with Crisco), and maybe even LA area as well with the first storm. That first one continues across Arizona bringing widespread, though light rains the central and northern mountains on Thursday the 27th.

Valid at 5 PM Thursday, the 27th. Upper left panel shows little brother trough over Arizona, and most of State covered by a little precip *lower right panel). — Valid at 5 PM Thursday, the 27th. Upper left panel shows “little brother” trough over Arizona, and most of State covered by a little precip (lower right panel). Big brother on the move offshore of Cal, flow reaching deep into sub-tropics.

Then “Big Brother” hits Cal beginning on the evening of the 28th, gets here late on the first or early on March 2nd. The LA Basin rains in the second one look like they’ll amount to 2-4 inches, and maybe something from a quarter to half an inch here in Catalinaland when it arrives.

Model?

Canadian GEM (General Environmental Model). Sometimes, like their hockey team, it defeats the US models in weather forecasting, and I am riding the fence that it will this time. In the interest of disclosure, the US WRF-GFS model has virtually NO RAIN in Arizona on the 27th (!), whilst the Canadian one has widespread rains (both using global data from 5 PM AST yesterday). So, I reject the US model, one that takes the first storm too far north to affect AZ much. (This has sometimes been a problem for our US models.)

Second storm?

Both models have rain on the 1st-2nd, but the Canadian, much larger amounts in southern California where I grew up and, while having poor grades after puberty and the realization of girls (!) hit, nevertheless had some success playing baseball. Could be nearly a month’s worth of rain in one storm in the LA area, which averages about 3 inches in Feb and March, both, IF the Canadian model verifies. Those kind of amounts upstream would also mean more rain potential for us here, too. But, the fact that they BOTH have rain, is really great to see. One would think that some rain is pretty much in the bag. I hope they put rain barrels out in Cal!

After the storm…

Oh, me, look at this “Lorenz” (the chaos guy) plot:

Valid March 8th, 5 PM AST. Its awful as a graphic to begin with, but when interpreted its even more awful in the kind of weather it implicates for us as we march farther into March; in one word, Hot and Dry! — Valid March 8th, 5 PM AST. Its awful as a graphic to begin with, but when interpreted its even more awful in the kind of weather it implicates for us as we march farther into March: in one word, Hot and Dry! Easterners won’t like it, either, as the severe winter continues back there, Lake Superior might remain frozen over until April! Jet stream is flowing along the red and turquoise lines, so cold air brought southward where lines aim toward the southeast, as over the eastern US.

A pattern like the one above is hard to maintain in March since the climatology of March-May leads to a trough in the western US. So hoping the awful pattern above will give way by mid-March or soon thereafter, as do easterners I would bet. Below, likely fantasy, since its WAY out on the forecast horizon, but this historic forecast (would produce historically cold weather in the East if it did verify, chances probably less than 30% as a wild guess. I just now saw it and it was AMAZING!

Valid March 9th, 5 PM AST. — Valid March 11th, 5 PM AST. LOOK at that high pressure area and cold air slamming down east of the Rockies and strong low over New England. Good grief! Would be headlines if it happens.

Yesterday’s clouds

9:22 AM. Altocumulus perlucidus. — 9:22 AM. Great example of Altocumulus perlucidus.

1:47 PM. Later became blobby with heavy virga; Altocumulus opacus virgae if you really want to know.

6:22 PM. Skipping ahead, these formations led to another in a long series of nice sunset shots. Hope you got one.

The End.

Hydrometeors shower down on Catalina

Note redundancy in title. A “meteor” is already going down, so you don’t need the word “down.” Hahaha.

They were small drops, some were as small as drizzle-sized (500 microns in diameter or smaller) and too far apart to be called an occurrence of “drizzle”, but they fell throughout Catalina allowing Catalinans to register a trace of rain yesterday, a trace that was not predicted by the best model we have around these parts just hours before the “rain” occurred. It’s not clear what the benefit of a trace of precipitation is, but we are sure some ants and other insects were made quite happy yesterday as a virga from a higher level snowstorm spit out a few drops.

Drops that reach the ground in these kinds of situations are due to melted aggregates or clusters of single snow crystals locked together that most people would call “snowflakes.” Single crystals can never make to the ground on a day like yesterday. And, “yep”, that “fog” you saw drooping down on the Catalinas from time to time yesterday afternoon was due to light snow.

No Catalina, Arizona, rain in US mod forecasts through the next 15 days (!–just horrible) as the US models continue to evaporate rain chances on the 6th-8th. A few days ago the system going by then was supposed to bring a substantial rain to most of Arizona. Now its just a dry trough passage in the model, like at watering trough¹ with a hole in the bottom. Phooey.

Oddly, the Canadian model, which first calculated a bust for rain here on the 6th-8th when the US model had lots, now has MORE rain in it near us here in Catalina on the 6th-7th than the lugubrious US model. The US model has NO RAIN whatsoever in the WHOLE State of Arizona ending on the morning of the 7th! How odd is that?

Below is the salubrious Canadian depiction for Arizona rain by the morning of the 7th, a rain that could be good for health of all of us and our desert:

Valid at 5 AM February 7th. Ttrough is already past us, but the Canadians believe that widespread rain will have occurred in Arizona during the prior 12 h as the trough went overhead. No such widespread rain in US model based on the same global dataset, the one based on 5 PM AST obs yesterday. — Valid at 5 AM February 7th. The upper level trigger for clouds and rain, a trough, is already past us and in western New Mexico, but the Canadians believe that widespread rain will have occurred in Arizona as it went by during the prior 12 h ! See lower right hand panel green and blue areas; use microscope.

Its interesting how you still can remember with fondness those people who affected your life so much, even if for a short time.

Below, after an important aside, your cloud day picture jumble, one that began with a brief, but memorable sunrise “bloom”, and one that also ended with great sunset color on the Catalinas.

9:43 AM. A brief clearing of a couple of hours duration led to pretty scenes of Altocumulus floccus trailing virga.

8:21 AM. Altocumulus floccus/castellanus trailing long trails of snow virga trails.

The End.

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¹Images of watering troughs, in case you’re from out-of-state and a city person and unfamiliar with western culteral expressions and don’t know what a watering trough is.

————–sports cultural note re Seattle—————

The polite, law-abiding folk of Seattle, celebrating Super Bowl victory at an intersection, waiting for the light to change.

Ice with them clouds

Not expected by this brain yesterday, but several of those many more Cumulus clouds than expected also fattened up to heights where ice began to form, also not expected. As you know, that means precip fell out, at least up there. As a weatherman-cloud person, there are always surprises every day (!) to delight and disappoint you. Its quite and exciting life we lead.

How cold were those tops?

Well, you know, colder than -10 C on a day with very high and COLD cloud bases¹. How high and cold were the cloud bottoms yesterday. Oh, about 0 C (32 F, of course) at 14,000 feet above the ground, 5,000 fee above Ms. Mt. Lemmon, the taller tops extruding upward to between -15 C and -20 C (5 F to -4 F), about right for the amount of ice that developed, “eyeballed” concentrations of a few to 10s per liter of air in those clouds (for size, think of a liter size plastic bottle of Bud Light with some ice crystals in it). (Remember, a LONG time ago in another area of the Universe^2,3, Mr. Cloud-Maven Person flew into such clouds with instruments aboard his Cloud and Aerosol Research aircraft and can say things like this with what appears to be some authority.)

Here are those clouds from yesterday, which I am sure you logged with excitement in your weather diaries:

2:55 PM. While out plant shopping at DS (Desert Survivor) this. Can you find the dead completely glaciated turret remains? — 2:55 PM. While out plant shopping at DS (Desert Survivors Nursery) this. Can you find the dead completely glaciated turret remains?

3:57 PM. OK, I'm making it easy on you here to find the ice. Wasn't there a song like that back in the 60s? "Make it easy on myself, oooo?" — 3:57 PM. OK, I’m making it easy on you here to find the ice. Wasn’t there a song like that back in the 60s? “Make it easy on myself, oooo?” I will look on the internet; it has everything!

4:59 PM. Largest of the the ice-producing Cumulus virgae, or are they, having precip, Cumulonimbus mediocris. I like the latter better. — 4:59 PM. Largest of the the ice-producing, “Cumulus virgae”, or are they, having precip, “Cumulonimbus mediocris.” I like the latter better, not that you would care that much.

Today the cloud bottoms are 1,000 feet lower than yesterday afternoon. But is it a diurnal effect where bases are always lower in the cool mornig (“morning”; intentionally spelled wrong to see if you’re paying attention) than in the afternoon? BTW, if you like soundings, go to the “Happy State of Wyoming, the nation’s happiest⁴, to see all the soundings you want at the University of Wyoming

But, we have a windshift in the middle levels traipsing over us late this afternoon (U of AZ TUS sounding forecast here), and that will be, we hope, something like a fork lift; help to push cloud tops up just it goes by. (However, I can find no evidence of such a windshift in larger scale models, so MAYBE I have mistaken a diurnal shift induced by our mountains as a “trough”. A trough would be a lot better, a diurnal turning of the wind, not so great a weathermaker. Another one of those “surprises”; they can come from all quadrants.

SO, high based Cumulus, some growing into Cumulonimbus clouds here and there, with some sprinkles because the bases are too high for a really good rain. But, hey, if you want a really good forecast, not a crummy one like this, see Bob and the NWS.

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¹Remember cloud bases can be cold, but NOT temperatures, which are high and low. The AIR is warm and cold.)

²Remember the solar system is speeding along (45,000 mph or so) in the Universe around the Milky Way Galaxy to god knows where (the constellation Hercules, according to the Stanford Solar Center).

³Quite fond of footnotes; they add a scholarly aura to trashy writing like this.

⁴OBJECTIVE HAPPINESS BY STATE We’re not THAT happy in AZ, BTW, but people are really happy in Wyoming, Montana, South Dakota. Huh.

The L. A. suns

We begin today by not talking about sports as the title suggests, but rather examining pretty castellanus, Altocumulus castellanus, that is, from yesterday morning:

5:38 AM yesterday from Equestrian Trail Road.

The brighter regions at the top are liquid droplet clouds, below, snow virga as the drops quickly freeze into ice crystals. As they grow and collide, snowflakes (“aggregates of single crystals) develop. But the dry air below the clouds prevents them from falling more than a few thousand feet below those white tops. Too bad. This is also what the tops of many widespread rainy/snowy storms look like if you could cut away just the top few thousand feet, those situations where there is moist air all the way to the ground.

L. A. suns? No, the PHX team did not move to a cooler venue as might be desired on these record breaking hot days. But our orange suns of late, particularly in the late afternoon, are reminiscent of those sunsets seen in smoky, smoggy regions of which this earth has too many.

6:37 PM. The smoky orange sunset yesterday. Ugh.

Furthermore, smoke gets in the way of rain formation, something noted by experimenters as far back as 1957, and later when burning sugar cane in Australia in the 1960s. The burning there stopped the clouds, relatively shallow ones, from raining. This is because smoky clouds have more and smaller drops in them. Smaller drops are resistant to forming ice, and a cloud must become deeper to generate drops large enough to coalescence with one another to form drops big enough to fall out.

So, not only are the skies messed up by smoke, but the formation of rain, too, is interfered with. Fortunately, if deep thundery clouds form, as we expect today in our vicinity, this smoke effect can be overcome at least in those clouds and rain will fall out.

Also, because small drop clouds send more light back into space from their tops, even moderate-sized Cumulus clouds can look awfully dark on the bottom, suggesting they are deeper than they really are.

The End

Less splotchy; more filling

The clouds yesterday were supposed to be “splotchy”, big clearings between interesting middle clouds like Altocumulus with long virga strands. Instead there was a vast coverage of Altostratus opacus “dullus” with long streaks of virga, with a few drops reaching the ground here and there but not here. There was some mammatus-t clouds, too. Also, the end of the clouds didn’t get here until after nightfall, not in the afternoon as anticipated from this keyboard.

The result was a much cooler day than expected, too. On TV, they were talkin’ low 80s for yesterday, a reasonable expectation given “splotchy clouds”, but in Catalinaland, it only reached 73 F under the heavy overcast. Very pleasant for being out-of-doors.

Oh, well. Maybe I’ll try building model airplanes and talk about those instead. Or make up historical anecdotes that aren’t true, mixing characters up from different eras and see if anybody notices. Now that would be fun! (Naw. Too silly.)

Here’s your day, beginning just before sunrise when some fabulous, fine-grained Cirrocumulus clouds came over top:

6:31 AM. Finely grained Cirrocu top of photo, line cloud would also probably qualify as Cc, though calling it Ac would not result in a fine from C-M. — 6:31 AM. Finely grained Cirrocumulus (Cc) top of photo, line cloud would also qualify as Cc, though the granulation is larger, still not large enought to be Altocumulus. With a little imagination, the top center cloud appears to be hanging down like those house Christmas lights.

Also at 6:31 AM. Here are your splotchy clouds. I can’t believe how good the forecast is going after an hour! There some much ice in the center cloud that you’d have to call it Cirrus spissatus, but an hour ago it was likely an Altocu cas, or floccus, one at very low (not “cold”, to be proper) temperatures.

7:41 AM. Clearings between clouds disappearing! Passing by, and from a thick Altostratus opacus cloud, a display of mammatus/testicularis left center (trying to be even-handed here in cloud nomenclature).

SONY DSC — Also at 7:41 AM. More mammatus-t over there, too. My mind has kind of drifted off to mammatus now. Quite nice dispay here. Note: Not associated with thunderstorms, as some urban myths have it. Look, I’m trying to make a dull day interesting. Its hard.

1:04 PM. Line of heavy virga from what else, Altostratus opacus, tops at Cirrus levels. Chance of late sun pretty much gone by now. BTW, if you saw a time lapse of mammatus clouds, you would see that the upside down Cumulus turret look, opens up to fibrous little shafts like these. — 1:04 PM. Line of heavy virga from what else, Altostratus opacus, tops at Cirrus levels. Chance of late sun pretty much gone by now. BTW, if you saw a time lapse of mammatus-t clouds, you would see that the “upside down Cumulus turret” look (as in the prior two shots), open up to fibrous little shafts like these.

6:50 PM. Good sunset, not great, as backside of As clouds finally comes into view on the horizon. — 6:50 PM, just before Husky softball defeated No. 2, ASU last night in Tempe, the heart of devil-land. Good sunset, not great, as backside of Altostratus (As) clouds finally comes into view on the horizon. The lower cloud specks at the base of the As layer are those comprised of droplets, not ice, as is the higher As. This shot helps show how different in appearance clouds of the two phases, liquid and ice, are. When they’re together, mixing it up, we call that a “mixed phase” cloud. Because there are so many particles that droplet clouds can form on (typically, in continental settings, there are hundreds of thousands per liter) those clouds have more detail and the drops are too tiny to fall as precip. In the higher Altostratus layer, the concentrations of ice particles that comprise it are probably only in the tens per liter, and those ice crystals/particles are far larger than the droplets in droplet clouds. Most of the ice particles in the As, therefore, are settling downward, evaporating. However, all ice clouds can produce light precipitation to the ground, one of the THREE ways we get precip out of clouds; all ice, mixed phase, and all liquid processes. (Some textbooks I’ve seen only talk about the latter two, BTW.)

If you want, you can go to this loop from the U of WA Huskies Weather Department here and see how the little splotchy cloud thing with that passing upper trough became a big fat thing as it came by. Also in this retrospective, you should examine the U of AZ Weather Department time lapse film. You’ll be amazed at all the stuff going on in a day that looked pretty dull all in all. Also, at the end (after 5 PM AST) you’ll seen the winds aloft change completely in direction as the backside of the trough, the clearing side, approached. I saw stuff I didn’t know was happening. You’ll also see how the mammatus pouches, if I may, open up into fibrous virga. Thank you, U of AZ Weather Department, for posting these great instruction films!

Not expecting clouds for most of today, but will likely see a couple of Cirrus streaming in from the NW late.

The weather ahead

Still no precip in sight, unless you consider lithometeors a form of precip, dust accumulations, that is, such as we had a few days ago. Half inch (of dust) I predicted wasn’t that bad (hahahah). Dust accumulations expected now on the afternoon of the 16th, and again on during the afternoons of the 25th and 26th of April.

C-M alive, local, and… finished with the dust report, now back to the studio.

The End.

April as seen in rain day frequencies; some wildflowers seen

update April — Captions included in diagram!

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Guest Statement/retrospective on March 2013 for Tucson by Mr. Mark Albright, a mostly temperature-centric climatologist specialist from the University of Washington:

“March 2013 was the 2nd warmest March in the past 65 years (1949-2013) at the Tucson Airport (KTUS) with an average temperature of 65.7 F which was +5.6 F above the 1981-2010 normal of 60.1 F. The only warmer March was 9 years ago in 2004 with a mean temperature of 66.6 F. By contrast, the coldest March occurred in 1973 with a mean temperature of only 51.6 F.

March 2013 precipitation totaled 0.01 inches at the Tucson Airport, the driest March since 1999 when ZERO precipitation was recorded in March. In the past 65 years ZERO precipitation has been observed in March 5 times: 1956, 1959, 1971, 1984, and 1999. March normal precipitation for the Tucson Airport is 0.73 inches.”

Mark may contribute more material in the future in the form of guest blogs when CM’s brain is fried.

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How about them Altocumulus castellanus/floccus virgae clouds yesterday?

8:54 AM. Altocumulus floccus virgae (with snow falling out) above a housing castellanus.

9:07 AM. Long trails of snow made these clouds exceptional. In the foreground, riding pal, Nora B, who talks mainly about birds and wildflowers (she and hubby have a book out on the latter) while I talk mainly about clouds and snow aloft on the rides. — 9:07 AM. Long trails of snow made these Altocumulus floccus clouds exceptional yesterday. In the foreground, riding pal, Nora B, who talks mainly about birds and wildflowers (she and hubby have a book out on the latter, Wildflowers of Arizony) while I talk mainly about clouds and snow aloft on the rides, so there’s no real communication on the rides (hahaha). I thought you would want to know that.

The wildflowers were better than expected along the trail, considering our once a month storm frequency for the past three months. Here are some for you. Can you name them?

Dry, windy, dusty blast coming on Monday, followed by air that’s too cold for April later that day into the middle of the week, but you knew that already. More on weather tomorrow.

The End.