Now THAT was a monsoon-like day yesterday, one right out of the western state of Kerala, India; the thick rain of mid-morning, seemingly thicker than most here, the clothes-gripping humidity outside, the strip of fog on the side of the western Ghats, oops, Catalina Mountains, the relatively gentle breezes in the rain, the subdued green hues under the overcast of light rain at the end of the unusual morning drencher, aspects that, en toto, made the morining seem so India-like to me (and I’ve been there in those Kerala rains). Take a look at our green state and State.
10:37 AM, after 0.76 inches of thick rain with occasional thunder. Nimbostratus up top, Stratus fractus along the Samaniego Ridge.10:53 AM. Looking toward Charoleau Gap.
In the Ghats, India, 1975, in case you didn’t believe that I have been in ACTUAL monsoon rains.
And while the rest of the day was sunny, humid and cool for us, the rain wasn’t over with another thunderbludgeoning last night after 9 PM that brought 0.25 inches and the day’s Catalina rain total to 1.02 inches. Drink up, desert!
We also had a nice Altocumulus lenticularis at sunset, suggesting some wind aloft. Seemed almost fall-like seeing this because they are more common with our winter troughs.
6:53 PM.
Another Big Day ahead
3 AM, Arizona obs. Several stations have dewpoints in the low 70s, with TUS reporting, along with light rain, a shockingly high dewpoint of 72 F, really extraordinary.
Get ready! A disturbance over southern California will help organize our storms into ones like those that occur in central Florida today, grouping them into large clusters, with some eye-popping rain amounts likely somewhere in the State (“eye-popping”, 3 plus inches). Don’t be too surprised if you hear about a “tube” somewhere as well. Tubes happen in conditions like these.
After today, its “mostly” dry through the end of September, with the best chance of rain on the 27th-28th.
Nice sunset yesterday, one consisting of_______, _________, ________ clouds, ones that always give us one of those “glad to be here” in Catalina, CDP, feelings. I might give the answers tomorrow, but please try to name these clouds and maybe get that, “Its fun being a cloud-maven, junior” T-shirt you’ve always wanted. It has clouds all over it, maybe even ones you’ve seen and logged!
Only got a trace of rain here in Catalina, though there were a few “be-a-moth” (as we used to say as kids) Cumulonimbus clouds here and there yesterday. Check the U of AZ time lapse movie at about 2:30 PM yesterday for a giant. A couple of examples from around here below:
3:55 PM. Now if we were talking pancakes, this would definitely be a “tall stack.” It was quite a sight, and I hope one of you out there got under this and have a rain report for us today. I would estimate, as you would now, in view of the little movement of the storms yesterday, bases about 8 C (pretty warm), that this giant gave someone 1-2 inches in the peak core.5:44 PM. Here’s a complex of Cumulonimbus clouds SW of Tucson (left of Twin Peaks). The television got pretty worked up about these, as did the TEEVEE weather presenters last evening.
As we know, we are beginning the overall decline in chances of rain each day now; the summer rain season is winding down gradually. Doesn’t mean that in any particular year like this one that it will, BUT you have to give credibility to longer term models outputs that are on the dry side because we’re not dealing with an unbiased coin. The head on the quarter getting flipped for the choice of kicking or receiving in a football game is getting heavier; go for the tail since the heavy head might cause tails to come up more often.
Lately the model runs have had a complete break in the summer rain season around the 25th for a couple of days, then a slow return to wetter conditions alternating with breaks. Go here, to IPS MeteoStar, to see their rendering of the WRF-GFS outputs from last night’s global data, concentrating on the Arizona portion of these maps.
So, what are the chances THIS output, with a reasonable amount of “green” (meteorologists love to color areas of precipitation green; always have and always will) in Arizona at the end of August and the first day or two in September will have summer rains lingering on?
Go next to the NOAA spaghetti factory here. Examine the contours for the end of the month and the first of September…. And, there you have it! Eureka! The confidence level you’ve been looking for.
The late afternoon yesterday was like a Carpenter’s song, i.e., “easy listening” interrupted by Metallica, Megadeath, Slayer, Black Flag, Helloween, The English Dogs (“She Kicked Me in the Head and Left Me for Dead”), etc.
A day filled with moderately promising Cumulus congestus and brief area Cumulonimbus clouds, was suddenly overrun by a black steam roller with a watering tank behind it, and also having a big fan, to wind up a semi-ludicrous metaphor, coming down out of the northeast bringing an early nightfall, blinding rains, and winds of 60-70 mph. It was an astonishing change, and if you weren’t watching, but rather watching TEEVEE: “Ka-blam! What the Hell?” (More on TEEVEE later; see last caption.)
Some rain totals, ones up to 2.64 inches (!) can be found here in the listing of Pima County ALERT gages. More results will be available during the morning from the U of AZ network here, and from the CoCoRahs network. BTW, if you haven’t joined up, it would be good if you joined up with both of these latter “rain gangs.”
Of course, neurotic-compulsive cloud-maven person was watching for you. I only wish I had a huge microphone yesterday evening so that I could have alerted the people of Catalina, “CDP”, to its impending weather doom.
Non-weather side note: “Catalina: its not a town”, but rather, a “Census Designated Place” (CDP) where people are clustered, according to the Census Feds. Namely, we’re Catalina, CDP, Arizona, 85739. Its quite amazing the kinds of things you might read here, and its usually right after I find them out myself.
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Enough collateral information.
The day, had a tranquil but portentful beginning filled with potentiation, with those low, warm cloud bases. However, with the rising temperatures, ones into the mid-90s, so, too, did cloud bases rise. This is normal. As the daytime relative humidity falls, the cloud bases form at higher and higher levels. I hope you didn’t get upset seeing that the afternoon bases were above the top of Ms. Lemmon. Still, those higher, cooler bases did mean that the rain had farther to fall through dry air, not as good as having them down on the Sam Ridge line.
10:23 AM. Turrets begin shooting upward from bases topping Samaniego Ridge. This is good.1:37 PM. Weak Cumulonimbus (Cb) finally forms in the area. Getting a little concerned at the lack of “progress”, and much higher bases now.1:56 PM. Another weak Cb forms over the Tortolita Mountains.
3:43 PM. Another weak Cb forms this side of the Tortolita Mountains. That promising dark base above Catalina unleashed a sprinkle! (Sarcastically spoken).3:18 PM. Finally, something close! Looks promising, but fizzled out.4:14 PM. Not looking good. The Catalinas are back to producing shoots, not Cbs.
5:25 PM. Then “The Man” showed up, a gigantic Cb, one like the model had been suggesting would occur in the prior evening’s run.6:28 PM. The “black steamroller” appears, about to blow over lawn furniture everywhere.6:56 PM. Rolling into Sutherland Heights above Catalina, CDP, this 30-minute “incher”. I wonder who was watching TEEVEE, perhaps planning a TEEVEE party tonight, and not watching?
For a great movie of yesterday’s clouds from the U of AZ, go here.
Oddity
An as yet inexplicable odditity to yesterday’s stupendous storm. The lack of cloud to ground strokes; I didn’t see ONE, and I was looking. Second, the frequency of lightning was as high as it gets. In the dusky light, a new flash within the Cb in less than ONE second at the peak. Its was remarkable. That same kind of activity could be seen last night as the storms receded from us with almost continuous in cloud lightning, but no strokes to the ground (at least during the time I watched.
Today?
Still humid, still unstable aloft. Mods say another active day, so watch it (not teevee)!
While “only” 0.42 inches fell here (a great rain, really), and 0.43 inches at the ALERT gage on the CDO bridge at Lago Del Oro, Sutherland Heights got whooped with a whopping 1.75 inches yesterday afternoon in a remarkably dense and windy rainshaft. But I am getting ahead of myself with this report and this sunset photo. First some more precip reports, here (ALERT gages) and here (U of AZ network). “And the winner is…” (as of 9:18 AM) for the greatest 24 h amount in ALL of Arizona, Bonita Canyon near the Chiricahua NM (2.06 inches) followed by Sutherland Heights!
Check the rainlog amounts above and here for CoCoRahs!
On to our story of the day, to be interrupted later by another learning module…
The day started like any other one, with our often observed morning Altocumulus perlucidus translucidus deck covering most of the sky. With the rising sun, Cumulus began to appear and grow rapidly with bases of those clouds topping the Samaniego Ridge line, something that is a rare occurrence. By 10 AM, showers were already appearing on the Cat mountains; those towering Cumulus clouds had already reached the precip forming level.
By 10 AM, you should have been VERY excited, talking to the neighbors about the low and warm cloud bases; alerting them to possible exceptional rains.
6:49 AM.9:29 AM.10:11 AM. Little acorns are turning into giant sequoias already!
At this point, I feel I have to insert a diversionary learning module. If you’re one of those people who doesn’t care about what’s going on “way down inside” these Cumulus clouds, as Robert Plant might put it if he was a nephologist instead of with Led Zepelin, then skip this module.
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Begin learning module.
With cloud bases as warm as 15 degrees C (close to 60 F!) almost certainly the first precip to form in yesterday’s clouds were drizzle drops (remember, to keep Cloud-Maven from getting mad at you, having “rain rage”, you have to remember that drizzle drops are between about 100 and 500 microns in diameter and that at that size, a few human hairs in diameter, they almost float in the air; umbrellas can be useless when it is drizzling.
Dirzzle is NOT a sprinkle of larger drops, dammitall, and its important to me that you know that!
Here’s the interesting part (he sez). Before drizzle and raindrops can form in a cloud without ice being involved, the droplets inside the clouds must reach 30-40 microns in diameter, maybe a third of a human hair in diameter.
Until they reach that size in the clouds, they will bounce off each other like itty bitty marbles or ping pong balls. After that “magical” size greater than 30 microns, they can coalesce, merge into one larger drop, which then falls faster, collects more drops, and, if the cloud is deep enough, fall out as a raindrop.
In the olden days, this was called a chain reaction process by cloud seeding nut and Nobel Laureate in chemistry, Irving Langmuir, who published a nice paper on this in 1948. Today most folks call it the “warm rain” process, because ice is not involved. Happens a LOT in the tropics, and places like Hawaii, but its rare here because our cloud bases are so warm as they were yesterday, and our clouds, being “continental”, that is, having high droplet concentrations (hundreds of thousands per liter of air) makes it hard for cloud droplets to grow up to be 30 microns in diameter. BTW, raindrops as big as 1 cm in diameter, the biggest known size, came out of a cloud in Hawaii that had no ice in it.
So, for me, a cloud-maven, it was quite interesting yesterday to see that our cloud bases yesterday were “Floridian”, and likely had a good deal of “warm rain” in them, even before they towered up to 50,000 feet, -60 C, and had a ton of ice in them. Its often the case that those raindrops are carried up to levels where they freeze and jump start the ice/hail forming process higher in the cloud via splintering (banging into drops and leaving fine ice shards in their wake) and shattering (they break up upon freezing).
End of learning module; you can wake up now…
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The payoff by those low, warm cloud bases? Exceptional looking clouds, a travelogue in the sky really, more like ones you’d see in Florida in the summertime, Bangladesh, Phillipines, Jakarta, etc. Here they are, before and during the Big Dump on the Sutherland.
12:49 PM. After a huge storm over the Torts, an ominous line of Cumulus clouds began extruding westward toward Catalina.1:07 PM. This is looking VERY good, but, with all the cool air, can these Cumulus bases really be hiding tall clouds? You never know until you see the streamers. Excitement level probably should have been around a 6-8 of 10 here, holding back that bit so that you’re heart is not broken by a later broken up cloud base.1:29 PM. “Thar she blow”s, though actually, its like an upside down spouting whale; the streamers begin to emerge in the distance.
1:28 PM. Just six minutes later!1:31 PM THREE minutes later. Excitement level 9 of 10.1:36 PM. Full blowed tropical Cumulonimbus shaft. Thinking about that “Rawhide” theme seeing this, after all, this is “Arizony”: Rollin’ rollin’, rollin’, though the streams are swollen, keep them dogies movin’, rawhide” rain and wind and weather, hell bent for leather….’
That last shot is of the one that rolled into the north Catalina area and Sutherland Heights, dropping 1-2 inches.
Tried to beat it up to Sutherland Heights but was late, visibility
was bad, lightning close by, so stayed in car with one of our (wet) dogs, Pepper.
As a result, in no “in the storm” shots. Sorry.
Oops, today?
Latest mod run from 11 PM AST last night by U of AZ here. Surprisingly, this model run thinks today is quite a down day, not much shower action here. Must be due to the cloud cover keeping the temperatures down all day (in the model) Or something else that is not immediately apparent to me, anyway?
But, temperature is NOT everything, as we saw yesterday. When the air is this humid, and deeply humid as yesterday, it doesn’t take blazing temperatures to launch Cumulonimbus clouds.
So, it seems likely, with the usual daytime thinning of these clouds, perhaps not enough of that in the model, that tropical Cumulonimbus clouds will once again arise here and there. I think Bob, our local scientist expert in these matters, will fill in some of my blanks on this later. He’s probably not up yet.
Only a marked change in the flow pattern at near the top of our Cumulonimbus clouds can really do much, and its not obvious any thing much is changing up there (is it helping air to rise, or to descend and dry out?) The latter can put a real damper on cloud development even if there is initial good humidity, and right now, it doesn’t get any wetter in AZ than it is right now, this morning!
Five consecutive days of afternoon and, or, evening rains are ahead. If you don’t believe me, go here, to the University of Washington’s model run from last night‘s GLOBAL data, showing where the rain areas will be (in color!) every three hours for the next FIVE days. You will see that EVERY afternoon and evening has regions of color in our area. I hope you’re happy now.
Instead of dwelling on yesterday’s drab conditions; all that water up there, and in the air around us as measured by those high dewpoint temperatures, air that produced almost no rain here in Catalina, I thought I would instead liven things up today with a learning module for you, delimited by a string of dashes for excitement.
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Below, is a link to the Environmental Science Services Administration (ESSA) pamphlet that tells you how to interpret today’s probability forecasts (10%, 40%, etc., chances of rain).
While I have provided this information as a public service, if you would like to obtain one of these pamphlets for yourself, you can get them for ten cents from the Superintendent of Documents, Government Printing Office, Washington, D. C.
Alert: there may be some questions in the days ahead to make sure that you read and understand this information. A sample test question:
“There is a large Cumulonimbus cloud on the Catalina Mountains but you can’t see them through the rainshaft coming out of that cloud. There is a flash flood warning for the CDO wash. The chance of rain is 10%?
True or false?
(The answer to this sample question will be provided in an upside down font when WordPress is able to to that.)
End of learning module. (I hope you’re happy now.)
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OK, here’s is a tiny sample of clouds from yesterday. I hope you recorded them correctly in your log book. Here they are, in case you miss them on some hot day ahead:
12:36 PM Sprinkles are around. Altocumulus opacus, could be labeled Stratocumulus underneath. Above the Altocu, Altostratus, the three layers helping to provide that Seattle drab look.
4:35 PM. Can you spot the Cumulus fractus under this Altostratus translucidus layer?
Heard thunder for about 12 h it seemed yesterday, but little came of it. Even the rainshafts looked anemic for the most part for the second day in a row.
Current 24 h rainfall totals from the Pima County ALERT gages here. U of AZ network here. “Coco” for Pima, here.
Got hopeful after a disappointing afternoon when an evening shelf of Stratocumulus with buildups spread westward from the northeast, shown in the first photo. Rain shafts began to appear in the upwind direction as the sun set with occasional cloud to ground lightning strokes, ones that continued until after dark. Those showers grew and then were almost dead by the time they passed over Catalina. So another disappointment. Seems you end up saying that a lot when you’re living in a desert and wanting some rain…
6:58 PM. Looking north6:59 PM. Looking NE.7:33 PM. OCNL LTGCG NE (weather texting example for “occasional lightning cloud-to- ground northeast”).4:48 PM. Got hopeful here, too, looking at this dramatic sky toward Charoleau Gap. But no; instead it went down the Catalinas, didn’t spread southwestward.5:27 PM. This is the same complex, now moving away into TUS. Dumped nearly an inch on the wealthy Catalina Foothills district where they probably don’t even need it because they can afford so much irrigation. It had missed us completely. I included this one with lightning because sometimes it seems like you are a people that enjoys fireworks more than a lecture about how graupel forms.
That Enviro Can model isn’t going to win a Gold Medal, another clever play on the Olympic Games now underway in London, with its forecast track for Hector-Ernesto. In our last episode, the Enviro Can mod had H-E drifting northward in a timely manner, and it had been that way in model run after run, so that portions of its remnant produced significant rains in southern Arizona.
The medalist in the H-E track forecast? The USA! WRF-GFS model. It had tropical storm Hector-Ernesto staying far away until it was dead, drifting glacially northward off Baja until it disappeared (as it is shown to do today) with only modest effects here. That USA forecast was better forecast all along.
We just did not get that upper level trough along and off the West Coast, required to steer H-E rapidly northward before it faded over the cool waters off Baja.
The good news is that there is no real droughty days ahead either, which means a steady diet of scattered thunderblusters for another week or so, and if we can get the cloud bases down from 14,000 feet above seas level to 8000-9000 feet (at the top of Ms. Lemmon), we could be back in the 1-2 inch rains in those scattered intense rainshafts. This morning’s sounding from TUS suggests they will be a couple of thousand feet lower than yesterday! Yay!
A quite active day is forecast for us today, beginning in the early afternoon rather than mid to late afternoon as has been the case. The first shower/Cumulonimbus cloud is forecast to form today on the Cat Mountains is by 1 PM, hours earlier than prior days. That would go along with the 5 AM sounding just in which has is more moist than previous days. Note that last night’s model run would not have had this new data.
So, chance of a hard rain in the afternoon if we’re lucky. But what could be really nice is that rain (in the model) continues here off and on overnight at a moderate rate, pretty unusual.
Fingers crossed that the “initial conditions”, the starting point for lat night’s run, are accurate, one of the biggest bugaboos in our models.
Why would such skinny, towering clouds be filled with thundery, gushing portent? Its really hard for a cloud to be tall and skinny. Why? Because too much dry air comes in as it rises, both from the tops and sides, and if that air is dry, it can’t go far without evaporating. Too, the drop in temperature with height has to be larger than normal for clouds like yesterday’s to shoot up to well beyond the level where ice can form (glaciate). But they did off and on all day. Mt. Lemmon functioned as a smokestack for Cumulus and even skinny Cumulonimbus, clouds all during the late morning and into late afternoon. There was some thunder here as ONE got big enough to rain that bit toward Charoleau Gap. So, you do get to record a TSTM (thunderstorm) in your log book. No rain fell here.
If you missed those bulimic clouds, here’s yesterday’s movie from the U of AZ. If you watch that time lapse, you will see some of the tallest turrets shooting up awfully fast; I thought they were rising about fast, at times, anyway, as any turrets I have seen in these movies, a marker for how rapidly the air cooled with height yesterday.
Also, here are a few shots of those skinny clouds from this angle here Catalinaland.
11:34 AM.11:36 AM. Skinny over yonder as well! Look at the behemoth behind it!
1:26 PM. “Smokestack Lemmon”, the old folk singer, still puffin’. Wonder if Sara smoked?
1:50 PM. This next puff showing more “calories”… Uh-oh. Head coming off, chopped off by dry air in the middle. Dammital.2:03 PM. The gruesome sight of a chopped off head of a Cumulus cloud that reached the ice-forming level. At least it had ice in it this time, showing the the puffs were getting taller.2:43 PM. Best one of the day, a Cumulonimbus cloud, was producing thunder at this time. A slight, transparent rainshaft was evident on Cat Mountains to the left of this shot. Notice that head of this cloud drifted away from the root or body. That means the rain falling out is going to pretty light, maybe as here, a hundredth or two.
OK, quiting visual cloud displays here. You’ve seen enough disappointing clouds, ones that did not live up to their potential like so many of us.
You would have thought massive clusters of Cumulonimbus clouds were about to roll in, spawned over the Rincon Mountains or from the high terrain near Pie Town, NM, rolling westward to pummel the townlet of Catalina again. Some of our more gigantic area storms have been preceded by morning “long tall sallys” like these.
But no.
Looking at today:
The boys in the weather club, like Bob and Mike, were talkin’ good storms today based on their very great and decades-long experience. I, too, am riding the Bob-Mike wave.
Way out ahead; major rain joy, maybe…
I am more excited about the longer term view, one in which when it gets here, will remember what I said with enthusiasm now. Remember our logo, one just like the big TEEVEE stations have:
“RIght or wrong, you heard it here FIRST! Live!”
What “first”?
Tropical storm remnant has been probably unreliably, but hopefully, forecast to come into southern Arizona in 192 h or so. Could be worse; what if it was a forecast that was 360 h from now?
Here it is, courtesy of those folks at IPS Meteostar who have rendered the 00 Z (think Olympics Time Zone) time maps for us. Here’s the low, shown on the first map, on Baja coast. The next map shows that the ENTIRE remnant has moved into AZ! Could be great.
What gives this storm a better chance of getting here than some? The upper level steering is set up to draw tropical storms northward should they drift too far northwest, like a bug getting caught in a spider web; the spider then hauling the bug to its hiding place. Gee, I never thought I would write about spiders here, but there it is; it just kind of popped out.
But, you ask, how do we KNOW, have any CLUE, that the steering, as by an upper level trough, is going to be properly placed to draw tropical storms northward so that they get caught up like a bug in a spider web which after being caught in the web, the spider comes down and takes it back to its hiding place. I really liked that metaphor. We are like that place where the spider is hiding!
Of course, you say, we go to the NOAA spaghetti factory and try to discern how likely it is that a trough will be along the West Coast, positioned to draw storms up thisaway.
The last image is a spaghetti plot of trough contours using what be called, “the bad balloon” approach. Hard to imagine, but the starting points for the model is deliberately altered a bit just to see how wild a few of the contours get. The wilder they get, the less reliable a longer term forecast is.
Valid for August 15 at 5 PM AST. Note all the green, denoting rain that fell in the preceeding 6 h.
NOAA “spaghetti plot” valid for the SAME time as the first map, 5 PM AST, August 15th. Shows that a trough along the West Coast is virtually assured. But the “devil”, the storm here, is in the details. While it is a necessary condition, it is not sufficient, since the flow might not exactly draw a tropical storm right to ME. Oops, “us.”
What an amazing, Biblical sight1 that came across the Catalina Mountains yesterday evening, that shaft of intense rain and attendant rainbow! After a day where it looked like rain might not happen here, those earlier Cumulus clouds being pretty lazy really, this behemoth powered across Tucson and the Catalina Mountains dropping 0.56 inches in momentarily blinding rain blown on 60-70 mph gusts, with numerous cloud-to-ground lightning strikes, taking down power lines, and causing a 6 h plus power outage in Catalina. 0.51 inches fell here in 10 minutes!
Oops, forgot to remind you: Don’t forget to go to the movies. Shows the backside of what hit us just as the day ends.
How great this rain will be, too, for our stressed desert-thornscrub vegetation after almost a week of dry conditions. (Only 0.17 inches at Sutherland Heights, though.)
For me, yesterday evening produced the most dramatic sights I’ve seen here in four years in Catalina. I hope you caught it, but if you didn’t, here are a few of the most dramatic ones. The first, penultimate shot was from the front porch about three minutes before bedlam hit Sutherland Heights. Below this, those shots leading up to it.
7:04 PM. The Arc! Woulda been outside, gotten a better shot, but just there was a cloud-to-ground strike about 100 yards away a little before this “whilst” I was being a dummy outside grabbing the shots below.6:34 PM. Storm hitting Tucson. TEEVEE weather presenters very excited. Its heading this way, but will it survive passage over the Catalinas? A successful passage will require the renewal by new rising turrets.6:50 PM. Looks like it will make it over the Catalinas. Note cloud base AHEAD of the rain shafts. This is looking pretty darn spectacular with the sun going down.6:54 PM. 100 photos later, “executive override brain function” for controlling impulsive actions failing. Taking too many photos; agog at what I am seeing. New cloud base holding up.6:58 PM. “Whoa, Nelly”, as Keith Jackson might say. An astounding sight; doesn’t look real. But note clearing just behind shaft. So its not a wide storm at all. Maybe it will miss us, as they have done lately. The “Arc” is just developing at left of the shaft. More importantly, the base now overhead has held up and promises a new dump will emerge. Each of these shafts only lasts a few minutes, and so you have new ones if you are going to get ROYALLY shafted (to use terminology appropriate for Olympics now in progress in Her Royal Majesty’s Britain).
A repeat of yesterday today? Not bloody likely.
Oh, well, any rain will be great, but drier air is moving in. Check it out here from the University of Washington Huskies’ (some former of whom, if that is correct english which I doubt, are in the Olympics, for example, women’s volleyball, but not in beach volleyball which I seem to be watching a lot of) Weather Department here.
Note the drier air moving in from New Mexico and west Texas in this loop. Just the same, it can still rain here some because while drier, it’s not dessicated air and so the usual isolated Cb should be around. So, keep watching, keep cameras ready and charged.
The End.
————————————————————————————————————————————————————-1Biblical allusion is to the “ARK of the Covenant” whose activity was demonstrated in a movie with Harrison Ford some years.
The only good Cumulonimbus (Cb) clouds seem to be occurring north of Golder Ranch Drive, about a 100 miles north. which of course, astronomically speaking is actually quite close. Yesterday, with no intervening clouds, it was another chance to see how far can you see the top of a Cb, then use the NWS radar to place it. The Cb top, with an arrow pointing to it in the first photo, is followed by a zoomed shot. The radar indicates that lone, very tall cell was about 10 miles SE of Kingman, or more than 150 miles away! It was common in South Dakota, working with radar in Mitchell and Parkston, to see Cb tops and anvils on the horizon that the radar was unable to see, partly because the radar beam is pointed slightly upward to minimize “ground clutter” as seen in the radar image below around PHX.
7:12 PM7:12 PM7:20 PM NWS radar mosaic rendered by the U of AZ.
Review of yesterday; another quiet day (Ed. Note: Getting tired of quiet days)
Yesterday was almost exactly like the day before, with a brief period of glaciating cloud in the same spot beyond the Charoleau Gap from Catalina as the day before. Here are a few representative shots of yesterday.
Can you pick out the icy top in that one little glaciating Cb? Its a little harder to detect this time compared with yesterday.
6:51 Cirrus for breakfast.10:31 AM. Small Cumulus over the Catalinas by brunch time.2:48 PM. Cumulus are really kind of in a post-lunch nap; inactive, not doing anything. It was pretty disappointing to watch all of this inactivity, lack of sprouts, into mid-afternoon.
4:03 PM. What’s this? Some bulk. Is that ice in those tops? I know, but do YOU? Means some rain fell out the bottom.
I feel uncomfortable labeling this little mush of cloud a “Cumulonimbus”, maybe “Cb calvus”, because the fibrous nature of the ice is not yet obvious.
Still it has the attributes of a Cumulonimbus, glaciating top, precip out the bottom, though we can’t see it here. It will produce a radar echo like the little Cb the day before. What we really need, to editorialize some, are categories for these situations like “Cumulonimbus humilis”, “Cumulonimbus mediocris” so that we know that we have miniature versions of those clouds.
We do have, though I avoid it, a category of “Cumulus congestus praecipitatio”, because visual examples, as shown in the last (1987) World Meteorological Atlas, cannot be differentiated from Cumulonimbus clouds, at least, not by me!
The weather ahead
“Quiet time” is coming to an end, not today so much, the computers say, but tomorrow, oh my, could be huge!
Trying to be excited for those around us who got all that rain yesterday while we received a paltry 0.18 inches here in the upper reaches of Catalina. Still it was another good little rain for our local desert.
The 24 h rolling archive from Pima County rainfall gages is here. Most seen here? 2.01 inches at Finger Rock and Skyline, Tucson. You’ll see that storm in the movies.
Also, check the more comprehensive U of AZ rainfall network here. In fact, you might as well join up, too. It would get you out of your rut. Think how exciting it would be to go out in the morning and see how much rain fell in your gage in the previous 24 hours! Maybe someday you might win the “rain lottery” and have the biggest amount anywhere in the State! The most reported so far this morning is a deluge of 3.17 inches over by Picture Rocks again. Good grief, have they been getting hammered.
What a July this is turning out to be!
Here we are in Catalina, its late afternoon, it has just rained again, the temperature is a chilly 70 F, dewpoint 68 F (almost saturated), with Stratus fractus just above eyeball level lining the hillsides! Its an amazing scene for an afternoon in Catalina and vicinity in July. And so DARK! Here is that odd scene from yesterday afternoon:
4:42 PM Stratus fractus is that low bar of clouds in the foreground just behind the tree. Makes you want to run over there and play hide and seek in it.
Relive yesterday, as though you were in the city of Tucson shopping possibly, here in this movie, courtesy of the U of AZ Weather Department. The movie is rated “R”, for violence since the sky goes WILD in the afternoon, winds going every which way.
Also, in this time lapse you will get a sense of how rapidly moist air is flowing across us from the east to east-southeast. This movie, comprised of still shots taken every 10 s shows movement, like the day before, that is phenomenal for summer, more like a winter scene when winds are normally strong. There are even Altocumulus lenticular clouds (almond shaped ones) hovering over and just downwind of the Cat Mountains! Amazing.
But check the CHAOS in the mid and later afternoon. Unbelievable. Areas toward the Catalina foothills, during this chaos, got another 1-2 inches again yesterday.
In contrast, let us now look at the very same day in a time lapse film in Seattle, Washington, where Mr. Cloud-Maven person spent 32 years, most with the U of Washington Huskies Weather Department. Here it is. I sum up the totality of that movie for July 29th below:
Bor-ring!
Those Seattle skies, for the most part, were like eating plain, cooked oatmeal everyday, all day.
Below, the start of our exciting day, the middle, and the end has already been shown above. Lots of nice rain shafts SUDDENLY collapsing down out of clouds. A sequence of the big northwest Tucson storm early in the afternoon that moved off toward Marana is included as part of the middle. That shaft really fell out fast, and how you could detect the icey tops BEFORE the shaft appeared. I try to point out how you might have been able to do that in this sequence, and thus, and quite importantly, impress your friends and gain status and some kind of weather sage.
Today?
Just looked at the latest AZ mod output, as you can here (forgot to past link until now, 8:08 AM). Colored splotches are where it is supposed to have rained that HOUR. That model has a much less active day today, but much more active tomorrow. Cumulonimbus clouds in sight today? Oh, yeah! But, none are SUPPOSED to get us today. But these mods are always slightly inaccurate, so keep watching this afternoon. Should be another photogenic day, if nothing else.
10:03 AM. What a pretty start!1:29 PM. Cumulus congestus converts into a Cumulonimbus calvus. While no rain is falling out the bottom, check the top peaking through above in the next shot.Also at 1:29 PM. Annotated. Icey tops barely visible, but reveal that this cloud is LOADED with precip, certainly would have a radar echo aloft now. In a perfect world, the flash flood warnings would go out NOW, even though it hasn’t gone out the bottom yet.
1:32 PM. The first fibers of rain are just starting to be visible at cloud base as the updraft collapses, too much weight up there in rain, hail, and snow.
1:36 PM. There it comes! Close up of the main dump.
1:48 PM. What was interesting was how huge this got in just a few minutes, how the initial outflow winds kicked off other cells around the first dump shown above.
