Oh, well. Was expecting at least 0.25 inches a few days ago, and thought maybe a heavy shower last night might pull that expectation out of the trash bucket. Monthly total now up to 0.70 inches (updated after reading NWS-style and CoCo gauges here), still significantly below average (0.96 inches). Not much else elsewhere, either. Double dang.
Mostly Cumulus humilis and flat Stratocumulus yesterday. Was looking for ice as the temperatures aloft cooled during the afternoon and evening, and only as the sun went down was a slight bit of virga visible to the west. That Stratocu deck over us was deepening upward, and began reaching the magic point where ice begins to form, probably around or a little below -10° C (14 °F) in clouds such as yesterday’s. Let’s look at a sounding from the U of AZ (as displayed by IPS MeteoStar) and see what it says about those evening clouds and see if the above is just a bunch of hooey (I haven’t seen it yet, either):
The TUS sounding launched about 3:30 PM from the University of AZ campus. Suggests the cloudy air on that side of the mountains was indeed reaching to -10° C and likely a hair lower in the slightly higher cloud tops. Our tops especially a bit later and being a little northwest of there, were surely a bit colder.
Yesterday’s clouds
9:31 AM. Nice scruff of maybe Stratocumulus lenticularis topped Ms Lemmon, and indication of the lower level moistening that took place overnight with a dry front going by, with another one on the doorstep. Gee, camera lens is dirty.2:45 PM. Not much going on, just a few Cu hum, “two riders were approaching and the (cold) wind began to howl.” Bob Dylan, in “All Along the Watchtower” by Jimmi Hendrix. Nobel Laureate Bob wrote a LOT of songs about weather!2:47 PM. The Mighty Fraidy Cat Zeus, waiting for the weather to change, the Cumulus clouds to fill in. Today’s blog is particularly boring so thought I would spice it up with a [icture of a large (16.2 hands) horse that saw a tire leaning up against a horse fence, twirled around and at a full sprint, as though being chased by a Tyrannosaurus rex, plowed into a clump of tall cat claw acacias and mesquite bushes. The first second of that bolt was really exciting and fun, the second second, not so much. CMP was knocked off in the midst of them, racking up a broken rib, and a lot of scratches that bled profusely. However, with all that blood on his long sleeved shirt as he walked the mighty Zeus back to his corral, also chalked up quite a few “man points” when passersby saw him, I am sure. Well, there was one passerby who didn’t seem to notice as he drove by and I had to scream, “I’m OK! Its nothing, really!”2:48 PM. Nice lighting. I don’t know how many hundreds of these shots I have posted here. I just never get tired of sunlight and shadows on our mountains! Clouds still not doing anything, but its only been a minute since the last report.3:11 PM. Now we’re talking! Those Cumulus clouds are beginning to expand, fill in, transitioning to a Stratocumulus broken to overcast sky, a Stratocast (nomenclature unrelated to Fender guitars), as expected as the next front and trough approached. This was exciting. But when will the ice form in them to give us the first virga and precip?3:53 PM. Looking SW over the Oro Valley. This is really looking good. In situations like this, the clouds are forming as they travel upslope toward the Catalinas, and while they’re not preciping now, its fairly common in the situation we had yesterday for them to start preciping as the tops get chillier and chillier, often with the clearing remaining in place to the SW. That’s what I thought might happen. Things were changing fast at this time.5:15 PM. Virga and light precip were occurring on the horizon NW-NE, and these heavier Stratocu began to virga a few minutes after this. The anticipation? A nice period of light to moderate rain during the early nighttime hours as this deepening and filling in continued. That didn’t really happen. The clouds began to rain lightly here, but it didn’t measure. It was a another band coming through before midnight that produced the 0.08 inches.5:24 PM. I know a lot of you like to see pictures of the sun, so I thought I would post one today. Looks pretty round, a little bigger than usual. Don’t see any sunspots (defects) on it. That’s probably good.5:30 PM. Just after sundown the virga began to emit from this layer just beyond the Tortolitas. Really thought this would lead to a generous rain with continued deepening. Guess that didn’t happen. Probably only the best virga detectors among you saw this little curtains starting to descend from this cloud deck. I’ve added arrows to where those two patches of virga are.
Still looks like a chance for some light showers before the month closes out, but will be hard to get enough to bring the total to an above average value. Dang.
Will update my reader on December’s early cold outlook as new information that agrees with my assessment comes in. Right now, that information is not available.
Let’s face it, for most of the people living in Arizona, their best years are in the rear view mirror, as are mine which were probably about 50 years ago… Following that thought, let us not look ahead to further declines, but rather look back at the last water year for Catalina, ending this past September 30th, and see what it says, if anything, about the changing global climate we hear so much about:
Your Catalina water year history, compiled through 2008 by the folks at Our Garden there on N. Stallion Rs. off of Columbus Blvd. where you can find fresh organic vegetables every Wednesday and Saturday morning. Tell them Art sent you! Haha.
Can’t say I see too much going on here in Catalina so far; things seem pretty stable in the precipitation arena for the full water year’s rainfall.
I point out again, with great redundancy since I have pointed this out before, that the Our Garden climate record started just as a monumental change in circulation patterns occurred. Most climate scientists would attribute that to a shift as due to the Pacific Decadal Oscillation, discovered by important scientists I know well, like Mike Wallace1, of the University of Washington Huskies Atmospheric Sciences Department where I worked for about 30 years, but in airborne studies of clouds.
The PDO shift, if that’s what done it, was a circulation pattern change that brought astoundingly wet conditions to Catalina and the whole Southwest US, wet conditions unlikely to be seen in our remaining lifetimes, which aren’t that much longer anyway.
You may remember that bristle cone pine tree rings in California, analyzed by Haston and Michaelson in 1994, found only one period in the last 600 years (!) that was as wet as the late 1970s into the 1980s there (certainly spilling into AZ).
Remember how the Great Salt Lake was filling up to record levels back in the 1980s?
And any long term resident here, like the ones that I have spoken to, will tell you about the days of yore when the washes around here were running all year.
Well, that wasn’t the norm. sadly. They were just so lucky to have seen that era.
In weather, what goes around, comes around. Count on it happening again at some point in the future IMO. (Some climate changers might disagree with this assertion.)
How about our summer rainfall, June through September. Well, here’s that graph, updated through this past summer! Hope you like it:
Not much going on here, either.
Yesterday’s clouds–another day, another rainbow, of course.
Sprinkles of rain occurred off and on all day yesterday, but couldn’t muster even one hundredth of an inch of rain! With a few exceptions, the clouds producing the rain weren’t too deep, though still icy ones, and pretty high off the ground, mostly above 8,000 to 9.000 feet above us, which doesn’t help.
First, a rainbow shot:
4:20 PM. Looking north toward the Charouleau Gap (on the right). We have so many rainbows in Arizona, maybe, following the example of the University of Hawaii (Rainbow Wahini), the Banner University of Arizona sports teams should call themselves the “Rainbow Wildcats”…4:42 PM. Here’s a problem for a great shaft of rain, sloping tops of Cumulonimbus clouds. Don’t see any shaft here, just rain. When tops slope like this, it indicates the updraft isn’t very strong and the ice in the cloud is going to collect very little in the way of “supercooled” cloud droplets because the ice that forms is ejecting downstream from where the greatest growth would occur due to collecting cloud droplets, ones that would stick to the ice crystal, eventually making it a graupel or soft hail particle, the kind of thing that our vertical shafts are largely comprised of aloft. Slopey tops mean not a lot of growth of the precip, more “stratiform” like rain with fewer is any pulses of big drops.5:31 PM. Of course, still another rainbow. Notice how the colors are not as vibrant as some rainbows. This would indicate the concentrations of drops are less, and smaller than in the bright ones. So, not a lotta rain falling over there.3:50 PM. Now here’s a shaft with a real top, a pretty vertical one above it. There were a couple of these. Once again the spaces between the shafts lined up to pass over Catalina, rather than the shafts. The Tortolita Mountains got most of this one. I love these scenes, the backlighting, though, so many times they have resulted in disappointments.4:01 PM. The “Torts” cleaning up with a decent rain as that complex passed over them.5:19 PM. But even with a rain disappointment, we get to see these scenes here in The Heights over and over, again and again, to add to redundancy, We are so lucky! The cloud line above the mountains would be Stratocumulus.5:21 PM. Here crepuscular rays of sunlight produced by falling light rain diverge from the sun’s position. Light from an “infinite” source is supposed to be parallel at great distances. This seems to prove that our reality, as is sometimes suggested by philosophers, is not what we perceive with our tiny human brains. These diverging rays demonstrate that the sun is much closer to the earth and much smaller than generally believed by astronomers… The true reality of life and the universe are sometimes right in front of us.5:37 PM. By this time, the crepuscular rays and the existential questions they raised were gone and our perceived reality back to normal. Here a pretty good Cumulonimbus with a pretty vertical top and big shaft heads in the general direction of Catalina, once again raising hopes for measurable rain. Instead, it faded to sprinkles and our total rain from them was only a trace.
The End
—————–
1Well, actually we said “hi” in the halls once in awhile, I gave a talk in his class once, and, along with a bunch of Atmos Sci faculty, got to watch the 1992 New Year’s Day Rose Bowl mash down of Michigan for the Washington’s 1991 NCAA Division I fubball championship at his house. He also mediated an authorship kerfluffle between Peter Hobbs and me.
Former Hurricane ‘Newt’ brought some real humidity, low clouds with unusually warm bases (around 15-20 ° C) to Tucson and Catalina yesterday as its remnant center passed just about over us.
Old Newt was “dragging” here as a tropical storm, aloft it was pretty strong still, brought near hurricane force winds on isolated, high, mountain tops. Mt. Hopkins reached 59 kts from the ESE before the “eye” passed nearby and the winds turned to the west. And in the Rincon Mountains a gigantic 6.39 inches was logged, and a site on Mt. Graham reported 6.43 inches. (Thanks to Mark Albright for these reports.)
While Sutherland Heights received only 0.29 inches in that all day rain, there were eye-popping totals in the Catalinas. Take a look at some of these, Dan Saddle near Oracle Ridge, nearing 6 inches in 24 h! Below, 24 h totals ending at 2 AM this morning, which pretty much covers Newt:
0.28
Golder Ranch
Horseshoe Bend Rd in Saddlebrooke
0.59
Oracle Ranger Stati
approximately 0.5 mi SW of Oracle
0.24
Dodge Tank
Edwin Rd 1.3 mi E of Lago Del Oro Parkway
0.35
Cherry Spring
approximately 1.5 mi W of Charouleau Gap
0.79
Pig Spring
approximately 1.1 mi NE of Charouleau Gap
0.47
Cargodera Canyon
NE corner of Catalina State Park
0.31
CDO @ Rancho Solano
Cañada Del Oro Wash NE of Saddlebrooke
0.39
CDO @ Golder Rd
Cañada Del Oro Wash at Golder Ranch Rd
4.13
Oracle Ridge
Oracle Ridge, approximately 1.5 mi N of Rice Peak
4.25
Mt. Lemmon
Mount Lemmon
1.61
CDO @ Coronado Camp
Cañada Del Oro Wash 0.3 mi S of Coronado Camp
2.17
Samaniego Peak
Samaniego Peak on Samaniego Ridge
5.91
Dan Saddle
Dan Saddle on Oracle Ridge
3.54
White Tail
Catalina Hwy 0.8 mi W of Palisade Ranger Station
3.66
Green Mountain
Green Mountain
1.77
Marshall Gulch
Sabino Creek 0.6 mi SSE of Marshall Gulch
Your cloud day yesterday; we don’t talk about today. That’s for tomorrow.
The day began with one of the great examples of Nimbostratus, that technically a middle -level cloud greeted us at daybreak in what was one of the great examples of the phantom cloud, the true precipitator, usually hidden from view by lower clouds such as Stratocumulus. But, yesterday morning, there it was, “Ns” naked as could be. I know many of you have been looking for a good shot of Nimbostratus to add to your cloud collection for a long time and I could feel the joy out there when I saw it myself. I only took a couple of shots myself, wish now I had taken more of an extraordinary scene.
6:49 AM. Nimbostratus! Note how high the bottom is, a bottom marked mostly by falling precip, usually snow because steady light rain is so relatively transparent.6:52 AM. Looking NNW toward parts of Saddlebrook/Eagle Crest developments. Notice the nice, relatively uniform, blurry gray, the “blurry” look due to falling rain, the perceived bottom, at the melting level, snow is melting into rain. In winter, therefore, the “bottom” or base of Ns, absent lower clouds, appears lower to us because the snow level is lower.
Then, as the light rain here moistened the air hour after hour, low clouds, such as Stratocumulus and Stratus fractus began to form along the mountains, producing some interesting “tracers” of the chaotic air movement over there by the Catalinas under nearly calm conditions. Newt disappointed in his wind accompaniment.
1:41 PM. Stratus fractus clouds lined Samaniego Ridge, Stratocumulus or weak Cumulus topped it, with a higher layer of Stratocumulus above that, That highest layer was once the much deeper Nimbostratus, but now has lost its deep part, so its no longer “Ns” since its not precipitating.1:42 PM. The deep stratocast has departed, the remaining clouds in the foreground are Stratocumulus. The darkening bases on the horizon southwest of Pusch Ridge are where Cumulus and Cumulonimbus clouds filled with rain are piling up, likely due to the light winds coming together down there, maybe in the low center that was once “Newt.”
Later in the day, as the highest, coldest cloud tops associated with those beautiful Nimbostatus clouds moved off to the NE, and our cloudscape became a mix of deeper Stratocumulus with Cumulus and isolated Cumulonimbus cells, they produced true drizzle and misty, visibility-reducing “warm rain”, that rare type of rain that falls here from clouds lacking in ice, began to be observed producing Hawaiian looking rain on our mountains, delicate shafts of rain whose small drops slanted away from the base.
2:32 PM. Misty drizzle and very light rain! When did this transition happen?2:32 PM. Hard to tell the difference here in a photo between the pure, naked Ns, and this lower drizzle,misty rain producing cloud likely topping out well below the freezing level. I’ve seen these transitions before, but I missed this one, where a Stratocumulus deck starts to look a little fuzzy on the bottom as the drizzle, very light rain starts to come out (due to tops rising, drops at the top getting larger, at some point crossing over the “Hocking” droplet threshold of larger than about 38 microns in diameter, where they begin sticking together when they hit). Here, the transition from non-precipitating Stratocu to I-don’t know what has already taken place during between the photos at 1:41 and 1:42 PM. Should drizzly, relatively shallow clouds like these now be termed, Nimbostratus? Or Stratocumulus praecipitatio,to emphasis the shallowness? A question definitely for the cloud philosophers to haggle about. No member of the cloud maven club would be punished for calling this scene one showing “Nimbostratus.” However, the drizzle and very light misty rain should have told you it was from a far different cloud structure than that associated with true Nimbostratus, always a deep cloud with ice in it, often topping out at Cirrus levels.
Here, you might well erupt with, “This doesn’t look like Hawaii, but Ocean Shores, Washington, or some other coastal location along the West Coast on a spring day having Stratocumulus with drizzle!”
You would be correct in that eruption.
Below, an example of drizzle drops on your car’s windshield:
3:50 PM. The tiniest drops you can make out on the window are drizzle drops. I focused on them and you’ll have to click on it to get the full size to be able to see them. I was so excited to see some more of them!
Later, it was to look little more “Hawaiian”, but if you’ve been to Hilo, you know its mostly cloudy all day.
“Warm rain” or rain due to the colllision-coalescence process, is also mainly associated with “clean” conditions, ones low in aerosol particles that can act as cloud condensation nuclei. The fewer the “CCN” the fewer are the droplets in clouds, and the larger the individual cloud droplets are when saturation and cloud formation occur. So, by yesterday afternoon, certainly, it was doggone clean here, no doubt aided by washout in that light rain we had.
Particularly heavy rain with low visibility fell just south of Catalina yesterday afternoon around Ina and Oracle just after 4 pm. However, that rain did not have those HUGE drops that we see from unloading, deep, Cumulonimbus clouds making this observer think as heavy as it was, it may have been due to a Cumulonimbus topping out at less than 20,000 feet, where the temperature would have been too warm for ice. The 500 mb temperature yesterday was a tropical-like -3.7° C on the TUS sounding, almost unheard of with a rain situation here. This, another sign of tropical Newt, since tropical storms/hurricanes have warm cores.
lacking in those huge drops we see in our thunderstorms, this rain likely formed from the “warm rain” process except maybe in the very heaviest rain areas. It was a special day.
You probably noticed how quiet it was; no thunder around, for one thing, indicating the updrafts in the clouds were not very strong, and that was another indicator that the clouds may not have contained ice. Without ice, hail and graupel, soft hail, you don’t have lightning.
The lack of lighting, the all day off and on rain, such as you might experience at Hilo, Hawaii, on the windward side, made it seem like you were in Hilo, Hawaii, or one of the other wet spots on the windward side of the Island.
3:27 PM. Another, to me remarkable misty scene reminiscent of oceanic and coastal Stratocumulus with drizzle and light rain3:52 PM. In the meantime a much deeper cell had developed to the SW of us, down around Ina and Oracle, where an inch and a half of rain fell. Look how the bottom is so close to the ground, like at a temperature near 20° C, about as warm as a cloud base can be here! And the warmer the base, the more water is going up into that cloud! Very exciting scene! Well, they all are to people of cloud maven persuasion.4:24 PM. Into the bursting cloud. Still, drops were not HUGE, as you would expect, but extremely numerous, rain rate over an inch an hour in the heaviest parts. Was taken I around Oracle and McGee, and of course, not while driving. That would be crazy. Only looks like it.6:32 PM. One of the more Hawaiian looking scenes, fine trails of rain dragging along the Catalina Mountains. The slope of the rain coming out absent much wind down low tells you the drops are small, probably near drizzle sizes. And the “shaft” if you will, is diffuse, indicating the small drops are spreading out due to the little turbulence there was making it fuzzy around the edges. Maybe, anyway.
7:21 PM, August 13th. A sky so full of portent that evening after a clear day. This our last chance for rain for quite awhile, but Sutherland Heights and Catalina whiffed on this incoming complex of thunderstorms. But, we had a fabulous light show from a cell that developed almost overhead, pf Sutherland Heights as dark fell, but a little to the SE, dumping heavy rains in the Romero Canyon/Pusch Ridge area.7:16 PM., August 13th. A very dramatic looking shelf cloud (Stratocumulus) spread across and otherwise completely clear sky that evening providing a great sunset photo op. Northerly winds of 25-35 mph and a temperature drop of about 10 degrees accompanied this scene.6:57 PM. The churning, roiling motion of this turret was remarkable, almost like time-lapse there was so much of it. That easily seen churning was evidence of how unstable the atmosphere was on this day. It was unusually cool for summer at 20, 000 feet or so above us. leading to a strong drop in temperature from the 100 F or so at the ground. So, as the warmer air that clouds represent relative to their surroundings, made them more buoyant than usual as they climbed upward; a hotter than usual hot air balloon, if you will, one that goes up faster. Stronger updrafts are thought to lead to more lightning compared with Cumulonimbus clouds having weak updrafts.3:57 PM, August 13th. Even slender clouds could shoot up and reach the “glaciation level” where the tops became comprised of only ice crystals, and sent long plumes of ice out from the parent cloud. The long trail of ice shows how much the wind increased with height at the top of this cloud. As that evening’s storm approached, all of the anvils from the many Cumulonimbus clouds that were approaching were mostly kept from view so that you couldn’t see them. This cloud also poses a naming enigma. Its got an ice plume, a very little rain fell out on the left side where Pusch Ridge begins, but no shaft is visible. It can hardly be called just a “Cumulus” cloud, and yet the more accurate label, “Cumulonimbus” with all of its attributes, makes one a little uncomfortable due to the lack of a visible shaft.
The End (of the cloud discussion)
New “not pubbed” item:
I’ve added RViewpoint_10-24-06_submitted date Aug 31, 2006_final, something that’s been sitting around for years! Spent a lot of time writing it, but ultimately deemed it a hopeless task that it would be published in the Bulletin of the American Meteor. Soc. under then current leadership in the weather modification domain of that journal, and ultimately never bothered to submit it. I was sick of the conflict, for one thing. Haven’t read this piece in years, either, but just wanted to do SOMETHING with it so here it is on this blog.
A longer piece, “Cloud Seeding and the Journal Barriers to Faulty Claims: Closing the Gaps“, also worked on again in spare time at home, for about two years, with the final rejection in 1999 under pretty much the same Bulletin editorial leadership. In this MS, I had a chance to get in, but the specific reviewer whose demands the Editor said I had to meet, insisted that I indicate in the manuscript that the lead scientists in the faulty published reports I wrote about “did the best they could under the circumstances” in the two early benchmark experiments, those in Colorado and Israel. I knew from direct personal experience that wasn’t true; I couldn’t write such a bogus statement that might have made the difference in “getting in.” So two years of on and off effort went down the drain. Sometime soon I will add this second futile effort to the “not pubbed” list! I have a number of those….. It didn’t help either that the two leading scientists whose work I questioned were also the two most beloved scientists in this field.
As with all but one of these pubs (Hobbs and Rangno 1978) in the domain of weather modification, they were done at home, outside of grant funding work while I was at the University of Washington in the Cloud and Aerosol Research Group. And, as I sometimes alert audiences to, working at home on stuff year after year. thousands of hours involved, could be considered a “crackpot alert”. Well, I think of myself as a “good crackpot.” haha.
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
———————
1Its gone now because I couldn’t finish yesterday. Went off to Benson for horse training with Zeus.
Punctuation: its hard. Not sure about that in the title. Oh, well. Kind of sad that English is my first language, too.
Yesterday was definitely more Stratocumulus-ee (clouds flatter than expected) than anticipated, which hurt since it was foretold here that it would be Cumulus-ee day. And there was but the slightest evidence of any ice around, something that was also expected. So the record of almost always being right on weather and clouds (i.e., >50% of the time) took a hit, which hurt, to repeat something about personal feelings.
Too, with noticeable breezes at times, the sky almost completely overcast at mid-day as well, and the temperature well below 80 °F, it seemed darn COLD for late April.
Today, looking ahead, the air cools over us again as it did two days ago as a puddle of cold air slams down the interior of the West Coast and into AZ, and we should see some nice, photogenic Cumulus/shallow Cumulonimbus this afternoon, and, since the coldest tops will be well below -10 °C, there should be some virga and light showers around. So, another chance today for a little measurable rain here in Catalinaland before April closes out. The jet stream at mid-levels remains south of us, too, a critical aspect for cool season rain in the Great SW.
With more instability today than yesterday, there should be some more sun around compared to yesterday since holes due to downward moving air around the upward moving air in cumuliform clouds will be out there. Looking forward to today!
Still looking for the good rains next week as extra jumbo-for-May trough crashes into Cal from the Pac.
Yesterday’s clouds
In reverse order, today. They imported that way, and am too lazy to move them all.
6:49 PM. Looking toward Romero Canyon. Very nice lighting and shadows on our beautiful Catalina Mountains. Hard to believe that enough folks voted to cut off views like this when Oracle was widened and sound walls were put up in front of their homes to save, oh, 2-3 decibels is all, AZDOT said.6:49 PM. Nice lighting on Samaniego Ridge as the sun went down.4:23 PM. Nice “muffin-like” Cumulus over Ms. Mt. Lemmon producing a huge shadow. (hahah; its the cloud overhead left that’s causing the shadow. Kind of a dramatic shot I thought.3:15 PM. Lots of cloud coverage by those flattened tops (Stratocumulus cumulogenitus) with small to moderate Cumulus clouds below.3:12 PM. Thought I saw just that slight veil of ice (center), but maybe “grasping for a seed and swallowing a camel” here.1:06 PM. Looking NNW at Cumulus cloud with flattening tops due to an inversion lurking north of Saddlebrooke village.1:06 PM. A mix of Stratocumulus with small Cumulus clouds below lurk over and west of the Catalinas.7:35 AM. “Regular” Altocumulus with underlying Stratocumulus lurk to the north.7:29 AM. Altocumulus lenticulars lurk behind the Catalinas.
0.02 inches of it, anyway, as the core of the jet stream at 18,000 feet or so passed by Catalina yesterday afternoon. Keep your eye on the orange and reddish streak in these progs from IPS MeteoStar yesterday morning beginning at 5 AM AST and how it slides over us as the clouds began to ice up:5 AM yesterday. Jet at this level races across central AZ. 11 AM yesterday. Maximum winds getting closer! Tiny Cumulus clouds begin to appear over the Catalinas and on the west to north horizon.
11:40 AM.
The jet separates deep cold air on the left side, looking downwind, and deep warm air on the south side. The deep warm air prevents Cumulus clouds from getting very deep due to inversions and stable layers where the temperature does not change much with increasing height, or even rises. The temperature at 500 millibars or 18,000 feet above sea level dropped from -17.7 °C to -21.1° C over TUS yesterday between 5 AM and 5 PM, while the temperature about which ice begins to form in our clouds dropped about 400 meters during that time. With the temperatures at the ground rising into the mid-70s as the colder air moved over us, Cumulus clouds deepened, reaching the ice-forming level between 1 and 2 PM.
Also with patterns like this, the cyclonic rotation (vorticity) in the air above us is increasing like mad, and that leads to a gentle upglide motion in the atmosphere, one that also helps cool the air aloft and usually produces sheets of clouds like Cirrus, Altostratus, Altocumulus and NImbostratus. But yesterday the air was too dry for sheet clouds to form.
First ice was noted just after 1 PM. Can you find it?
1:11 PM. Looking N toward the Charouleau Gap. Tiny puff of ice ejects from a Cumulus humilis cloud based at about 8 thousand feet above ground level. Bases were running about -5 °C
2:31 PM. Cumulus and Stratocumulus clouds launched off Pusch Ridge and the Tucson Mountains stream toward Catalina. The sky begins to fill in rapidly.3:44 PM.3:49 PM.3:57 PM. A horse eating as it clouds up.4:33 PM.5:09 PM. Light rain falls in Catalina/Sutherland Heights.6:04 PM. RW- (light rain showers) continue in Oro Valley.
5 PM yesterday. Just passed! B y this time, Sutherland Heights had 0.02 inches as the tops of Cumulus and Stratocumulus complexes continued to cool and ascend. The sounding from TUS at 5 PM AST (launched about 3:30 PM AST) indicated the coldest tops had reached -20 °C or so, plenty cold enough for ice, virga, and light rain showers. Too bad the bases were so high since we could have had some real rain if they had been lower.
But, we were “lucky” to get that. Even the great U of AZ model had no rain anywhere near us late yesterday afternoon when it fell! THAT does not happen very often.
Looking ahead….today:
Nice Cu, ice, too.
Farther out:
Substantial rains, maybe half an inch or so, still on tap between May 6th-8th as previously foretold here. Yay! May averages 0.38 inches here in Catalina. More rain likely after that episode, too. So an above normal May in rain is pretty much in the bag now. Could be an especially great May, too.
People were wearing jackets as temperatures got locked down below 80° F the past few days, the wind blew once in a while, sometime lifting baseball caps off “gray hairs”, and gray skies hovered over Sutherland Heights for TWO and a half days!
A surprise, few-minute gusher in the early afternoon yesterday was enough to tip the old Davis tipping bucket rain gauge once1, too, to add another 0.02 inches to the 0.08 inches we were drenched with the night before.
What’s ahead. I dunno.
Really thought THIS storm was gonna be a doozie here, not in Mexico as it is now, for Pete’s Sake. Some weeks ago it was read by my reader (s?) here that we had only a 10% chance of LESS than 0.20 inches. In fact, we had a 100% chance of 0.10 inches.
I did not see that coming. But at least March 2016 has recorded SOME rain. Some insects benefited I’m sure.
Climate folks (Climate Prediction Center) are still predicting a wet March-May for us, at least as of mid-Feb. Unfortunately, its only a little more than two inches that makes that three month period wetter than normal here in Catalinaland as we begin to dry out, and heat up.
Time for another, “I love this map so much”, so fully packed with portent:
“Valid” (what a joke) in two weeks, March 24th, 5 PM AST. Giant low moves SEWD toward the Cal coast. Strongest winds on the back side tells you its shifting southeastward. Look how big it is!
Frankly, now as the jet stream in the northern hemisphere goes to HELL in the spring, the “Lorenz plots” or “spaghetti” are pretty clueless. As an example of “clueless” look at the spaghetti plot that goes with the map above:
For March 23 at 5 PM AST. No real clustering of lines anywhere so forecasts will be wild for this far in advance. That low could really be anywhere. There’s not quite so much chaos in the heart of winter when the jet is strongest and geographic jet stream anchors are strongest, like Asia.
Bottom line: NO rain days ahead, maybe a close call over the next TWO friggin’ weeks. Expect to see 90s on a day or two, as well. “Dang”, as we say in the Great Southwest.
Some clouds of yore, including yesterday.
As a cloud maven junior person, you should compare the shots below and try to chronologically unscramble them using your photos. Also, I would like you to name these clouds. Please keep your answers to yourself. hahaha (ACtually I am being lazy and just threw these in “willy-nilly” (huh, what’s that from? Will have to look it up some day.)
Am working on a true science story-book talk, something I wanted to write up before “tipping the bucket” as we meteorologists say about death. Its kindle-sized, maybe would take 3 h to present if it was an actual talk, having more than 250 ppt slide-pages! I won’t be at the TUS book fair, however, this year….
The End.
—————————-
1FYI, when a meteorologist dies, we meteorologists say that he has “tipped the bucket”, NOT “kicked the bucket.” Its an especially reverent phrase for us.
When some of you were weather browsing this morning, and you saw this forecast map from IPS MeteoStar, valid for next Tuesday, which shows a very late in the season tropical storm off Baja heading toward the Southwest US, while a vigorous winter storm bashes the West Coast, I had a feeling that it reminded you immediately of one of your early weather memories of a similar situation. First, the IPS map.
Valid at 11 AM AST, Tuesday, November 24th. This from last evening’s 5 PM AST global data. The green and blue areas are regions where the model thinks it has rained during the prior 6 hours.
The map below is from an era when you were a little child and maybe you, too, were clipping weather maps out of the Los Angeles Daily News, if that’s where you lived:
Actual map from the Los Angeles Daily News, November 30, 1951, clipped by the present writer. Note that with isobars the Daily News was not afraid of challenging its readers with a non-Mickey Mouse weather map. The tropical storm on this map is down there to the lower right where the scale of miles is. Like this winter season, 1951-52 was a Niño year, though not of the great magnitude of this one.
Looking back, but a little closer, like yesterday and the day before…..
Nice storm we just had. 0.65 inches fell in Sutherland Heights. Would not have predicted that much over these past couple of days to be honest. Total for month now 1.10 inches or a little above the 38 year average of 0.97 inches.
After a long dry spell though at least the next week, November will close out on a dry or wet note, which is pretty encouraging.
Yesterday’s clouds, ice and sun: a soliloquy on ice
Fair amount of ice yesterday in our low clouds. As you would guess on your way to becoming a cloud maven, bases AND tops were especially cold for AZ. Afternoon cloud bases were running about -8° to -9° C, whilst tops were about -15° C. Still ice was not plentiful. How’s come? Well, it seems the amount of ice in clouds is dependent on both the cloud top temperature and the droplet sizes in the coldest parts of the clouds (see Rangno and Hobbs 1994, Quarterly Journal of the Royal1 Meteorological Society) (Hell, no one’s going to read this, though it is now available without having to go through a “pay wall” and the page linked to above has been updated with new pdfs!)
In sum, a cloud with a base of -10° C and a top of -20° C will have LESS ice than a cloud with a base of 0° C with the same cloud top temperature (-20° C) because with a warmer base, the drops near the top of the cloud in second example will be larger.
That seems to be the way it works. So, yesterday’s thin cloud with cold bases had smallish drops, and ice production was a little limited.
Also, if you monitored Ms Lemmon, and the Catalinas in general, you probably were thinking, “Where’s the ice?”, in those cold Stratocumulus clouds as they piled up against them.
Well, when you have strong winds at cloud level as we did yesterday, and with ice crystals taking a little time to appear from some of the droplets that freeze in the cloud stream, grow, and eventually fall out, you’re not going to see much evidence of ice on the windward side of the mountains in these kinds of situations. The ice is going to appear and fallout as snow or virga downwind a good distance downwind, and that’s what was happening yesterday to nearly all of those deeper clouds (with slightly colder tops and larger cloud droplets in them) that formed over the Catalinas.
If you don’t believe me, yesterday’s time lapse movie from the our great weather resource, the University of Arizona, shows this. You’ll see a lot of precip and virga falling of those clouds as they stream eastward from the Catalinas. So, we didn’t get to SEE much ice from those Stratocu clouds but it was there.
Lastly, the sun, as it appeared yesterday at sunset in the dust-haze kicked up by that powerful low that brought us our rains. The jet stream, as was pointed out by a friend, was about 200 mph overhead of TUS at 40 kfeet. Wow.
5:21 PM. The sun. Stratocumulus sans virga at top. Droplets too small, temperature too high at cloud top apparently. Sun seems to be free of blemishes, too. Are we still in a sunspot minimum, thought to drive cooler climates, one that might rival the Maunder Minimum? I don’t know. I am a weatherman, not an astrologist.
The End.
—————————
1″Royal”–that is so funny; “hey”, guys, wake up, its the 21st century!
We’ll have to suffer through a few days for the next storm, i. e., experience sunny weather with pleasant temperatures. Its amazing that people all over America come to Tucson to experience sunny days with pleasant temperatures!
0.45 inches total in The Heights of Catalina in this latest round of rain, sounds of rain. Actually, there was also some tiny graupel/soft hail in the rain yesterday, too.
Graupel indicates a lot of cloud droplet water overhead, and that ice crystals were colliding with them until they lost their identity and became little snowballs. In regions where there are very few ice crystals, graupel and the harder version, hail often form. Its likely that nearly all those rain drops that came down with the little baby graupel were melted graupels.
Graupels….. Makes me think of that rock group, Led Graupelin, didn’t have the impact of Led Zepelin. But I have LG’s one and only album entitled, “Compare to Led Zepelin.” Was only $2.99, too! Where’s my guitar? I think I will play, “Stairwell to Heaven” now…
When graupel or hail occur, there’s a pretty good electric charge up there in those Cumulonimbus clouds. Its best to be indoors when its hailing until you know if a strike might occur (if there hasn’t been one already). Besides, its not comfortable being out in hail. And if you were listening to the rain, you heard a few blasts of thunder toward Lemmon around 2 PM that came out of one of the more enthusiastic Cumulonimbus clouds that went by. Got 0.12 inches total to add to the night before’s rain of 0.33 inches.
Yesterday in clouds; a sojourn in clouds from morning to evening, in that order with no times noted
I know how much you like to see pictures of rain, so here’s one. You’re not like the “others” are you those people around you every day?
Then the piston of atmospheric subsidence slammed down to squash our Cumulus cloud tops to levels and temperatures where ice could not form….
Two picures in a row of a NWS-style rain gauge. Probably has never been done before. Has been getting a workout lately. Everyone should have one.
The weather ahead
Kind of funny to see the Canadian GEM model internally plagiarize itself. Compare last night’s panel at 500 millibars (below) with that same level’s panel foretold for six days from now.
Yep, its the same thing over again in six days, though with less rain IMO:
In another interesting model development, the best USA model, the WRF-GFS is having an internal CONFLICT of major proportions. Check these progs out generated by data only six hours apart. The first one, showing a big trough coming into Cal, was generated by global data taken at 5 PM AST last evening. The panel below it was generated by the same model based on global data taken just six hours later, at 11 PM AST (so it the most recent WRF output available) and has a big ridge along the California coast.
Valid at 5 PM AST November 20th.
“Which one will the fountain choose?”, to quote old song lyrics1:
5 AM yesterday. Jet at this level races across central AZ.
11 AM yesterday. Maximum winds getting closer! Tiny Cumulus clouds begin to appear over the Catalinas and on the west to north horizon.
