It was quite a surprise to this observer who claims to be a “cloud maven”, but whose credentials must be questioned, even if I do say so myself. Was thinking plain old small to moderate Cu, hold the ice.
But in a long cloud street, appearing to emanate from Kitt Peak, some ice started to show up in the cloud row upwind of us. Wonder if you saw it? The first ice happened around 3:45 PM, followed by a couple drops at 3:59 PM. Well, as Rob Reiner might say, enough of my yammering, lets get on with the cloudumentary:
Yesterday’s clouds, lot of ’em
12:00 Noon. Small Cumulus clouds have arisen all over, its breezy, and some Cumulonimbus clouds can be seen on the distant horizon, on is there on the right. SO NICE to see our usual deep blue skies back!12:00 PM or is it AM? Noon, anyway. Cumulonimbus calvus launches northeast of the town of Oracle. Can you tell that this fatter cloud is all or mostly all ice in its upper portion?
12:01 PM. There’s a little cloud street coming off Pusch Ridge and heading toward Catalina. Later the wind direction changes and the cloud streets come from the southwest rather than south as here.12:36 PM. Not much has changed. Maybe its because its only been 35 minutes since the last photo….2:38 PM. Still not much going on. No ice or anything, Cbs way over there to the north. Might as well take a nap than be conscious through this slack period. Nice shadow though… Wonder what’s causing it?2:38 PM. Hah! A cloud street is right over ME!!! Looks like its coming from as far away as Kitt Peak! Cloud streets are pretty harmless, don’t really do anything except cause shading over favored areas. They recur over the same sites over and over again when the moisture and wind are right. Notice, too, that the wind has shifted in direction some 45 degrees or so since the cloud street that formed over Pusch Ridge around noon.3:28 PM. That old cloud street off’n Kitt Peak is still chugging along, passing right over Catalina/Sutherland Heights. Can’t really expect anything to happen though in the way of “weather.” Just a harmless cloud street…3:35 PM. Cumulus clouds are fattening up, though. Maybe they’re getting some extra calories, solar ones! Wow, where did that come from?!3:36 PM. Even some ice starting to form in these little guys! Wow, did not expect that! (That little whitish veil, center right. That means precip is coming out, snowflakes melting on the way down. But, coming out the side of the cloud like that means its almost impossible for them to survive the fall to the ground.3:56 PM. Cloud street still intact. But, OMGosh, one has ice in it! Can you see it, that frizzy stuff, center? And, its going to pass right over! (A few drops fell for just seconds at 3:59 PM!) Amazing, did NOT see this coming!Approximate locations of Catalina and Kitt Peak OBSY on a 4 PM 1-lm resolution visible satellilte image from the University of Washington Huskies Weather Dept. Image used without permission. That little white, broken streak is our cloud street that passed overhead, some cloud developing into congestus sizes, and spewing ice.4:51 PM. Cloud street still intact. Windy, too. Maybe that fatter cloud, center, will develop some ice….. Its gonna pass right over, too.5:09 PM. Abandoned station to get supplies, and on the way back on Golder Ranch Drive, this nice scene of the shadowed Catalinas. Not taken while driving, of course, That would be crazy! As a photographer you live for these kinds of moments.5:14 PM. Cloud street still intact! Large drops falling from cloud overhead; would be from melted graupel/soft hail up there!5:14 PM. Looking straight up at all that ice up there. Amazing since it wasn’t expected.5:26 PM. Since we were on the threshold where the ice was just forming up there, more rain fell out just downwind of us. If you look closely you’ll see there’s a rainbow to prove that I am not lying about more rain falling downwind from us. Might even have measured!5:47 PM. Our cloud street is releasing from its origin point and the tail end will now pass over, No more drops, as the cloud elements became shallower under a fading sun.6:31 PM. The remaining small Cumulus clouds made for some golden color at sunset. Very nice.
Enough lower level moisture for Cumulus again today, but even smaller ones than yesterday. Since the wind is already noticeable now at 6:26 AM, better mention that we could have noticeable winds again today. (Much windier yesterday than anticipated by CMP; wind was not on my radar if wind could be seen by radar (well, of course it can when they are raindrops or bugs. Hah!)
Big intrusion of unusually cold air still coming into the West in about a week. Some of that will reach right here in Catalina really giving the sense that its truly football season.
Nothing much else here of too much interest except the usual cloud blabber… haha
7:00 PM.7:04 PM. Hope you saw these!5:50 AM. Moon dodging clouds, Altocumulus ones. Moon dodgers? Did you know that the University of Washington sport’s teams were once known as the “Sun Dodgers”? How funny izzat? It’s truly amazing to me what you learn here.2:47 PM. Icy tops move toward the Catalina Mountains.3:54 PM. Not much going on over the Catalinas. But, can you spot the first ice from these clouds? You’d have to be pretty darn good to do that.3:54 PM. Zooming…. There it is! Have to look hard for the arrow and the bit of ice haze below that flat section. This would be a great ob day for an aircraft, since it would mark the threshold of temperature where ice is starting to form. Deeper, colder clouds from this threshold level would have more ice, a lot more. This level can vary from day to day, depending mostly on the sizes of droplets in clouds. With bases near freezing yesterday, this level would likely have been at the -12° to -15°C level, up around 20,000 feet above sea level. Bases were around 14,500 feet above sea level.5:23 PM. Nice lighting. I like lighting and lightning, no so much lightening, since a storm could be ending then, or if its around dawn, its OK. You can see two eyes, squinting….5:43 PM. Nice base streaming from Pusch Ridge enlarges as it came almost overhead! Looks promising for a SPKL. Moving car out from carport so’s I don’t miss a few drops.5:54 PM. Fine strands of rain now becoming visible!6:19 PM. Strands of rain in full display in RW-. Its measuring, not just a few drops! Need to roll up windows in car!7:13 PM. Not much happened just a little west of Catalina. Nice sunset, too.
Looks like another day for a chance of rain late….
Haha, most readers won’t even notice! But maybe some cow-centric, instead of cloud-centric, folks will drop by, raising the worth of this blog to above $35 if sold….that according to a “biz” site.
Had a rainbow yesterday. Hope you noticed. It was pretty early and overhead west. I think the clouds did not have ice in them. The rain echoes were not showing up on the radar, suggesting the beam went over the tops. Sounding suggested tops might have been as cool as -5°C. In any case, the drops were able to tip the bucket a couple of more times, and along with yesterday afternoon’s brief, light rain showers our total has climbed to 0.37 inches for the storm. Not bad, though as in money, you always want more.
These storm breakup days are always our prettiest, and that’s often what this site is about, being pretty. Yesterday had some fabulous scenes; couldn’t stop shuttering cam. It is a real neurotic compulsive behavior pattern, as afflicts some of us cloud and storm-centric folk. Check Mr. Olbinsky’s work; his work goes beyond phenomenal whether you want a wedding photographer or want to see a storm chasing video. But it takes that kind of eccentric energy to be special, to stand out as he does.
Here, though, we let the storms and cloud scenes, such as they are, hope for the best, and let them come to us…. Kind of a lazy storm chaser’s attitude.
5:49 AM. I really do think this rain came out of clouds that had no ice…maybe 70% sure.6:27 AM. Stratus fractus springing to life as Cumulus clouds lining the sides of Sam Ridge (Samaniego). Showed how much instability, the ease of which the slightly warmer air in these clouds could jut upward yesterday6:49 AM. Just pretty and so green after the rain.6:50 AM. Same scene, focusing in on a highlight.7:01 AM. More prettiness in a highlighted baby turret.7:01 AM. In case you missed it, here it is again, a little zoomed.9:03 AM. Rise of the Cumulonimbus capillatus incus (has anvil). This scene had a lot of portent for the day. You knew more would be forming, maybe drift over us later.9:33 AM. I thought this was a pretty neat scene, though its just a cloud shadow lining up with the rise of the Catalina Mountains.9:36 AM. Hmmmm. What the HECK is happening now? Low center was off in the direction, headed for us, with still cooler air aloft. But where are the Cumulonimbus clouds that should come with it? (They formed rapidly, but later.)2:23 PM. By mid-afternoon, things were swell all around, lots of Cumulonimbus clouds. They seemed to fade, though, as they marched toward Catalinaland, as this complex did. The rather sharp line in the lower part of the photo, and beyond which you can see distant clouds, is where the melting level was. This is often appears to be the “cloud base” but its really not in the sense of having cloud droplets. If you were to fly in it, all you would see is rain and melting snow just below this line, and just snowflakes above it. If the whole sky was covered in this, we’d call it Nimbostratus, and say the base was at that melting level.3:42 PM. Another pretty major band appears to be headed this way, rotating around that low center, shifting northward. Didn’t make it.6:35 PM. Somewhat promising that a nice dark line and heavy shafts were out there, thinking they might shift northward again. Nope. Fizzled.
Still cold aloft, so having some nice Cumulus today is in the bag, the early Stratocumulus devolving into Cu, that is.
Light rain showers overnight, just before midnight, and again just after 1 AM AST, raised our Sutherland Heights storm total to 0.33 inches, decent but disappointing in view of model and personal expectations (0.60 inches).
What was especially interesting is that those nighttime light showers didn’t show up on the TUS radar, suggesting very shallow tops, perhaps a “warm rain” event, one not having ice, or an “ice multiplication” event with tops warmer than -10° C, about where the tops were on the 5 PM AST TUS sounding.
By this morning, the tops were barely below freezing (about -3° C). Don’t expect to see ice today, except at Cirrus levels!
5:53 PM.
5:52 PM. Drawing back a little. Pretty dramatic scene I think with that sun break running along there underneath the Stratocumulus clouds.7:06 AM. Had another round of amazingly shallow Stratocumulus clouds precipitating on the Catalina Mountains. Hardly any depth at all to this cloud, and yet there the precip on the mountain! Tops were hardly higher than Ms Mt Sara Lemmon! Must have been drizzle. Let’s check the sounding nearest this time, see what’s up:The NWS at the U of AZ balloon sounding, launched around 3:30 AM. Seems to indicate cloud tops were colder than -10°C, plenty cold enough for ice formations, so not as exciting as if they were, say, at -5°C. So, I retract my excitement excitedly!11:00 AM. Still overcast with Stratocumulus clouds, but occasionally ones showing precipitation, making them the whole scene, Stratocumulus stratiformis (covers a big portion of the sky) “praecipitatio” (is emitting precip, here maybe drizzle) or it may be very light snow. You can just make out the snowline (center), around 6,000 feet on the Cat Mountains.2:01 PM. Eventually the sky broke open to reveal that deep blue we see in the wintertime as Cumulus clouds began to take shape. Aren’t these scenes tremendous, so clean looking, like you’re out at sea, far away from land?3:51 PM. Gradually the tops of the Cumulus clouds reached up to lower temperatures where ice could form and something resembling our summer rain shafts began to appear here and there.5:12 PM. The front side of somebody’s nice rainbow over there toward Marana.5:45 PM. And a little before the rainbows, some nice, dramatic lighting on our desert vegies under a dark overcast of Stratocumulus.
Last of the Cal rain blasters is making its way across the State today, with another 5-10 inches expected in favored Sierra and coastal ranges in the next 24-36 h. Numerous sites north of SFO have now logged over 100 inches since October 1st! Imagine. Great to see that Cal drought vanquished in a single year, so unexpected. Let’s hope the Oroville Dam, N of Sacto, holds.
The End
PS: Using point and shoot cam now with “real” camera in the shop for awhile.
Catalinans experienced a FOURTH cloudy day in a row, and, over the past few days, including yesterday’s few drops that fell at 4:24 PM, have experienced over an inch of rain!
Some grumbling has started concerning muddy, pot-holed and puddled up dirt roads, about the washes running across roads lately, water and mud splashing on the car day after day, and brutally low temperatures dipping to well below 50° degrees in the morning now for several days in a row. Its 40° F here as I write this.
While a brief respite is in progress now, Catalinans were discouraged to learn that more strong storms are due in this weekend, bringing possibly damaging winds and heavy rains that will augment the poor road conditions.
How much rain?
Let us look below and see how much has been calculated by our best model at the University of Arizona’s Wildcat Hydro and Atmos Sci Dept (I am so glad they provide this service; I donate to the Dept, as we all should!):
Precip totals by 8 PM, January 23rd after a few storms have gone by. As you can see lots of red and yelleows in Arizona’s critical mountain regions for snowpack, and we’re in the inch or so of rain, pretty much like the amount produced here by the last storm. What a January this is turning out to be!
Hah! We can’t complain too much about inclement weather compared to California’s pluvialities. Here is a table and map of precip amounts for that State through just the first 14 days. Prepare to gasp:
A map and table of the highest 20 rainfall totals in California and Nevada just through January 14th. Astounding! And 10-20 inches more are expected at some of these sites before the month is out. Yep, by Jan 14th, one station was closing in on 40 inches of rain!
The remarkable aspect of this rainfall anomaly on the West Coast and in the Southwest, which is also quite wet, is that it could not be seen in climate forecasts days to a couple of weeks in advance. Its not that the folks at the Climate Prediction Center aren’t the best that we can get, its just a statement about how hard it is to get a longer term forecast right. Many are right, but lately, recalling the “Big Niño Bust of 2015-16” where the forecasts of a wet Southwest and central and southern California went terribly awry, those forecasts have taken a beating. Here’s what was expected this winter by the CPC, first, for January, a forecast made on the last day of December. when the forecast models we use day to day would have had some influence:
The precipitation forecast for January 2017 by the CPC.
As can be seen, the extreme rains that hit California, and our own well above normal precip, though on the doorstep on December 31st, were unforeseen. That’s how tough it is.
Below, the forecast for January through March, also going astray, though a recovery could be had by a very dry Feb and March in Cal and the Southwest, something not likely to happen now.
Below, the forecast for the three month period of January through March, also now going astray.
Glad I’m not forecasting for a month or three months! Gads, yesterday we had ice galore here and there, and I had predicted that morning that it was doubtful that ice could form in our clouds yeserday and how about that rainbow yesterday afternoon, to change the subject quickly, but smoothly; hardly a ripple, something gleaned from the election debates:
4:59 PM. A rainbow, an implicit indicator of ice in clouds yesterday. There was a lot in some areas, particularly over the Catalinas in the late afternoon.
Some additional views, including a horse, which should increase web traffic:
Horse, muddy corral, and supporting rainbow evidence for why the corral is muddy. Horse “Chero-key”: “Why is that rainbow on my butt?”Rainbow empties into a NWS-style, 8-inch diameter rain gauge. Real weathermen have real rain gauges, not the cheap plastic toy types. Just kidding, CoCo and rainlog, orgs that use cheap plastic toy-type gauges. Just kidding again, CoCo and rainlog. orgs.5:09 PM. Here a completely different rainbow, because I moved a few feet, and the rain drops in the prior bows have fallen to the ground, empties into yet another 8-inch diameter rain gauge, a tipping bucket one which is online at KAZCATAL4. Its been under-measuring the rain, however, for some time.
OK, now for the rest of the day, your daily cloud diary:
8:09 AM. You got yer normal TUS exiting smog plume heading for Mark Albright’s house in Continental Ranch over there on the right. There is some Stratus fractus in that plume as well. The damp air has caused some of the hygroscopic particles to swell up; be deliquesced, which increases the opacity of smog. Such an effect is particularly bad on the East Coast ahead of cold fronts when warm, humid, smog-laden air is brought northward ahead of fronts. Gads, its awful. Even when the sky is cloudless, you can hardly tell its blue! Above the smog, Stratocumulus.9:36 AM. Had evidence of a little smog up thisaway, too. Again, the whitish haze is due to deliquesced partilces. As the air dries out and the day warms up, this effect disappears. even though the aerosol particles that were “deliquesced” are still around. The Five Satins, “Still Around.” Gads, that takes me back a-ways when I was 2 inches taller than now….10:10 AM. Smog plume, as sometimes happens, begins to drift northward as the mountains start launching Cumulus clouds and cause the wind to move toward them. Can’t say too much about the central cloud feature, a gesture of some kind it would appear.10:27 AM. Nice lighting scene I thought. Cumulus turrets were rocketing upward at this time.1:48 PM. Not much going on. Underlying Cumulus bases lifted, some Cumulus spreading out adding to the slightly higher general Stratocumulus deck. No ice around, as was forecast.3:02 PM. Something is going terribly WRONG with the anticipation of no ice producing clouds yesterday. Rain begins to fall on the Catalinas.3:20 PM. A totally humiliating, completely glaciated tiny Cumulonimbus remains breaks into view from the Stratocumulus deck. On the other hand. another fascinating day of ice multiplication here in Arizona! Look at that little guy, all ice, and tops almost certainly warmer than about -12° C from sounding data. This would mean that those 10s to hundreds per liter of ice that you’re looking at are needles and hollow column ice crystals called “sheaths.” Man, I wanted to sample that cloud so bad! What happened to cause this cloud was that at one point its top got a couple of degrees Celsius colder than the surrounding clouds that did not produce ice. Rain was reaching the ground at this time o er there even though it is in the dissipating stage, too.3:43 PM. In the meantime, the showers emitting from the clouds over the Catalinas were getting more enthusiastic (read, “personally insulting”). No doubt if you could get on top, they would have looked exactly like that dissipating Cb shown above.
But, then there were some great sun and lighting scenes in those showers, not to mention the brilliant rainbow that was to come:
4:47 PM. Its a little crazy, I know, but I just love these rainy, sunlit scenes on our mountains, or those sun and shadow scenes that I post so many of. Just never will get tired of them.4:51. More of same. Notice inclusion of man-sized rain gauge in foreground. Its a nice touch if you, too, have one, which I hope you do. It really says who you are.
0.24 inches was recorded after 7 AM yesterday, bringing our voluptuous rain total to 0.95 inches1. How nice.
Dry spell ahead now, maybe a LONG one. “Fiddle-dee-dee.”
Yesterday: another day shallow precipitating clouds and “ice multiplication”
Seemed to be another day of “ice multiplication” here in southeast Arizona, a term that was coined in 1969 by Peter Hobbs of the University of Washington when he and his group reported that clouds were snowing on the peaks of the Olympic Mountains when the cloud top temperatures were warmer than -10° C (14° F). They had a hut on the top of Mt. Olympus at 7,000 feet! Lots of stories about that experiment, many swirling around Abdul Alkezweeny, a Peter Hobbs grad student in those days. An aircraft with skis landed up there to bring supplies! Imagine. (Yours truly was not embedded in the Hobbs group at that time.) It was an exciting time in that group, prior to the acquisition of their first research aircraft, WWII B-23 “tail dragger.” Peter himself, did not fly in this with RARE exception. Many flights were quite sickening, bumping around in Cumulus and small Cumulonimbus clouds, spinning around power plants stacks, wings vertical to ground….
In a nostalgic mood, posting this photo of our venerable B-23 research aircraft in which I spent SO MANY hours!
His group’s observations, however, were not the first, but were among many airborne and ground reports in the mid and 1960s that left jaws dropping about how much ice was in clouds at these moderately supercooled temperatures, even in clouds with tops as warm as -4° C. It was believed, in various ways that ice nuclei measurements were made on the ground, or in aircraft measurements, that not much ice would be found in clouds until the top temperatures was lower than -20° C. In fact, it was generally believed that only about one ice particle per liter would be found in clouds with tops as cold at -20° C, while actual observations were telling a much different story.
This discrepancy between measured ice nuclei concentrations is a scientific enigma that is still being investigated today! And it appears that me and you cloud maven juniors out there got to see it again yesterday, the second day in a row to see an cloud-ice enigma (“nigma” for short)!
Let us continue this module by examining the assertion of “ice multiplication” with the TUS balloon soundings for yesterday morning and evening as rendered by IPS MeteoStar:
The TUS rawinsonde balloon data from yesterday morning. Launched around 3:30 AM AST.The TUS rawinsonde profile yesterday afternoon, balloon launched at about 3:30 PM AST.
These soundings strongly suggest at the start and end of the day, that coldest cloud tops were warmer or no colder than -10° C.
However, the fly in the oatmeal here is that a cold front and associated wind shift came through in the mid-morning hours, heralded by an little arcus cloud, and cloud tops would have been somewhat colder during that period of rain; we don’t know for sure how much, and satellite imagery suggested lower temperatures, though possibly due to over-riding CIrrus cloud above the “Nimbostratus” layer that produced the steady light rain.
However, the rain before the front went by, and the very light rain showers that fell in the late afternoon were likely well represented by the TUS soundings. That’s my case! Wish I’d had a cloud-instrumented yesterday and the day before. Woulda got a paper out of it: “Ice multiplication rampant in Arizona!”
Yesterday’s actual clouds
No more hand-waving…. Let’s see if it really was raining near the time of the TUS soundings above. Picture of the day:
5:18 PM. Rainbow goes INTO a RAIN GAUGE! Amazing. Proves that it was raining, though very lightly (RW–) at 5:18 PM, when the sounding profile was likely valid for these light showers. Q. E. D.! Yours for $2,000, today only. Should get a lot of money out of this photo. I had to practically have the camera on the ground to get the right alignment and illusion. 8:08 AM. Misty, light rain showers shower on the Catalinas and in Catalina itself.
8:50 AM. Misty light rain continues from relatively shallow clouds. No shafting observed, something that would suggest much taller cloud tops. These were likely “mounding” up there, like rolling hills, mounding the most prior to releasing slightly heavier rain. Here’s where you would be thinking, “Could this be ANOTHER ice multiplication day? Wow, if so.” And, of course, the thought of it being a warm rain process day (no ice, thank you) can’t be ruled out either, since rain can form at below freezing temperatures in clouds, though supercooled raindrops are the most vulnerable to freezing at high temperatures, to go a little deep here, and complex the interpretation some.
That was phase one of yesterday’s weather, rain from shallow clouds.
Phase 2 is, “The front marches in across the OV! Cloud depth not so certain, but is probably not real deep, as inferred from the disappointing amount of rain that fell so lightly from the frontal band in spite of its dramatic entrance, fronted by an arcus, wind shift cloud.”
9:55 AM. Here comes the front and arcus wind shift cloud!10:06 AM. Here the approaching front and wind shift appeared to have jacked up a cloud top near Pusch Ridge. Was thinking, as you were, maybe we’ll get some thunder today.10:14 AM. Arcus cloud rolls fast across the OV; rain follows.10:19 AM. Arcus cloud passes over Sutherland Heights, and light curtains of rain begin to fall from it.11:26 AM. The end is near. The sun became visible after only an hour of steady, very light rain, and a tenth of an inch of rain. Thought there might be a gush in this, but, no. This also points to shallow, mounding or even flat cloud tops, not tall ones. This was not a good sight.
But, as those who live here know, some of our best scenes are AFTER after the rain has stopped and the skies partially clear. Yesterday was no exception. But first, the Stratus, which you don’t see too often:
1:09 PM. Looking north at a Saddebrooke highlight. Stratus is beginning to break up out there.1:11 PM. Stratus in the cold air following the frontal passage (“FROPA”, in weather speak or texting). Not budging yet.1:35 PM. Yep, only 25 or so min later, this! So pretty. Stratus fractus lining the area around Charouleau Gap.2:30 PM.2:57 PM. Cumulus puffing up by the minute. Will they form ice?3:04 PM. Just a pretty scene of Cumulus over there toward Saddlebrooke.4:02 PM. A bit of a surprise as a group of precipitating Stratocumulus like clouds came rushing in. No shafts, suggesting tall tops were seen, so likely again just mounding tops up there.5:24 PM. As the last sprinkles ended and the sun peaked through an opening to the SW, our mountains and clouds lit up with an orange tint. As the air cooled the Stratus fractus clouds (highlighted) again were once again straddling the side of mountains near Charouleau Gap.
Looks like only streamers of high and middle cloud from the tropics as California gets blasted with extremely heavy rains over the next two weeks. Totals in favored central and northern California coastal ranges, and in the central and northern Sierras will fall between 20 and 30 inches of rain during this period. A great place for you and me to be would be near the King Range, Shelter Cove (see below), or Honeydew to see those pounders.
Part of Shelter Cove, CA, with King Range in the background. A coastal jet rams the King Range and causes prodigious rains from ordinary looking storms. Average precip more than 100 inches, farthest south point for such a high average rainfall on the West Coast.
The End
—————————– 1The online gauge is a Davis tipping bucket. It has been consistently under-measuring totals recorded in the NWS 8-inch diameter gauge, and the 4-inch diameter, ground-mounted (it sits on the ground among grasses and weeds) CoCoRahs gauge. CoCoRahs is a national organization of rain and snow measuring nuts (haha, just kidding-they’re really precipophiles like me) all over the country and overseas as well. You can find them here. Part of the reason for the under-measurement of the Davis instrument is loss due to wind. That tipping bucket sits up at about 6 feet off the ground, thus sees a lot more wind than gauges on the ground. A gauge on the ground, away from tall objects, is always the best way to go! The reason for this explanation is because if you go to Wundermaps or Weather Underground and see the total for this site, it is ALWAYS going to be low compared to the actual amount that fell. This is a degradation that has come up over the past year or two.
3:55 PM. Rainbow fragment and solar home, an extraordinary combination.. It was yesterday’s visual highlight. Yours for $1995.95. And, if you order now, we’ll throw in a second, exact copy of this extraordinary, magical scene FREE!
Here’s a nice one from the day before as the clouds rolled in, starting with Cirrus and Altocumulus, lowering to Stratocumulus later in the afternoon.
Yesterday’s clouds; an extraordinary day with a little drizzle amid light showers
Hope you noticed the true drizzle that occurred yesterday, namely, fine (larger than 200 microns, smaller than 500 microns in diameter), close TOGETHER (critical to the definition of “drizzle”) drops that nearly float in the air. They may make the least impression, or none, when landing in a puddle.
When you see drizzle, you have the opportunity of chatting up your neighbor by educating them informally to what drizzle really is (many, maybe most, TEEVEE weatherfolk do NOT know what “drizzle” is, btw), and 2) by telling your neighbor, if he/she is still listening to you, that the droplets in the clouds overhead must be larger than 30 microns in diameter, or better yet, “larger than the Hocking-Jonas diameter of 38 microns, at which point collisions with coalescence begins to occur” and “drizzle is not produced by ice crystals in the clouds overhead; they’re not enough of them to produce ‘fine, close together drops.'” Your neighbor has likely left the building at this point, but, oh, well, you tried.
Here, in Arizona, shallow clouds, such as we had yesterday, hardly ever can produce the broad droplet spectrum in which clouds have droplets larger than 30 microns in diameter. Its because this far inland from the ocean, where the air is very clean, the air has picked up natural and anthro aerosol particles that can function as “cloud condensation nuclei” (CCN). As a result of ingesting dirt and stuff, clouds have too many droplets here as a rule for the droplets in them to grow to larger sizes. They’re all mostly less than 20-25 microns, sizes in which even if they collide, they can’t coalesce.
In “pristine” areas, if you go to one, such as on a cruise out in the oceans, droplet concentrations in clouds are much lower, and even a little water that might be condensed in a shallow cloud can produce a broad spectrum, one that extends to droplet larger than 30 microns.
So even little or shallow layer clouds can precip over the oceans, produce drizzle or light rain showers (in which the larger drops are bigger than 500 microns in diameter). Of course, here we recall that the (whom some consider “villainous”) geoengineers want to stop drizzle out over the oceans so that clouds have longer lifetimes, are darker on the bottom, and reflect more sunlight back into space.
Those guys can be lumped into the same ilk as those who want to change the color of the sky from blue to whitish or yellowish by adding gigantic amounts of tiny particles in the stratosphere, again for the purpose of cooling the planet! Unbelievable. Please ask before doing this!!!
A Pinatubo sampler for what “geoengineering” would do to our skies, say, sunsets in particular. I took this photo from the University of Washington’s research aircraft in 1992 off the Washington coast in onshore flow. But we saw these same sunsets, sunrises, yellowed by the Pinatubo eruption of June 1991 everywhere we went, including in the Azores in June 1992.
OK, pretty boring, whiney, really, so inserting picture of a nice horse here to make people feel better if you’ve been depressed about what our scientists have been pondering to do about global warming other than controlling emissions:
8:57 AM. Zeus. Led cloistered life for 13 years; likes to bolt, now that he’s getting out on the trails.7:40 AM, yesterday, Dec. 31st. The low hanging Stratocumulus clouds, about 1500 feet above Catalina, and the mountains had a bit of an orange tinge. It was probably due to sunrise color on a separate much higher layer.
Later….drizzling Stratocumulus, same view:
10:30 AM. Stratocumulus praecipitatio, if you want to go “deep” into cloud naming. “Stratiformis”, too, covers a lot of the sky. Note misty-like view, lack of shafting.12:48 PM. More Stratocu P., an example of those clouds in the distance that kept dropping little and light rain showers on Catalina.1:01 PM. Highlighting amid the RW– , (weather text for “very light rain showers”). Stratcu P., with maybe Stratus fractus or Cumulus fractus below. The shadowed, dark shred clouds in the mddle would be Stratus fractus IMO.3:55 PM. Zooming in on that pretty rainbow. You know, this is a cloud heaven here. I hope you all appreciate it! Maybe that’s why I get upset over “geoengineering” and changing the sky anywhere.3:57 PM. Between showers, but new ones erupted upwind. This one have a shaft, implying a higher cloud top than the prior, non-shafting clouds that brought us semi-steady RW–.
The second extraordinary thing about yesterday was that the top temperatures of these clouds was around -10° C (14° F), temperatures that ice does not form act as a rule in Arizona. To get ice at temperatures that high, you also need larger cloud droplets, and they have to occur in the -2.5° C to -8° C range. In this range, it was discovered that falling ice crystals, mostly faster falling ones like “graupel” (aka, soft hail) when colliding with larger drops, ice splinters are produced. The cloud droplets must be larger than 23 microns in diameter in THAT particular temperature zone, something that would occur more often in our warm, summer clouds, but would rarely be expected in our winter ones.
Why?
Again, it goes back to clouds in inland regions ingesting lots of natural and anthro aerosols that cut down on droplet sizes in clouds (by raising droplet concentrations in them). Our recent rains have helped cut down on that process on ingesting dirt, for sure, and was a likely player yesterday. Furthermore, our winter clouds are moisture challenged relative to the summer ones with their tropical origins and high cloud base temperatures, a second reason not to expect larger droplets in our winter clouds.
Here is the TUS sounding with some writing on it for yesterday afternoon from IPS MeteoStar. (Satellite imagery was also indicating warmer than usual tops for precipitating clouds yesterday.):
The TUS balloon sounding (“rawinsonde” in techno speak) launched at about 3:30 PM yesterday afternoon. Balloon rises at about 1,000 feet a minute, FYI. Typically they pop up around 100,000-120,000 feet! Instrument package is parachuted down so it doesn’t conk somebody on the head. Sometimes they are found and returned to the NWS and re-used! How great is that?
Here’s the punchline: If clouds are drizzling, then they are ripe, if the tops get to lower temperatures than about -4° C for what we’ve termed “ice multiplication” or “ice enhancement”. A very few natural ice nuclei at temperatures between -4° and -10° C, say, starts the process, those forming “soft hail” which then leads to ice splinters. This is the leading theory of this anomaly of ice in clouds at temperatures only a little below freezing, if you think 23° to 14° F fits that definition.
There are exceptions where this process did not explain the ice that formed at such high temperatures, so standby for further elucidation about how in the HECK ice forms in clouds at some point in the future.
As usual, no time to proof, so good luck in comprehending what’s been written.
The weather just ahead:
The second main rainband is just about here at 9:25 AM. Cloud tops will be deeper and colder than in the prior rains, raising the possibility of some thunder today, and maybe another third of an inch of rain. Watch for an windshift line cloud (“arcus” cloud) might well be seen today. That’s always dramatic and exciting here in Catalina cloud heaven.
Let’s face it, for most of the people living in Arizona, their best years are in the rear view mirror, as are mine which were probably about 50 years ago… Following that thought, let us not look ahead to further declines, but rather look back at the last water year for Catalina, ending this past September 30th, and see what it says, if anything, about the changing global climate we hear so much about:
Your Catalina water year history, compiled through 2008 by the folks at Our Garden there on N. Stallion Rs. off of Columbus Blvd. where you can find fresh organic vegetables every Wednesday and Saturday morning. Tell them Art sent you! Haha.
Can’t say I see too much going on here in Catalina so far; things seem pretty stable in the precipitation arena for the full water year’s rainfall.
I point out again, with great redundancy since I have pointed this out before, that the Our Garden climate record started just as a monumental change in circulation patterns occurred. Most climate scientists would attribute that to a shift as due to the Pacific Decadal Oscillation, discovered by important scientists I know well, like Mike Wallace1, of the University of Washington Huskies Atmospheric Sciences Department where I worked for about 30 years, but in airborne studies of clouds.
The PDO shift, if that’s what done it, was a circulation pattern change that brought astoundingly wet conditions to Catalina and the whole Southwest US, wet conditions unlikely to be seen in our remaining lifetimes, which aren’t that much longer anyway.
You may remember that bristle cone pine tree rings in California, analyzed by Haston and Michaelson in 1994, found only one period in the last 600 years (!) that was as wet as the late 1970s into the 1980s there (certainly spilling into AZ).
Remember how the Great Salt Lake was filling up to record levels back in the 1980s?
And any long term resident here, like the ones that I have spoken to, will tell you about the days of yore when the washes around here were running all year.
Well, that wasn’t the norm. sadly. They were just so lucky to have seen that era.
In weather, what goes around, comes around. Count on it happening again at some point in the future IMO. (Some climate changers might disagree with this assertion.)
How about our summer rainfall, June through September. Well, here’s that graph, updated through this past summer! Hope you like it:
Not much going on here, either.
Yesterday’s clouds–another day, another rainbow, of course.
Sprinkles of rain occurred off and on all day yesterday, but couldn’t muster even one hundredth of an inch of rain! With a few exceptions, the clouds producing the rain weren’t too deep, though still icy ones, and pretty high off the ground, mostly above 8,000 to 9.000 feet above us, which doesn’t help.
First, a rainbow shot:
4:20 PM. Looking north toward the Charouleau Gap (on the right). We have so many rainbows in Arizona, maybe, following the example of the University of Hawaii (Rainbow Wahini), the Banner University of Arizona sports teams should call themselves the “Rainbow Wildcats”…4:42 PM. Here’s a problem for a great shaft of rain, sloping tops of Cumulonimbus clouds. Don’t see any shaft here, just rain. When tops slope like this, it indicates the updraft isn’t very strong and the ice in the cloud is going to collect very little in the way of “supercooled” cloud droplets because the ice that forms is ejecting downstream from where the greatest growth would occur due to collecting cloud droplets, ones that would stick to the ice crystal, eventually making it a graupel or soft hail particle, the kind of thing that our vertical shafts are largely comprised of aloft. Slopey tops mean not a lot of growth of the precip, more “stratiform” like rain with fewer is any pulses of big drops.5:31 PM. Of course, still another rainbow. Notice how the colors are not as vibrant as some rainbows. This would indicate the concentrations of drops are less, and smaller than in the bright ones. So, not a lotta rain falling over there.3:50 PM. Now here’s a shaft with a real top, a pretty vertical one above it. There were a couple of these. Once again the spaces between the shafts lined up to pass over Catalina, rather than the shafts. The Tortolita Mountains got most of this one. I love these scenes, the backlighting, though, so many times they have resulted in disappointments.4:01 PM. The “Torts” cleaning up with a decent rain as that complex passed over them.5:19 PM. But even with a rain disappointment, we get to see these scenes here in The Heights over and over, again and again, to add to redundancy, We are so lucky! The cloud line above the mountains would be Stratocumulus.5:21 PM. Here crepuscular rays of sunlight produced by falling light rain diverge from the sun’s position. Light from an “infinite” source is supposed to be parallel at great distances. This seems to prove that our reality, as is sometimes suggested by philosophers, is not what we perceive with our tiny human brains. These diverging rays demonstrate that the sun is much closer to the earth and much smaller than generally believed by astronomers… The true reality of life and the universe are sometimes right in front of us.5:37 PM. By this time, the crepuscular rays and the existential questions they raised were gone and our perceived reality back to normal. Here a pretty good Cumulonimbus with a pretty vertical top and big shaft heads in the general direction of Catalina, once again raising hopes for measurable rain. Instead, it faded to sprinkles and our total rain from them was only a trace.
The End
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1Well, actually we said “hi” in the halls once in awhile, I gave a talk in his class once, and, along with a bunch of Atmos Sci faculty, got to watch the 1992 New Year’s Day Rose Bowl mash down of Michigan for the Washington’s 1991 NCAA Division I fubball championship at his house. He also mediated an authorship kerfluffle between Peter Hobbs and me.
Kind of getting tired of gorgeous rainbows every day, ones without a lot of rain here in The Heights. But, here they are again:
5:44 PM5:54 PM.
Upwind Cumulonimbus clouds faded as the trudged toward Catalinaland yesterday, bottoms evaporating, raining out, leaving only a big patch Altostratus cumulonimbogenitus way up (at least ten kft above the ground) there with rain drops just big enough to survive evaporation and reach the ground just before 3 PM.
2:18 PM. Heading for Catalina, right side will maintain–note nice flat base, left side of heaviest shaft is a gonner. So, hope is on the right (not a political statement, but rather referring to the part of the cloud you want to be heading for you, which is not the shaft itself due to the short lifetime of shafts, but the new parts where new shafts will emanate. No renewing base/updraft over there on the left. You hope that segment isn’t exactly heading for you. We shall see in just a few minutes of yesterday time.2:24 PM. OK, we’re done as far as rain goes in Catalina from this. The updraft and solid base are propagating to the right, meaning that nice appearing rainshaft will be what targetis us. But the lives of shafts are so short without renewal, and that renewal is going to slip to the west of us. Notice how in six minutes the shaft on the left is almost completely gone.2:48 PM. Hard to believe that this is all that’s left of that pleasant Cumulonimbus cloud, an Altostratus translucidus cumulonimbogenitus , maybe with praecipitatio as well with it since you can see a veil of preicpitation is reaching the ground. Note the sun is shining through larger ice particles like snowflakes, its disk cannot be made out, though its position can. If this cloud was a thin droplet cloud, the sun’s disk could be seen as a sharply outlined disk.
In the meantime, all the excitement, possibly spurred by the gusty outflow winds that accompanied the above seen, was happening almost overhead to the NW-NE, as a great line of Cumulus bases blackened. They were already passed us, but if they unloaded and sent a pulse of wind out and toward us, then we might end up in a wind clash zone, with huge clouds forming overhead. OK, was dreaming again, but here’s what was going on, which ultimately led to another major dump on the CDO watershed.
2:20 PM. Dark Cumulus bases mass over Saddlebrooke and north. No precip trails yet, but they were virtually assured. Started videoing this scene about now.2:28 PM. In just eight minutes this has become really menacing, possibly a major dump on Saddlebrooke with more golf balls flooding down into the CDO wash as happened the previous day. Now looking for the first strands of the largest hydrometeors (likely hail or graupel) to drop through the updraft, which is looking very substantial at this time due to that well-formed base.2:30 PM. Here’s a close up of that base over Saddlebrooke, now placed in the “Cloud Base Collection” series that we offer to readers from time to time. We’re hoping ot get into a gallery soon.2:37 PM. “Thar she goes!” This is really hard to see, but at top center the rain/hail/whatever is just starting to show out the bottom. Some of these, likely gigantic drops, are already reaching the ground. Notice the slight dimming of the Cumulus clouds in the background. That would be the developing rainshaft is going to be.2:39 PM. Now even little teeny babies can see the shaft dropping out.2:42 PM. For all to see now….just three minutes later.2:44 PM. Just another two minutes later. Its pretty remarkable how fast these things collapse. The whitish strands are likely hail/graupel shafts, often located on the upshear/upwind side of thunderstorms.2:49 PM. Soon the plop of all that rain push enough air out of the way that the shaft extruded outward toward the west. Note that rain would be falling on people from a raining cloud some mile or three away. The heaviest rain seen in the ALERT gauges from this event was only 0.79 inches at Pig Spring, near the Charouleau Gap. The peak rain was probably in the 1-2 inch range.
Hiked over to see if the Sutherland Wash, east of the similarly named housing development, Sutherland Heights, had a good flow from our “Mighty Kong” of prior day. It had:
3:45 PM. The Sutherland Wash scene showing that it flowed bank-to-bank as did the CDO here in Catalina.
The weather ahead
Seems Remnant Roslyn will spit out another snippet of moisture ahead of our fall-like cold front passage late Sunday or early Monday bringing clouds, and with clouds, a slight chance of measurable rain. Don’t hold your breath for measurable rain IMO. Hope I’m as wrong as the prediction I made to a friend that the Stanford Cardinal would trounce the wildly overrated Washington Huskies fubball team last night.
Just back from a horsey ride with Zeus the horse. Rode into the CDO to see the surprising view that it had run bank-to-bank last night after that mighty cell passed by along the foothills. In the wash, were golf ball-sized golf balls scattered throughout the wash, indicating that it hit the planned community of Saddlebrooke with it many golf courses very hard. No golfers were found.
The Pima County ALERT gauges really did not call out that such a flow would occur from precip data around here, the greatest amount being barely over an inch, and its likely that such a flow in the CDO, bank to bank would need 2-3 inch dump in its watershed.
This morning around 10 AM in the CDO south of the E Golder Ranch Drive bridge,
———-end of updated material unless I get more updated——
After an afternoon of “steady-state” Cumulus congestus and small Cumulonimbus clouds trailed northward from the Catalina Mountains, the “Mighty Kong” erupted about 5 PM providing one of the most intimidating, yet majestic and beautiful scenes of the summer rain season; this or any.
Cloud Maven Person was indoors drowning his sorrows concerning what appeared to be a a grotesquely failed forecast of a good rain day (“about half an inch”) here in Catalina in flavorful Indian cuisine when the unexpected began to take place outside. So, the photo record is incomplete for this event. “CMP” had given up on the day.
Just measured in NWS-Style 8-inch gauge and CoCoRahs gauge:
0.12 inches was our total here in the Heights.
And, the photos aren’t quite as good as they should be, slightly out of focus since CMP didn’t adjust his camera for the dark scenes his was seeing. Oh, me. Missed the great sunrise, too, due to not having memory stick in the camera! Oh, me.
6:48 AM. The day started propitiously enough with a ton of clouds, and a line of weak Cumulonimbus heading for us from the SW -W. horizon. A small Cb ahead of this line can be seen on the left.7:14 AM. Looking at this scene, and pondering a day and evening of these, “CMP” is wondering just how many inches of rain we might have,
However this line faded, bringing only sprinkles, a trace of rain to Catalina, and was followed by a huge clearing and sunny skies, thought to be a good thing at the time. Soon, gigantic Cumulonimbus clouds would erupt to over the mountains all quadrants… Nope. By mid-afternoon, only Cumulus congestus had formed with an occasional bit of ice and rain visible, all to the north.
2:08 PM. Cumulus congestus repeatedly formed in the lee of the Catalinas. Occasionally one produced a shower. The clouds are moving from right to left in southerly flow, probably pinching together in the lee of the Catalina Mountain “sky island” as happens in the lee of real islands.4:21 PM. Another nice Cumulus congestus, but where’s are the Cumulonimbus clouds, that big line of them coming in from the S and SW? Pretty much threw in the towel, gave up except to document for purposes of training a little conversion from water to ice visual lesson in one of these turrets that climbed just high enough to convert.4:25 PM. Thus in a series is just 5 min long. Shows how fast the liquid looking cloud can convert to one that is all ice and droplets evaporate due to incursions of dry air, and their molecules race over to that ice crystal next to them. When water and ice are together, its supersaturated with respect to ice, and water molecules head toward any ice around, accumulating as a solid on the ice (a process called deposition), racing over there as a vapor.4:27 PM. A very slight change has taken place. The tight cauliflower look due to liquid water “cells” (such as those on the left side where a new turret is rising up) are disappearing, Its not very obvious at all, but you should be thinking even with this little bit of change, “There she goes! It made it to the “glaciation level” today.”
4:28 PM. Underneath this converting turret are ice particles that are just starting to fall out. Can you see the little fibers of ice? Since they don’t have a long water path to fall through, these would be pretty pristine ice, maybe only lightly “rimed” covered in frozen cloud droplets. Notice to here and in the next shot, that they are sloping a bit, indicating they’re not heavy ice particles at all. If you’re really good, you can see that the whole turret has changed, no longer looks “watery”; that tight, hard, cauliflower look has “mellowed”, the crenelations have mostly disappeared. What is a “crenelation” anyway? Better look it up….4:30 PM. Its a gonner here, no liquid water is left in that turret. The question we still struggle with is how this conversion happens so fast?
This was the last photo I took until walking out of a local Indian restaurant and exclaiming, “What? When did this happen?” It was so clear to the S-W with the exception of a single dissipating Cb that it didn’t even seem worth a photo.
6:04 PM. Hope for that great, meaningful rain in Catalina, though I am in Rancho Vistoso when shooting this.6:04 PM. Looking over the Catalina Mountains as much as I could. Look at that nice, solid base!6:08 PM. Luxurious shafts of rain begin to pour out of solid cloud bases. And look at the one protruding outward toward Rancho V. THis is looking incredible for something humongous to happen. Not sure why this happened? Was there a trigger aloft that was going over this late in the day?6:11 PM. Now, a rainbow to boot! This shot from Honeybee Canyon Park.6:13 PM. This is becoming something memorable. Losing control, photos every minute or so, but ISO level too low!6:14 PM. In the meantime a shelf of clouds, Stratocumulus I’d say, spreads westward from the storm. Would they, could they erupt, too? No, as it turned out.6:16 PM. As darkness fell at Honeybee, and the rainbow faded, it was now becoming evident that this odd late eruption was becoming something special. The rest of the time was spent racing home to be there when it hit Catalina/Sutherland Heights.6:26 PM. Got this kind of crummy shot waiting at the light at Rancho Vistoso Blvd and Oracle Rd. By this shot, I am thinking, unbelievable what has happened! This has become the “Mighty Kong” of summer storms, and its spreading away from the mountains toward Sutherland Heights!6:33 PM. Car was blasted going down Golder Ranch Drive by not blowing dust but blowing gravel as outflow winds slammed down Golder Ranch Drive. Estimated gusts 60 mph. Afraid to look at front of car this morning. Also look at how firm, solid that leading base is, telling you that there is a strong updraft feeding into it. More cells will develop downwind. That’s Jenny and Matt’s house shining in the sun on the hillside.6:33 PM. Looking from Golder Ranch Drive toward Samaniego Ridge, obscured in rain.
Well, as it turned out it was a near hit, only 0.06 inches fell in a violent few minutes of huge drops at my place in Sutherland Heights. From what I saw going by, and needing 0.44 inches on yesterday morning’s forecast of 0.50 inches in Sutherland Heights. about 500 yards farther west for this remarkable, dramatic storm would have given us that amount easily. 1.06 inches was recorded at Cargodera Canyon, NE corner of Cat State Park, and several sites in the foot hills of Catalina toward the mountains area had more than half an inch.
A quickie take on a U of AZ model run from last evening’s global data, has Cumulonimbus clouds developing to our southwest and rolling across Catalina in the afternoon. This would be, appropriately, considering the definition of the end of our summer rain season as September 30th, very appropriate.
