Cloud-maven – Page 68 – About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno

Cold slam

That’s your weather forecast for today. There’s nothing you can do about it. Why go on about it?

Next, these from yesterday–was under control, only took 127 photos. Every thousand or so shots I take is NOT of a cloud, and yesterday there were two exceptions, which I will post here as an anomaly; a quirk really:

5:48 PM. Sun broke through the Cumulus and Stratocumulus clouds for this orangy foreground as the white light of the sun is burned orange at low sun angles by passing through a denser portion of the atmosphere. The shorter wavelengths (blueish) are scattered out leaving reddish hues to come shining through. Banner cloud remains in its same crevice on Samaniego Ridge like a trap door spider or a piece of lint in a corner of the room you haven't vacuumed for awhile. — 5:48 PM. Sun broke through the Cumulus and Stratocumulus clouds for this orangy foreground as the white light of the sun is burnished orange at low sun angles due to having passed through a denser portion of the atmosphere and the shorter wavelengths (blueish) are scattered out leaving reddish hues to come shining through. Banner cloud remains in the same crevice as yesterday on Samaniego Ridge like a trap door spider or a piece of lint in a corner of the room you haven’t vacuumed for awhile.

2:55 PM. Horse demonstrating that the appearance of water in a tributary to the Sutherland Wash was real, not an illusion. Thanks, horse. The bit of water in the Sutherland dried up just down from the private land fence opposite the rusty gate. — 2:55 PM. Horse demonstrating that the appearance of water in a tributary to the Sutherland Wash yesterday was real, not an illusion. Thanks, horse. The bit of water in the Sutherland Wash itself dried up just down from the private land fence opposite the rusty gate on the east side. (Horse people know where this is.)

5:56 PM. Gritty view through wires and a telephone pole of the highlight color of yesterday's sunset. Sometimes I think you're here only for the eye candy. — 5:56 PM. Gritty view through wires and a telephone pole of the highlight color in Stratocumulus clouds of yesterday’s sunset. Sometimes I think you’re here only for the eye candy.

Yesterday’s rare ice-forming anomaly

I was hoping you wouldn’t read this far. Something incredible happened, rarely seen here in Arizona. Our slightly supercooled clouds, with top temperatures between -5 and -10 C, formed ice. When I first saw the indication of something falling out of those shallow clouds on the Catalinas, I was beside myself. Here’s what I saw, not taken while driving¹:

11 AM. A shopped photo of the ice fall on the Catalinas to make it look like it was taken from a car, the way you might have seen this. — 11 AM. A shopped photo of the ice-fall from these Stratocumulus clouds on the Catalinas to make it look like it was taken from a car, the way you might have seen this ice fall. Note how I cleverly tilted the image to make it look like it was taken in a hurry before the light changed.

Same image with writing on it. — Same image with writing and an arrow on it to help you out.

I thought it was some kind of fluke since it was indicated just yesterday from this keyboard, based on prior experience in Arizona, that ice rarely forms in our clouds at temperatures above -10 C (14 F). Maybe someone was nefariously cloud seeding I wondered…. Or had flown an ice-producing aircraft through these clouds upwind somewhere. (Its about what cloud seeding would do in marginally supercooled clouds like these, too, not much but something.)

———academic discussion—–

Ice appearance in clouds with tops warmer than -10 C is common in “clean” environments like over the oceans (see the works of Mossop in the Australian Pacific, Borovikov et al in the Atlantic, Hobbs and Rangno in the Washington State coastal waters and the Chukchi Sea offn Barrow, AK, or Rangno and Hobbs in the Marshall Islands) in clouds with warm bases (ones substantially above freezing for the most part) that can be anywhere even in “continental” environments far inland where cloud droplet concentrations are high due to natural and man-produced aerosols (see Koenig in Missouri, Hallett et al in Florida, Rangno in Israel) among many others). We sometimes have those warm-based clouds here in the summer, too.

——-end of academic interlude——–but not really——

These fuzzy very light snowshowers soon ended and the day went on as foretold, no ice in the clouds.While out on Old Jake, shown above, I was taking photos of particularly dark based clouds and was going to tell the story about why they looked so black, and yet did not precip–to warm and cloud top, and drop sizes near the top, too small for ice initiation. Just about every case in which aircraft measurements have been made in such clouds that form ice at top temperatures above -10 C (14 F), inside them are cloud droplets larger than 30 microns AND a few drizzle drops (liquid drops between 100 and 500 microns in diameter, or rain drops. Droplets larger than 30 microns and substantial concentrations lead to collisions where the drops that collide can coalesce into a single drop. Let us not forget Hocking or, later, Jonas and Hocking and the 38-40 micron drop size limits they found for this to happen from lab experiments. Below that 30-40 micron diameter size, the little cloud droplets act like marbles; too much surface tension.

OK, there’s that little discussion preparing you for what comes next. Continuing with the story…was there one? Well, anyway, Mr. Cloud Maven person, riding on his own forecast made that early morning for no ice in the clouds (meaning no rain), decides to also ride on his old horse, Jake, who needs some more of that exercise.

Confidently, though dark Cumulus clouds underlying a broken to overcast deck of Stratocumulus, looked even exceptionally dark in places, Mr. Cloud Maven person smiled at this darkness of the cloud bottoms, knowing that the darkness in the bases of shallow Cumulus only spoke to how high (and small) the cloud droplets were in those clouds; they had to be highly “continentalized”clouds, ones with tremendous droplet concentrations in them and because of that, all of the droplets in them have to be tiny, being so great in number. And, in being a Cumulus cloud with an appreciable updraft, even more droplets are activated in “continental” air than are at the bottom of a layer cloud like Altocumulus.

When the drops are tiny, more sunlight is reflected off the top of the cloud and the darker they get on the bottom, and the more removed they are from producing a drizzle drop, or are in having the precursor droplets to drizzle drop formation, cloud drops larger than 30 microns.

This is what a Cloud Maven person thinks before he gets on a horse….

So, as I am riding along near the Sutherland Wash, these patches of dark bases form nearly upwind…. I watch them for awhile, quite unconcerned, and smiled again, thinking about the other horseback riders, people on bikes out there that likely turned back in fear of a terrific downpour, not really having the knowledge they need about clouds.

Then suddenly I noticed ice streamers coming down NW of Catalina only a couple of miles away! It was falling from the downwind part of these darker clouds, where after a period of time, ice, if it was going to form would be. But, how could this happen?!!!! Before long, the thicker regions of the cloud began to emit stranded precip, a sure sign of graupel up top in the cloud. Graupel in clouds with supercooled droplets only 23-25 microns in size, much smaller than those required for coalescence, and the present of those droplets leads to ice splinters when they are banged by a graupel particle. A coupla graupel (soft hail) and after awhile, (10-30 minutes) a cloud can have a lot of ice, 10 per liter or more in concentration, plenty enough for precip beside the graupel-melting to rain stranded part. Here is a shot of the further, SHOCKING development:

3:06 PM. First graupel strands emit from base of Cumulus congestus. More ice aloft can be seen on the right. Horse's ears show that he, too, is surprised by this sight. — 3:06 PM. First graupel strands emit from base of Cumulus congestus. More ice aloft can be seen on the right. Horse, too, noting precipitation in the distance, is surprised by this sight. “It’s OK, Jake, its over there and moving away from us.”

3:18 PM. I smiled, a sardonic one, as the drops began to fall (see smudge, lower center). A dark-looking complex of Cumulus topped by Stratocumulus had formed ice upwind of me, and now, me and horse were going to get wet. — 3:18 PM. I smiled, a sardonic one, as the drops began to fall (see smudge, lower center). A dark-looking complex of Cumulus topped by Stratocumulus had formed ice upwind of us (see upper right), and now, me and horse were going to get wet.

I had to laugh at myself on the way back, the rain drops wetting us down, when I thought about being quite confident yesterday morning about no ice would form in our clouds. When you have an occupation that tends toward error, its good to have a sense of humor. There’s nothing worse than a humorless meteorologist at a party, one whose likely obsessing over his error-filled life.

So, why ice? The TUS sounding at 5 PM AST did not suggest tops colder than -10 C Z(moisture top was about -5 C is all), but where the moisture ended, the air was incredibly dry, reported as “1 percent” relative humidity. Here is that 5 PM TUS sounding:

Arrows point to main top height, and where the highest Cumulus tops might have gotten to as they momentarily, due to inertia, mounded above the main moisture level. Normally, they plop back down because they get chilled, and the tops are cold relative to the surrounding air.

So, an overshooting top COULD have gotten to -10 C, and certainly, with that incredibly dry air just topside, those drops in those evaporating turrets would have chilled a couple of more degrees C. So, maybe that’s it, in fact, the overshooting moderate Cumulus tops DID reach to, or below, the -10 C normal ice-forming temperature here.

However, the concentrations that developed in these clouds HAD to be due to other processes beyond just the run of the mill ice nuclei since there are so few of them at -10 C, and that where drops larger than 23 microns come into play. Without those, there would never have been showers yesterday, only a very isolated drop or two. Those larger than 23 micron size drops lead to “ice multiplication” where just a couple of initial ice particles can “multiply” like rabbits in clouds because of ice splinters shed when hit by graupel. However, as we speak, the full understanding of how ice forms in clouds with these “high” temperatures has not been pinned down. Some researchers, the present one included, believe that ice splintering alone is not sufficient to explain the rapidity in the appearance the high concentrations (10s to 100s per liter) that develop in clouds like we had yesterday. You probably don’t care about what I think, but rather go with the majority opinion… Oh, well, it always safer that way.

As a test of even deeper knowledge that an aspiring cloud maven junior might have, this question:

What kind of ice crystals and other frozen particles would have been in those clouds yesterday?

Quiz music here No help from the audience, that other person who reads this blog.

No cheating; don’t get out your Magono and Lee (1966) translated-from-a-Hokkaido-University monograph on ice crystals and the temperatures and humidities that control their shape.

Answer1: What is a (hollow) sheath?

Answer2: What is a needle?

Answer3: What is a graupel (more a lump around a pristine ice crystal or frozen drop than just an ice crystal?

Answer4: What is an amorphous ice fragment?

Congratulations and adulation! You are now officially a cloud maven junior. Don’t forget to order that CMJ Tee.

Below, examples from the “ice crystal bible”, Magono and Lee 1966:

Needles, followed by sheaths, followed by “lump” graupel, and then some ice fragments in the last two panels.

——————–

Only a crazy person would take photos while driving, like that crazy woman I once knew whose hobby was taking photos of dust devils while driving! Oh, my.

Jan 25th-26th storm creates billions in beneficial rains

Oh, yeah, billions and billions of tons of rain dropped out of the skies over AZ, and much of the SW over the past two days. It, too, might have saved billions in dollars by deterring crop losses, vegetation and critter stress, and own our stress over the drought, “Will it get worse?” That watery relief was so great. Could hardly stay indoors yesterday. 267 photos of clouds and rain, which I think says something about neurotic-compulsive behavior.

(BTW, too many clouds shots “is” WAY down at the bottom after too many rain tables–this is really a horrible blog today.) Continuing….

Totals?

The 24 h rainfall records that were set are here.

Amounts in Catalina “proper” ranged from 1.03 inches at Our Garden garden, 0.80 inches in Black Horse Ranch, 0.71 inches at the bridge over the CDO wash at Golder Ranch Dr, to 0.72 inches here on “Upper Wilds Rd.”

Check the happy totals from the Pima County ALERT network for the 24 h ending at 4 AM today. Since its a “rollling archive” you’d better look at it when it partitions the best 24 h storm total or you’ll miss it. Hence, this pdf:

The great Jan 26th storm total pdf

The U of AZ rainlog network totals are here, but to get the full 24 h storm amount you’ll have to go to the upper right hand corner and select “date range”, then put the 25th to the 26th in that window (the U of AZ assigns the 7 AM total recorded today to the previous day on these maps. So, that early morning rain before 7 AM yesterday was assigned to the 25th. That’s why you have to appear to be lumping two days together to get a 24 h storm total. Sorry its so complicated.

A national organization that has different gauges in some cases is “CoCoRahs”. Their statewide totals for 7 AM can be found here. Again, like the U of AZ, you’d have to lump two dates together to get the 24 h total, in this case, the 26th and 27th since CoCoRahs records the rain on the date of the measurment, does not assign it to the day before as Rainlog does. Confused yet? The CoCoRahs method corresponds to the NWS methodology. Confused yet? The rainlog method works great for summer when the 7 AM measurements almost always correspond to rains the REALLY did fall on the prior day. Confused yet?

Mind is worn out now, will rest for a minute…. There….moving ahead again.

USGS statewide totals, the greatest in this list, 2.78 inches at Salt River below Steward Dam. Since this is a rolling archive like the Pima County ALERT system, I’ve made a couple of jpegs of the list for the time of the most precip in 24 h, so you’ll get a better idea of how ridiculous it is to have to go to so many sites to get a comprehensive view of rainfall in ALL of Arizona, all available data. Kind of remarkable that being concerned with drought and climate change that one has to go to SO MUCH “darn” TROUBLE to get a comprehensive view of rainfall! (End of rant)

NWS reports as of 5 PM AST, also in jpeg format so that they can be easily read. These include the regional and statewide reports for the 18 h ending at 5 PM. (I have no idea at present why these amounts are for the 18 h instead of 24 h):

Finally, those totals from folks who report to Weather Underground can be found here.

The rain data at WU default to a 24 h midnight to midnight rain day and so to get the storm totals, you’ll have to select yesterday’s date (also, since you’re likely to display weather stations showing just the temperature and wind direction data, you have to go the “weather station” dark blue button and open that window up and select “precipitation.” Is anybody still out there reading this? I doubt it. Well, now I just found that it only displays the hourly values for the date I chose! Forget it.

The vortex that passed just about over Catalina, the very heart of this generous storm is made visible here in the water vapor imagery from the U of WA. Watch how a vortex develops from the buckle point over central Baja, and as it approaches, spawns the heavy, heavy rainband that suddenly moved over Oro Valley and Catalina between 10 and 11 AM. Pretty cool, huh? There was some thunder in it, but it you didn’t hear it then, you had another chance beginning after 3:10 PM as a thunderstorm develops over the north end of the Oro Valley and tracked across Saddlebrooke.

Some clouds to go with those numbers:

8:06 AM. First rainband has moved through producing 0.40 inches. Looking SW at Stratocumulus during slight break in rain.

8:47 AM. Skies remain dark, low hanging and dramatic, then evidence of cells, Cumulonimbus towers probably five to ten times higher than the Stratocumulus clouds emerge to the SW. — 8:47 AM. Skies remained dark, low hanging and dramatic, then evidence of cells, Cumulonimbus towers probably having tops five to ten times higher than the Stratocumulus clouds emerge to the SW. It was going to be a rest of the good day.

9:48 AM. During a momentary sunbreak, this trapped cloud below the Samaniego ridge. The wind is blowing from right to left, but the cloud is recirculating in the lee of this ridge. On a mountain peak, such a cloud in the lee of the peak is termed a "banner cloud." — 9:48 AM. During a momentary sunbreak, this trapped cloud was seen below the Samaniego ridge (just above the Los Cerros Water Co tank that needs repainting badly; looks kind of shabby though the water company itself is pretty good). The wind is blowing from right to left, but the cloud is recirculating in the lee of this ridge. On a mountain peak, such a cloud in the lee of the peak is termed a “banner cloud.” It was neat to see it here.

9:59 AM. Here comes that wild, torrential rainband, just having been spawned by the little vortex whose center passed so close to us yesterday. This was so great to see because the rain totals were going to be jacked up significantly. 0.31 inches fell as it went by Upper WIlds Road", but places nearby got twice that! Some thunder occurred here--showed up on the LTG network. Clouds? Line of Cumulonimbus. — 9:59 AM. Here comes that wild, torrential rainband, just having been spawned by the little vortex whose center passed so close to us yesterday. This was so great to see because the rain totals were going to be jacked up significantly. 0.31 inches fell as it went by Upper WIlds Road”, but places nearby got twice that! Some thunder occurred here–showed up on the LTG network. Clouds? Line of Cumulonimbus.

10:12 AM. The rain pouring out of that Cumulonimbus iine shoved the air out of the way and this arcus cloud raced ahead of the line, akin to our summer storms. The wind shift and gustiness flowing out from the storms are a little ahead of the cloud's position. — 10:12 AM. The rain pouring out of that Cumulonimbus iine shoved the air out of the way and this arcus cloud raced ahead of the line, akin to our summer storms. The wind shift and gustiness flowing out from the storms are a little ahead of the cloud’s position.

11:19 AM. Post-rainband evidence of a substantial amount.

12:12 PM. Some of the prettiest cloud shots come right after a rain. Here, in the tops of Cumulus over the Catalinas shearing toward the right, the apparent curvature in the whole scene including the low Stratus fractus along the mountains, hints at the curvature seen in the eye of a hurricane. — 12:12 PM. Some of the prettiest cloud shots come right after a rain. Here, in the tops of Cumulus over the Catalinas shearing toward the right, the apparent curvature in the whole scene including the low Stratus fractus along the mountains, hints at the curvature seen in the eye of a hurricane, and may well have reflected that little vortex that went by yesterday.

2:21 PM. Dramatic skies develop again(!). These clouds developed strong showers that marched across Oro Valley. — 2:21 PM. Dramatic skies develop again(!). These clouds developed strong showers that marched across Oro Valley and across Saddlebrooke.

2:30 PM. Same clouds just 9 min later. Just like summer, ice forms up top, out the bottom comes the precip!

3:17 PM. Even more like summer, this thundery shaft. Four in-cloud discharges occurred. — 3:17 PM. Even more like summer, this thundery shaft.
Four unusual-for-January in-cloud discharges occurred.

4:55 PM. So appropriate for near the end of such a fine rain day, a rainbow.

Clouds today?

Some great scenes of wash fog, such as in the CDO just now. But after that scattered to broken moderate Cumulus, probably grouping into clumps more like Stratocumulus, filling the sky some this afternoon.

While the U of AZ model has showers developing today, cloud tops now, and in the model forecast appear to be to warm for ice development. So, for today, it seems that only clouds and not showers are going to happen.

We’re on the edge of precip when the cold blast hits tomorrow just after dawn. It seems that the range for that would be a miss (0) to a tenth of an inch at tops is about all we can must of that event early tomorrow morning.

“We interrupt this drought with an important rain”

Might be worth MILLIONS…

First rain drops here at 3:30 AM. Checked sat images and they’re looking about as good as they could for us, clouds to the southwest of us, curling around that little upper level low center like a boa constrictor, buckling, and dragging all that tropical air toward us. You can see that here in a loop of the satellite imagery from the U of AZ. and take a look just off Baja and in the Gulf of California.

4:10 AM AST, the latest I got while doing this. — 4:10 AM AST, the latest I got while doing this blog–I can’t keep updating it or I’ll never finish. Updating is up to you now. Thanks.

Cloud bands curling around the center and the center heading this way? Its as good as it can get for us, and means the rain bands should be pretty potent. Some Cumulonimbus clouds can be seen in the sat imagery, too, in the main rain band. Looks like it will take about 8 h for the main part of this to go through, too, with passing light showers into the afternoon and evening. So, light to moderate rain for maybe 8 h should lead to around half inch to an inch. Yay!

Paulden, near Prescott, has, as of 4 AM AST, received the greatest amount, already recording 0.95 inches. You can see the statewide totals at the US Geological Survey network here. The Pima County ALERT gage data are here, with the first measurable rain being reported at 4 AM AST. With southerly flow at mountain top level, the south sides of the Catalinas will likely get the most from this storm compared to Catalina townlet, Census Designated Place, proper. Hoping for some lightning, too, today, as there are some Cumulonimbus clouds in the main band here and there.

The best part of this situation is that most of Arizona gets drought-reprieving rains over the next 72 h, counting today, with the models thinking that all of this may amount to several inches of water in the mountains of central Arizona where its so badly needed. And with just this ONE storm sequence, January will come out looking like a decent rain/snow month in the record books.

Model musing….

In the model prediction business, today’s rain was not even seen at first while rain on the 28th has been there for at least 10 days! Then, rain began to show up today, Saturday, about 5-6 days out, but it was hardly anything at all–wasn’t even mentioned here the first time it did because it seemed so tenuous.

But look how reality has turned out! This little circulation from the sub-tropics is certain to dump more precip than the storm on the 28th, the one so long foretold. I guess this is why we weatherman like weather. The unknowns, the surprises, are still pretty great.

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4:30 AM. First hundredth of an inch, off to slow start, but like that legendary horse of old, Silky Sullivan¹, should end in a hurry.

Yesterday’s clouds

7:24 AM. Rising sun illuminates the bottom of an Altostratus mammatus layer.

11:16 AM. Thickening and thinning skies all day until late, brought sunny spells as here with thin Altocumulus perlucidus.

4:18 PM. An unusual site. See note messing up photo. I worked pretty hard on it, though an english language-maven might find fault in it.

5:16 PM. Close to sunset, and almost an exact replica of the day before at this time. No sunset "bloom" seen, but a brief hole allowed a golden illumination of the Catalinas for just a minute or two--next photo. — 5:16 PM. Close to sunset, and almost an exact replica of the day before at this time with an overcast of Altocumulus opacus clouds. No sunset “bloom” seen, but a brief hole allowed a golden illumination of the Catalinas for just a minute or two–next photo.

5:40 PM. Charoleau Gap orangified by setting sun peaking through....through...what? Altocumulus opacus, in this case droplet clouds with little or no ice whatsoever. You didn't see any virga did you?("Gritty AND pretty", $1025) — 5:40 PM. Charoleau Gap orangified by setting sun peaking through….through…a hole in what? Ans: Altocumulus opacus, in this case droplet clouds with little or no ice whatsoever. You didn’t see any virga did you?
(“Gritty AND pretty”, $1,025)

Quitting here–haven’t even looked at models (oops, except Canadian–just remembered that; just eye-balling stuff, but this piece, long enough!

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¹Hardly a person alive then in the late 1950s did not know of THAT horse, yes, just a horse! Check the video for something truly amazing! Silky Sullivan gave hope to all those that fall behind. His reputation lives on.

“Sprinkle rain”, thought to be only capable of a trace, piles up 0.06 inches in Catalina

Yesterday’s news, of course, and a surprising development “locally” where measurable rain during the day seemed remote, at least at 6 AM yesterday. But, a blob of rain moved in around noon and gave out 0.06 inches. We’ll take it.

And as you all know, much more rain from our tropical system off Baja is just ahead, U of AZ mod says beginning late tonight and continuing into most of tomorrow morning as you can see here. If you want to see the forecast rain/snow in all of Arizona pile up over time, go here (from the U of AZ). The model is thinking between 0.25 and 0.50 inches here, an inch or so on top of Ms Mt Lemmon. Gut feeling is that we’ll see more than half an inch here from this, with a good chance that it will go beyond noon tomorrow when the mod thinks its all over. Hoping, anyway.

Below, amounts forecast by the U of AZ model ending at noon tomorrow. The model was run on data from last night at 11 PM AST.

Also yesterday, we had a very brief but fabulous sunrise “bloom” illuminating the bottoms of the thick Altocumulus clouds overhead. It looked something like this¹: Hoping for same today.

7:23 AM. Year different from 2013 because Mr. Cloud-maven person did not have a memory card in his camera.... — 7:23 AM. Year different from 2013.

In case you missed it, here’s what gray skies and light rain look like, falling of course, from that great steady rainmaker, Nimbostratus.

12:31 PM. "Riders were approaching (under Nimbostratus), the wind began to howl...." That Dylan line would been that bit better with "Nimbostratus" in it.(From "All along the Watchtower") — 12:31 PM. “Two riders were approaching (under Nimbostratus), and the wind began to howl…”² Well, OK, one rider. Note rain haze against Pusch Ridge and smoothness of sky due to precipitation fallout that obscures cloud detail. When you saw that smooth sky approaching from the SW, that was the time to turn your horse around and head for the barn, as here.

The rest of yesterday? Blasé. Steady diet of overcast Stratocumulus/Altocumulus clouds sometimes with splotches of virga, and a sprinkle here and there. Here’s pretty much what the rest of the day looked like:

SONY DSC — 2:01 PM. Two layers of Altocumulus are visible, the lower one on the S horizon beyond Pusch Ridge. Cloud detail (rumples and such) shows that there was no precipitation falling from these clouds. If someone asked you why, you’d say that the layer was not cold enough to produce ice crystals-snowflakes, things that would grow and drop out the bottom. The cloud droplets in these clouds are too small to fall, and even if they did float down and out, they’d be gone in a few seconds because they are so small.

4:46 PM. Creamy-looking Stratocumulus. Sometimes cloud bottoms look this way because of a moist layer overrunning dry and stable air, air that raggifies the cloud bottoms. — 4:46 PM. Creamy-looking Stratocumulus. Sometimes cloud bottoms look this way because of a moist layer overrunning dry and stable air, air that “raggifies” cloud bottoms and wind shear at cloud bottom can produce concave (inverted bowl-looking bases). TUS sounding at 5 PM shows air speed sped up a little at cloud base over wind just below them and wind direction turned about 10 deg from that just below cloud base. Was it enough? I guess so, but not really sure except by sky.

Rain still foretold for Sunday night into Monday morning, followed by a cold blast, but amounts have been on the decline. Could be just a few hundredths to a quarter inch is about all this one can produce.

Clouds today

More interesting scenes today of “multiple layers” as we would call them, and not as widespread as yesterday overall; Altocumulus (and with the wind picking up aloft, a lenticular here and there–look to the NE of Ms. Mt. Lemmon) Altostratus, Cirrus. And, with luck, a great sunset.

Way ahead…….

In the usual model vagaries, absent rain in them after this Monday for awhile, rain has shown up, beginning on the 4th of February. This is a new development in the models for that period. The NOAA spaghetti plots give this system pretty good support–that is, something is likely to approach the central and southern California coast a day or two before our possible “storm” on the 5th. but thereafter, not much confidence for a storm here. So, likely to be on the doorstep for us on Feb 3rd or so as it. Interestingly, it rains for two days off and on here, Feb. 4th and 5th, and the rain follows a trajectory from the Pacific much like we have today, which is always a good sign since the atmosphere likes to repeat itself. You can see the full sequence here.

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¹A replica of yesterday’s sunrise since Mr. Cloud-maven person’s camera failed to ingest a memory card prior to a dozen or so snappages. Camera acted like there was nothing wrong!

²That Dylan line would been that bit better, more dramatic, with “Nimbostratus” in it.
(From Dylan’s, “All along the Watchtower”, the best version, it goes without saying, performed by Seattle’s own Jimi Hendrix.)

“Cloudy”

“Cloudy/The sky will be gray and white and clou–oooowww–deee.”

If you don’t remember the 60s and songs about weather, a silly reprise of that Simon and Garfunkel song here. If S&G had been weather forecasters, they might have written satisfying lines like the one above for today.

At times today, with all the virga around, it might really look like its, “hanging down on me” as the two depressed boys sing in that song as waves of thick middle and high clouds eject northeastward over Catalina from the tropical Pacific. Looks like the heart of the upper level disturbance and its main rain shield will pass Friday night into Saturday, with a break in rain on Sunday, then rain again on Monday into Tuesday as the cold punch of this storm sequence rattles down from the north Pacific Coast. Great news, but not new news to anyone paying much attention to our local weather forecasts.

Catalina seems destined to get a good dumping from the two combined (the warm one, then the cold one), likely to exceed a half an inch, and boy, do we need it. Nothing after this in rain, the mods say (for now).

As a note in passing, the droughty Plains States don’t get so much relief from this system now as the models have faster movement of the storm through that region than they had a few days ago when it was part of a “trillion dollar” beneficial storm sequence across the country. That faster movement of the storm has been repeated in the mods now over and over. Faster movement equals less rain, less time for humid air from the Gulf of Mexico to race northward and be ingested into the low center that forms in the Plains States in a few days. I actually feel kind of sad seeing that change happen and hope its dead wrong. “Dang”, as we would say.

Yesterday’s clouds

Here are some shots of those great Cirrus clumps and formations yesterday some of which were exceptional because of the instability up there, that is, how tall and Cumulus-looking some of the Cirrus castellanus turrets got, biggest I’ve seen. You can reprise the whole day here, from the U of AZ. First, a shot of the great sunrise.

In the AZ movie, you will also see these brighter flecks appear, brighter because they have smaller, more numerous particles in them when they first form compared to even minutes later as they disperse. The behavior of CIrrus forming like this is like a puff of smoke that suddenly appears in the sky, but no more smoke is added. As happens with these Cirrus flecks, the smoke would gradually disperses and thins after a thick beginning.

Later in the movie, you’ll see the “convective” Cirrus we call castellanus go by, producing a little virga. Another oddity, is that some Cirrus uncinus trails go by with the streamers of ice that are falling out, go faster than the higher tuft from which they fell from, indicating a wind speed increase as you go down, a little unusual at that level.

So, lots to see in this time lapse movie.

7:18 AM. New flecks of Cirrus floccus-later to be Cirrus uncinus form beyond Pusch Ridge. Lower Ci Spissatus in the distance. — 7:18 AM. New flecks of Cirrus floccus-later to be Cirrus uncinus–form beyond Pusch Ridge. Lower Ci Spissatus in the distance.

1:42 PM. Cirrus castellanus slightly below Cirrus spissatus clumps--Altostratus as a name would be OK, too. — 1:42 PM. Here, continuing with the innovative “gritty-not-pretty” photo style: “Cirrus castellanus slightly below Cirrus spissatus, both above parking area and partially occupied buildings.” $525

2:13 PM. Giant Cirrus castellanus turret springs from Cirrus streak. When they're flattish, you'd call them Cirrus spissatus. If in more of a sky covering layer, sans breaks, Altostratus, not Cirrus, because of the shading. ONLY Ci spissatus can have shading and still be termed Cirrus. — 2:13 PM. Giant Cirrus castellanus turret springs from Cirrus streak. When they’re flattish, you’d call them Cirrus spissatus. If in more of a sky covering layer, sans breaks, Altostratus, not Cirrus, because of the shading. ONLY Ci spissatus can have shading and still be termed Cirrus.

5:40 PM. Not great, but there was a knife-edge leading edge of an Altocumulus bank on the far horizon that added some drama to it. Note Ci uncinus, too. — 5:40 PM. Not a great sunset, as was hoped for, but there was a knife-edge leading edge of an Altocumulus bank on the far horizon that added some drama to it. Note Ci uncinus, too.

Watch for a sunrise color bloom this morning. Might happen, though coverage would appear to be a bit too much right now. And with so many clouds around, a good chance of a great one this evening. Charge camera battery.

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¹There’s get a modicum of applause at the end of this video; no one really wanted to hear S&G play THAT song: “Why didn’t they play something good?” And, “Why are their heads floating around in the clouds?”

Before the rain: a LOT of clouds, some smoke

Got pretty upset later yesterday afternoon when I saw these scenes off to the south through west, creating a little “sky rage”:

4 PM. View to the southwest toward Twin Peaks.

4:58 PM. Vierw toward the west and southern part of Tortolita Mountains. — 4:58 PM. View toward the west and southern part of Tortolita Mountains.

Its not CIrrus or Cirrostratus you see, my friend, though as a nascent cloud expert, a CMJ, you may well have told a neighbor at the time of these photos, “Look, here comes the lead Cirrostratus undulatus (its had waves in it) clouds that precede our rain in a couple of days.”

You might even have gone on quite a bit about it, but you’d have been so WRONG and had to have apologized to your neighbor the next day, “after further review.”

What did you review?

The satellite infrared (IR) imagery, locally available. What would have been the obvious problem with your pseudo-astute cloud discussion?

If there is no cloud indicated in the IR imagery and KNOWING that if it IS Cirrostratus, no matter how thin, if its pretty widespread, as it is in these images, it WILL be detected in the satellite IR images¹.

Let’s check if there is a cold cloud encroaching on Catalina around the time of these photos:

4:15 PM AST. Cold-topped clouds not even close, though they are moving this way fast. Maybe we'll see some lead clouds on the horizon at sunset... Post event thought. See 3rd photo. — 4:15 PM AST. Cold-topped clouds not even close to Catalina. What were you thinking, saying you saw some Cirrostratus? However, those high and cold-topped clouds ARE moving this way fast. Maybe we’ll see some lead Cirrus clouds on the horizon at sunset… Post event thought. See photo below.

Nope.

5:56 PM. Note thin linear shadows in front of Cirrus clouds.

Let’s also check, too, with our AOD (Aerosol Optical Depth) sensor on a satellite to see if it has any smog in it around here (below). Now this image below is an integrated view all the way to the ground, and so it can’t tell you what height smog is at. But, from the ground yesterday afternoon, we could “fill in that blank” by seeing that its way up there, probably at or above 20, 000 feet above sea level.

: Below: valid at 3:15 PM. Shows region of thin smog clockwise, south through west through NW of Catalina toward where the first two photos were taken.

Next, after you’ve apologized to your neighbor, he might well ask of you, “Where did it come from, if that’s a smog layer up there?”

To prepare for such a query after you had learned that it was not a CLOUD, but rather smog, you would have used an estimate of its height (say, 7 km above sea level as a starter value), and gone to NOAA’s Air Resources Laboratory’s HYSPLIT model and prepared a few back trajectories for a few days, ones that end at Tucson, or even our exact lat and long. If you had done that, here’s what you would have seen this morning for a back trajectory for FOUR days, ending over Tucson at 5 PM AST yesterday for 6000 meters above sea level:

The star is the end point for 5 days of model calculated backward air trajectory for that air over Tucson at about 7500 meters above sea level, about 5000 meters above the ground. — The star is the end point for 5 days of model calculated backward air trajectory for that air over Tucson at about 6500 meters above ground level, a first guess (not really) for the height of the smog layer in the photos. Other levels above this level look pretty much the same. Each fat triangle is a day. I put a LOT of writing on this, I HOPE it helps, but not sure. These graphs should have the start point for the vertical cross section at the bottom on the other side!

So, it would appear that our smog layer may have originated as part of something coming across the Pacific from Asia. There are no fires in Canada and in the Rockies that could have lofted a smoke layer like the one we saw yesterday. Confidence level? Moderate at best since the height of the layer had to be estimated by eyeball. You can go HERE to make your own plots like these, that is, to the Air Resources Laboratory of NOAA.

Clouds? Must talk about clouds.

There’s a lot of them headed our way. Check this annotated gif with writing on it from a couple of hours ago:

At 3:30 AM AST. I’ve written some things on it, and since we know from recent educational attainment studies that US students lack much geographical knowledge, like where the Pacific Ocean is, I thought I would see if anybody notices a problem here.

Big Pac IR loop from the U of WA Huskies Weather Department here. I had to use these images for the whole western Pacific down to the Equator so that you could see the whole of the cloud system that is now impinging on the West Coast of North America, from Manzanillo, MX, to Alaska. Pretty cool, huh?

Of course, as we know, the first of these clouds coming toward us, and for the next couple of days, will be high and middle clouds like Cirrus, a lot of Altostratus, and some Altocumulus. Might see, as happened yesterday afternoon, a Cu fra over the high terrain. (There is a little moist layer around 10,000 feet above sea level, according to this morning’s Tucson sounding.)

The rain gets here, the mods say, finally on Saturday morning, the 26th. There will be breaks in these high and middle clouds, and with luck, one or more super-spectacular sunsets/sunrises in the next three days.

Enough! Quitting…..TE.

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¹Itty-bitty patches of Cirrus won’t be detected in the IR imagery. Its has to be a couple of square kilometers to be detected by the NOAA GOES satellites, the kind from which most weather imagery originates. Usually though, when Cirrus clouds occur, its detected because there are many larger patches besides the tiny ones. Tiny ones in isolation are rare, often associated with contrails.

Warm and cold “combo” storm’s rains in route, and sooner rather than later!

Wow, over the past 24-36 h the models have been wetting it up more and more for Catalina! Check this depiction out for the first day of the rains, now on the 26th, this Saturday. from our Canadian friends and their big weather forecasting model–rains not waiting until Monday, the 28th as the models were predicting a couple of days ago:

: Valid at 5 PM AST, Saturday, the 26th. The green areas are where the model thinks it has rained in the prior 12 h. Where the green goes to yellow or orange, the model is very excited about a LOT of rain in those regions.

I’ve added arrows to point out the vast area of rain arriving the western coast of all of North America from Anchorage to near Mazatlan from a combination of storms. Don’t see that happen too often; maybe in December 1994 or was it January 1995 was the last time when it started raining in Seattle and San Diego at the same time?

This is because our little low in the sub-tropics, now off’n Baja, will be shoved out of its position earlier and with more water in it, after fiddling around out there, not doing much, by an encroachment of the westerlies. Spinners, like that one off Baja right now, don’t like that and they really go to pieces. Instead of being circles with the air going round and round, sitting more or less over the same spot, they become “waves”, “troughs”, little dents in the westerlies that whoosh on toward the east or northeast, more commonly, carrying all that juicy moisture with them.

Here’s the scene from last night at 5 PM AST from the U of WA:

And look what happens after our tropical spurt, it just keeps on preciping as a polar trough from deep in the main westerly current drops down into the SW from the Pac NW. This could be real great for precip here. In cuisine, this sequence is going to be be like having a bowl of chicken soup followed by a bowl of ice cream.

Valid at 5 PM AST, Sunday, January 27th. Its still got precip in it for us as a the cold punch of this "combo" storm settles into the SW. — Valid at 5 PM AST, Sunday, January 27th. Its still got precip in it for us as a the cold punch of this “combo” storm settles into the SW.

And, this rain, likely ending on the 28th with a close call for snow here in Catalina with temps in the last bit of rain down into the 30s.

Earlier guesstimate of half an inch here Catalina, made too soon for truly responsible weather journalism, might even be too low. Imagine? We need a good rain so badly! Think of the cost benefit of this precip for all of AZ if these storms play out like this. And, this close in time, our models should be pretty accurate. So, lots of reasons to be happy for crops and critters today!

Yesterday’s Cirrus and Cumulus (?)

Some gorgeous Cirrus formations floated slowly overhead yesterday, first going one way and then another as the day worn on. I wonder if you noticed that band of Cirrus that sat overhead almost all day before trudging off to the south and then disappeared? That change in winds at Cirrus-level during the day yesterday, is evident in the U of AZ time lapse.

Here are a couple of shots of that overhead band that hung up there almost all day–began to think that the photos I have been posting are “too pretty”, and so I thought I would add some grittiness to them:

2:09 PM. "Hooked and dense Cirrus over water tank." — 2:09 PM. “Hooked and dense Cirrus over water tank.” (Uncinus and spissatus mostly).

2:22 PM. "Dense and tufted Cirrus above gas truck." ($500) — 2:22 PM. “Dense and tufted Cirrus above gas truck.” ($500)

Finally, can you find the Cumulus (fractus)? Believe it or not, there were large Cumulus and Cumulonimbus clouds near Nogales yesterday afternoon, and lightning was spotted from there!

: 3:34 PM. “Find the Cu”, a new game from the manufacturers of WeathKit.; There were some gorgeously fine strands from these clouds yesterday, too. Hope you saw them.; TE

While waiting for the rain, yesterday’s Cirrus

In case you like to go to the end first, a quite nice one:

A little whirl in the air overhead and to our south now seems to have spawned some Altocumulus castellanus (Ac with vertical spires), according to nighttime sat imagery. Could be a very nice sunrise this morning, and because they’re going to be cold (colder than 0 F), likely to be some virga around, something that would really enhance the sunrise color.

It now appears the skies will clear completely later in the day as it passes by.

“In other news….” the tremendously cold air foretold in the models, supported by spaghetti, to ravage the East maybe ten days ago is now beginning to arrive. They’ll be some whining from back East (as in the next segment). Perhaps some folks in the East will now throw in the towel and finally decide to move to Arizona. Pretty sure some will.

A whiny, Seattle note: one of the HARDEST things to take when I lived there and biked to work for about 25 years, was the very pattern we have now with Seattle sitting under a HUGE, high amplitude bubble of warm air known as a ridge. The jet stream and storms are about as far away as possible in January from Seattle, and its nice and toasty along the West Coast IN GENERAL. Here’s a loop of the 500 mb maps (requires a lot of bandwidth). Below, the 5 AM AST map for this morning, illustrating the CLASSIC, “Warm in the West, cold in the East” one:

But not “warm in the West” for Seattle.

Fog forms in Puget Sound under these situations and the sun is too weak in all that clear warm air just a coupla hundred feet above you and often cannot burn off this shallow fog that you can see through a lot of the time!

And even if it does clear up, as it eventually did yesterday afternoon (time lapse there from just about where my Dept lab-office was), its still cold and clammy all day (yesterday it was 38 F in SEA with the sun out in the late afternoon). Sometimes the fog was so thin you feel like you could reach up and touch the warm air you knew, as a weatherman, was just above you.

So, like the last few days in SEA, you get foggy days, and “high” temperatures in the 30s, often with frost and ice on the roads in the mornings, so you can’t even bike to work in this “fair weather” pattern. It was tough to take because you had such a great chance for a sunny day with the storms pushed elsewhere, and it didn’t happen.

End of whine; glad to be in Arizona. I did love my job and my pals there in SEA, still do.

Rain still ahead here for the 28th; varies in amounts from model run to model run. Moisture from that storm now off Baja in the map above (its got lightning in it) will fiddle around out there until some westerlies “swooshes”¹ the remains of that system this way late in the week.

Sadly, there appears to be no rain in sight for us after the 28th episode.

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¹Can I say that without a Nike copyright release? FYI: the Nike “swoosh”…cost Phil Knight $35 to have it made.

The trillion dollar storm

First, let’s catch up on drought…from who else but the Drought Monitor folks at Big Red (UNL). They know best:

The scoop

A storm from the Pacific passes slowly over Arizona on the 28th bringing desperately needed, soaking rains to almost all ag units, wildllife, desert vegetation, and us. It then plods on across NM and into the Plains States doing the same, eventually exiting across the Ohio Valley, having drenched some of our most drought-ridden regions between the 28th and 30th. These beneficial rains across so much of our country might be worth a trillion in 2013 dollars¹, hence, the moniker, “The Trillion Dollar Storm.”

Here are a few IPS MeteoStar panels (I favor their depictions) from yesterday’s 5 AM AST model run because they’re a bit more spectacular than last evening’s 5 PM AST run (remember from spaghetti the storm on the 28th is in the bag for AZ, and that each model run from here on out will be more or LESS spectacular in rain production, so why not take the “best of the best”? A few panels with the most rain in them to put in your model outputs scrapbook? Too, I was afraid you hadn’t seen these, and I just couldn’t let go of them myself, like pictures of an old girlfriend you just can’t throw away but probably should:

2013012812_2013011912_CON_GFS_SFC_SLP_THK_PRECIP_WINDS_216 — Valid for 5 AM AST, January 28th. Been talkin’ about rain on this day lately, and here it comes from the Pacific across both California’s.

5 pm 28 Jan 2013011912_CON_GFS_SFC_SLP_THK_PRECIP_WINDS_228 — Valid at 5 PM AST, on the 28th. Soaking rains cover much of the State especially in the central mountains.

29 Jan 5 AM 2013011912_CON_GFS_SFC_SLP_THK_PRECIP_WINDS_240 — Valid at 5 AM January 29th. The storm is slow to depart, and more soaking rain has occurred in the 12 h prior to this map (dark green and blue regions). How much is such a rain worth to our wildlife and vegetation alone?

5 PM 29 Jan 2013011912_CON_GFS_SFC_SLP_THK_PRECIP_WINDS_252 — Valid for 5 PM AST, on the 29th. A storm center has intensified in the central Plains States and a tremendous rain, snow to the north, has enveloped it. It moves out slowly with a soaking rain shield to the north and west of the center.
It could hardly be better than this given the intensity of drought in this region.

Pretty much the same thing popped out of the models from last night’s 5 PM AST global crunch, so its great now that we have 4 model runs separated by 12 h each that have substantial AZ rain! Gives confidence that this rain will occur as predicted, as well as that confidence that came from yesterday’s venerable spaghetti plots. I am so pumped! In the depictions above, Catalina gets about an inch of model rain!

Reality, of course, will be something else, but now, in these model outputs, us Catalinians are more into the rain areas predicted than on the edge as was the case a couple of days ago, less “iffy” for a rain to happen. So, I am going for it: one half inch in Catalina on the 28th. You won’t hear your favorite media weather presenter telling you this today because its not really responsible to say an amount this far in advance. But, here on the internet? Anything goes, and I have demonstrated that just now.

Clouds?

I know that if I were to read your weather diary for yesterday it would read something like this;

“CIrrus lurked on the south to through west horizon all day. Didn’t come over Catalina, just kind of stayed down there. I was hoping to see more of it.”

Here is that stagnant Cirrus at sunset that you wrote about yesterday. You DO have a weather diary, don’t you?

Expect some more patches of Cirrus today. You can see the “moisture front” these clouds were in yesterday here in this water vapor loop from the University of Washington Huskies Weather Department. That whitish area on the southern AZ border is where the Cirrus clouds were yesterday. You will be able to see the “white stuff” (areas with more water vapor) beginning to head this way.

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¹In the 1960s we would have termed this upcoming storm a “Million Dollar Storm”, but with today’s economic realities, where we talk about “trillions and trillions” of dollars all the time, a “trillion dollar” this or that seems more appropriate, more “with it.” Its great that dollars are only made out of paper; there will always be more paper for dollars! If they were made of anything else, I am sure we would run out of it.

Increasing panels of rain on the 28th

Twenty-four hours ago there was ONE panel of rain over Catalina, a “spittance”, a taunt, and now there are TWO panels of rain for Catalina on Friday, the 28th of January, ones that have appeared in the model output from last night’s 5 PM AST global data crunch. FOUR panels, total, having rain/snow SOMEWHERE in Arizona are now calculated with that same storm!

And, today, its only NINE days out from real time, which is better than 10. Has a tad more credibility. Here are two of the AZ rain (snow in the north) panels from IPS MeteoStar for you personal inspection:

Valid for 5 PM AST, Thursady, the 27th. Big storm approaches Catalina. — Valid for 5 AM AST, Friday, the 28th. Big storm approaches Catalina. Tropical moist plume formerly sitting around not doing much way off Baja, sucked into Baja. Colored areas denote those where the model thinks rain/snow will have fallen in the prior 12 h. Remember, this is from a numerical model having a lot of equations in it, not from hand-waving.

Valid at 5 PM AST on the 28th. An arrow has been added to help you locate Arizona.

Valid for 5 PM, January 28th. Classic upper level pattern supporting rain here. Big trough in the Far West.

So, for a credibility check on rain, “Who you gonna call?”
Spaghetti busters!

Well, more completely, “spaghetti possible storm busters!”

Here is last night’s “ensembles of spaghetti” from the NOAA supercomputers for the 28th.

A quick glance of no more than 1 second will tell you that this storm in the West on the 28th is just about guaranteed now. Deliberate little errors introduced in the model run at the outset of data crunching, little errors that produce all the different lines (contours) did not shake the original output to death over the West; we still got us a big trough as indicated by the red and blues lines both dipping to the south in the western US. That “coherence” in those lines means a welcome widespread precip event in the interior of the West, including Arizona on the 28th.

As in so many cases this season, we are a bit on the edge here in Catalina, so rain here is more “iffy”, not guaranteed, as it would be, say, for Flagstaff, but rather just, “likely.” Certainly another temperature plunge after a string of pleasant days is “guaranteed” about this date with this system. Hoping for more than lowering temperatures and cold air.

Where are we today?

The long foretold scenario in the models, strongly supported by spaghetti, “Toasty in the West, brutal cold in the East”, is about to happen.

80s forecast for southern California, nice here, too, now. 69 F here in Catalina yesterday.

Meanwhile some godawful cold air is readying for a southern plunge from the Arctic, colder than the air ALREADY plunging across the northern Plains States today. Here is the actual map, from the quite wonderful maps provided by the University of Washington Huskies Weather Department of which I was a member until I retired because, “It was time to go” as I wrote in my resignation letter; didn’t want to “hang on” kind of like Willy Mays¹ did past his prime, that is, to impede progress in science by “hanging on” as brain dimmed, thus squandering public monies from research grants. That’s why I am here in sunny Arizona writing silly blogs like this one..

Oh, yeah, that map:

: 5 AM AST THIS morning. Its got writing on it.

As much north and south amplitude as is shown on this map shows, there will be even MORE amplitude in the next 48 to 96 hours with warm and cold temperature extremes reaching their peaks. Expect to read about them affecting the East in that time frame.

Then all of this amplitude you see above “melts down” into more of an west to east flow pattern–remember flow is along the (green lines, aka, “contours”). With west to east flow, temperatures moderate from extremes.

Clouds?

There’s a clear air gap in those tropical Cirrus clouds that we saw yesterday. Another batch, now over Baja (see map above) is creeping northeastward toward us, and we’re likely to see some of them before sunset.

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¹Willly Mays, one of the greatest baseball players of all time in New York as an outfielder with the Giants. But when the team moved to SFO, Willy was past his prime, didn’t make those great catches anymore, and his batting average went to hell. He was even booed in SFO! Hard to imagine. But then the saying arose about him, “He played too long.”