Its been this way for quite a while, actually since the big rains of late January, but I only found out about it yesterday: “Thousands Gather Under Cloudy Skies for Beach Fun at Catalina State River and Beach Park !” (if one were writing a newspaper headline). See below.
2:40 PM. Here, dozens of kiddies are seen frolicking in the water of the Sutherland River at Catalina State Park.2:44 PM. Soft Cumulonimbus capillatus and calvus turrets line the distant SW horizon while hundreds frolic in sand and water at Cat State Park.2:46 PM. “Ricky” (real name, “Parikit”), who also happened to work in the SAME lab office as the writer for a few years, prepares his daughter for the popular beach activity of sand castle construction.
Before reaching the beach at the State Park, saw some luxuriant spring undergrowth among the trees, and a nice Cumulus turret, one that went on to grow up and be a weak Cumulonimbus:
1:51 PM. Typical of the lush grasses along the Birding Trail at Cat State Park, also due to the generous January rains.2:21 PM. Nice. Altocumulus clouds (upper left) lurk around a Cumulus congestus turret over the Catalinas.3:36 PM. A remarkably summer-like sky, Cumulus congestus in the foreground, Cumulonimbus capillatus cloud lining the SW horizon. Temperature, 70 F.
The weather ahead, as you and I both hope it will be
Been a lot of phony storms in the 10-15 day range indicated by the WRF-GOOFUS model, ones presented here with regularity, then ended up jilting us. So, today when the Canadian model came up with an appreciable rain pattern for AZ in only SIX days, Feb. 21, it was time to exult, switch models, and climb back up on the blog saddle:
Valid at 5 PM AST, Saturday, February 21st. Based on the global observations taken at 5 PM last evening. AZ covered in rain!
What’s even better in this map is that the rain has only begun on the 21st. As you can see, the bunching of the contours off the Cal and Oregon coasts and west of the center of the low, upper left panel, tells you immediately that more rain would be ahead for us if this configuration is correct. That’s because the low will propagate southward, and closer to us, not move off in some untoward direction with a stronger wind field on the back side than on the front (east) side. Also, in a pattern resembling the Greek letter, “Omega1“ as we have in the eastern Pacific and West, lows like to nest in the SE corner of the “Omega”, getting cutoff, stagnant, out of the main jet stream flow, all of which prolongs bad weather in that sector of an “Omega” (here in the SW US). So, lots to be optimistic about today. Strong support in spaghetti for this Omega pattern, too.
Now I haven’t looked at the US WRF-GFS model based on the same obs because it might have something different, a storm that’s not as good as the Canadian one, and I don’t want to know about it. Still feel pretty hurt by the big storm presentations for AZ that weren’t very sincere in that model. And, as we know, sincerity is mandatory in a relationship, even one with weather maps.
a lot….beginning tomorrow afternoon or evening, not today. Today is “pause” day. Also, its trash day today here in Catalina, mentioned here as a public service.
Slow moving, sub-tropical system to drop several inches of water content in rain/snow in mountains, sez our best model, that run by the U of AZ. Thank you, U of AZ, btw. Below a snapshot of the total precip from that 5 PM AST global data crunch, “nested” for AZ. This plodding gigantostorm should keep the water coming down the washes, luxuriate our sprouting wildflowers, some of which, like desert asters, are beginning to emerge and even bloom1:
Total precipitation ending just after midnight, Feb 2nd, as seen by the WRF-GFS model run from 5 PM AST last evening. Catalina/Oro Valley appears to be in a bit of a shadow, so while Ms. Lemmon and vicinity are forecast to get several inches of water content in rain and snow, Catalina gets an inch–though hard to see in this graphic. Why? Likely south to southeast flow coming downslope off the Catalinas. But, I think its WRONG!
Lot’s of gray sky photograph opportunities ahead. Get camera ready. Not much in the way of rain seen in mods after this, so enjoy this rain “chapter” of your life as fully as you can.
Yesterday’s clouds
After another light shower boosted our storm total another 0.02 inches, a fabulous, wonderful, almost Hawaiian like day followed with a little humidity in the air, deep blue skies, and white puffy clouds, ones a true cloud maven would call, Cumulus clouds and would be ashamed if he just said they were “puffy clouds.”
7:34 AM. Sun tried to break through some puffy clouds over the Catalinas after our 0.05 inch shower. A few, very small shower cells were around, but didn’t look like much at this time.7:53 AM. Gee, a strong, though narrow rainshaft developed SSW of Catalina, upwind! Suggests a Cumulonimbus-like protruding, icy-looking top up there on top of the shaft.
8:08 AM. The three amigos rainshafts, headed this way, evnetually dropped another “surprise” 0.02 inches. Earlier model runs had indicated the rain would be over by dawn yesterday.
8:34 AM. One of the “amigos” hit Ms. Lemmon and Sam Ridge nicely. Ms Lemmon racked up 0.59 inches out of the storm overall. Very nice, considering our 0.07 inches total.8:53 AM. As we know so well, sometimes the best, most dramatic shots are those after the rain passes, and the rocky surfaces glisten in a peak of sunlight, here enhanced by crepuscular rays due to the falling rain. A rainbow was also seen, but not by me somehow.
8:54 AM. Closer look at glistening rocks toward the Charouleau Gap.
11:45 AM. The deep blue sky, the puffy clouds topping Sam Ridge, the strong sun, the bit of humidity, the bird flying along on the left, gave the sense of one being in Hawaii I thought.12:32 PM. Puffy clouds still top Samaniego (Sam) Ridge.
2:28 PM. Small puffy clouds provide a “postcard” view of Catalina, Saddlebrooke and environs. Visibility here well over 100 miles. Never get tired of these views! You got some Cirrocumulus up there, too.
2:51 PM. Another postcard view of our beloved Catalina. Rail-X Ranch and the Tortolitas off in the distance, left. Nice patterned Cirrocumulus up top above the little puffy clouds.
5:58 PM. The day ended with a nice sky-filling sunset as a Cirrus layer was lighted from below by the fading sun. The lines of virga show that while Cirrus clouds don’t have a lot of water vapor to work with up there at -40 C (also -40 F), the crystals that form are still large enough to settle out as precip.
The End
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1Desert Aster (I think) in bloom seen on the link trail from the Baby Jesus Trail to the Deer Camp Trail.
Seen on big hike, Jan. 22nd. This plant will be so happy by next week!
7:20 AM. Altostratus with pouches of virga7:23 AM. Ditto. Ac len is the fine line cloud upper center.7:27 AM. Ditto, pretty much.7:30 AM. Nice lighting (not lightning) for just a few seconds.8:19 AM. Altocumulus trailing snow/virga. Tops, though the coldest part of the cloud, are composed of mostly of droplets at temperatures far below freezing. A few ice crystals form and drop out leaving the supercooled droplet cloud mostly intact.
12:55 PM. Just about the first boundary layer cloud, this a Cumulus fractus fragment. Hope you recorded this event in your cloud diary. Its pretty mandatory to note developments like this if you want to move on to the next level of cloud-mavenhood.
3:03 PM. Those boundary layer clouds, Cumulus ones, were reaching their maximum depth about this time. This would be a Cumulus mediocris, estimated depth 2500 feet or so.5:14 PM. Whilst clouds locally never got beyond the “mediocre” stage, or produced ice under them, to the north where the air was colder aloft, Cumulus clouds were able to grow taller and become Cumulonimbus capillatus (hairy looking with ice) incus (the last term just meaning it has a flat anvil, a flat head.)
5:47 PM. This post sunset shot shows layers/lines of smog at the same level where some flat Cumulus remains are. The smog is so visible because the air is ALMOST saturated near those clouds at their level, and some of the smog particles (hygroscopic ones) have deliquesced, have gotten much larger by absorbing water vapor, or might even be haze droplets where water has condensed on them (“smoglets”). It therefore, by definition, cannot be a “pretty sunset.”
The model rain ahead; two episodes
The low that plunks down off the coast of Baja this weekend from southern California, circles around out there for a couple of days, before deciding to move back over southern California with clouds and rain. If it was a song, it would be The Wanderer. Yes, that fits. Its expected to scoop up a generous helping of middle and high clouds from the deep tropics as extra baggage. The “extra baggage” (model predicted rain) arrives here late on the 26th (Monday) and continues off and on through Tuesday night. The first clouds, of course, high ones like Cirrus, will begin arriving a day ahead of the actual rain, on Sunday.
It is virtually certain that there will be some high-based Cumulonimbus clouds and thunderstorms in these masses from the tropics, though maybe not here. Most of the rain is projected for eastern California and western Arizona where rain is really needed–and how great is that?
However, we should be in for a quarter inch or so, anyway. Last time I guessed limits on a storm, even the lower limit of 10% chance of less than 0.05 inches wasn’t even realized. Pretty pathetic forecast. But, moving forward and forgetting past errors, this one seems to have a similar range of possibilities, the least amount 0.05 inches, the most, 0.50 inches. The chance of measurable rain here in Catalina in this first 36 h storm period is probably, from this typewriter, about 80%.
“But wait! There’s more!” “Maybe!”
A second system floats in right after that and from Jan 29th through early in Feb, and more welcomed showers are possible.
You can check out these prognostications in a more professional way at IPS MeteoStar, this link to the latest model run from 11 PM AST last evening.
Wednesdays here in Catalinaland are, of course, trash and recycling days. And, along with T and R day, we found ourselves amidst some pretty pretty scenes, and in some cases, extraordinary ones,….and a little rain (a trace here in The Heights). I reprise those scenes in case you missed them; you probably did because you’re not some kind of photonut like the writer.
However, be advised that some of the mid-day photos will show smog, smog that was ingested into our poor clouds.
That smog bank, emitted from the Tucson area, almost reached Catalina yesterday during the day. It came up around Pusch Ridge and up along the west side of Samaniego Ridge and almost reached Catalina before its advance was halted by a north wind push and it retreated to the the south. My heart was beating so fast that it might overrun us! Marana and Oro Valley were heavily contaminated for awhile. And smog is like a cloud cancer1.
7:46 AM. A rare display of Stratus along the Tortolita Mountains. If you were hiking and were in this, it would be fog to you, still Stratus to me viewing it.7:46 AM. Rare shot of what appears to be ground fog or just fog rolling eastward out of Tucson. Some flakes of Altocumulus above, and a higher layer of Stratus on the Tucson Mountains.
8:49 AM. This was an amazing sight, to see a thin Stratus cloud fronting an early morning Cumulonimbus capillatus. The Stratus is hard to see, but its the thin dark line on the horizon above Priscilla’s house below the turrets and ice of the Cb. The only other time I have seen such a sight was in Seattle after a snow with Stratus clouds and fog all around the city, but with warm Puget Sound sending up plumes of big Cumulus clouds.
10:37 AM. The day was not without some cloud levity, as these “twin tower” Cumulus clouds show, drawing attention to themselves.
11:26 AM. First ice in clouds becomes visible. It was obvious a few minutes later, but if you saw at this time, or can find it here, you are a pretty CMJ, worthy of an accolade. Of course, if you looked at a radar map of the area, you would have known where to look in advance since there was a small echo in this complex by this time. The precip just was not enough to form a shaft. Note, as well, that Twin Peaks, Continental Ranch area is NOT visible due to the smog bank that was going to move up this way, as it turned out. And look how gorgeous it is toward the Tortolita Mountains!
11:38 AM. OK, here the ice from that turret in the prior photo is now obvious (center frizzy area). However, it was also obvious that the smog toward Marana/Continental Ranch was now closer, even while we had a north wind here in Catalina. Was that southwest wind going to win and mess up our fantastic skies?11:42 AM. Here you can see the smog as it was advancing around Push Ridge and had gotten farther north along the side of Samaniego Ridge. Those lower cloud fragments along Pusch Ridge at the top of the smog tell you that the air was more moist than the air our Cumulus clouds were forming in, and therefore, that this advancing smog bank likely associated with deliquesced aerosols from cars and other urban effluents (aka, “air sewage”) accumulated during the Tucson fog earlier that morning that was now being mixed into a deeper layer and heading this way! To think of breathing air like that. in a short while..it was a ghastly thought.
12:12 PM. To make a short story long, the advance of the smog, with its lower based clouds got as far as Golder Ranch Drive over there by Samaniego Ridge (whitish area below the lowest cloud base on the left), before receding under a freshet of north wind. However, some southern parts of Catalina were affected for a short time.
1:14 PM. By this time, larger complexes of Cumulonimbus clouds, pretty weak ones, were developing over and north of the Tortolita Mountains and upstream of us offering the hope of some measurable rain in Catalina, the smog pretty much pushed back to the southern parts or Oro Valley and Marana.
2:00 PM. Widespread light rain showers were in progress from these weak Cumulonimbus clouds, but sadly, bypassing Catalina. But huge visual payoffs were ahead as the clouds broke at times, and some stunning sights emerged.
2:35 PM. Stunning….to me, anyway. View this in full screen mode for best impact. Later, more accessible stunning.
3:01 PM. Breathtaking; in total awe of this scene! Note gliaciated tower at right.
4:28 PM. And those scenes just kept coming! It was hard to be indoors for even a minute.
5:28 PM. The fading sunlight and the fading Cu only got more breathtaking. And we realize how lucky we are to be here and see scenes like this so often.
5:38 PM. The smog belt, held at bay during the day, still lurked to the SW of us, compromising our sunset by providing a reddish-yellowish sickening hue to it, a sign of a smoky presence, that may compromise today if we’re unlucky.
The weather ahead and way ahead
Well, RIP El Niño, an EN expert has written me just yesterday. Not much left of it he says, having a attached a map of ocean temperature anomalies to kind of rub it in. So we can’t count on hot water in the eastern Pacific to help fuel Southwest storms as was expected by the CPC and others last spring. But, that doesn’t mean that there can’t be a juicy late winter and spring, but the odds are down.
And, we won’t see clouds like yesterday until the long-foretold-by- spaghetti trough arrives around the 22nd of January, and with it some chance of rain. Doesn’t look like it could possibly be very much. BTW, Only 0.02 inches total in three days of light showers in the current situation. :{
BUT…..in the longer term, spaghetti is once again HINTING at a break-on-through-to-the-other side situation, your writer’s favorite as a kid, 10-14 days from now. A high builds up along the West Coast and in the eastern Pacific, gets too big for its britches, can’t maintain its giant north-south range, drifts farther and farther north and begins to break up, kind of looking like a horseshoe with the open end down (toward the south) as the jet stream “breaks on through to the other side” and “underneath”, that being a jet stream comes through from the warm subtropical central Pacific to the southern areas of the West Coast.
The north part of the West Coast and Gulf of Alaska are dominated by higher pressure with lower pressure to the south, so its kind of an upside-down-from-normal looking weather map, pretty rare, and that’s why its cherished by yours truly.
The End, at last!
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1As you know, when clouds are heavily contaminated with air pollution, they can’t rain as easily because the droplets are smaller inhibiting rain in two ways: by preventing the formation of drizzle and rain drops, and making it more difficult for ice to form since the formation of ice happens at higher temperatures when cloud droplets are larger. So, clouds have to be taller when they are polluted to produce rain, either way.
When one first encounters this title with its unexpected play on words, we wonder what the author had in mind. Of course, most of us know that at Christmastime, we are often regaled by a Christmas tune called, “Frosty the Snowman1“. But here, we are surprised as we continue reading the title that instead of encountering the word, “snowman,” we encounter the word “Lemmon!” Hah!
What is meant here? What is author trying to tell us? Perhaps the word, “lemon”, has been misspelled. But if so, why would a “lemon” be frosty? Perhaps there was a cold spell in Florida and the author is harkening the reader to a long ago memory. Or, perhaps misspelling “lemon” was a literary device to emphasize that word in an eccentric way.
Yet, upon further investigation, we find that the issue is more complexed than first imagined. We find that there was an art teacher, nurse, and eventually, a self-educated botanist from New England, Sara Plummer Lemmon, who, with her husband and another worker, hiked to the top of the Catalina Mountains right here next to us, and while doing so, they logged the vegetation that was unique to the area. In their excitement when reaching the top, they named that highest peak after Mrs. Lemmon.
So, what does this piece of history add to our literary dilemma encapsulated in the title?
Perhaps Mrs. Lemmon did some work in the field of glaciology as well, hence, the word “frosty” as a possible hint of that work. Yet, upon investigation, we find no mention of work on ice crystals, hoar frost, nor glaciology not only in the work of Mrs. Lemmon, but neither in the work of any the team that mounted what is now known as Mt. Ms. Lemmon. We add that the note that the Lemmons, J. G. and Sara, were on their honeymoon at this time, historians tell us. Perhaps there is another avenue we can explore due to that latter element.
Could it be, too, that we are missing a characterization of Ms. Lemmon by our author? Perhaps she was shy, seen inadvertentlhy as “cold” by some, or was not particularly interested in the physical advances of her husband, J. G. The word “frosty” alert may be alerting us those possibilities.
Ultimately, we remain perplexed by this title; it forms an enigma that may never be confidently resolved.
But then good titles, and good books, are supposed to make us think, try to imagine what the author is telling us through his/her use of metaphor and other literary devices, and this title has done that.
We, of course, reject the most plausible, superficial explanation, that the author’s play on words was merely describing a local, snow and rimed-tree mountain named after Ms. Mt. Lemmon, as in the photo below. No, Occam’s Razor, the idea that the simplest explanation is usually the best one, will not do.
4:43 PM. Those trees are rimed, like the airframe of an aircraft that collects drops that freeze and cause icing. Here the wind blowing across the mountain top, and cloud droplets that were below freezing, hit the trees and froze over a period of many hours, creating this scene. Its not snow resting on the branches. That would’ve blowed off in the strong winds up there.
———End of Literary Criticism Parody Module———-
There was a rousing 0.24 inches of rain yesterday! Our storm total has topped out at 0.89 inches!
In other photos from yesterday:
9:42 AM. Altostratus translucidus again, with a few scattered Altocumulus cloud flakes, but this time with bulging Stratocumulus topping Samaniego Ridge, giving portent of a good Cumulus day if the As clouds will only depart and allow a LITTLE warmth. They did.
10:24 AM. Before long, cloud bases darkened here and there, indicating mounding tops above a general layer, and with the low freezing level of about 7,000 feet, the formation of ice and precip was not far behind.10:51 AM. Mountain obscuring showers were soon in progress due to both a little warming, but also because of a cloud energizing swirl in the upper atmosphere that passed over us at 1 PM AST. Did you notice that windshift aloft as that bend in the winds went by up there? You probably noticed that it was no dice, er, no ice, after 1 PM as the mash down of air that follows “troughs” did that very effectively after 1 PM.
10:52 AM. As the clouds (weak Cumulonimbus ones) broke, there was a fantastic rainbow for just a seconds to the north, landing on my neighbor’s house. It was even better before this, but was slow getting to the camera! Dang.
10:54 AM. “Pictures a poppin’ ” now as breaks in clouds allows those fabulous highlights of glinting rocks and scruffy Stratus fractus or Cumulus fractus clouds lining Sam Ridge, those highlight scenes that we love so much when the storm breaks. And these scenes change by the second, too!
11:00 AM.Also 11 AM. Out of control with camera now…..
11:12 AM. Meanwhile, back upwind… This line of modest Cumulonimbus clouds fronted by a weak shelf cloud roared in across Oro Valley to Catalina. What a great sight this was since now there was a chance of some more decent rains! Before long, the rains pounded down, puddles formed, and another 0.18 inches had been added to our already substantial total of 0.65 inches.
12:01 PM. But that wasn’t the end, was it? Before long, a heavy line of Cumulus and weak Cumulonimbus clouds formed again to the southwest and drenched Catalina with another round of rain, this time, only 0.06 inches. And with it came the End. This line of showers was spurred by that upper level wind shift that was going to occur over the next hour.
1:01 PM. Sometimes those clearing skies, the deep blue accentuating the smaller Cumulus clouds provide our most postcard scenes of the great life we have here in the desert.2:13 PM. While it was sad looking for ice in the afternoon clouds and finding none, the scenes themselves buoyed one. The instability was great enough that even brief pileus cap clouds were seen on top of our Cu.2:21 PM. Pileus cap cloud (right turret) tops honest-to-goodness December Cumulus congestus cloud. No ice nowhere.
2:28 PM. And if the sky and mountains splendor isn’t enough for you, then consider our blazing fall-winter vegetation as evidenced by a cottonwood tree in the Sutherland Wash,’ that yellow dot, lower center. We have it ALL now!2:48 PM. And, as the cloud tops are kept low, we get those fantastic, quilted, richly colored scenes on our Catalina Mountains we love so much. Here, looking toward Charouleau Gap and Samaniego Peak. I could show you so many more like this from just yesterday!
5:08 PM. Even our lowly regarded teddy bear chollas have luster on days like this, the weak winter sunlight being reflected off its razor-hook-like spines, ones that many of us know too well.
5:12 PM. And like so many of our days here in old Arizony, closed out with a great sunset.
Possibility raised in mods for giant southern Cal floods, maybe some flooding in AZ floods, too
Something in the spaghetti plots has been tantalizing as far as West Coast weather goes. They have been consistently showing a stream of flow from the tropics and sub-tropics, blasting into the West Coast. Recall that yesterday, that tropical flow was so strong and so far south, that at least one major gully washed was shown to pass across central and southern California on New Year’s Day, but weaken and shift to the north of southern AZ after that.
Well, my jaw dropped when this model run from yesterday at 11 AM AST came out, re-enforcing, even raising the bar on flooding, in central and southern California, and with those stronger storms, the possibility of flooding and major winter rains here in Arizona was raised. The severity of the pattern shown aloft is not one I have seen before, and for that reason alone, might be considered somewhat of an outlier prediction, one really not likely to occur.
Now, while there is some support in this model flooding “solution” in the spaghetti plots, the main reason I am going to present a series of what a disastrous Cal flood looks like is just FYI and how it develops. The closest analog to this situation was in January 1969 when a blocking high in the Gulf of Alaska (GOA), forced the major jet stream far south across the central and eastern Pacific on several occasions producing disastrous floods in southern California in particular, where one mountain station received more than 25 inches of rain in ONE DAY!
Also that blocking high in the GOA in Jan 1969 also forced unusually cold air into the Pac NW, where Seattle (SEA-TAC AP) accumulated 21 inches of snow over the month, still a record.
Here we go, in prog maps of our WRF-GFS rendered by IPS MeteoStar:
In the Beginning, the blocking high, shunting the jet stream to the south and to the north takes shape in the GOA. Note low far to the south between Hawaii and southern California. Get sand bags out now! This is for 11 PM AST, 28th of December.
24 h later:
Valid at 11 PM AST 29 December. Southern Cal flooding underway. Cold air pocket in Oregon has slipped southwestward helping to energize the lower band of jet stream winds by bringing cold air out over the ocean. The greater the temperature contrast between the north and the south, the greater the speed of the jet stream between the deep warm air to the south, and the deep cold air to the north. Note, too, high is getting farther out of the way in the Gulf of Alaska.
The situation continues to strengthen, and leads to this Coup de Gras, 11 PM AST January 1st. A system this strong barging into southern Cal is mind-boggling, and this panel is what brought this part of the blog, to show you what a devastating flood in that area would look like:
Valid at 11 PM, January 1st. In my opinion, I doubt the Rose Bowl game between the Oregon Ducks and Florida State would take place in Pasadena, CA, if this were to transpire.
Now for AZ. Here’s the prog for 12 h later, 11 AM AST January 2nd, Cactus Bowl Day in Tempe, AZ between the Washington Huskies and the Oklahoma A&M Aggies, to continue with sport’s notes here. Rain would be expected for that game should this pattern persist:
Valid at 11 AM AST, January 2nd. This is an unbelievably strong wave that has roared in from the lower latitudes of the Pacific. While it rushes through Arizona in a hurry, heavy rains, and some flooding are likely should things transpire like this.
Now for a gee-whiz, scary analog….one from WAY back in the winter of 1861-62 when the situation decribed above was likely very similar to what it was in that terrible flood; severe cold in progress in the Pac NW, as it would be in the upcoming situation; a tropical torrent raging in from the Pacific. This 1861-62 flood episode is still remembered. However, it went on for 30-40 days (!) with recurring episodes turning much of California’s central valley into a lake, Los Angeles area, too, where there was a report of 35 inches of rain in 30 days.
What’s ahead, really?
Well the models are going to fluctuate on the strength of this breakthrough flow “underneath” the blocking high in the Gulf of Alaska. But almost certainly one major rain event will break through as that this happens. Its kind of a fragile flow regime, so it usually doesn’t last long.
Whether it will be stupefyingly historic, or just another ordinary southern Cal gully washer, can’t be pinned down. But, if you lived down there, you’d want to be looking around and seeing what you could do to divert water, fix a roof, etc.
There would be strong, damaging winds with one of these “coming-in-underneath”, too, and, for surfers, giant waves!
Interesting times ahead! “Floodmagedon”, as we like to say these days?
No real weather here for awhile, except around Christmas when a mild cold snap, and a little chance of precip occurs as a cold front goes by.
The End, for awhile.
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1The most intellectually satisfying version of “Frosty the Snowman” was, of course, has been rendered by Bob Dylan.
6:20 PM. Cumulonimbus calvus pileus. Hope you had your camera. This would have been a good example to add to your collection. “Calvus” or “bald” is a short-lived period when a Cumulus congestus top is converting to a fibrous (“capillatus”) appearance. That left bulge is clearly loaded with ice. The pileus forms in moist air being pushed up by the rising turret below it. I wanted to be inside that cloud so bad! There’s real magic going on when the droplets are being converted to ice, along with the appearance of hail and/or its soft, squashable version, graupel.
Fantasy storm of the day
….popped out of the WRF-GFS run from 12 Z yesterday, rendered, as we say, by IPS MeteoStar. Tropical storm “Q” is shown in the Gulf of Cal/Sea of Cortez racing north into Arizona. Pretty cool, huh?
A map configuration like this hasn’t been back yet, and wasn’t there in any run before this one, so we can throw it in the trash pile of bogus model predictions so far, though the models DO have a strong hurricane “Q” in the works. Mods now show it going NW and out to sea off Baja. Still its fun to see how much fantasy rain can fall in Arizona. Kinda reminds one of the track of infamous Tropical Storm Octave, October 1983, almost passing over Tucson on the same day 31 years ago. You remember “Octave” I am sure. You can read about it and a very similar eastern Pacific hurricane season to this one here.
Valid Wednesday, October 1st at 5 PM AST. Flooding rains from tropical storm “Q” move into Arizona.
The Cumulus ahead
Whilst CMP was glumly anticipating the end of Cumulus clouds, tropical ones on a daily basis anyway, due to the onset of westerly winds aloft, it has been pointed out by more astute forecasters, like forecasting legend, Mike L, at the U of AZ, TEEVEE ones, NWS, etc., (i e., namely, everyone else who knows anything at all about weather) that tropical air will still be feeding in enough from the east below the westerlies to keep some Cumulus going here and there, some even becoming Cumulonimbi with rain! Your errorful CMP was actually glad to be “informed”, glumness disappearing.
Also, we got that cold front coming on the 27th or so, with another chance of rain as humid air is drawn northward ahead of it. So, another coupla chances to make this a decent water year, one that ends on September 30th. We’re just surpassing 15 inches now; the normal, computed from 37 years at Our Garden here in Catalina, is a little less than 17 inches.
Had another rainbow from those cloud “warriors” we call Cumulonimbus on the Catalinas. But, “If traces are your thing, Catalina is king!” as we recorded but a trace of rain again while soaking rains poured down just a couple of miles away on the Catalinas, to form a sentence with too much punctuation and a sentence within a sentence1.
More interesting perhaps to some, this modest rainbow formed just after 5 PM yesterday toward the Charouleau Gap, as seen from Catalina, and was still in almost the same spot after 30 minutes. Have never seen that before since both the sun and the showers are drifting along and so the rainbow should change position.
First, in today’s cloud story, the strangely believe it rainbow part:
5:12 PM. Rainbow first spotted toward the Gap. Cumulonimbus cloud not sporting ice at top; ice is below flat top due to weak updrafts that allow the ice crystals to subside while the top remains mostly liquid appearing. The smoothness on the side of the cloud above the rainbow is due to ice particles5:42 PM. While the observer has moved some few hundred yards, the rainbow has stayed pretty much where it was after 30 min. A course in optics would be required to explain this and that’s not gonna happen (accounting for the sun’s movement, the rain, and the observer’s movement).
The whole day represented several phases, the early, spectacular eruption of clouds on the Catalinas as it started to warm up under clear skies, those low bases topping the mountains again indicating stupendous amounts of water are going to be in them when they grow up, the rapid appearance of “first ice” just after 10 AM, the heavy showers and cooling on the mountains and here (little thunder heard), the clearing due to the cooling, the warming, the rebuilding of the Cu on the mountains, and new showers–the rainbow was part of the second growth phase, and then the gradual die out of the Cu as sunset occurred.
Huh. I just realized that what happened to our temperatures yesterday was like a mini-sequence of the earth’s climate over the past 200,000 years or so, the prior Ice Age in the morning temps, the warm Eemian Interglacial as it warmed up, the last ice age when the cooling wind from the mountain showers hit, then the warm Holocene when the clearing and warming started up again in the afternoon! Cool, warm, cool, warm. Below, the Catalina temperature record that emulates earth’s climate over the past 200,000 years, beginning with next to last “ice age.” I can’t believe how much information I am passing along today! What a day you had yesterday!
Mock climate change for the earth’s past, oh, 200, 000 years or so as indicated in yesterday’s Catalina/Sutherland Heights temperature scale. But, we have a LOT of days like yesterday’s in the summertime, but only now after 7 summers has it hit me how it mimics our earth’s “recent” past climate.
Cloud Alert: Yesterday might have been the last day for summer rain here. U of AZ mod from last night has plenty of storms, but we’re on the edge of the moist plume, and those storms take place just a hair east of us it says. So, while they may be on the Catalinas today, unless we get lucky, they’ll stay over there. Drier air creeps in tomorrow, too.
Here is the rest of our day in clouds, from the beginning, even if its not that interesting. In the interest of efficiency, you’d do a lot better by going to the U of AZ time lapse site to see all the wonderful things that happened yesterday, instead of plunking along one by one as you have to do here. (PS: Some functions in WordPress not working, would not allow some captions to be entered as usual.)
9:21 AM. This tall, thin Cumulus cloud was a reliable portent for yesterday’s early storms on the mountains. It just shot up!
11:57 AM. Thunder and downpours are widespread on the Catalinas.
2:46 PM. After the long clearing, Cumulus begin to arise on the Catalinas again.5:46 PM. A pretty, and isolated Cumulus congestus with a long mostly water plume ejecting toward the NW. Some ice can be seen falling out of that ejecting shelf. Now here’s a situation where an aircraft measuring the ice output from such a cloud can miss it because its formed as the turret subsides downstream, and most of the ice is substantially below its top, and under the shelf. If you cruised along the top of the shelf, you would miss most of the ice and measure ice particle concentrations that are much lower than what the cloud put out.6:17 PM. This same quasi-stationary cloud with its long shelf, still shedding ice just downwind of the cloud stem, is about to disappear. Note, too, that the ice fall quits after awhile going downstream even though cloud top temperature is the same for quite a distance. The ice was actually formed at lower temperatures in the protruding turret, not at the temperature of the shelf, which apparently were too high for ice to form. Also, cloud droplet sizes shrink from those in the protruding turret as evaporation takes a stronger hold. Larger droplet sizes are associated with greater ice formation at a given temperature.6:12 PM. Like aspen leaves in the fall, but every day, our clouds change color as the sunsets. Here’s another memorable site, not only due to the color, but how tall and thin these Cumulus clouds are, showing that the atmosphere was still extremely unstable over the depth of these clouds, probable 2-3 km deep.
The End.
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1Hahah-these are just a couple of the grammatical gaffes I actually know I’ve done!
The sky was packed with tropical Cumulus congestus and a few Cumulonimbus clouds in the distance at dawn yesterday, an unusual sight for Catlanders. A few of those Cu around the Catalina/Saddlebrooke/Oro Valley area grew overhead into “soft-serve” Cumulonimbus clouds with heavy, tropical-feeling showers you could hike in with great comfort; no lightning/thunder observed.
Up to an inch likely fell out of the core of the largest ones yesterday morning, but only .09 inches was recorded here in the Sutherland Heights. The Golder Ranch Drive bridge at Lago del Oro got 0.28 inches, Horseshoe Bend in Saddlebrooke near one core got 0.71 inches, Oracle, a half inch. Due to the exceptionally warm cloud bases, about 60 F again, warm-rain processes were certainly involved with those showers, though glaciated tops were usually seen, too. In warm base situations, they can act together.
Now here’s something interesting of me to pass along to you, something you might want to pass along to your friends when the opportunity arises: ice doesn’t seem to make much difference in the rainfall rates of true tropical clouds in pristine areas, only a little “juicier” than the ones that we had yesterday. Early radar studies in the 1960s1 indicated that the rainrates of tropical clouds peak out BEFORE the cloud tops reached much below freezing, a finding that has been confirmed in some aircraft studies of rainrates in tropical clouds2. Icy tops going to 30 thousand or more really didn’t do much but add fluff. All that really heavy rain that developed before the cloud tops reached the freezing level was just due to collisions with coalescence (AKA here, but nowhere else because its too silly, as “coalision.”) So, “coalision” can be an extremely powerful and efficient way to get the water out of clouds and onto the ground!
Scattered storms beautified the sky the whole day in the area. More are expected today, as you likely know. Have camera ready! Hope you get shafted!
Cool snap, maybe with rain, virtually guaranteed now for about the 26th-27th. Should make a good dent in the fly season, if you got horses and have been battling them all summer you’ll really welcome this.
Your Cloud Diary for September 19, 2014.
We start with an early morning vignette, down there somewhere:
6:32 AM. Overcast Stratocumulus (likely with bulging tops) and the distant top of a Cumulonimbus, that bright sliver, lower right. 6:33 AM. Cumulonimbus top NW of Catalina, an usual sight since it had arisen from such low based clouds in the “boundary layer”. Usually this only happens due to heating by the sun later in the morning or in the afternoon, of course.
Vignette: When this cloud bank above Sutherland Heights (shown above) darkened up, looked more organized, and with Cumulonimbus tops visible and showers already nearby, I made the not-so-surprising comment to two hikers about to leave on their hike hour long hike, “Watch out for these clouds overhead!”
They got shafted, see photo below; came back soaked, their dogs, too.
But, I had done my best. True, it was early morning, and after all, those hikers were likely thinking, “it doesn’t rain much here in Catalina in the early morning” (unless its FOUR inches like two weeks ago).
7:30 AM. Heavy rain falls S of Sutherland Heights, on hikers who had been warned about a dump; produced a warm feeling.
8:14 AM. Those showers moved off into the Catalina Mountains and the early morning sun provided a spectacular scene. (From the “Not-Taken While-Driving” Collection, though certain attributes here suggest that someone just pointed a camera in any old way and got this shot. Pretty clever to make it look that way, kind of adds an “action: attribute to the shot.
Cloud of the Day:
1:47 PM. I meet a friend, southbound, on Equestrian Trail. I advise her that if she drives under this cloud, she will get dumped on. She continues on. There is no outward sign of ice, and no shaft, however.
1:49 PM. Thunder begins to grumble repeatedly from this cloud only two minutes later! The conversion from a droplet top to an ice (glaciated) one is clearly in progress. My friend has disappeared over the horizon, which isn’t that far in only two minutes.
1:58 PM. Kaboom! I was actually a little late getting the fallout to the ground. Will have to look at the video to see the shaft plummet down. Produced a nice little haboobula, too, on the left side, where the shaft is densest. I wondered if my friend had gotten “shafted”, as we say here when folks are under the rain shaft.
2:57 PM. An isolated Cu congestus thrusts three turrets out. Who will it turn out to be?2:53 PM. Stable layer halts growth of the two outer turrets and they begin to flatten, but caulifower top in the middle shows that further growth will occur. Will those wings develop ice? Beginning to look like a rocking horse, I see…Look! Its Snoopy with wings! (Ice seen on the right, also on the left, but less obvious).4:31 PM. Pile of Cumulus congestus clouds weighs down the Catalina Mountains again as they did the previous evening. Had to pull off the road this time, jump out car to get this grand scene, well, to me anyway. Hungry passengers a little annoyed at the pre-dinner delay. You know, had to complain a little.6:18 PM. Another sunset reason why we live here and love it so much.6:20 PM. Late storms continue on The Rim, toward Globe
The End, enjoy our last couple days, it would seem, of our summer thunderstorm season. Oh, me.
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1Saunders, R. M., 1965; J. Atmos. Sci.
2Cloud Maven Person with Hobbs, 2005, Quart; J. Roy. Met, Soc.
Yesterday, in the wake of TD Odile, it was about as Hawaiian a day in Arizona as you are ever likely to see. First, the high dewpoints, ones that replicate those in HI, mid and upper 60s (69-70 F in HNL right now), cloud base temperatures of around 60 F, and with misty, even drizzly warm rain around at times. The only thing we didn’t see was a rainbow, so common in HI they named a sports team after them.
If you thought the clouds looked especially soft-looking yesterday, I thought they were, too. That soft look that also characterizes clouds in Hawaii and other pristine oceanic areas arises from low droplet concentrations (50-100 per cc), characteristic of Hawaiian clouds.1 Both low updraft speeds at cloud base, and clean air result in low droplet concentrations in clouds.
The result of these factors?
The droplets in the clouds are larger than they would be forming in air with more aerosols (having “cloud condensation nuclei”, or CCN) and stronger updrafts at cloud base. Yesterday, you could have remarked to your neighbors late yesterday morning, as the rain and true drizzle began to fall from that Stratocumulus deck out to the SW-W, that the droplets in those clouds, “….must’ve exceeded Hocking’s threshold” of around 38 microns diameter. Lab experiments have demonstrated that when droplets get to be that large, which isn’t that large at all, really, that they often stick together to form a larger droplet, which in turns, falls faster and bumps into more droplets, and collects them until the original droplet is the size of a drizzle (200-500 microns in diameter) or raindrop (greater than 500 microns in diameter) and can fall out the bottom of the cloud.2
6:10 AM. Light drizzle or rain due to collisions with coalescence rather than due to the ice process falls from yesterday morning’s Stratocumulus deck (fuzzy, misty stuff in the center and right; eyeball assessment). Quite exciting to eyeball. 9:46 AM. So clean and pure looking, these clouds during a brief clearing yesterday morning. These might well have been seen off the coast of Hawai’i. 10:23 AM. One of the Hawaiian like ambiance of yesterday was both the low clouds, the humid air, and the green texture on the mountains highlighted by the occasional ray of sunlight. Fantastic scenes!
11:31 AM. Being a cloud maven, I wasn’t too surprised to see drizzly rain start to fall from our Hawaiian like Stratocumulus clouds, but I was excited!
11:41 AM. Stratocumulus clouds mass upwind of the Catalinas. Hoping for a few drops at least.
12:07 PM. An especially tropical looking scene I thought, with the very low cloud bases, the humid air; the warm rain process likely the cause of the rain on Samaniego Ridge.
6:08 PM. As the day closed, this fabulous scene on Samaniego Ridge. Clouds might be labeled Stratocumulus castellanus.
6:25 PM. As the air warmed in the clearings to the southwest and west of us, King Cumulonimbus arose. Expect some today around us.
Mods still coming up with cold snap at the end of the month, even with rain as the cold front goes by. How nice would that be to finish off September? Still have a couple of days of King Cumulonimbus around as tropical air continues to hang out in SE Arizona. Hope trough now along Cal coast can generate a whopper here before that tropical air leaves us. Am expecting one, anyway, in one of the next two days, probably our last chances for summer-style rain.
Speaking of Odile….
the thought that inches of rain might fall in Tucson, something we all heard about two eveings ago WAS warranted by the gigantic amounts that occurred as Odile slimed its way across extreme southeast AZ. In modeling terms, the error in its track was pretty slight, but the predicted amounts that we COULD have gotten were pretty darn accurate. I did not see these amounts until after writing to you yesterday. Note those several four inch plus values around Bisbee, and the one in the lee of the Chiricahuas. That one 4.45 inches over there suggests to me that the Chiricahuas like got 4-6 inches. Check’em out:
24 h rainfall ending at 7 AM AST yesterday for SE AZ (courtesy of the U of AZ rainlog.org site).
The End
———————— 1Except those affected by Kilauea’s “VOG” which have much higher concentrations, and look a little “dirty.”
2A thousand microns is a millimeter, in case you’ve forgotten, and that’s only about 0.04 inches in diameter. Most raindrops are in the 1000 to 3000 micron diameter range, though the largest, measured in Brazil, the Marshall and Hawaiian Islands, can be about a centimeter in diameter.
Odile passed to the S and E of Cat land, leaving only 0.13 inches here in the Heights, the Sutherland ones. Didn’t even get the half inch I hoped for. Oh, well, we can be happy for the droughty areas of New Mexico that got the brunt of that tropical system as did portions of extreme SE AZ. You may know that for many days in advance and up until 11 PM the night before last (shown here), our best models had O practically passing right over us with prodigious rains indicated.
Unfortunately, we meteorologists often “go down with the ship” when this happens due to model forecast consistency. Only in the last minutes, so to speak, did the model runs get it right (but too late to be of much use) and finally indicated that the true path of the heaviest rain was NOT going to be over us, as was already being discovered via obs. O was such a cloud mess, the mods may have been off in locating where the center was. Not sure. Will have to wait for the panel report.
Seems to be preciping on the Cat Mountains right now, though doesn’t show up on radar, so its likely a RARE “warm rain” event here in AZ where the rain forms by collisions between larger cloud drops to form rain drops and the cloud tops are low1. Maybe that’s O’s legacy; tropical air and a warm rain day sighting.
BTW, whilst Catalina and most of Tucson didn’t get much, it has continued to rain steadily in our mountains over the past 24 h with Dan Saddle, up there in the CDO watershed, leading the way with 2.09 inches in 24 at this hour (5 AM) and its still coming down lightly, as noted. Its been a fantastic rain since it was steady and soaking up there over that whole 24 h period, much like in our winter storms. Below, some totals from the PIma County ALERT gauges. You can see more totals here.
Gauge 15 1 3 6 24 Name Location ID# minutes hour hours hours hours —- —- —- —- —- —- —————– ——————— Catalina Area 1010 0.00 0.00 0.00 0.00 0.16 Golder Ranch Horseshoe Bend Rd in Saddlebrooke 1020 0.00 0.04 0.04 0.04 0.20 Oracle Ranger Stati approximately 0.5 mi SW of Oracle 1040 0.00 0.00 0.00 0.00 0.12 Dodge Tank Edwin Rd 1.3 mi E of Lago Del Oro Parkway 1050 0.00 0.00 0.00 0.00 0.16 Cherry Spring approximately 1.5 mi W of Charouleau Gap 1060 0.00 0.00 0.00 0.00 0.16 Pig Spring approximately 1.1 mi NE of Charouleau Gap 1070 0.00 0.00 0.00 0.00 0.04 Cargodera Canyon NE corner of Catalina State Park 1080 0.00 0.00 0.00 0.00 0.20 CDO @ Rancho Solano Cañada Del Oro Wash NE of Saddlebrooke 1100 0.00 0.00 0.00 0.00 0.08 CDO @ Golder Rd Cañada Del Oro Wash at Golder Ranch Rd
Santa Catalina Mountains 1030 0.00 0.04 0.04 0.08 1.73 Oracle Ridge Oracle Ridge, approximately 1.5 mi N of Rice Peak 1090 0.00 0.00 0.04 0.04 0.75 Mt. Lemmon Mount Lemmon 1110 0.00 0.00 0.00 0.00 0.43 CDO @ Coronado Camp Cañada Del Oro Wash 0.3 mi S of Coronado Camp 1130 0.00 0.04 0.04 0.04 0.31 Samaniego Peak Samaniego Peak on Samaniego Ridge 1140 0.00 0.08 0.28 0.35 2.09 Dan Saddle Dan Saddle on Oracle Ridge 2150 0.00 0.00 0.04 0.08 0.71 White Tail Catalina Hwy 0.8 mi W of Palisade Ranger Station 2280 0.00 0.04 0.12 0.16 1.02 Green Mountain Green Mountain 2290 0.00 0.04 0.04 0.04 0.47 Marshall Gulch Sabino Creek 0.6 mi SSE of Marshall Gulch
BTW#2, true CMJs (cloud maven juniors) will want to photograph the rain from these shallow clouds, this rare, Hawaiian-like rain event2, lining the Catalinas this morning as soon as its light enough. It would be like photographing a parakeet on your bird feeder here in Catalina, one migrating from South America. I think that’s where they come from. Anyway, your cloud-centric friends from other part of the world would be quite interested in seeing your photos of this.
Is the summer rain season over?
No way! (But you already knew that, though it sounds more exciting to put it that way, in the form of a question like the TEEVEE people do)
Now we get into some interesting weather times as we go back into the scattered big thunderstorms feeding on the moist plume that accompanied O. That moist plume will be around for the next few days. These coming days, with their thunder squalls, may well be the most “productive” ones for rain here compared to the piddly output of O here in the Heights. We have upper air goings on that are likely to make storms cluster more into big systems a time or two during the next few days instead just the one over here and over there kind of days, the ones you hope you get lucky on to get truly shafted. So, “fun times at Catalina High” ahead, to paraphrase something.
Yesterday’s clouds
11:15 AM. The look of a stormy sky: Stratus fractus lining Samaniego Ridge, orogrpahic Stratocumulus topping the Ridge, overcast Nimbostratus producing R– (very light rain).4:56 PM. By afternoon the deeper clouds were gone leaving Cumulus, a couple of distant Cumulonimbus clouds with their rain shafts, and an overcast of Stratocumulus or Altocumulus, no precip coming out of them.6:28 PM. The sunset, while OK, like O was a little disappointing since more clouds could have been lit up by the setting sun but weren’t.
The weather way ahead
Cool weather alert: based on model consistency, which I have already discredited earlier, there are cold snaps now appearing for the end of September and early October. They’ve shown up in a couple of runs now. They have some support in the NOAA spaghetti factory plots.
The End.
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1There’s a nice description of “coalision” , the warm rain process not involving ice, in Pruppacher and Klett (1998) if you really want a nice book about cloud microphysics in your library.
2Mostof the rain that falls in Hawaii falls from relatively shallow clouds with tops at temperatures above freezing, no ice involved, contrary to the usual situation here where ice is necessary.
