About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno
Will be resting mind here for a few days; its kind of depleted of creative sophomoric (AKA, “lame”) humor and expert cloud talk for awhile after the long summer of clouds.
Just going to lay back and enjoy the storms in the next couple of days, not think about cloud stories. Thanks to both of you for your patience.
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….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.
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.
The End
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:
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!
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.)
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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.
We start with an early morning vignette, down there somewhere:
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).
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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
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.
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:
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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.
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.
Old Man O is kind of a mess now. Still hoping for half an inch here in Catalina/Sutherland Heights, but now even wonder it that will materialize as O goes by today and tonight. Darn!
But, even though O MIGHT be a rain disappointment here in Catalina, there are plenty of opportunities to get substantial rains AFTER O goes by due to lingering tropical air combined with the presence of an upper low pressure center along the Cal coast in the days ahead. Cloud Maven Person thinks (of course, as an “unofficial weather thinker”) that more rain will fall in the spotty thunderstorms here in the Catalina area in the five or so days after O than in O today. We shall see, won’t we?
However, before moving along, let us examine in the colorfully annotated map below those results produced by the truly great thinker inside the “Beowulf Cluster” at the University of Arizona’s Dept of Atmospheric Meteorology to compare the dinky amount CMP is dreading. Its only fair.
Shown below is more like a heavenly rain here, some 1-2 inches is predicted to fall over a number of hours, not in one dump. Hoping for what is shown below, but think it will be quite a bit less.
Besides, rather than having completely cloudy skies, as today’s sky will likely be, those heavy guys in the days ahead will be far more “photogenic” you might say with their black shafts and sparks. Rainrates will be greater, too, in those situations than from O’s clouds, which are a little too stratiformy and all mixed together for the blinding rains we see in our thunderstorm rain shafts. Also, since O’s little circulation will pass just to the east of us, the flow off the Catalinas will be a little downhill from the east, which helps to reduce what we might get here, too.
In contrast to the semi-steady rains of O later today, our summer thunderstorms can drop an inch or even two in 15 minutes (yep, its been recorded in gauges). The flooding rains we had a week ago last Monday, the rates were 1-2 inches. Makes quite a difference in erosion.
—-rambling aside below—-
Its interesting to me, stepping aside from direct weather commentary into a more philosophical one, how the story of O resembles life in general as happens to all of us growing up. All of the promise that O had for producing heavy, but mostly beneficial, rains here in Arizona, has been reduced, like that of a youngster growing up that gets straight A’s in the 7th grade, 8th grade, but then loses all of his focus when puberty hits and notices all those wonderful, endlessly intriguing, fascinating, “can’t take my eyes off of you”, creatures around you that seemed so boring and non-existent just a few years earlier. But now they have become the greatest conundrum in all of life! Instead studying, you, as I did, began making jokes in class as a way of getting the opposite sex (!) to notice you because you didn’t have any other social skills to interact with “girls” with. And, like me, you started getting kicked out of class and sent to the principal’s office for causing distractions. THESE humiliations after all those straight A’s and accolades we got from teachers just a year or two earlier. All of our promise, like O’s, dissipated: you’ve discovered that you’re a Saffir-Simpson Category 5 heterosexual, to continue a tropical theme here.
The life of O has been just like that; the once proud storm, so organized, so full of rain potential for Catalina, became “distracted”, disorganized, and torn apart by mountains, vagaries in the topography and lack of warm water to feed on. O’s life reflecting our own lives when hormones hit, blind siding us, deflecting us from the productive lives we thought were ahead but instead into poor grades and lack of self-control, which meant we had to go to a community college instead of real college. And even then, when you find you have a Spanish class there with Miss Wisconsin of 1961, the distractions and poor grades continue… You can’t even get into UCLA after seven years of JC!
Yes, O’s story IS the story of every man. Believe me, I understand what you went through and how hard it was to dissipate so much promise early in life, as tropical O has likely done for us here in Catalina.
—–end of RA—-
Here is a nice, but sad loop of radar and satellite imagery of O during the last 12 h or so from IPS MeteoStar, one that documents O’s decline.
One size fits all it seemed yestserday, but I am giving you three anyway, so here they are, your cloud day.
Unless the younger folks watch Turner Classic Movies or something like that, they will be clueless about what ther the reference to “dialing” is in the title. Oh, well. Heck, who even remembers what a Walkman was these days?
The heavy cloud shield of TS Odile is moving in with some light, spotty rain hereabouts right now. It will be interesting to see if today’s rain amounts to anything. Seems it could be a very Seattle-like rain day with those heavy layer clouds over us (Nimbostratus/Altostratus) and intermittent very light rain all day. Boring! (Is “boring” with an exclamation mark an oxymoron of sorts?)
NWS is excited about Odile, as any meteorologist not having snow in his veins would be, and have posted some daily rainfall records for this week. Of course, we’ve already set some rainfall records for September; can it happen again? They seem to be concerned about that possibility. Many of those September records, as many of you will remember I am sure, were associated with tropical storm Norma that busted into Arizona in early September 1970 as you will see1. Workman Creek got 11 inches in one day back then. You can read about Norma’s doings here and whether the NWS forecasts were adequate.
The meteorological situation was very different with Norma, and that may be why we precipophiliacs could be “disappointed” by rain amounts with Odile–Norma had help from the configuration aloft; Odile not so much. However, in the days following Odile’s passage, that upper level trigger does fall into place over southern Cal, and we’ll have to watch out for some big thunderstorms in the couple of days AFTER Odile goes by when that upper level trigger (trough) still has some tropical air to work with. So, some really “interesting” weather ahead, the kind of weather we’ve forgotten can happen here in the many droughty years we’ve had lately.
Here, just hoping for some nice steady rains, not just sprinkles, that add up to something significant like a half an inch or more, keeping the desert green that bit longer, and maybe, some good scattered thunderstorms for a few days after the big cloud shield of Mr. Odile fades away. That will pretty much do it for our summer rain season I’m afraid.
Now, since we don’t like to do work that can be done better by others, these ones and this one, for example, so on to yesterday’s pretty cloud pictures. (Can’t get over the thought I might be disappointed in Odile’s rain here, expectations not real high, so don’t want to express them and make you a little sad; keeping a lid on thoughts of a big Odile rain for Catalina, don’t want to get too manic, etc.) Will just lay back and enjoy it…whatever comes.
11:59 AM. Towering Cumulus and Cumulonimbus clouds begin lining the International border. Warning: adult commentary included in photo, the kind you see every day on TEEVEE.
Followed by a great sunset, one deserving of more than one example. No details, just enjoy.
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1The present Arthur was in Durango starting his first job as a weather forecaster for the great Colorado River Basin Pilot Project, a randomized cloud seeding experiment, when Norma’s remains hit and flooded the Animas River there. I was inside a vaudeville theater listening to the rain pound on the roof, the audience of that melodrama, too, distracted a time or two, and also being distracted by Durango school teacher, Janet James, whom I had taking a liking to. She was there that night, too, but not with me. Wonder what happened to her?
2 Caution: one photo is annotated with adult humor.
The link below, goes to a rendering of last night’s 06 Z WRF-GFS model run. Has a lot of rain for the Catalina area. We only need 2-3 inches to make this water year (October 1st-September 30th) look pretty normal. This is a great sequence for that. Get ready!
http://wxweb.meteostar.com/models/ipsm_looper.php?PROD=2014091506_CON_GFS_SFC_SLP_THK_PRECIP_WINDS
The End.
Against the deepening blue skies over us as the sun continues its descent to overhead of the Equator, coming right up (September 22nd, AZ time), our late summer Cumulus and thunderheads become even more spectacular. You can see the whole cloud day here, courtesy of the University of Arizona, if you would like to avoid the tedium of examining photos and captions by yours truly.
I got very excited about a small thunderstorm that took shape almost overhead of Sutherland Heights, and you know what that means. Yes, too many photos of almost the same thing! See below. Captured it, too, BEFORE it even started to rain, or even thought about it. Produced a large number of cloud-to-ground strikes in the vicinity, too, more that you would expect from such a small storm. Also, if you could see them, you saw repeated split strikes, ones in the core of the rain, and at the same time a branch in clear air to the north, a mile or two quite a ways from the rain shaft. I had not seen that before happen over and over again. Samaniego Peak reported the only rain, 0.28 inches, in the ALERT Catalina Mountain gauges, like twice that in the core of the shaft.
Then, of course, we had a lot of LTG in the early evening and nighttime hours to the NE-S-SW as storms marched across Tucson, Marana and Oro Valley. Missed us, though. A place in Avra Valley got an inch.
That’s pretty much it for your cloud and weather day yesterday. Farther below, the details….
Mods see nothing for a couple of days, until Monday, when the moisture from now Hurricane Odile begins to work its way into AZ.
