Lot of great scenes on the 18th, but, ultimately with hopes raised for appreciable measurable rain in Catalina, it was a disappointing day. Nice temperatures, though, for May if you’re a temperature person. Only a sprinkle fell (4:15 PM), and if you weren’t outside walking the dogs you would NEVER have noticed it.
Here is your full cloud day1, as presented by the University of Arizona Weather Department. Its pretty dramatic; lot of crossing winds, as you will see, and an almost volcanic eruption in the first Cumulonimbus cloud that developed near the Catalina Mountains.
That blow up was indicative of an remarkable amount of instability over us yesterday morning, one that allowed really thin and narrow clouds to climb thousands of feet upward without evaporating. Usually the air is dry enough above and around skinny clouds that even when its pretty moist, they can’t go very far without the drier air getting in and wrecking them (a process called, “entrainment”). Here are a few scenes from your cloud day yesterday.
5:45 AM. Gorgeous grouping of Altocumulus castellanus and floccus. They’re coming at you. (If you thinking of soft orchestral music here, you may be remembering well-known orchestra leader, Andre Castellanus.7:37 AM. Here a castellanus turret rises five to six thousand feet above its base. Had never seen one this skinny and THAT tall before. Was really pumped about the mid-level instability at this time. It wouldn’t last. The great height is indicated by the luminosity of the top,Also at 7:37 AM, another amazinging tall turret rises up from quiescent bases, ones not connected to ground currents. The bouoyancy in these clouds is due to the heat released when moist air condenses (latent heat of condensation). When the temperature drops rapidly with increasing height, that bit of heat released is enough to allow weak updrafts to rise great distances, sometimes becoming Cumulonimbus clouds and thunderstorms. These clouds, due to their size, would no longer be considered just Altocumulus andre castellanus, but rather Cumulus congestus. Here’s where our cloud naming system falters some. Later, a couple of these grouping did become small Cumulonimbus clouds with RW- (light rain showers).7:11 AM. The great height of these tops was also indicated by the formation of ice, that faint veil around the edges. Stood outside for a few minutes, thinking I might experience some drops, but didn’t.7:38 AM. The top of this Cumulus congestus has just reached the level where ice will form in the top.10:22 AM. Cumulus congestus clouds began their transitions to Cumulonimbus clouds early and often over and downwind from the Catalinas. Can you spot the glaciating turret in the middle, background? Pretty good skill level if you can.10:23 AM. Here’s a close up of that turret in rapid transition to ice. It was this kind of phenomenon that led Hobbs and Rangno and Rangno and Hobbs to reject the Hallett-Mossop theory of riming-splintering as THE major factor in ice production in Cumulus to Cumulonimbus transitions like these. The high concentrations of ice particles happened faster than could be explained by riming and splintering, or so it was thought. Still think that, but am in the minority, though there have been reports of inexplicable, fast ice development like that Stith et al paper (with Heysmfield!) in 2004 that for a time appeared to put the “icing on the career cake.” Incredible ice concentrations were found in updrafts of tropical Cu for which there was no explanation! That finding hasn’t been replicated by others, casting doubt on the whole damn paper! “Dammitall”, to cuss that bit.11:04 AM. Nice Cumulonimbus capillatus incus (has anvil) pounds up toward Oracle way. Tops are not that high, maybe less than 25 kft.3:41 PM. The air aloft began to warm and an inversion capped most of the convection causing the tops of Cumulus clouds to spread out and create a cloudy mid to late afternoon. Nice, if you’re working outside in mid-May. Since the tops were colder than -10 °C (14 °F) the ice-forming levels, some slight amounts of ice virga and sprinkles came out of these splotches of Stratocumulus clouds. One passed through the Sutherland Heights, but if you weren’t outside you would never have known it!4:38 PM. Isolated rain shafts indicate some top bulges are reached well beyond the ice-forming level. Note grass fire in the distance.7:22 PM. Pretty nice sunset due to multi-level clouds, some Stratocumulus, Altocumulus, and a distant Cumulonimbus anvil.
More troughiness and winds ahead during the next week as has been foretold in our models, and reinforced by weather “spaghetti” plots, after our brief warm up today. No rain here, though. Seems now like rain can only occur at the very end of the month where weaker upper troughs coming out of the Pac appear to be able to reach down and fetch some tropical air.
The End
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1Its gone now because I couldn’t finish yesterday. Went off to Benson for horse training with Zeus.
Got a little homesick yesterday looking at the white sky, the barely visible mountains in the distance, like Twin Peaks, eyes a little teary, not from sadness so much, but from smog and smoke. Grew up in the San Fernando Valley you know, Reseda. Lots of smog there at times, though not as much as in Burbank, thank heavens, where it banked up against the San Gabriel Mountains.
Reseda, as you know is quite famous from the Karate Kid movie and was even mentioned by Frank Zappa in his Tinsel Town Rebellion album so I like to tell people that I grew up there, went to Reseda High School, played some sports. Maybe I should add a sports highlight to convince you that I went to such a famous high school, and maybe, too, mention that overpowering, incapacitating crush I had on Rozzi R. when I was 15 years old, since a story like that would titillate your interests more than a sports story, or maybe even stuff about weather. I think I know the people who read this blog pretty darn well.
Below is that “nostalgic” LA sky we had yesterday, thanks to fires in New Mexico, the second one of the yellowish-orange sun typically associated with smoke particles. Of course, the “white sky” is common on humid days back East, and in the global warming domain, is our friend.
Yes, that’s right, smog is our “friend”, because, as was likely yesterday, in spite of record heat, the temperature would have even been a tad HIGHER without that smoke layer!
In fact, one of the conundrums in foretelling climate in the coming decades, is how much smoke, our “friend”, will offset the warming due to trace gases like CO2. Imagine, a world of never-blue-but-always-white skies and no more worries about global warming!
As the cliché goes, “Beam me up, Scotty” if such a world came to pass! So, lets knock off the fires, all smog, in fact, and untoward gases!
More clouds, less smog today
In case you missed it, some sunrise Cirrus today! Finally a cloud. Who cares if its at 45,000 feet above the ground! It shows there can still be humidity in the air.
Probably had some….OK, your guess… on the ice crystal type up there in those Cirrus clouds.
Yes, that’s right, bullet rosettes, would be an excellent guess, crystals with a solid “germ” center from which columns radiate outward like these ones below captured in Cirrus clouds over Barrow, AK, some years ago.
Update on “dusty coolsnap”, foretold many days ago for around June 5th.
Here, from the NWS Tucson, you will see that “dusty coolsnap”, foretold by the models many days ago, has been evolving into “breezynotashotsnap”, if you can call that a “snap”, a word that implies more suddeness that what will likely happen. Still, a trough brushes by to the north, just doesn’t have the amplitude it once did in the models; we’ll see only some moderation in temps. How can they not “moderate” after record highs, so that was an easy thing for me to say.
Still no rain in mods for hereabouts, but some close calls from afternoon thunderstorms in New Mexico every now and then.
The awful indications is, just beyond a week from now, more record HIGH temperatures lasting for a few days! Yikes.
From dawn til dusk, Catalina was plagued by a smoke layer from the fires in western New Mexico, ones you wouldn’t ordinarily think that smoke would get here from.
An example of the mid-day smoke that looked so much like a cirrostratus layer.Ditto here.
Here is a loop of the water vapor imagery that will show you the air movement from where those fires are to us in Catalina. Also, even more dramatic, showing this is the visible satellite image from the Atmos. Sci. Dept at the U of WA, whose sports teams are not involved in NCAA baseball or softball playoffs, BTW. The arrow points to Catalina, and you can see that by the time of this image, 5 PM AST, we were not in the thickest part.
Now, as many of you know, air flowing down from the northeast is often a VERY good thing for rain here in mid-July since the afternoon thunderstorms over the White Mountains coming bopping on down in the evenings from that direction, driven by driving outflow winds from the northeast, pushing over and around Charoleau Gap. Can’t you just see the blackening July sky, the cloud-to-ground strokes to the northeast, then as close as they are to us, parts of the Catalina Mountains beginning to disappear, no longer visible through the dense rainshafts! Ah, yes, our great July weather…
In the sat image, you can also see that thunderstorms, best represented by the whitest dots in this image next to duller, smooth regions, are not so far away from us. Those whitest parts likely represent the regions of the storms where there are liquid cloud drops and updrafts, the cumuliform part. Those less white zones that appear so smooth, the “stratiform” or anvil portions composed solely of ice.
Rain is usually not occurring at the ground in most of the anvil regions; its just icy fluff, ejecta, and in many cases, counterproductive you might say. That’s because anvils can shade a huge area and kill of the Cumulus that might otherwise grow into storms.
Any rain indicated in the models for Catalina in the next 15 days?
In case you missed it, due to all the dust, yesterday’s sunset:
Moreover, if you go to the NWS Tucson site and the forecast for Catalinaland, you will see icons showing pretty much the same thing for today and tomorrow as is in these photos. It will be interesting to see how deep the dust gets.
Where did all that dust come from, that plume of dust that moved into Tucson and environs during the mid-afternoon?
The Mexican Sonoran Desert NE of the Gulf of Baja.
You can see rivulets of dust being raised in this visible satelllite imagery loop (this will take a LOT of band width!) if you look hard at the desert regions southwest of the AZ border. Also check out the U of A’s loop here, but that one will soon be overwritten, so good luck, and there’s nothing I can do about it.
Below, a still from that loop for 6:30 PM AST, near the time of the photos, with the dust origin region annotated with a red circle, something I have only recently learned to to with Apple’s Preview photo viewing software. Dang. The plumes are oriented SW-NE. So, a few tons of Mexican desert came across the border yesterday to make AZ that bit higher in elevation.
Also in this sat image is the horrible fire near Silver City, NM, northeast of the red circle, the one that grew so much yesterday in the wind and heat. You can see that the smoke plume was already reaching as far as Texas by the time of this image, 6:30 PM AST!
BTW, smoke particles are, in general, much smaller than dust particles are (hundredths of microns vs. a few microns) and the color of the setting sun can be used to help tell what you are looking at as far as aerosol particles go. Smoky sunsets tend toward orange and red; dusty ones toward yellow, as above.
Yesterday afternoon smoke from the Gladiator-Crown King and Tonto fires began spreading toward Catalina. Here are a couple of photos taken toward evening. The first photo is of the Gladiator fire plume and the second has the Tonto fire plume on the horizon on the right. You can see a bit of separation between the two plumes.
As is typical of fires, they flare up during the hot daytime hours as these did yesterday, and those plumes are the evidence from that. This morning, like yesterday morning, the plumes are likely to be more like haze layers than plumes, but then the plume characteristic will likely return this afternoon and evening as the fires heat up again.
Plumes like these in the photos show fairly close origins of fires, where smoke that has drifted in from Alaska or Asian fires would not have the streaks and irregularities in density that you saw yesterday evening. Those from very far away would be more of a whitish vellum over the whole sky in which the layer seems to be almost the same thickness as you look toward the sun. Generally, you don’t see those “long-range transport” layers when looking opposite to the sun.
Below, a satellite image from the University of Washington showing where the two fires were as of 6:15 PM yesterday relative to Catalina (the circle). You can just barely make out the plumes that were heading our way.
Also you can see how close a bunch of Cumulonimbus clouds got to us yesterday evening, ones moving from the N as a new round of rain spread over eastern Arizona, New Mexico and Texas. Sadly, they will stay well to the east of us.
Earth on fire map
How does fire activity in the US and Arizona compare with worldwide fires? Not so bad.
Below is a summary map of fires for the last ten days of this past April as detected by satellite. This image was provided by the University of Freiburg, Germany. These are not campfires, but full blown deliberately set or wildfires.
Kinda depressing. Those in the Saudi desert may just be those due to the burnoff of natural gas, yikes what a waste!
Also, you may notice not so much going on in the Brazilian rainforest, say compared with the jungles in central Africa-Zambia. This is mainly due to the fact that the rainy season is just coming to a close in Brazil,and most “biomass burning” takes place during the dry season, one that peaks in August, but also due to the Brazilian government’s attempts to reduce such fires in the “Green Ocean.”
Moreover, if you go to the NWS Tucson site and the forecast for Catalinaland, you will see icons showing pretty much the same thing for today and tomorrow as is in these photos. It will be interesting to see how deep the dust gets.
