Doesn’t happen every November, thunder, but it sure pounded away at times yesterday. Seemed louder than usual thunder a few times even with the lightning over there by the Tortolita Mountains. Of course, that’s where the heaviest rain fell as several T-storms tracked along a similar path over there just a little to the W through N of us, Bio2, in one of the heavier cloberations receiving 1.17 inches.
Here, in The Heights, we received a disappointing, but nevertheless welcomed final total of 0.24 inches. This brings our total here in Sutherland Heights for November up to 0.60 inches. Average is 0.96 inches1. Here, the regional totals as the storm was coming to an end:
“Us” is here in the Sutherland Heights; “Them” is Bio2. Wanted to reflect the general world situation now days by using oft used cliché terms.
As is proper, let us begin examining the nubilations of our storm by looking at those clouds that preceded the actual rain day yesterday.
7:02 AM. This pretty sunrise over the Catalina features a couple of flakes of Altocumulus clouds, and a vast layer of Altostratus.7:04 AM. Yes, the sun is coming up, though really its the earth rotating toward the sun. The sun does not go around the earth every day; it only SEEMS that way. We’re looking at the same two cloud generas, btw. Nice rays produced by pretty regular humps in clouds over the horizon, a little row of Altocumulus castellanus might cause these rays/shadows.7:05 AM. This was pretty interesting, to use “pretty” again. This would be an Altostratus mammatus. Men often find this formation especially interesting and pretty. Here you can also see how a cloud protuberance can produce a shadow. But why is there only one feature like this? Typically mammatus are like upside down Cumulus turrets representing downward moving cloudy, in this case, air filled with ice crystals). Adjacent to this feature, the ice crystals and snowflakes are just settling out. As the moving downward air in mammatus features slows, these breast-like globules open up and you’ll have ordinary virga. The ice crystals are typically rather small and not rimed (that is, have not collided with cloud droplets) or they would fall out and not be constrained to this pretty, rounded shape.7:07 AM. The underside of the Altostratus is lit up, showing the detailed areas of virga. Altostratus, by definition, is a precipitating cloud. Its just that the bases are too high for the precip (snow) to get to the ground, though sprinkles could occur in the thicker, deeper versions. When and if it starts to rain steadily, the cloud is better termed a “Nimbostratus,”11:20 AM. The Altostratus deck departed with its pretty mammatus and virga, leaving great examples of Altocumulus opacus clouds most of the morning and into the early afternoon.3:24 PM. An example of Altostratus translucidues doesn’t get better than this. Hope you captured it. The As (abbrev. for “Altostratus”) cloud over took over by mid-afternoon as the moist layer deepened again following the Altocu. Tops of this all ice Altostratus layer, in spite of being able to make out (“discern,” not “make out” in the social sense of the phrase–still thinking about that mammatus formation) the sun’s position, are usually around Cirrus levels, the top of the troposphere. The TUS sounding suggested “bases” (actually where the ice crystals are evaporating rather than droplets that comprise the bases of Cumulus, Altocumulus or other droplet clouds) at 14,000 feet ASL, and tops around 34,000 feet ASL Subtract about 3 kft to get heights above the ground here in Catalina.
Moving ahead to yesterday…..
7:13 AM. With an approaching upper level trough and big low center in the Great Basin, the winds had become gusty, and the clouds had lowered to Stratocumulus status, topping the Catalinas. I thought the lighting was really pretty here, and that shaft out there shows that turrets are climbing shooting up well beyond the general tops of the shallow Stratocu. Pretty exciting since it meant that the tops of other Stratocu might bunch into other Cumulonimbus clouds, which is what that shaft tells you.8:18 AM. A line of Cumulonimbus quickly erupted and it looked like it was about to crash into the Oro Valley Catalina area, but instead stayed to the west over the Tortolitas. Thunder heard!8:19 AM. Looking WNW toward the Tortolitas.9:27 AM. As some light showers passed along the Catalinas, this pretty scene the sun broke through. Note the glistening rocks that added such pretty highlights.9:28 AM. Pretty nice over toward the Gap, too! I will never get tired of these scenes!11:12 AM. Disappointingly, in view of all the rain predicted here (0.575 inches) that first line of Cumulonimbus clouds stayed stayed west of Catalina. But, that line of Cumulus or Stratocumulus clouds on the horizon is full of stormy portent, that a windshift line might be about to strike and generate another line of Cumulonimbus clouds. Any solid line of clouds like that, kind of by itself, suggests a windshift; it more than just a fair weather “cloud street.”11:11 AM. Zooming in on that line of clouds. Its fun to zoom, since you are in a way, flying toward what you’re looking at, getting so much closer! I wish that line of clouds was here already!
11:27 AM. Yep, there it goes, fattening upward into Cumulus congestus and to the N, Cumulonimbus clouds! This one will surely blast across Catalina as the upper trough and associated cold front approach; heck, maybe that’s the cold front windshift line and temprature drop right there!11:27 AM. Yep, there it goes, fattening upward into Cumulus congestus and to the N, Cumulonimbus clouds! This one will surely blast across Catalina as the upper trough and associated cold front approach; heck, maybe that’s the cold front windshift line and temprature drop right there! Repeated for emphasis.11:29 AM. A Cumulonimbus cloud is a bit farther north in this line. This HAS to be the windshift and cold front!11:46 AM. Was inside for a few minutes (18) and that cloud line just exploded over there. Here looking again toward the Tortolitas. But surely they will wall out and crash the sunny party in Oro Valley (I was thinking).11:52 AM. Well, these followup Cumulonimbus clouds aren’t looking so great, no evidence of strong turreting, weak and leaning, wispy, frail, “indolent”, cloud “couch potatoes.” Hope fading for a big shafting here in The Heights12:12 PM. The cloud line, as expected is progressing across Oro Valley, but shafting is meager. Its real windy, though, adding some drama. Gusts to 40 mph! Note however the weak shafting, as evidenced by a slope across the whole thing; no heavy, large particles falling out of this guy as we see in those vertical summer shafts. Indicates that the tops are getting very high, producing lots of condensate. So even here, with a nice dramatic scene, you’re thinking (to put words in your brain) that its going to be a disappointment in rain production, and you might be missed altogether!12:24 PM. It was pretty much all over 12 min later, that is, the chances for a real shafting. A well formed Cumulus congestus base formed just upwind of Catalina, but as so many do, slipped a little east before reaching Cumulonimbus stage and unloaded on the Catalina foothills NE of Catalina. Sometime, when clouds like this are overhead and show no precip, it just can dump out of the black. But, it didn’t happen yesterday. By now, the wind had shifted, the temperature was falling, and soon, the light to briefly moderate rain fell as the cold front went by.1:14 PM. By this time, you could pick up a couple of nice photos of just Stratocumulus clouds following the passage of the front. Here we see some indications of mammatus formations (upper center, right) in a droplet cloud, an extremely rare event since droplets evaporate so much faster in downward moving air that the pouches represent. One can surmise that those pouches may have contained higher amounts of liquid water, and the downdrafts were very slight. OK, so we’re kind of fixated on mammatus today…. No apologies; I’m just a man.
The great thing about yesterday was that because the upper trough lagged so much behind the cold front, you could be sure it wasn’t over, that is, the rain chances. In fact, as the wind turns aloft from a southerly or southwesterly direction to a more westerly one, we here in Catalina have a better chance of having the clouds pile up over us, even if they’re not full fledged Cumulonimbus clouds, they can still reach depths where they precipitate while upwind, they don’t because they may not be deep enough. The Catalina Mountains provides the lift that helps do this, and we saw that happen later in the afternoon and evening when it began to rain again long after the cold front and it so-so rain band went by.
3:06 PM. Starting to look more favorable for rain and the clouds began to cluster after the boring spell of Stratocumulus except for the brief display of pretty mammatus. The air aloft was getting a little colder, too, helping the Cumulus clouds deepen upward in spite of cool temperatures following the front. This view is looking upwind to pal Mark Albright’s house there in Continental Ranch, Marana. Mark is a fellow U of WA research meteorologist, though he hasn’t thrown in the towel yet, is still working.3:34 PM. Even as the clouds filled in and the light showers began, some pretty highlights were observed where the sun peaked through holes in the overcast. Here, Eagle Crest to the north of The Heights is spotlighted. If you are a resident of Eagle Crest and you would like a copy of this photo entitled, “Spotlight on Eagle Crest”, you can get one today for $1200, If you call now, you can get two for $2400.5:25 PM. FInally, as the light rain fell, adding a few more hundredths to our total, sunset occurred! You can see it WAS raining by the drop on the camera lens, I didn’t just say it was raining because I wanted it to. Note the lack of shafts. This tells you the tops of the clouds are pretty uniform, not protruding much above us. The rain was “pretty” steady, another indication that the clouds are relatively uniform in the horizontal.
The End, FINALLY!
—————–
1If we don’t get more rain by the end of November, I will delete the sentence of a week or so ago stating that November would have above average rainfall. No use having people see that.
Rain? Cumulative totals predicted here from the University of Arizona Hydro and Weather Dept. Starts overnight Sunday. For those too lazy to review the information at the link above, here is a map of the rainfall totals ending at 11 PM, November 21st:
Note that within this swath, Catalina is predicted to get over an inch of rain! Note that the swath is not very wide. A wide swath of heavy rain would be one as wide as the State. So, we have to figure that this is a lucky hit at this time, and count on something less as a virtual certainty since the swath above will move around as new model runs look at it. Typically, they shift a little east over time in those future model runs. Hope not.
Have cameras ready for a pretty sunrise. Lots of high ice clouds up there.
The weather WAY ahead
Spaghetti suggests more rain chances after a several day dry spell following the Monday rains. Check out the “pretty strong” indications that we are in the trough bowl as the month comes to an end, meaning troughs should be populating Arizona during the last days of November. In turn, good November rains, and one seems to be in the high confidence pipeline for SE Arizona as a whole, means the spring wildflowers will be given a boost. I will go on record here as now forecasting, if that’s what this is, a wetter than normal November rain total1. Our November average since 1977 is 0.96 inches.
The ensemble or spaghetti plot from the NOAA spaghetti factory from last evening’s global data.
The End.
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1This sentence will be deleted in the event of a drier than average November and will, therefore, not be on record.
Every once in a great while, we have days where fairly thick clouds do not produce even a sprinkle, even though their tops are a little below freezing, but not quite cold enough for natural ice to form. Yesterday was one of those days.
And it was a day you, a cloud maven junior member, could likely have done something about it: rented a small plane or helicopter capable of flying up to around 15,000 kft ASL, taking a bag of commercially available dry ice pellets, then drop them into the fattest, highest Cumulus tops you saw while nipping them in VFR flight mode, and, “violet!”, ice would have formed along the path of the falling dry ice pellets!
So what were the ingredients that made yesterday so special for a little renegade cloud seeding?
The clouds that did not rain were pretty thick for ones that didn’t rain naturally, maybe 5,000 to 6,000 thousand feet thick in their maximum “overshooting” tops, and temperatures at top were a little below freezing, but warmer than -10° C. At lower top temperatures ice would likely have formed naturally. Here’s the annotated TUS sounding from yesterday afternoon from IPS MeteoStar:
The 00 Z (5 PM AST) rawinsonde from TUS, typically launched about 3:30 PM AST. The upward pointing arrow shows what the in-cloud temperature would have been like. The lapse rate, from aircraft measurements is virtually never along the “pseudoadiabatic temperature line (one of which is where the horizontal arrow heads are), but somewhere between that and the dry adiabatic temperature lines that show the temperature drop in a rising dry parcel of air (one of which is where the upward pointing arrow begins). Cumulus protrusions carry the boundary layer air from the surface, that air that forms the Cumulus clouds, into the stable,, and warmer overlying air. So, protruding tops sink like a stone; don’t stay long at their lowest temperature, also hurting the chances that ice will form. That’s why you have to do it.
Here’s how it works: the dry ice pellets, themselves at -72° C, will chill the air it comes in contact with to -40° C, resulting in the formation of jillions of tiny ice crystals in each pellet’s wake, which are then spread over a wider region in the following minutes due to turbulence in the cloud. In essence, each pellet is creating a tiny, vertical “contrail” in that cloud, as least in those upper parts of the cloud below freezing. (Bases yesterday were a little above freezing, around 2° C, while the highest afternoon tops locally appeared to run between -5° and -10° in clouds that were forming in more haze and smoke than usual (wonder if you noticed that?) Haze and smoke tend to reduce droplet sizes, and in doing that, make it harder to form ice and rain, especially in marginal clouds for that, such as we had yesterday.
What happens next is that the “supercooled” water in the cloud evaporates around those crystals due to the dry ice bombardment, while the crystals take up that evaporated vapor. When the crystals get large enough, they may collide with some remaining cloud droplets, if there are any around. Usually all those crystals that have formed will not left too many droplets in their vicinity.
As the crystals grow in size, and because they are in such high concentrations, they will bump into one another and form clusters of ice crystals we call snowflakes. Cloud Maven Person has, along with Professor Doctor Lawrence F. Radke, the latter the “Flight Scientist” in those days with the University of Washington Huskies’ Cloud Physics Group1 in the late 1970s, made snowflakes the size of pie plates (fluffy light ones without a lot of water content) in Cumulus clouds like yesterday’s here.
IMO you would have created not something of much importance, but rather just an annoying sprinkle or very light shower for those out hiking, horseying around on their horses, biking the trails, on an otherwise perfect day for outdoor activities.
One of the problems, long known about in such seeding experiments as could have taken place yesterday, is that the cloudy air is moving THROUGH the cloud, exiting at the downwind location. That is, lower clouds in particular, move SLOWER than the air itself2.
So, you drop some dry ice in a nice turret, the air you dropped it is, along with that turret’s air, will be moving downwind and is going to go out into clear air eventually. So, if the crystals don’t stay in a turret and upward moving air, but goes out the side of the cloud or into “shelf clouds” like yesterday, those crystals/snowflakes aren’t going to grow much, and will remain “light and fluffy” even though they could be huge because they are like “powder snow” not a lot of water mass in them. When they melted at cloud base, they might end up being just drizzle-sized drop (less than 500 microns across) or very small raindrops. So, that’s why you would likely have gotten just a sprinkle or very light rain shower had you done some unlawful, renegade cloud seeding yesterday. Remember, just like when you hike in the State Land Trust areas, you need a permit to seed legally.
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Yesterday’s clouds
7:02 AM. Tall, but not so tall to form ice, Cumulus clouds boil up off the Catalinas. Made you think some Cumulonimbus clouds might form later on. They didn’t.10:26 AM. Disorganzied Cumulus still lurking on on the Catalinas, but the main thing here is how much smoke was in the air when you might have been expecting a very clean morning due to the previous evening’s thunderstorms and rains. Very upsetting to this smoky scene.10:27 AM. Looking NE at some Cumulus congestus, no ice evident from this view, but I would not rule it out, Forgot to check radar to see if there was an echo with this cloud.2:10 PM. By mid-afternoon skies started to look a little threatening with a Cumulus congestus having formed over and extending downwind from the Tortolita Mountains.2:14 PM. Looking for ice to appear in the oldest top portions, now evaporating, top of photo. None seen.2:39 PM. Someone needs to get up there on top of this Cumulus congestus, drop a little dry ice in it. Nothing came out, though I thought I would feel a drop at any moment! Some sort of birds can be seen, lower right.3:19 PM. Looking downwind at part of the base of this Cumulus congestus cloud line that sat over Catalina for awhile. The top has the base, to the left is the “shelf cloud of Stratocumulus spreading out from other tops and drifing downwind. If precip falls out of the shelf cloud, once part of a turret, you can see I hope that it would fall out of a thicker column of dry air.
4:01 PM. The scene before a lot writing appears on this photo.The same photo with a lot of writing on it.
The weather way ahead
While warm weather returns to AZ over the next week to12 days or so, there is now, and this goes with climo, a big trough that barges into all of the West Coast in two weeks.
When I say climo, I mean that there is a noticeable tendency for this to happen in mid-November in the longterm upper air records so that in some areas of California, for example, there is a modest increase in the chance of rain in mid-month over other times in the month. These kinds of things in weather are termed, “singularities” like the supposed, “January thaw” back East. This mid-November annual trough passage may be related to the increasing speed of the jet stream in the Pacific as winter approaches, something that changes the spacing between the troughs. Pure speculation.
But in any event, be on the lookout for a major change in weather here between the 17th and 20th of November. Something like this is starting to show up in the models.
The End
——— 1Later renamed the Cloud and Aerosol Research Group.
2Something that was even noticed in small tradewind Cumulus in the Pacific in the 1950s by Joanne Malkus (later, Joanne Simpson) and her colleagues.
We’ve waited a LONG time for a rain day. It was so nice, so photogenic as well. I hope you enjoyed it as much as I did.
Also, you may have seen the Froude Number1 in action as Cumulus congestus and Cumulonimbus clouds developed and went around the sides of the Catalina Mountains instead of developing over them and dumping big shafts of rain on them. The heaviest rains yesterday were due to streamers of showers and with an OCNL TSTMS that were north and south of us, Oracleville, Bio2 area, and Marana, Avra Valley where over half an inch was logged in some places.
Still , we managed a third of an inch here in Sutherland Heights, the first appreciable rain since I don’t know when, though, I could look it up. Too long, though, even for Catalina.
Some regional totals, 3 AM to 3 AM: Precipitation Report for the following time periods ending at: 03:19:00 11/04/16 Data is preliminary and unedited. —- indicates missing data Gauge 24 Name Location ID# minutes hour hours hours hours —- —- —- —- —- —- —————– ——————— Catalina Area 1010 0.08 Golder Ranch Horseshoe Bend Rd in Saddlebrooke 1020 0.12 Oracle Ranger Stati approximately 0.5 mi SW of Oracle 1040 0.08 Dodge Tank Edwin Rd 1.3 mi E of Lago Del Oro Parkway 1050 0.16 Cherry Spring approximately 1.5 mi W of Charouleau Gap 1060 0.16 Pig Spring approximately 1.1 mi NE of Charouleau Gap 1070 0.24 Cargodera Canyon NE corner of Catalina State Park 1080 0.20 CDO @ Rancho Solano Cañada Del Oro Wash NE of Saddlebrooke 1100 0.16 CDO @ Golder Rd Cañada Del Oro Wash at Golder Ranch Rd
Santa Catalina Mountains 1030 0.04 Oracle Ridge Oracle Ridge, approximately 1.5 mi N of Rice Peak 1090 0.16 Mt. Lemmon Mount Lemmon 1110 0.16 CDO @ Coronado Camp Cañada Del Oro Wash 0.3 mi S of Coronado Camp 1130 0.28 Samaniego Peak Samaniego Peak on Samaniego Ridge 1140 0.08 Dan Saddle Dan Saddle on Oracle Ridge 2150 0.16 White Tail Catalina Hwy 0.8 mi W of Palisade Ranger Station 2280 0.04 Green Mountain Green Mountain 2290 0.16 Marshall Gulch Sabino Creek 0.6 mi SSE of Marshall Gulch
Santa Catalina Foothills 2090 0.04 TV @ Guest Ranch Tanque Verde Wash at Tanque Verde Guest Ranch 2100 0.16 DEQ Swan Swan Rd at Calle del Pantera 2160 0.08 Sabino @ USFS Dam Sabino Creek at USFS Dam 2170 0.24 Ventana @ Sunrise Ventana Canyon Wash at Sunrise Rd 2190 0.16 Al-Marah near El Marah on Bear Canyon Rd 2200 0.04 AC Wash @ TV Bridge Agua Caliente Wash at Tanque Verde Rd 2210 0.00 Catalina Boosters Houghton Road 0.1 mi S of Catalina Highway 2220 0.04 Agua Caliente Park Agua Caliente Park 2230 0.04 El Camino Rinconado El Camino Rinconado 0.5 mi N of Reddington Rd 2240 0.04 Molino Canyon Mt Lemmon Highway near Mile Post 3 2390 0.24 Finger Rock @ Skyli Finger Rock Wash at Sunrise Rd
Yesterday’s Clouds
6:50 AM. “Shape of things to come1.” “Nothing could change the Cumulus shapes of things to come” yesterday, to paraphrase here, as evident in this Cumulus shedding ice in the downwind decaying end on the left.7:35 AM. Look at this little guy, so full of ice. Another harbinger of the ice-filled clouds about to arise, and with ice, precipitation, snow aloft, graupel (tiny soft snowballs), and even some hail (solid ice). You could guess here from how shallow this Cumulus cloud is that the bases must be at near the freezing level, and tops must be at least as cold as -10° to -15° C, cold for such a small cloud. But what would we call such a small cloud? Cumulus congestus praecipitatio or virgae (since the present of ice absolutely means some precip up there, not likely reaching the ground though. Shoot from the hip estimated depth 2 km, or around six thousand feet.11:37 AM. Sure enough, as it got warmer, Cumulus congestus/small Cumulonimbus clouds arose trailing ice northwestward in huge plumes of ice. Note to airborne researchers: be sure to sample the older parts of the turrets that have trailed downwind and turned completely to ice even though that trailing portion doesn’t look much like a Cumulus cloud. It you only sample the newly risen portions, you will cheat the cloud out of how much ice it can produce since it takes a little time for all the ice to form. Lotta early airborne researchers made this error, reporting too little ice, but, of course, if they were in the cloud seeding business, they wouldn’t mind at all since they could report that clouds needed more ice, that from their seeding activities!11:37 AM. Oh, so pretty, those dark blue skies punctuated by a little muffin Cumulus cloud. Aren’t you glad you live here?1:25 PM. Showers and weak Cumulonimbus clouds trail off the Catalinas north of Bio2.1:25 PM. In the meantime, stronger Cumulonimbus clouds and showers track westward south of Catalina toward Avra Valley while the clouds over the Catalinas dissipate or remain disorganized while heading toward us.2:33 PM. A voluptous Cumulus congestus in the process of transitioning to a Cumulonimbus calvus (ice is visible but top stil pretty firm and round looking), then Cumulonimbus capillatus (fibrous top) AN older turret, looking all ice, leans to the left. Precip was already dropping out the bottom of this fat cloud. What kind would it be? Grauple, without doubt since so much supercooled liquid water would remain in this cloud amid the ice crystals forming inside. Those ice crystals, nice and pristine when they first form, would have their pretty forms obliterated by droplets that would freeze instantly on them, making them little snowballs, falling faster and faster, collecting more droplets.2:46 PM. Moving rapidly away from Catalina, of course, that cloud has now become a Cumulonimbus capillatus (hairy, fibrous top a,most completely composed of ice–some liquid may still arrive at cloud top in new turrets before quickly converting to ice.) A portion of a rainbow can be seen at almost ground level.2:48 PM. In the meantime, pretty strong storms, now having thunder, rage S through W of Catalina.3:14 PM. While we didn’t have any great clouds near us, at least we had some nice lighting (not LTG) on the mountains from time to time.3:41 PM. Finally, the dramatic skies were shifting northward and measurable rain was on the doorstep. Looking SW toward Pusch Ridge and the Tucson Mountains.4:43 PM. Took awhile, but a decent Cumulus with a nice base now transitioning into a Cumulonimbus plopped some big drops and hail down. Streak at right is a hail particle with its fall distance in about 1/400 of a second.4:47 PM. The hail got a little bigger and I took a picture of one of the stones, a little smaller than pea-sized in case you don’t believe me that some hail fell, too. Sometimes I think people don’t believe what I write, especially in footnotes….5:02 PM. While the sunset was dramatic, it didn’t bring the color hoped for, but this line of dark clouds presaged another bit of rain for Catalina.
Except for a morning or afternoon sprinkle, no rain in sight, just a warm up back to above average temperatures. Dang.
The End
———————-
1The young fluid dynamicist, Richard Penniman, fascinated by the flow around mountains, and who later became known as the rock and R&B entertainer, “Little Richard”, first brought the Froude Number to public attention in his song, “Tutti Froude-e.” The title, after an early release failed to capture the public’s imagination, was later revised for greater “accessibility”, to the song we know today as, “Tutti Frutti.”
2Who can forget “Max and the Storm Troopers” and that great song? I would submit, “everyone.” Of course, few know that after 1968 they changed their name to “Led Zeppelin.” And that, my friends, is “the rest of the story”, as Paul Harvey might say if he was lying about something anyway.
Sure, there’s a bit cooler weather heading our way in the next few days, but “May” will reappear after that, and people will be complaining again that they evacuated their domiciles in northern climes or high altitude sites too early when they returned to their winter homes in Arizona. I am hearing a lot of that kind of complaint.
Heat, devoid of thunderstorms, is truly tough to take here in AZ.
Unfortunately the little troughs so well predicted to occur in NOAA spaghetti plots at the end of October did not bring any rain, and this next one, which slipped from late October into the first of November, looks like its going to be dry, too.
Damnug.
October will end with but 0.01 inches of rain here in The Heights. Our average is 1.13 inches (1977-2015). Last year we had over two inches in October AND November, setting the stage for a good spring wildflower display! Below, a reminder:
The light bars are the averages; red bars the observed.
But, “hey”, looks like southern New Mexicans will get a lot of rain, so let us be happy for them this coming week, and not sad for ourselves when we read about all the rain THEY are getting so close to us. Its only right.
But here’s the killer plot, just out from the NOAA spaghetti factory. I couldn’t believe how bad it was for us. You, too, I am sure will be frustrated and mad when you see it:
Valid at 5 PM AST November 12, 2016 for about 18, 000 feet above us. Notice how the blueish lines pretty much the heart of the jet stream) are way up there in Canada, and our area is devoid of lines (see yellow line and south of there). This strongly suggests an upper level, warm high center or at least a bulge of high pressure aloft will sit on top of us and the adjacent states, maybe some jet flow way down around Mexico way. This may be one of the worst forecast maps for AZ of all time, considering the time of year. Warmth, with desiccated air, dead ahead right into mid-November after our little, brief cool down this coming week. Note, too, the indications (blue lines) that a big trough will populate the East, bringing cold conditions there.
In the meantime , we can rejoice at the bountiful October rains they are having in California. Some records will fall. Some stations in the extreme north will approach 30 inches for the month of October by the time the month ends, and many stations south of those, including ones in the Sierra Nevadas will log 10-20 inches for the month.
Outstanding. But, it needs to continue, not dry up….to take a real bite out of drought.
7:25 AM arrives as usual. Seeming radiating bands of Altostratus stream toward Catalina (little too thick and gray to be “Cirrus”). They also appeared so smooth as to resemble lenticular clouds.1:14 PM. Since its summer again in Arizona in late October, not surprising to see afternoon Cumulus clouds originating in air from the Tropics clustering over our mountains again.1:38 PM. The curved brightening at the bottom of this otherwise normal halo is likely a “lower tangent arc.”1:40 PM. Zooming in with excitement here. Is it really a lower tangent arc? Not positive, but will go with that description anyway.2:59 PM. That Cirrostratus thickened into Altostratus (usually, btw, due to the bottom of the cloud lowering) and at the same time the lower moisture, evidenced by these Cumulus and Stratocumulus clouds, also increased. However, none of these lower clouds got cold enough to produce ice, so likely tops were warmer than -10°C (14°F).
4:32 PM. Mix of Altostratus and Altocumulus clouds, with just remnants of the lower Cu. Here it appears that a liquid layer of Altocumulus now resides at the bottom of the Altostratus, or may be embedded in it. The globular masses in the middle of this photo represent droplet clouds that appear to have merged into a plate. In the distance, the telltale sign of lowering tops: only droplet clouds, with a occasional splash of virga can be seen.
5:23 PM. Just a little before a great sunset, which I missed due to a social engagement, the shallow Altocumulus droplet clouds are plainly evident around the sun’s position. Above to center, the backside of the deeper Altostratus clouds with much higher tops, is about to pass over us. Here you can see, how much lower the Altocumulus cloud fragments are than the Altostratus layer as they are illuminated by the sun (upper center highlighted clouds).
All in all, a pretty pleasant day with interesting clouds passing by, though ultimately disappointing since at one time, this was to be a day with showers here. Oh, well, that’s weather forecasting for you.
Another minimal chance for showers comes up in the middle of next week…
A horse photo will always enhance a blog about clouds. Expecting a little uptick in readership due to this ploy, maybe will break out of the single digit column.
Not much happened early on, a thin film of Cirrostratus covered much of the sky, delaying the expected development of convection, as would be evidenced by the formation of Cumulus clouds, until mid-afternoon.
But they did form, mostly to the S through W of Catalinaland, upwind of us, and eventually rumbled in on their last legs as weak thunderstorms with gushes of sprinkles and gusty breezes, maybe ones over 15 mph!
Over there in Marana and Avra Valley, those places upstream of us, some spots got more than half an inch. But, i it seems this year that storms die when they move toward Catalina, and especially, toward MY house and its many raingauges (3).
Still, it was nice to feel cool breezes, air chilled by falling rain, even if elsewhere.
Here are a few dull and disappointing cloud shots from yesterday, including one with a horse:
10:56 AM. Horse looks ahead, examining the vellum of Cirrostratus cloud overhead, wondering if it means anything. If this was Seattle, such a layer would thicken and lower into a steady rain within hours 70% of the time. Pretty true for most higher latitude locations in the cooler time of the year. (This was horsey’s first true trail ride, going up and down rocky gullies with loose rocks along side the Sutherland Wash. Previously this horse had spent most of its 14 years in a small corral so this was all pretty new to him; rider tension high.)2:49 PM. A soothing gray of Altocumulus undercut the layer of Cirrostratus. Building Cumulus clouds can be seen toward the Mexican border on the horizon. Pusch Ridge is in the foreground. As you can see, no virga is falling from those Altocumulus clouds, so they must be pretty “warm”, warmer than about -10° to -15° C at cloud top.3:38 PM. Looking suggestive of rain here in Catalina. However, these storms were in the late, dissipating stage. Note too how the anvils have merged with the Cirrostratus layer and lean far out from the storms toward us, helping to cool the ground, ruin the chances of new Cumulus buildups ahead of them.4:19 PM. Not much going on over the Catalinas. Notice how broken up into light and dark patches these otherwise dark looking lower clouds are. Shows there’s no hope for any buildup out of them, though, lower clouds like these under precipitating Altostratus cumulonimbogenitus (that higher cloud here which is really the result of anvils) can help sprinkles get to the ground. That’s because drops or snowflakes falling out of the higher cloud, won’t evaporate while falling though these clouds (representing saturated air with respect to water).4:33 PM. Nice shaft, some cloud-to-ground lightning strokes toward south Tucson, but who cares? Wasn’t moving this way, and would be mostly dissipated by the time it got here anyway.4:57 PM. Some rain with an occasional lightning outrage did reach the southern parts of the Catalinas, eventually making it all the way to Ms. Mt. Sara Lemmon where 0.24 inches was recorded. SPKLS fell in Catalina.5:42 PM. Last gasp, last chance for rain here, dying shower with some new bases to the right, offer another slight hope that the new stuff will develop into showers like this one. It didn’t.
Still have rain chances last few days of Oct into early Nov.
Well, I think so, anyway, and those rain chances seem to carry right into the first week of November. I think you can see that in these graphics from NOAA based on last night’s global data. As in “Where’s Waldo”, can you find the State of Arizona? The US?
Since my risky forecast, and going beyond professional standards of some days ago seems to be working out, I thought I would update you on it. Of course, if it was not working out, you would hear nothing more about it. Below, for October 29th, as rendered by IPS MeteoStar. We seem to be in a bull’s eye for rain amounts. Wouldn’t that be great!?
But, as you know, gotta get through a heat spell first…
Valid at 11 AM AST October 29th. This was the wettest model output I could find, and, it just came in from the 11 PM AST global data ingest! Wow. I’m kind of screaming in that annotation.
Valid at 5 PM AST October 28th. 2016 based on global data from 5 PM AST last evening.
You got yer ridgy flow on the top (“top” meaning, “Canada”, around where that yellow line humps toward the north) and yer broadly cyclonic flow on the bottom (“bottom” meaning, “Baja Cal and Mexico”) that is, across the whole western part of North America. This indicates that we will have a configuration that suggests a “split flow” where part of the jet stream and a trough is forced into the Southwest. Models are showing a big trough and cutoff that brings substantial rains to Arizona!
Of course, model forecasts are pretty dicey at this range, more than 10 days, and so that’s why I am reporting it fully here with great excitement! That’s what we do here, go over the edge, not just up to it.
And, for that slight amount of additional credibility, the “WRF-GFS” has been spitting out big storms for Arizona over the past several runs during this late October period. See Arizona rain below from this rendering from IPS MeteoStar:
Valid at 5 PM October 27th, 2016. The colored regions denote where the model thinks in has rain in the prior 12 h. The rains are foretold to just be arriving at this time, and continue for a couple of days. Nice!
Since I ran out of anything more to say, I will post a second version of this same map as a public service for international readers who are clueless about states in the USA:
Same as above, but for international readers of this blog, and others who may be geographically challenged.
Below, the upper level configuration that goes with the pattern above:
Also valid at 5 PM AST October 27th, 2016. Notice how a lot of the flow comes down this way after extruding into Canada, but some continues on across Canada. Disclosure note: this configuration has more amplitude (and thus a bigger chance for rain in southern Arizona, than was seen in the plot from the NOAA spaghetti factory. Few readers may get this far, so that’s why I am placing some element of doubt here. A announcement that rain might fall in southern Arizona makes people happy, and that’s why I will show those models that predict the most rain here, not ones that skimp on a future rain. Doubt about a future rain disappoints, makes people sad. Oh, yeah, and the latest WRF-GOOFUS model run, that from the 11 PM AST global data, had none of this. What a poop that run was! Does that later run affect the thought of rain late in the month? Nope.
So, there are some questions about the magnitude of this event, will it be a spring wildflower energizer with a major rain, or a just a breezy spell with a dry cold front going by? I’m on the side that a good soaking rain will fall sometime in those last few days of October.
