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
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.
A few more hundredths fell after 7 AM yesterday, boosting our storm total to a remarkable 1.42 inches, January now about twice our long-term average.
Here’s what all that precip did to our beloved Cañada del Oro Wash:
After a few more hundredths of rain, the skies broke open, and as we know well, some of our most spectacular scenes occur under deep blue skies punctuated by puffy Cumulus clouds, shadows and highlights on our now snow-capped Catalina Mountains.
In the meantime, more highlights on Sam Ridge:
Finally, that incredible sunset afterglow on our mountains:
Oops, oh yeah, storm tomorrow, supposed to begin in mid-day to afternoon hours. Looks like a third of an incher. Also looks to be a bit colder than the last storm, may see a flake or two by Tuesday morning.
What a gorgeous day yesterday was with deep blue skies dotted with Cumulus and one or two shallow Cumulonimbus, highlighted by our snow-capped Catalina Mountains. After the brief warm up, more storms ahead for Catalina!
Explanatory module below
After the brief warm up ahead, still looks “troughulent” and stormy in the SW as December closes out, continuing into January.
A very few small, isolated drops fell between 4:50 and 5 PM here in Sutherland Heights from what appeared to be nothing overhead. You’d have to be really good to have not been driving, and to have anticipated the possibility (by recognizing ice in upwind clouds) and then having observed it. You would be recognized, given some extra adulation, at the next cloud maven junior meeting if you did observe it, that’s for sure.
So, a long blog about anticipating and observing a sprinkle of rain (RW—, “RW triple minus” in casual weatherspeak or text).
We start with some nice, but inapplicable to our main story photos from yesterday.
(What about those gorgeous Cumulus congestus and Cumulonimbus calvus clouds over toward and well beyond Charouleau Gap about this time? Maybe later or tomorrow.)
“Just Another Day“, btw, one of the many great songs by Oingo Boingo, if you’ve ever heard of them. We’re not just about clouds here. Trying to broaden your pop cultural knowledge with distractions like this.
Yesterday was remarkable in how exact it was to the day before in clouds, but ultimately disappoiting.1 There was supposed to be more cloud action, shafting around, that kind of thing, but there wasn’t. It was virtually identical in every way, including having only two clouds that got high and cold enough to have ice in them. I am sure you recorded them in your cloud diary, and this will be a little tedious as a result, but….what the HECK.
Here is your cloud day for yesterday, focusing on the detection of ice in clouds:
Today is another day. More hope for a shower late today or tomorrow, models say, then likely another dry spell as the summer rain season ebbs again for awhile until that possible super hurricane Dolores drags some moisture up this way. (Dolores, now just a tropical storm, was just born off southern Mexico near the coast. Will be interesting to see just how strong she gets.
1Some fans like to see misspelled words here. Amyone see that criminal who was sentenced to “life in person” as described in the AZ Star? That was pretty grate.
We received 0.08 inches here in “The Heights” for a third day with measurable rain in May already. 0.12 inches fell at the Bridge on Golder Ranch Dr. , while Saddlebrooke got up to a quarter of an inch (as estimated by CMP) in a tiny streak of clouds that erupted into shallow Cumulonimbus clouds, anvils and all yesterday afternoon between 4:30 and 5:30 PM. It was pretty much all over by 6:00 PM, those shower clouds passing off toward Mammoth.
No rain was reported at mountain sites, to give you an idea of how localized that was, localized practically to Basha’s Market parking lot, Sutherland Heights’ Equestrian Trail Road, and Saddlebrooke’s Acacia Drive, to exaggerate some.
The astounding aspect of a tiny line of showers that suddenly erupted over and a little downwind of Catalina was that it was EXACTLY predicted in the University of Arizona’s 5 AM AST model run yesterday morning, one whose results are available by mid-morning! So, there would have been a few hours notice of possible rain here in Catalina.
However, unless you were in the right spot, you might not have even known that it rained, the shower streak was so narrow.
Below, the astoundingly accurate predictions for 3, 4, and 5 PM for that model run from yesterday morning. No rain whatsoever is shown at 3 PM, as you will see.
To be “fair”, NO RAIN was predicted anywhere NEAR Catalina by that same model crunching the data from 5 PM AST the evening before our little rain event, leading CMP to be a little asleep at the wheel yesterday morning, no blog.
Some cloud shots before and as this predicted (or unpredicted, as the case may be) rain began to happen. Of course, if you want to go to the movies and see this, go here, from the U of AZ: Yesterday’s cloud movie
Below, sat view of this cloud streamer with radar, from IPS MeteoStar. The image below is at the same time as the last photo above:
Here some more cloud stuff from the sounding launched at the U of AZ around 3:30 PM AST.
Here’s a diagram of when ice forms in the type of clouds we mostly have in Arizona, “continental” ones with high droplet concentrations, and when ice should form in them. As you can see, ice should form in them soon after the top temperature gets colder than 10 C WHEN the base temperature is about what it was yesterday.
“CMP” is not mentioning it at all, but yesterday was another kind of mucked up sky, not a Catalina postcard sky, with lots of aerosols making the sky a whitish-blue, the lower aerosol stuff again from Mexico, but there was also a layer far above the cloud tops, likely a long-range transport event from thousands of miles away.
This higher haze layer still seems to be around if you look toward the horizons right now (5:59 AM).
We’ll be between two jet streams today, kind of a jet stream sandwich, and the stronger one is now approaching from the northwest with that mega upper low over Cal. That means no rain today, subsidence rules, though we’ll have small, non-ice producing Cumulus, and likely some Altocumulus lenticulars, maybe a Cirrocumulus patch here and there. Should be a pretty nice day for cloud photos, haze aside.
The best chance for rain is still after midnight tonight into mid-day tomorrow as the core of the stronger jet stream goes just about over us. Still thinking a tenth of an inch will occur here, though mod run from the U of AZ at 5 PM completely dry. A little snow likely on Ms. Mt. Lemmon, too!
Well, those showers were a surprise to “me and my model” yesterday morning, at least the one I looked at just before going on the air. There were no upstream echoes in the clouds upwind of us, either, something normally seen before cool season showers get here. Fortunately, I was able to get in a prediction that rain would fall just as the drops began coming down.
However, there are a few times when that bit more lifting as the air moves from the lower ground to the southwest of us to here can trigger precip; the tops get that bit colder, form ice, voila, out drops the rain (and snow). That’s probably what happened yesterday to cause a sudden development of light showers, “all quads” it seemed.
Cloud tops may not have gotten colder than about -10 C yesterday, too, and so our rain likely fell from ice crystals rarely seen in Arizona, hollow sheaths and needles (columnar crystals), which have to be in big aggregates before they can form a drop big enough to reach the ground. So, not only are they rare here, but there also have to be a LOT of them )10s to 100s per liter in the clouds) for them to form big enough snowflakes so that a drop reaches the ground. In fact, when columnar ice crystals form in clouds, they often do so prolifically so that, at least at the University of Washington where the present Arthur worked for about 30 years in airborne studies of clouds, needles and sheath crystals were always associated with the highest concentrations of ice crystals that we observed. Some of those rare ice crystals were STILL forming in the clouds above us near the time of the second sounding, shown below, launched at 3:30 PM! That was really shocking!
This ice crystal happenstance, and the surprise light showers, made yesterday particularly worth commenting on from this cloud pulpit, if that’s what it is. Some nice examples of needle and hollow column ice are shown here at CalTech. These kinds of crystals are rare in Arizona because they require larger (greater than 23 microns in diameter2 in clouds at temperatures between -3 and -8 C. Like the needle crystals themselves. Since the clouds were shallow, one has to speculate WHY the cloud droplets might have been extra large. It may have been that there were few of them (seems kinda unlikely this far from clean oceanic air. More likely, those clouds had large (micron-sized) dust particles in them, known to help form larger cloud droplets. So, I’m guess those clouds were helped by dust so’s they could have larger droplets in them, ones big enough to help produce ice splinters consisting of needle and hollow sheath crystals at such high temperatures (higher than -10 C).
Our U of AZ model predicted soundings were pretty much what we saw, too, cloud capped by a stable layer that got stronger as the day went on, and the air drier above it. Below, from IPS MeteoStar, these TUS soundings from yesterday morning and afternoon.
But let’s drag this out and look at yesterday’s clouds now…
During the afternoon, a nice cloud “street” formed, came all the way from Mexico way, one that spawned a little more anomalous ice, and those few raindrops; see below for evidence if you don’t believe me.
BTW, here’s our cloud street as seen in the “visible” satellite imagery at 4 PM AST, just before the drops fell on my windshield. You can see that it originated near the border with Mexico, as many things do.
The End, except I think there will be some more rain tomorrow morning, trace to quarter of an inch are the bounds, meaning about a tenth is the most likely amount from this cloud pulpit.
The End, again.
1I prefer this spelling today; more “o’s” than “l’s” in that word make you think more of a thing full of air; maybe a few more “o’s” would help even more, too, like “baloooon”…
2That size is considered “large” for a cloud droplet, and lab studies have shown that they splinter when they hit something, like soft hail, also called “graupel.” Splintering is thought to lead to all those extra ice crystals at temperatures between -3 and -8 C.
In case you didn’t notice, there was a prolonged street of clouds emanating from possibly as far away as Kit Peak, or maybe just the Tucson Mountains. Lasted for a few hours.Happens only on days with relatively shallow clouds (cloud-topped boundary layer) with a little wind, meaning that the thermals from the surface heating ended up being capped by an inversion or other stable layer, and those thermals form clouds in some places. In this case, a long line of intermittent clouds formed from an initial air bump caused by those mountains far to the SW of us. CTBL is more often invoked as a term by cloud folks when the sky is much cloudier in low clouds than these shots from two days ago, such as when the sky is covered in Stratocumulus clouds.
These kinds of streets occur over the same places whenever a day like this comes along. Think of it, especially here in Arizona, as a row of shady air under which you might like to live compared to those areas on either side of this cloud “street.” In Seattle, where the “cloud topped boundary layer” is almost a daily occurrence, you want to avoid being under the cloud street, where it can block the sun, and instead find the clearer slots!
For those sharpies that day and logged in their cloud diaries that ice formed in those shallow Cumulus clouds, they will be a little chagrined by this TUS sounding. This sounding suggests the clouds around the balloon were topping at -8 C, too warm for ice formation in shallow Cu. Let us begin to explain this puzzle by presenting evidence of ice formation in those clouds on the 18th:
Simple answer to our connundrum; due to lifting of the air as it approached and went over the Catalina Mountains, the tops of the clouds reached those temperature below -10 C where is begins to form. We would guess even closer to -15 C in that cloud in the distance beyond Charouleau Gap due to the amount of ice. Ice increases with decreasing cloud top temperature, but the temperature at which ice onsets can change on a daily basis; higher onset of ice temperatures on days in which the clouds have larger drops in their tops (a phenomenon originally reported by Ludlam in 1952, then re-discovered by Rangno and Hobbs (1988) who did not, at that time, know of the Ludlam finding, and thus, did not cite it. Pretty embarrassing, really. Was cited later in an update, however.
The weather way ahead
Seasonal rains beginning to show up in southern Arizona now on models beginning around the 4th of July as a big anti-cyclone parks itself over the Four Corners area in the latest model run from 11 PM AST last night. Very excellent run.
The weather way ahead after the upcoming heat wave
I have been staring at this weather Rorschach test for a few hours now, and there’s not much to say about it, except that there seems to be two eyeballs near the North Pole, and maybe one of the yellow lines forming a jaw down there toward Greenland, possibly a tilted drivers cap toward Russia.
Clearly the global patterns are “unsettled”, to use one of our favorite forecasting words. (“We will have ‘unsettled’ weather over the next few days”, as one might say in Seattle most of the year.)
Below, “troughing” is suggested in the SW, but not much. The Asian trough, anchored along the coast of Asia, is shown moving offshore here as it should during the spring, and that in turns helps form a trough downwind in the SW US, as we see happen in the spring over the long term (in climatology). So we can only hang our hat on climo, that these uncertain times shown below in the plot below will resolve into something better than more drought.
We can also ponder the larger question of, “How’s come we can put a man on the moon and various space junk on Mars and can’t forecast the weather beyond about a week?” Its crazy.
Or even the vastly larger question concerning chaos theory, a theory that rests on the phenomenon that small perturbations in the initial state of unstable systems are able to make huge changes over time, thus:
“Will a space probe, going off into deep space, as is happening now, an artifact that’s not supposed to be there, unsettle the unstable Universe?”
Pretty thoughtful blog today, I thought. Usually don’t go this deep, but it just kind of happened.
Too dark for the best sight, our 14-year old flat-coated retriever mix dog, at first seeming to be walking slowly up the dirt driveway in back of the house with another dog. I could just make out two outlines. I wondered whose dog had gotten out and was in our backyard? Moving closer, I see that our dog is walking side-by-side up the dirt driveway, not with another dog, but with a javelina, like they’re buddies! Then two more javelinas came out of the brush to join the slow walk uphill forming a peccary herd containing a dog! After about 10 yards of this group slowly ascending the driveway toward me, the javelinas turned off into the brush. Too dark for photos; dang.
Next, its raining in Tucson and I am eastbound on Prince Avenue about to turn left on to Oracle. I was feeling good that its raining downtown, and it was not just here in Catalina that rain had fallen. A car swerves across a lane in front of me to turn left on Oracle, and it turns out to be the best car ever evaluated by Consumer Reports! Its the all electric Tesla Model S!
I am not a car buff, but this was a very great sighting for anyone knowing much about the direction cars are taking! Its made by a tiny company in Fremont, California. No gas used of course, its not a hybrid; you have to find a charging station. But those stations are increasing pretty fast. You can go about 200 miles or so on a charge.
Anyway, if you have $90,000 or so, I think you should buy one right away. No, really. It would be worth it to be an “early adopter” and drive the market forward so that the price descends rapidly.
Sports AND clouds….
The Seattle Seahawks are in the Superbowl today. The city where I worked is going bonkers over this because besides the team, they really like some of the players, like Russell Wilson whose really too small to be an NFL QB, and hasn’t been in jail ever. The entire city has come together, including liberals and conservatives to root on the Seahawks! Reminds one of the afterglow of the first Gulf War when Arab cars were sporting American flags!
Cells in the rain
The weather ahead…
Looks like a minor rain in the works for Monday into Tuesday evening. Probably will begin in the mid-day hours and probably will only produce a few hundredths to a tenths is all here in Catalina. There’ll be more snow in the mountains, so that will be good to keep some of the creeks running.
The following storm, the one that looked substantial, has been diminishing in the model runs of the past day or so. Dang. The Enviro Can mod has given up completely on rain here in this trough that moves in on Thursday and Friday, the 7th and 8th. Then, voila, the US one began to follow suit, though showing a less bountiful rain, but at least still has some beginning Friday the 7th and then has it dribbling into Saturday, the 8th (this from the 11 PM AST global run from last night). Looking more like maybe a quarter inch of rain here in that one, but very dicey now in view of those Canadian calculations. Sometimes their model does better than ours.
Still looking like a LONG, warm dry spell after next Saturday….
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