Been dreaming about a white Lemmon for quite awhile, ever since the New Year’s Eve snowstorm here. Finally got one yesterday, as we saw. Here are a few extra Lemmons for you:
3:11 PM.3:42 PM.Finsihing off here with an orange Lemmon, if that’s possible, at 6:50 PM.
Yesterday’s clouds
(includes photo of a small, cute dog)
7:58 AM. Not one, but two layers of Stratocumulus.7:58 AM.7:59 AM. Interesting how the scattering of diffuse light through the clouds lights up our cherished cholla cacti.8:57 AM. Paper flowers still going…. They’re not used for making paper, btw.9:30 AM. Occasional sprinkles fell from these clouds. Likely was due to ice, but texture if the precip also suggests drizzle formation (or warm rain processes, wherein larger cloud droplets collide to form drops big enough to fall out.) I hope your cloud diary also reflected this ambiguity.3:42 PM. Later in the afternoon, small Cumulus provide the light and shadow show on the Catalinas, one of the best things about living here. No ice evident.
Looking closer, I hope you recorded the slight fall streaks (fallstreifen, ger.) in the scene above. It would have been quite an important observation for you to have acquired since these small clouds had not shown ice prior to this time. See below for the VERY delicate trails emanating from this Cumulus mediocris cloud; look between and above the orangish rock faces on the top of Sam Peak and a bit to the left:
6:48 PM. Fine snow trails fall between and above the two orange colored rock faces on the left side.The baloooooon sounding launched from the U of AZ at 3:30 PM yesterday. Where the lines pinch together was likely around cloud top, or about -10 C, close to the natural ice forming temperature we usually see here in AZ. More ice fell from layer clouds to the north at sunset, that were colder still.
The weather ahead, way out there
Next rain chance in about a week. Looks like May will start out hot, but “too hot not to cool down”, to quote Louis Prima and Keely Smith doing the Porter songbook, and pretty much that cool down before the month is hardly underway. I am sure lingering snowbirds, not wanting to have their feathers singed, will be glad to receive this news.
How can we say that with any acuity?
Check the spaghetti! Looky below at how troughy the flow is by about the 8th of May (red lines dipping toward the Equator along the West Coast). No extreme heat then, just normal warmth or below average “warmth.” This is a circulation pattern that persists, too. And with “troughy”, there’s always the chance of a rogue rain.
Valid on May 8th, 5 PM AST. No heat here. Some snowbirds have clearly left too early IMO.
While depressed about a waterless trough approaching us today, well, maybe a few hundredths is all that can fall from its passage, I thought I would depress you that bit more by showing how our smoggy world is connected.
Perhaps you thought, wrongly, of course, that the smoke layer above us yesterday was from from southern California or Mexico. After all, smoke and haze does leak into the SW deserts from the LA area all the time.
But no.
That layer was too high up (estimating above 20,000 feet above sea level); it was in a very noticeable thin, dark layer to the southwest in the morning, then spread over the sky during the day.
Maybe yesterday morning after sunrise you even thought it was “cirrostratus nebulosus”, that vellum ice cloud with little internal structure.
Let us look at the smoky evidence (before any clouds formed):
9:51 AM. Its not Cirrostratus nebulosus. There was no indication of cold clouds over us, as would be the case with Cirrostratus nebulosus.9:51 AM. a thin smoke vellum covers sky. Best seen toward the sun. Looks dark on edge when the sun is shinning on it, like to the southwest yesterday morning.4:21 PM. Still there, ABOVE the Cumulus fractus, though the Cu fra is also impacted by smoke. The faint undulations are above the Cu fra, and show gentle waves, the kind that exist above the “boundary layer” and are not mangled by surface convection and Cu formation.6:46 PM. “Ugh” sunset. Smoky haze layer now really evident. More waviness, betraying its high altitude.6:49 PM, looking SW. Ditto.
Below, a satellite looks at our smog invasion, as indicated by the values of the “Aerosol Optical Depth” (AOD), how muddy-looking it is from up there. Blue is clear, anything else is muddy. Red is incredible. You can see it streaming in from the southwest yesterday morning, 5 AM AST. An annotated version below, in case you’re lost.
Same image, annotated.
Now, let’s see where it came from using the NOAA HYSPLIT model for obtaining backward trajectories for FIVE days, ending at yesterday morning. We saw it streaming in from Mexico, but did it really originate there? Nope.
Backtrajectories for three parcels of air at three levels above us, ending at 5 AM AST yesterday morning. The model thinks that two of the layers above us started way up above 30,000 feet some five days ago, but were lower when they arrived over us. The stuff about 20,000 feet above us (the red line), started lower than those, but was rising as it got to Tucson, that due to passing through the trough that’s approaching us this morning, One would expect to see more layering of smoke today.
And there you have it, “smog across the waters”, the Pacific ones.
Hard to say how it got up there, often its due to forest or other fires in Asia, rather than comes from low level urban smog. It gets here mostly in the springtime because the low pressure systems with their rain belts are weaker, less able to process smog via rain out as smoke layers cross the Pacific, while the jet stream is still quite strong and can carry layers a long ways in a hurry.
Dust plumes from Asian deserts like the Gobi also make it across the Pacific to the US from time to time, again, mostly in the springtime.
—–end of smoke diary module——
Expect shallow to moderately deep, high-based Cu today, ones that will form ice and virga, and of course, it will be windy as well. Seems too dry for much anything to reach the ground here in Catalina below those high bases, a pitiful situation with such a strong trough passing over us today. Check out the U of AZ model for further details. Maybe we’ll see some great lenticulars above the Cu tops…
“I think a year ago I sent you the early alert that Eel Ninyo is coming!!! Well, I think I was about 1 year early … the real deal seems to be gearing up for a more major appearance this year … check it out: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml
“My fingers are crossed for a much more typical event for 2015/16, but then again we seem to be in a very similar place as we were last year at this time (caveat part of e-mail) only a bit warmer in the tropics.”
“We shall see!”
—-from Nate M., NOAA SW Fisheries Center El Niño expert, personal communication, received just yesterday! Excitement abounds!
But, we will see as well…
Below, a different SST anomaly visual from NOAA:
Global sea surface temperature anomalies from NOAA, as of March 30th. The eastern Pacific and eastern equatorial waters are aflame, figuratively speaking, of course. Both the “Classic Niño” (off Peru) and “The New Niño” regions, the latter in the mid and eastern Pacific, have above normal water temperatures!
There is a LOT of warmer than normal water out there! As we know now, the newly discovered “California Niño” helped tropical storms whisk into Arizona late last summer and fall stronger and wetter than they normally would be by providing warmer waters than normal over which they traveled while heading toward AZ. Think of something like the highly-caffeinated “Jolt Cola” in sea surface temperatures for those storms.
Slackening onshore winds along the West Coast last spring and summer created the Cal Niño, something now known to occur from time to time over the decades. And that warm water wasn’t much perturbed by strong storms during the winter, ones that can mix colder water to the surface. The Cal Niño means that IF any storm strikes the West Coast, they would be a little wetter than usual since the air holds more water in it when its warmer.
In the meantime, the much-heralded El Niño of a year ago1 deflated like a New England Patriots game time football into a pile of nothing, wrecking the expectations of frequent late winter and spring rains in the Great SW. Thankfully we had that ONE great, several inches rainstorm at the end of January2 and a couple of vegetation-sustaining rains thereafter.
What does all this mean for our immediate future? Will the late spring be wet? Will we have a great summer rain season?
I don’t know.
But, next winter could be great!
Today’s clouds and weather
Rain is expected to be around today, sprinkles, maybe some thunder due to a weak low aloft passing to the south of us. Cloud drift is supposed to be from the east off the Catalinas, and with the unusual warmth, the day will LOOK like a day in July or August, nice Cumulus building off the mountains in the later morning, reaching the ice-forming level fairly quickly, and then, as you know, out pops the virga and precip. So, it will be a nice photogenic day for you. Check this nice graphic of the expected temperature profiles today from the U of A.
The weather WAY ahead
Recall that today and tomorrow, at one time, as was mentioned here, we were going to experience one of the greatest storms ever observed for this time of year. Well, today’s situation is what’s left of that forecast, a coupla puny showers around, and, sure a trough is here all right, but what a disappointment!
In the meantime, forgetting about the perpetual disappointments for big rains foretold about two weeks in advance, we are once again excited by another great rain here in the far model horizon of just two weeks from now, in mid-April!
Valid at 5 PM AST, April 14th, only 348 h from now! Could put a real dent in our usual April dryness! Colored regions denote those areas where the WRF-GOOFUS model has calculated through VERY sophisticated means, where precipitation has fallen in the prior 12 h! This from global obs taken at 5 PM AST last evening.
Yesterday’s clouds and more
From two days ago. Another comet passed over. Didn’t read anything about it, though. I guess the astronomers have seen enough comets. Probably a little jaded by now by so many of them.Close up. You can see its trailing ice and dust, burned off by the sun. Its great to live in a place where so many comets go over! I think that’s two or three in the past year!Awful green here in Arizona. I wonder how many people know how green it is here? I think a LOT of people have no idea how green it is here (at this time of year).
5:58 PM. Thought for a fun shot I would show you some castellanus from yesterday.6:45 PM. Post sunset, Altocumulus under patches of Altostratus, or, Cirrus spissatus if you like.
The End
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1Not just here, but by people that know more than I do, like the CPC.
2Water is still coming down from the mountains from that 4-6 incher in the Catalina Mountains, water that can be seen still pouring over great boulders in the higher reaches of our mountains producing the morning “glistening rocks” phenomenon. “Glistening Rocks”…. That would be a great title for a love song, a sad one, because as we all know, sooner or later, we won’t see the water producing glistening rocks anymore from the big January rain. So it would have to be about a love that starts out so strong, but then fades over time, finally disappearing altogether.
Litterfolk continue to prefer Bud Light cans and bottles over craft beers. While its interesting to make these surveys, CMP reminds readers, “Litter responsibly; in a receptacle.”
The trash you see here was collected during a single trip to the Sutherland Wash and back.
The Sutherland Wash Flow Report
A little water has resumed flowing in the Sutherland Wash hereabouts due to our recent rain:
The Sutherland Wash yesterday near the Baby Jesus Trail Head. Dog head also included.
The Cottonwoods Blowdown Report
The wind damage below was confined to an area only about 100 yards wide, and at the bottom of a small canyon leading down from Samaniego Ridge. Once suspects that a narrow microburst, some supergust, hit just in here as a rivulet of air collapsed down from the east-northeast after having gone over the mountains. It was likely further funneled by that little canyon and blasted these poor trees.
Note shoe size in lower left of photo.
Yesterday’s clouds report
Cumulus got off to an early start, a line of Cumulonimbus to the north providing a hint of what was to come when the sun came out.
7:06 AM. Cumulonimbus line the northern horizon.7:07 AM. An interesting set of very narrow shadows appeared briefly. The darker one might have been due to a young contrail. They seem too narrow to have been caused by cloud turrets.10:34 AM. Cumulus congestus clouds arose early and often on the Catalinas, becoming Cumulonimbus clouds later in the afternoon.12:07 PM. Some Cumulus congestus clouds sported the rarely seen “pileus” cap, suggesting stronger than usual updrafts pushing moist air above the top upward slightly, just enough to form a sliver of cloud.12:07 PM.12:54 PM. Before long, 47 minutes actually, big complexes of Cumulonimbus capillatus had formed to the north, and distant SW of Catalina.1:47 PM. While pretty, but this expansive Cumulonimbus capillatus incus (has an anvil), pointed to a potential rain-inhibiting problem: perhaps the exuberant convection would lead to an over-anvilated sky? Yes, it became a concern, I’m sure to all of us. Cumulus cloud killing anvilation.3:54 PM. While lightning forked in distant rainshafts, over-anvilation pretty much terminated any chance of rain in Catalina due to Cumulus buildups. The anvil debris clouds are termed, “Altostratus opacus cumulonimbogenitus.” Only clashing winds due to outflows from showers could possibly force rain now.4:43 PM. Clashing shower winds (SW in Catalina, NE towards Oracle) did produce a large final shower in the area. That lower cloud on the left side marks the area above and a little behind outflowing NE winds. Sadly, that wind push from the NE, one that could have launched a big shower here, fizzled out.
The weather ahead and WAY ahead report
More pretty Cumulus clouds today, likely some will reach Cumulonimbus stage (develop ice) and shower here and there. Flow will be off the Cat Mountains and so we here in Catalinaland are a little more elgible for a shower building on those mountains and drifting this way.
WAY ahead?
The models continue to occasionally produce a very heavy rainstorm in southern AZ on or about April Fool’s Day, once again appearing yesterday on the 18 Z (11 AM AST) run. See below, a really pretty astounding prediction again. This system comes from deep in the Tropics, so deep you wonder if it might have some hair from a giant Galapagos tortoise with it. It comes and goes in the models, but there is continuing modest support for a low latitude trough to affect Arizona in the “ensemble” outputs, or “spaghetti” plots.
The End
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1“The Cottonwoods” is a local name given to a portion of the Sutherland Wash next to the Baby Jesus Trail Head. It appears on most trail maps, and is a popular spot for underage drinking parties on weekends.
Drops, that is. There were about 140 or so the night before last, noticeable only if you left your dusty car outside, and TWO drops yesterday between 4:08:22 and 4:08:51 PM, as the last remnant of a shower cloud moved overhead from The Gap (the Charouleau one).
You HAD to be outside running around to encounter them, I do mean “running”, to increase the sample volume and your chances of detecting a drop in marginal rain situations. You have to “want it”, to be the best you can be about traces, that is. And I wanted to report another trace real bad. I love to report traces of rain, the most underrepresented rain event of all, the poor relative of measurable rain.
And, of course, more shower chances ahead, March 17th through the 20th, as remnant of the upper level trough that produced our last two days of clouds and sprinkles returns to us like a boomerang after producing generous rains in Mexico. It also meshes with a weak trough from the Pac at this time, so its pretty troughy for a few of days. Nice.
Today’s cloud pic archive will begin with the sunset the evening before last, since domestic responsibilities1 prohibited posting the usual tedious cloud array yesterday.
6:32 PM, March 12th. Rosy glow, a nice name for a female western singer, as well as a sunset, that bloomed late in the day (was less spectacular than expected that day, but still something). Lots of virga spewing out of iced up, high and cold-based, Stratocumulus clouds. Since you wanna know more, the TUS sounding indicated bases at -10 C, and tops at -20 C (4 F), that latter temperature explaining all the ice that formed that day.
Yesterday’s clouds
The temperature structure aloft was pretty much the same as the previous day, except that cloud bases were slightly lower and warmer, “only” -7 C or so, with tops again around -20 C (4 F), plenty cold enough for plenty of ice and virga from the modest Cumulus and Stratocumulus clouds that developed later in the morning.
Rainshafts were that tiny bit heavier it appeared, seeming to reach the ground with more gusto than the similar day before.
11:44 AM. Groups of small Cumulus began forming over the mountains.1:23 PM. Cumulus and Stratocumulus fill in the sky. Slight virga is apparent if you look really hard.2:29 PM. A light rainshower douses Marana and vicinity. Note the rumpled top of this cloud suggesting dominance of the water phase with just ice underneath. The dark bottom of the cloud is often called a “cloud base” by pilots, but is really the transition zone where the snow is melting into the more transparent rain and is not really a Cumulus cloud base, one composed of droplets forming in an updraft, as in the prior photo.
3:58 PM. Rain shaft on The Gap. Can you detect it? Its coming right at us! Here’s where the responsible observer realizes that he must be outside, or provide another means of detecting isolated drops as the cloud head begins to pass.
And, below, why we love our mountains and desert, especially on these kinds of days. About this time, the “light show” begins, ending with a dramatic sunset.
6:14 PM. Even the horrible becomes beautiful in the evening light.
The End
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1I had to take my mom, whose she’s really old and fragile, to the doctor , and then to the supermarket. This personal information posted for the purpose of inducing empathy in case I have a really bad forecast. People will remember that I take my mom places.
This link will bring up the window below. There’s a little tutorial below on what to do once when you get to this window:When you get to this page, the latest model run data will come up in red. Here, to see precipitation in colors on a map, click on the name, “1000_500_thick” for the best view of the many Arizona precipitation days ahead. You will see the precipitation totals for three (or six hours late in the model run) for the next 15 days as calculated by the WRF-GFS model, considered OUR best, but not as good as the Euro model some say1.
This is the same stuff that is rendered so nicely by IPS MeteoStar. I thought I would take you to the source, since its available an hour or two before the IPS renderings are completed.
In sum, its pretty amazing to see this many days with rain predicted so late in March and I thought you should see it, maybe brighten your day up.
Below , your March rain parade, a list of the NINE days with rain in the “general2” Catalina area from this latest model run based on global obs at 11 PM AST last night:
12 RW- VCTY3 (today)
13 RW- VCTY (recall, too, that spaghetti suggested an enhanced chance of rain between March 11-15th some coupla weeks ago)
14, 15, 16, 17 No rain indicated on these days
18 RW- VCTY
19 RW- VCTY
20 RW- VCTY
21 R4
22 RW- VCTY
23, 24, 25 No rain indicated on these days
26 RW- VCTY
27 R
Below, a peak at the latest 15 day spaghetti plot based on last evening’s 5 PM AST global data. I think you can see that there will be a lot going on in 15 days …
Valid at 5 PM AST, March 26th.
Your cloud day today
Heavy dense deep middle clouds with sprinkles in the area are passing overhead now. Will give way to an at least partial clearing in the late afternoon, meaning a great sunset is likely.
Rain not likely to be measurable today.
Yesterday’s cloud shot
5:29 PM. Nice display of Altocumulus castellanus virgae with some Cirrus and Cirrocumulus above them. Note the tufted, or protruding top4 of Altocumulus cloud in the center.
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1Remember how Superstorm Sandy, the one that battered the East Coast a couple of years ago, was better predicted by Euro mod rather than our own model, causing quite a weather flap?
2“General” is taken here as any rain that falls within a 10 mi radius of Catalina.
3“RW- VCTY” is text for “Light rain showers in the vicinity” (of Catalina, not necessarily ON Catalina, but we hope so.
4“R”, indicates steady rain of moderate intensity, namely that the models are predicting more substantial rain here where an “R” appears.
5As soon as I formulated this description about a protruding or tufted top, I realized it could be taken as untoward, perhaps even a salacious reference. Are we men so cursed that it’s always about the woman, the things we think6?
6As a further example, on a Cumulus cloud study in the Marshall Islands, I was acting as the person responsible for which clouds to sample with our research aircraft7, I noted a newly risen Cumulus turret a minute or two ahead, on the right. Speaking to the Director of the Cloud and Aerosol Group, Peter Hobbs, I reported over the intercom that there was a “young, firm, protuberant Cumulus cloud at 2 O’clock”, “Shall we penetrate it?”, I asked.
“Yes, they’re the best ones”, Peter replied.
The all male crew burst out laughing.
Q. E. D.
7A Convair 580 Turboprop. See below:
The Cloud and Aerosol Research Group’s Convair 580 readying for takeoff at Paine Field, Everett, WA.
The author has made two claims. Let us look at the evidence, the first of which was obtained yesterday morning in support of one of those. A hiker/walker, the author met, we will call him, “Bob”, though it seems doubtful that’s his real name since he had quite a strong northern European accent, said there was no running water in the Sutherland Wash, “only dampness.”
This proved to be an incorrect statement. I wonder how many other people I have corrected just now?
The wash has now been running without interruption for about six weeks. Below, two photos with dogs in them taken yesterday of the flowing Sutherland Wash at the Baby Jesus trail head, aka, “The Cottonwoods”:
8:42 AM. The Sutherland Wash in flow near the Baby Jesus trail head.8:42 AM. Dog ponders a drink from the FLOWING Sutherland Wash at the Baby Jesus trail head.
Q. E. D.
2) Can it rain again in March in the Sutherland Heights (epicenter of the above titular forecast)?
It could, but the assertion by the author is stronger than “could.” Let us again look at the evidence for such a claim.
There are several opportunities for rain here during the remainder of March.
1) the upper low that goes over tomorrow and Friday will produce scattered mountain showers in the area; a sure thing, but light ones.
2) then that SAME low, after nesting in the Tropics for a couple of days comes back over us with an even greater chance of rain next week since its had a chance to scoop up some tropical air (think Altocumulus castellanus, unstable clouds that can become little Cumulonimbus clouds).
3) In the longer term, “troughiness” (“cyclonicity”) is indicated to reside in our Great Southwest by spaghetti maps. Some individual model runs have even had big rains in the area in 12-15 days from now. Below, an example from IPS MeteoStar, which for some reason did not follow through on the “fee-for-service” they had been announcing was coming for about three months so’s that we would have to pay to look at their nice renderings of government model stuff1:
Boffo trough bops Arizona on…ooops, annotated version below to help you locate Arizona on this map.Forecast map valid on March 25th at 5 PM AST.
Another example of the wettest model run I could find, trillions and trillions of galloons of water released in storms in the SW:
Forecast map valid on Saturday, March 21st at 11 AM AST.
So, at LEAST three or four days in the remaining days of March with a chance of measurable rain, and THAT equals 100 % chance of rain falling within a 10 mile radius of the Sutherland Heights housing district between now and, and pushing the forecasting frontier even farther, say, the end of March! Going that far with such high confidence (100%) forecast is inappropriate for professional forecasting, but not here. So, this is a forecast for measurable rain on or VERY near us covering an amazing 19 days!
BTW, spaghetti thinks a trough of the magnitude above is goofy; see below. HOWEVER, there is a pretty strong tendency for cyclonic action here, just not as strong as the one above. The one above is likely goofy, an outlier model run….at this time. But, just like that New England win over the Seahawks in the last second when the Seahawks were about to run it in, but goofily passed the ball instead for an interception, outliers do occur.
Will keep an eye on this fun forecast from this keyboard, and get back to you from time to time IF it rains in the area. Otherwise, you will not hear from me again on this matter.
Below, some morning spaghetti for you.
Valid at 5 PM AST, March 26th. No sign of bluish lines, representing the heart of the jet stream penetrating the SW US as shown in that model run above. However, red lines, southern portion of jet stream, do dip southward over the SE and northern Mexico, indicating a good chance of lower latitude troughs here at the time of this map. Note that the blue and red lines suggest an “out of phase” jet stream pattern, highs in the far north, disturbances leaking into the SW US underneath them.
So hope for additional rain before the end of March is not dead, as it seems today, but has much life, in fact, to repeat, “100%” life.
1) Let yesterday morning’s color show speak for itself, just incredible, speaking for it anyway.
2) Please review the U of AZ time lapse film here to understand why it takes the biggest computer Fujitsu can build to calculate what the atmosphere is doing. Also reviewing this let’s you escape from the tedium about to be presented below.
3) Expect a similarly photogenic day today.
6:42 AM. First light, this incredible scene. Altoculumulus lenticularis downstream from Catalinas. Thought I would misspell Altocumulus to see if anyone is reading this. Sun seems to be coming up earlier and earlier….6:42 AM. Looking to the left or north of the lenticular….6:44 AM. That lenticular again, the bottom structure now highlighted.6:49 AM. What can you say? So pretty all around. Another lenticular was in progress to the main one.6:53 AM. If the scene wasn’t spectacular enough, a display of iridescence (rainbow colored area) then enhanced the original Ac len even more. It doesn’t get better than this and I hope you saw it “live.” I was just beside myself, taking too many photos, losing control, rationality.8:28 AM. Both lenticulars still in place, but now augmented by a layer of Altocumulus perlucidus (honey-combed look) and a scruff of low clouds that topped the Catalinas marking the invasion of a low level moist air. The feel of rain was in the air then, too.8:28 AM, the same time as the prior photo, but looking upwind over Oro Valley, toward Marana and beyond at a line of Stratocumulus, with Altocumulus perlucidus and patchy thin Cirrus above those. Even here, the scene seemed exceptional.9:41 AM. That Altocumulus deck began arriving overhead and you could see the little “heads” trailing ice crystals like comets with long tails. When the heads are gone, you’d call it Cirrus and never know how it got those fine strands. In the meantime, the Stratocumulus and Cumulus clouds were slowly getting deeper.1:19 PM. Looking over Catalinaville1: Stratocumulus was becoming the dominant cloud form. No ice, no precip, too warm at top; also, largest droplets in them below the Hocking-Jonas Threshold (30-40 microns in diameter) for collisions with coalescence to occur, if you care to learn things.3:42 PM. One of the many pretty scenes yesterday, these Altocu perlucidus, no ice. So, much warmer and lower than those trailing ice in the earlier photo.4:19 PM. Then, as the Stratocumulus filled in again, we got our late afternoon “light show”, those drifting spots of sun illuminating our mountains, though here our own Sutherland Heights subdivision, if that is what it is. So pretty.5:19 PM. Can’t be inside when these scenes are happening…. Have problem.6:13 PM. That sunset glow we see on our mountains every day, except a little more dramatic when dark clouds are overhead.6:19 PM. The day finished as gorgeous as it began as a clearing to the far west allowed the sun to light the bases of the overhead Stratocumulus layer.
The rain just ahead
Rain masses will be forming to west of Catalina today and will pound eastern Cal and western AZ for about 24 h before roaring in here tomorrow morning. Staying the course, best guess, from extremes of at least 0.33 to a max of 1.50 here, is 0.915 inches (the average of the worst and best case scenarios) here in “Catalinaville” as the total amount from this “hit” tomorrow and the showers afterwards into later Tuesday, as a second storm part comes by. Thunder tomorrow seems likely from this keyboard as the big rainband goes over.
During the passage of the rainband tomorrow, rainrates are likely to get up to an inch an hour, at least briefly, (this is the rate, NOT the duration) and typically, with several hours of moderate (0.1 to 0.3 inches per hour) to heavy rain (greater than 0.3 inches per hour) we should get a nice drenching.
The weather way ahead, 10 days or more
After a long dry spell following this upcoming rain, spaghetti is strongly indicating we have more troughiness in our future after the temporary dry spell!
Check it out, spaghetti connoisseurs2:
Valid at 5 PM AST, Saturday, March 11th. Note clustering of red and blue lines in trough off Cal.Valid at 5 PM, Sunday, March 15th. Southward bulging red lines, so many of them, indicate a very good chance of a trough here at that time. Blue lines, for a colder part of the jet stream, also tend in this direction, a good sign.
The spaghetti plots, taken together, indicate to the present Arthur that the chance of rain twixt spaghetti 1 and spaghetti 2 shown above is about 70%. It will be extremely FUN to see if this interpretation works out for rain between March 11-15th, at least one event anyway, to continue overusing that word.
The End, finally.
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1Didn’t Jimmy Buffet do a song about Catalinaville? Has a nice ring to it. Maybe we should think about it… Or maybe, in a vein similar to Carmel-by-the-Sea, “Catalina-by-the-Catalinas.”
2Remember, spaghetti is better than the model in the medium range forecasts that are presented based on the global data. Spaghetti is there to help you decide whether that model output is from the WRF-GFS looney bin or not. Here’s how:
Spaghetti is the result of DELIBERATE little errors put into the model when they start crunching the data to see how the forecast that you see on the maps could go wrong if there are errors in the data.
Of course, there are ALWAYS errors in the data! So, when the Fujitsu Computer DIvision made gigantically capable computers for us that were better than the ones we could make, ones that could do teraflops per second, we in the weather community could then run many permutations of the same model with itty-bitty errors in the initial data to see how the results changed (diverged) in the longer term.
Remember, too, in weather itty-bitty differences can add up to large ones in the longer term. So, when the model permutations with little errors cluster and DON’T diverge, it provides more confidence that the forecast storm, for example, is more likely to happen in that fuzzy forecast range of beyond 10 days or so. End of giant footnote.
Immediately, “BS” is for “Big Storm” ahead, not something untoward.
OK, first a piece about yesterday’s unusual clouds at Cirrus levels; you wouldn’t want to be flying in, or underneath these:
1:25 PM. Suddenly, a patch of phony Cumulus fractus appeared at Cirrus levels! I wondered how many CMJs were fooled and thought these clouds were just a little higher than Ms. Lemmon’s top.1:25 PM. Zoomed view of phony Cumulus fractus.1:26 PM. “Compare to real Cumulus fractus,” as the imitation, knock-off, phony, generic brands like to say about the real thing you like, but they’re never as good are they? They don’t think that you’re REALLY going to compare the real one with the phony one and that’s why they say that. They think you’re lazy. I’m thinking of Danny Elfman1 and “Grey Matter”…..1:46 PM. Here CMJs can easily tell that those clouds, though they appeared tufted and like they might have had droplets in them when they first formed, were at ice-forming levels high in the atmosphere. Here you see the expanding “ghosts” of several of the tufts that formed (upper left center), originally a dense concentration of ice crystals or a momentary droplet cloud, a dense cloud of ice that disperses in time, no further ice forms and so acts like a puff of smoke, and thins out, often disappearing as some of these did.
You can also these specks fly by in the U of AZ time lapse film. If you look at the film when they do, you can see them twisting around. Cirrus at that level (CM estimated 25,000 to 30,000 feet above the ground) are normally like sculptures; frozen in time as they pass by this time lapse camera with little or no internal movement.
You could also detect internal movement from the ground in real time in these specks (as we can with Cumulus clouds all the time, since we’re so close to real Cumulus fractus) so it must have really been churning up there.
This patch of specks only took a few minutes to pass by, so you were lucky if you say them.
Of course, you’re only interested in the Big Storm just ahead, not turbulence….probably have grown impatient by now, not wanting to read about itty bitty specks in the sky that might have been associated with strong turbulence. Well, its still “in the bag”, no need to worry. See below this map from our Canadian friends’ model. I really like this map, so no need to look farther. Also, I wrote some things on it for you:
Valid for Monday, 5 AM AST, March 2nd. I just had to go, “wow” when I saw this forecast map.
That “kicker” trough just off the Cal coast is going to kick that trough “ball” just off Baja at us as in a field goal in American football, and we are the goal posts.
When a trough is booted out like this one will be out of its nest, the upward motion in front of it is in enhanced, so that the clouds and precip intensify, become more widespread. Its going to head right for us, as it accelerates toward the NE.
This means, in turn, that the very strong rain band already in place in western Arizona, will intensify as it moves east across the State. This is pretty darn exciting because from here it would mean quite the downpour, hours of rain, and almost certainly thunderstorms on March 2nd. However, flooding is likely as rainrates will likely get up to an inch an hour or even more as the band passes over us.
Still sticking with 0.9 inches as “best guess” here in Catalina, top amount, 1.50 inches, if band lingers longer. Secretly hope I’m low….
In one last forecast panel, this MONSTER approaching the Cal coast. Its pretty far out there, as I am being today with the notes on band favorite, Oingo Boingo and sociobiology below, to be reliable, but its shown up a couple of times now in our model runs. It is unbelievable in strength to be forecast as far south as off central Baja, and I wanted to show you what an amazingly strong storm for so low in latitude would look like, if nothing else:
Valid at 11 AM AST, March 11th, Wednesday. A trough from this low a latitude barging into southern California would likely bring rains of 10-20 inches. And, while we’re downwind behind mountains, it would still bring appreciable rain here, too. BTW, rains of 10 inches or more, even in just 24 h, are not terribly unusual in the mountains of southern Cal.
The End.
PS: A powerful jet stream is near us now, so more strange clouds, lenticular-sliver clouds, and fine granulations in Cirrocumulus and such, are likely to be seen over the next couple of days. Have camera ready.
PPS: Still some flow in the Sutherland Wash as of yesterday.
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1The genius of Danny Elfman, that is, composer of the Simpson’s theme song, and the only composer to be nominated for two film scores in the same year, and also the leader of Oingo Boingo, an LA punk rock/ new wave band in the early 1980s, formerly known as , “The Mystic Nights of the Oingo Boingo”, more like a Spike Jones gag band. An early influence on Elfman was the concept of sociobiology, as represented in “Only a Lad“, a song about an inherently bad “lad”, satirizing some popular, widely held concepts on the causes of mischievous behavior in that song. A sample below, if you care2.
“The lady down the block,
She had a radio that Johnny wanted oh so bad,
So he took it the first chance he had.
Then he shot her in the leg,
And this is what she said
“Only a lad. You really can’t blame him.”
“Only a lad. Society made him.”
“Only a lad. He’s our responsibility.”
Oh, oh, oohh oh oh oh
“Only a lad. He really couldn’t help it.”
“Only a lad. He didn’t want to do it.”
“Only a lad. He’s underprivileged and abused.”
Perhaps a little bit confused?”
2Being a rad-lib in those days, I thought it was INCREDIBLE to hear such a song with THOSE lyrics in the early 1980s on the University of Washington student radio station, KCMU-FM, again, if you care.
In fact, the chance of MEASURABLE rain in Catalina is at least 100%, maybe as high as 300%, between 5 AM AST, Sunday, March 1st and 5 AM, AST, March 4th. Namely, its gonna happen.
Now, its not gonna rain that whole time, likely starting later in the day on the 1st. Pretty darn exciting to have a sure thing in the future! Check out this 4-panel presentation of maps from Enviro Can, I really like them:
Valid for Monday, March 2nd. Heavy rains foretold in western AZ by this time. Likely will be here by this time, too, though THIS model thinks the rain is still to the west.
Perhaps going farther than one reasonably should, the likely minimum amount will be 0.33 inches (10% chance of less) and top amount, gee, this situation has a big top, 1.50 inches, due to this trough’s deep reach into the sub-tropics, meaning it could pulling extra wet air toward us if everything works out in the “best” possible scenario. The best guess, between these two extremes is the average, or about 0.9 inches during our rainy spell. Should keep the washes flowing, though this one being colder than January’s tropical rains, should pile up lots of snow on top of Ms. Lemmon, so
Moving ahead to yesterday……
A pretty nice 0.09 inches fell yesterday morning in The Heights. “Nice”, because some model runs a few days in advance of this had no rain as a dry cold front went by.
When did the cold front pass?
9 AM yesterday, marked by a freshet from the NW with gusts to maybe 20 mph, with a falling temperature. Fell from 51 F to 42.x F by mid-morning, snow down to about 5,000 feet on Samaniego Ridge, too, though it melted almost immediately.
A push of wind like that virtually always builds a cloud above it, and yesterday was no exception. Here’ the cloud associated with that “freshet”:
8:31 AM. Wind shift line cloud shows up NW-NE of Catalina. Get ready!8:32 AM. Mini-rainbow appeared for just a moment.8:34 AM. Tiny holes in clouds produce pretty highlights on Eagle Crest as the windshift line cloud approaches.8:34 AM. Ditto above.9:03 AM. Windshift and line cloud pass over Sutherland Heights. Starting to rain here, though very little.9:03 AM. Close up of the bottom of the windshift line cloud.12:39 PM Post frontal passage quiet time with flattened clouds.1:28 PM/ Clouds swell up, first ice seen. Can you find it? More to north at this time.2:24 PM. Lots of pretty cloud “streets”, Cumulus clouds aligned in a line. Here’s a common one coming at you, one that comes off the Tortolita Mountains on Cumulus formation days with a westerly wind in the boundary layer (the layer between the ground and the tops of these clouds).3:19 PM. Walkin’ dogs now, but spotted trace of ice overhead in that SAME cloud street coming at me from the Tortolitas. Uh-oh. Do you see the trace of ice up there?3:21 PM. Few raindrops beginning to fall. Can you detect that bit of a rain haze on the left of center in this photo, out toward the Torts? Very hard to see, but there was an nearly invisible “shaft.”3:33 PM. Tiny snow shaft hangs from this same cloud line as it began to shift to the south and east. Can you find it?
Of course, the best part of days like yesterday is the play of the light and shadows on our mountains:
5:19 PM.5:58 PM. Stratocumulus clouds above the Charouleau Gap.
Looking closer, I hope you recorded the slight fall streaks (fallstreifen, ger.) in the scene above. It would have been quite an important observation for you to have acquired since these small clouds had not shown ice prior to this time. See below for the VERY delicate trails emanating from this Cumulus mediocris cloud; look between and above the orangish rock faces on the top of Sam Peak and a bit to the left:
