Art Rangno – Page 29

Loud May rain totals 0.47 inches in Sutherland Heights, Catalina

After last evening’s surprisingly heavy rain, we have now met our average for May for Catalina, having received 0.47 inches of rain over the past 24 h, some 0.36 inches during some house-shaking thunderclaps last evening.

Below are the 24 h local totals, ending at 4 AM today from the Pima County ALERT gauges rolling archive , these totals pretty much capturing all of our beautiful storm:

    Gauge    Location
    ID#
    —-     —-       —-        —-       —-         —-       —————–            ———————
Catalina Area
    1010     0.63      Golder Ranch                            Horseshoe Bend Rd in Saddlebrooke
    1020     0.83      Oracle Ranger Station          approximately 0.5 mi SW of Oracle
    1040     0.55      Dodge Tank                   Edwin Rd 1.3 mi E of Lago Del Oro Parkway
    1050     0.75      Cherry Spring                approximately 1.5 mi W of Charouleau Gap
    1060     0.79      Pig Spring                   approximately 1.1 mi NE of Charouleau Gap
    1070     0.39      Cargodera Canyon             NE corner of Catalina State Park
    1080     0.63      CDO @ Rancho Solano       CDO Wash NE of Saddlebrooke
    1100     0.35      CDO @ Golder Rd              CSO Wash at Golder Ranch Dr

Santa Catalina Mountains
    1030     1.18      Oracle Ridge                 Oracle Ridge, 1.5 mi N of Rice Peak
    1090      0.35      Mt. Lemmon                   Mount Lemmon
    1110      1.34      CDO @ Coronado Camp          CDO Wash 0.3 mi S of Coronado,       1130          0.83      Samaniego Peak               Samaniego Peak on Samaniego Ridge
    1140      0.79      Dan Saddle                   Dan Saddle on Oracle Ridge
    2150     0.24      White Tail                   Catalina Hwy 0.8 mi W of Palisade RS
    2280     0.24      Green Mountain               Green Mountain
    2290      0.12      Marshall Gulch               Sabino Creek 0.6 mi SSE of Marshall Gulch

For more rainfall info, go here and here. And here to the USGS, too, not to mention the NWS rainfall tables. Too bad they can’t all be in one gigantic table!

The clouds and weather just ahead

A little cold morning rain, and even snow on The Lemmon, is looking likely for Saturday morning. Presently, the core of the jet stream at 500 millibars or around 18,000 feet associated with a mighty upper cold low that sits on Arizona on Saturday is forecast to be south of us (as was yesterday’s jet), a pretty black and white discriminator for cool season (Oct-May) rain here.

However, if that jet core around the low does not circumscribe TUS, you can forget rain. From IPS MeteoStar, this rendering of the upper level configuration for Saturday morning, showing that it WILL circumscribe TUS:

The 500 mb heights and winds predicted for 5 AM AST, Saturday morning, May 10th. Its gonna a cool Mom's Day, too. One would expect rain here in Catalina with this configuration. Note how max winds are in a band well south of us. That banding circumscribes the deeper parts of the Pacific moisture that came in with this trough. — The 500 mb heights and winds predicted for 5 AM AST, Saturday morning, May 10th. Its gonna a cool Mom’s Day, too. One would expect rain here in Catalina with this configuration. Note how max winds are in a band well south of us. That banding circumscribes the deeper parts of the Pacific moisture that came in with this trough. This rendering is from the global crunch of data taken at about 5 PM AST, yesterday evening. These runs are updated every six hours.

In the meantime, “troughiness” today, tomorrow and Thursday, with secondary jet stream to south of us, will give us some more photogenic high-based Cumulus, maybe with some with virga in the afternoons. Today, as our upper low says goodbye, subsiding air is supposed to keep clouds from attaining tops high and cold enough to form ice. So, no rain today.

Yesterday’s clouds (going deep, as in pedantically)

There were some great scenes yesterday, summer-like ones, odd for May here, with massive rainshafts as the cloud bases lowered, reflected a huge jump in surface dewpoints to summer-like values in the mid-50s. Cloud bases yesterday morning, riding the tops of Samaniego Ridge, were near 7 C, compared with -5 C the afternoon before.

This warming of cloud bases greases the precipitation “wheel” since clouds with warm bases are be able to rain easier than ones with cold bases (say, near or at below freezing temperatures). Droplet sizes have to be larger at any given level above cloud base compared to the clouds of the day before since more moisture is forming in those updrafts at the higher base temperature. And, oddly, the larger the droplets, the higher the temperature at which ice can begin forming in clouds. And when ice forms, snow, then rain, come out the bottom.

To go on too long on this in covering all rain possibilities for yesterday, a base temperature of 7 C here is on the edge of being able to produce droplets big enough so that some begin colliding with one another and sticking together so that drizzle, then raindrops can form, a couple to a few thousand feet above cloud base, and those sizes of drops can really accelerate the formation of ice and then rain out the bottom. Are there any readers left? I doubt it.

Let us go even deeper…. It was hazy, smoky looking yesterday most of the morning, even when some good thunderstorms formed. So what? Well, smoke is bad for storms. Remember when it was reported by Warner and and the U of Arizona’s own Sean Twomey (1967) that sugarcane burning made it stop raining downwind from those fires in Australia? That effect has been verified in satellite measurements by cloud seeding nemesis, Danny Rosenfeld² of the HUJ in Science a few years ago.

Well, too much smoke can choke droplet sizes down and inhibit the formation of rain by collisions, and delay the formation of ice. And so we had that counter effect of smoke from somewhere, maybe LA this time since it was in the boundary layer, not aloft like that smoke layer from Asia was a couple of weeks ago.

So, cloud microstructurally-spekaing, it was an especially interesting day, one, if he were cloud maven person, wishes he would have had an aircraft to sample them.

But let us look now and see what all the fuss is about:

5:40 AM. Dewpoints in the 50s, Stratocumulus clouds top Samaniego Ridge! — 5:40 AM. Dewpoints in the 50s; Stratocumulus clouds top Samaniego Ridge!

6:41 AM. Soft-serve Cumulonimbus forms over west Tucson, Oro Valley. Icy top looks like its comprised of needles and hollow sheaths to me, ice that forms at relatively high temperatures for ice formation, higher than -10 C.

6:42 AM. In the meantime, drama over Oro Valley to the west and north of Catalina as a deeper cloud unloads. Thunder, too.

7:19 AM. Haze and rain. This was a pretty astounding sight, so much haze/smoke in the rain as evidenced by these intense crepuscular rays.

8:19 AM. A real summer-looking sky on a big rain day. Frequent lightning was emitted by this behemoth that went on to pound Saddlebrooke.

8:37 AM. Unusually strong May thunderstorm pounds Saddlebrooke.

3:42 PM. In spite of lots of convection and scattered Cumulonimbus clouds, the sky remained almost an eastern whitish due to smoke, which I will blame on southern California, absent any facts or investigation. No time.

3:42 PM. In spite of lots of convection and scattered Cumulonimbus clouds, the sky remained almost an eastern whitish due to smoke. — 8:37 AM. Unusually strong May thunderstorm pounds Saddlebrooke.

3:42 PM. In spite of lots of convection and scattered Cumulonimbus clouds, the sky remained almost an eastern whitish due to smoke, which I will blame on southern California, absent any facts or investigation. No time.

6:59 PM. Our major evening rain and thunderstorms were developing upstream.

The End

————————————-

¹Warner, J. and S. Twomey, 1967: The Production of Cloud Nuclei by Cane Fires and the Effect on Cloud Droplet Concentration. J. Atmos Sci., 24, 704–706.

²Rosenfeld a “nemesis?” See the references and discussion below for kind of an interesting science story aside….

Rangno, A. L., and P. V. Hobbs, 1997a: Reply to Rosenfeld. J. Appl. Meteor., 36, 272-276, and…..

Rangno, A. L., and P. V. Hobbs, 1997b: Comprehensive Reply to Rosenfeld, Cloud and Aerosol Research Group, Department of Atmospheric Sciences, University of Washington, 25pp.

With the publication of voluminous (en toto) commentaries/critiques in 1997 by a few of our peers, but mainly by Danny Rosenfeld of the Hebrew University of Jerusalem, that concerned our 1995 paper reanalyzing the Israeli randomized experiments, yours truly and Peter V. Hobbs, had attained, according the the Technical Editor of the Journal, the status of having become the most criticized meteorologists in the history of weather–well, in the history of the Amer. Meteor. Soc. journals, anyway! How fun is that? Its fun.

Our findings, that the two benchmark Israeli randomized cloud seeding experiments conducted in the 1960s and 1970s were largely misperceptions of cloud seeding effects due to storm biases on seeded days, were independently verified in peer-reviewed publications by researchers at Tel Aviv University some many years later.

Operational cloud seeding has ended in Israel in favor of more fruitful avenues for obtaining the water they so badly need.

TSTMS overnight and this morning drop 0.11 inches

Well, it could have been more I suppose; some areas of central and northern Arizona have gotten between a half an inch and an inch of rain overnight. Nevertheless, it was great that a passing thunderstorms (“TSTMS” in weather texting) happened here in Sutherland Heights overnight, fabulous, really. Dropped 0.28 inches on Mt. Lemmon, btw.

More scattered showers, and maybe a thunderstorm or two, should develop today. Keep cameras well-oiled for some great cloud scenes.

Yesterday’s clouds

8:04 AM. In the beginning….. Unlike the day before, our shower clouds didn’t move in, but rather had to start from something akin to poppy seeds. Still water highlights on Samaniego Ridge.

12:06 PM. Cumulus increase in size and number. No ice yet.

2:14 PM. First minute amount of ice begins to show up underneath downstream cloud portions. You’ll have to be awfully good to find it!

3:37 PM. Ice, and now well-developed virga, is plentiful in many of these shallow clouds.

4:00 PM. Numerous light rainshowers and glaciating shallow Cumulus clouds dot the horizon to the SW,

6:58 PM. Shows the fine structure of virga, trails that can be only 5-20 feet wide as they drop out of a cloud. Seems like a nice scene, too. — 6:58 PM. Shows the fine structure of virga, trails that can be only 5-20 meters wide as they drop out of a cloud. Strands like this are usually soft hail, or what we call “graupel.” Snow virga like this tells you that cloud bases are well below freezing, and on a warm day are very high above the ground. Yesterday’s late afternoon cloud bases were up around 14 thousand feet above sea level, at about -5 C (23 F). The virga melted into raindrops behind the cloud below it.

7:04 PM. A light rainshower advances on Catalina. Where the pinkness disappears below the main cloud base is where the snow virga is melting into less visible raindrops.

7:06 PM. Another fiery sunset highlight involving a Cumulonimbus cloud. Cloud tops were beginning to deepen noticeably by this time.

The End

A cool May ahead?

Well, let us define “cool”….that is, cool for Catalina in May; that is #2, below normal temperatures.

What led to this thought?

I was gasping when I saw this from last night’s NOAA spaghetti factory, as you will as well, and decided I would have to say something about it.

Valid on the 17th of May, 5 PM AST. Wow! And with a persistent pattern like this (red lines dipping so far toward the Equator (which is that dashed line that goes through Hawaii and Mexico1), which we now seem to be in following our little warm up, now in gradual retreat, big flooding will occur in the central and southern Plains States, the kind that makes the 5 o'clock news (or is it 6 o'clock?). Wow. — Valid on the 17th of May, 5 PM AST. Wow! And with a persistent pattern like this (red lines dipping so far toward the Equator (which is that dashed line that goes through Hawaii and Mexico1), which we now seem to be in following our little warm up, now in gradual retreat, big flooding will occur in the central and southern Plains States, the kind that makes the 5 o’clock news (or is it 6 o’clock?). Wow.

Pretty unbelievable.

What does it mean for Catalinans: a personal view?

Oh, big windy episodes from time to time during the month, good chance for above normal rain for Catalina, and probably most interesting, the late spring ovenly weather that we like to brag about how we get through wherein so many of our Catalinans and “Tucsonians” flee to the high country, or to Michigan, is held at bay by recurring puddles of cold air up top.

That’s my prediction for May, which has already been ludicrously posted in a prior post many days ago. We might look back at May some day to see how this incredibly unprofessional forecast for a whole month based on one spaghetti run worked out.

If you want professionalism in medium range weather forecasting, then get the hell off this site now! Maybe you’re the kind of person that would rather see a forecast from the NOAA Climate Prediction Center for Catalina and environs. If so, you don’t belong here.

But lets see what they say, anyway for May, then for the whole of mid-April through July…..to add that bit of uncharacteristic professionalism to this site. See maps below:

Looks like they’re pretty clueless about what the temperature’s going to be like here for May–“EC” means equal chances for below normal OR above normal. So, they could be right no matter WHAT happens! But not me. I think Cal is goona be wrong, too; below normal, not above normal temps. Its great when you can just type things like that!

The Big Boys don’t really know what’s going to happen with the May rain here, either, since we are also in an “EC” area. But boy, look at the May rain foretold for the Plains! Looks like a great place to spend May! OKC, maybe. WCWS begins at the end of May, amateurism at its best.

But, at the same time, for the whole of mid-April through the end of July, the Big Boys at the CPC are expecting the drought in areas of the central southern Plains States to persist or intensify–see dark brown areas below.

It will be interesting, being serious for the moment, to see how these predictions, seemingly in some conflict, work out. Note that in the longer view below, Catalina is in an area where drought “persists or intensifies”, even through JULY! Egad.

Nice clouds yesterday….

6:00 AM. Mamma to the S. — 6:00 AM. Mamma to the S, pretty big mamma. Indicates unstable conditions aloft, maybe some showers will reach the ground.

10:01 AM. Heavy vIrga pummels air above Catalina/Saddlebrooke.

4:20 PM. High-based Cumulonimbus clouds approached from the south promising blasts of wind, maybe a few drops. No drops here, though.

6:47 PM. Cumulonimbus and rain reaching the ground passed to the W-NW of Catalina. Darn.

DSC_5779-1 — 7:04 PM. The moon AND pink virga in the SAME photo! Yours today for $900. Trying to follow through on an Atlantic Mag article, “Blogging for Dollars.” That would be great, but it hasn’t happened yet.

DSC_5784-1 — 7:09 PM. Your Catalina sunset, May 2nd, 2015, Altocumulus castellanus with Cumulonimbus capillatus, along with a Cal palm silhouette.

—————-

Yeah, I saw that report that America’s kids don’t know much about geography, so we’re just checking here to see how bad it really is by suggesting that the Equator goes over the Hawaian Islands (hahaha). But, maybe, they’re really the Galapagos Islands… Am I being too subtle? Sam Cook once pointed out about himself, “Don’t know much about geography”…in his song, “What a wonderful world it would be“. it was a movement that apparently caught on.

A nice white Lemmon

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:

Finsihing off here with an orange Lemmon, if that's possible, at 6:50 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. Two layers of Stratocumulus. — 7:58 AM. Not one, but two layers of Stratocumulus.

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. — 8:57 AM. Paper flowers still going…. They’re not used for making paper, btw.

9:30 AM. Occasional sprinkles fell from these clouds. Might have been due to ice, but texture 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. — 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. Small Cumulus provide the light and shadow show on the Catalinas, one of the best things about living here. — 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.

The End.

Surprise late April rain, thunder strike Catalina! Snow piling up on Ms. Lemmon!

Gasp these late April totals from the Pima County ALERT gauges, as of whenever you look, along side our Sutherland Heights total, as of 7 AM now, of 0.58 inches. This total is about the normal for the month of April here. Fantastic. Several nearby mountain and Catalina foothill totals are well over an inch with Oracle Ridge having 1.50 inches! However, the top of Ms. Mt. Lemmon is reporting nothing, which means the precip there is falling as snow. Nice couple of thunderblasts last night between 1:30 and 2 AM, too.

Yesterday, the latest wrf-goofus model (executed by the U of AZ at 11 PM AST night before last), had no rain in Catalina, and only a pittance in the mountains east of us.

Still a chance for measurable rain during the day today, too, but it’ll be gone by tomorrow, and it’ll likely bt a long time before rain returns.

Yesterday’s clouds

5:39 PM. Disappeared for awhile, then came back.

5:52 PM. The look of a storm, Altostratus above Cumulus and Stratocumulus.

The End, for now, anyway.

—————

¹Total is from a CoCoRahs gauge, not the Davis Vantage Pro online tipping bucket, which registers slightly low.

Surprise showers drop 0.02 inches in Sutherland Heights; April won’t be rainless!

Well, those showers were a surprise to “me and my model” yesterday morning, at least the one I looked at just before going on the air. There were no upstream echoes in the clouds upwind of us, either, something normally seen before cool season showers get here. Fortunately, I was able to get in a prediction that rain would fall just as the drops began coming down.

However, there are a few times when that bit more lifting as the air moves from the lower ground to the southwest of us to here can trigger precip; the tops get that bit colder, form ice, voila, out drops the rain (and snow). That’s probably what happened yesterday to cause a sudden development of light showers, “all quads” it seemed.

Cloud tops may not have gotten colder than about -10 C yesterday, too, and so our rain likely fell from ice crystals rarely seen in Arizona, hollow sheaths and needles (columnar crystals), which have to be in big aggregates before they can form a drop big enough to reach the ground. So, not only are they rare here, but there also have to be a LOT of them )10s to 100s per liter in the clouds) for them to form big enough snowflakes so that a drop reaches the ground. In fact, when columnar ice crystals form in clouds, they often do so prolifically so that, at least at the University of Washington where the present Arthur worked for about 30 years in airborne studies of clouds, needles and sheath crystals were always associated with the highest concentrations of ice crystals that we observed. Some of those rare ice crystals were STILL forming in the clouds above us near the time of the second sounding, shown below, launched at 3:30 PM! That was really shocking!

This ice crystal happenstance, and the surprise light showers, made yesterday particularly worth commenting on from this cloud pulpit, if that’s what it is. Some nice examples of needle and hollow column ice are shown here at CalTech. These kinds of crystals are rare in Arizona because they require larger (greater than 23 microns in diameter² in clouds at temperatures between -3 and -8 C. Like the needle crystals themselves. Since the clouds were shallow, one has to speculate WHY the cloud droplets might have been extra large. It may have been that there were few of them (seems kinda unlikely this far from clean oceanic air. More likely, those clouds had large (micron-sized) dust particles in them, known to help form larger cloud droplets. So, I’m guess those clouds were helped by dust so’s they could have larger droplets in them, ones big enough to help produce ice splinters consisting of needle and hollow sheath crystals at such high temperatures (higher than -10 C).

Our U of AZ model predicted soundings were pretty much what we saw, too, cloud capped by a stable layer that got stronger as the day went on, and the air drier above it. Below, from IPS MeteoStar, these TUS soundings from yesterday morning and afternoon.

Baloon (I prefer this spelling) sounding launched from the U of AZ yesterday morning around 3:30 AM AST. Shows tops were marginal for ice in AZ at this time. — Baloon¹ sounding launched from the U of AZ yesterday morning around 3:30 AM AST. Shows tops were marginal for ice in AZ at this time.

2015042500Z_SKEWT_KTUS — The baloon sounding from the 3:30 PM AST launch from the U of AZ. Where the lines pinch together is the top of the boundary layer where cloud tops were, -10 C. A few shocking rain drops fell in Catalina (stop light at Oracle and Golder Ranch Drive construction zone) soon after this launch (4:22 PM) from a shallow complex of Cumulus/Stratocumulus clouds. Unbelievable. Carried out a little photo documentation when I saw them on my windshield to record the remarkable event. It was pretty darn exciting, and I hope for you, too, if you felt a coupla drops about that time.

But let’s drag this out and look at yesterday’s clouds now…

6:13 AM. Clouds much fatter than expected this morning, but nothing to worry about. Not gonna rain. Mod says so.

6:14 AM. Looking to the north, not much, just some harmless Stratocumulus. Maybe will go inside, not think for awhile….

6:33 AM. Its raining over there, cloud has a tremendous amount of ice in tops (that smooth area to the right and above Pusch Ridge. Unbelievable, since the tops aren’t that high!

6:34 AM. Another soft turret filled with ice trailing light rain! That softness suggests to this observer that they are not the usual ice crystals, but rather jillions of needle and hollow column (sheath) crystals, too.

7:38 AM. By this time, the light showers were everywhere, especially in Oro Valley and drifted over Catalina for the next few hours. Here. light rain, not haze, produces crepuscular rays.

3:29 PM. By mid-afternoon, the clouds had gotten shallower, not warmer though, as bases rose more than the tops did. Tops were still around -10 C at this time, but the bases were higher, above the mountains, as you can see here. And, we had our usual "mountains shadows" (would be a nice motel name) light show. — 3:29 PM. By mid-afternoon, the clouds had gotten shallower, not warmer though, as bases rose more than the tops did. Tops were still around -10 C at this time, but the bases were higher, above the mountains, as you can see here. And, we had our usual “mountains shadows” (would be a nice motel name) light show.

During the afternoon, a nice cloud “street” formed, came all the way from Mexico way, one that spawned a little more anomalous ice, and those few raindrops; see below for evidence if you don’t believe me.

3:39 PM. Long cloud street trails over Catalina. Isolated veils of ice formed, with a few drops reaching the ground. See car front windshield below for the shocking evidence.

4:20 PM. Raindrops fell on windshield as part of the long cloud street still in progress overhead. Grabbed camera immediately, of course, as this astounding event occurred! Was at the Golder Ranch Drive and Oracle intersection “war zone” as we would call it these days. (Hope they’re done before 2020. :}

BTW, here’s our cloud street as seen in the “visible” satellite imagery at 4 PM AST, just before the drops fell on my windshield. You can see that it originated near the border with Mexico, as many things do.

Visible satellite imagery for 2300 UTC (4 PM AST) from the U of AZ.

The End, except I think there will be some more rain tomorrow morning, trace to quarter of an inch are the bounds, meaning about a tenth is the most likely amount from this cloud pulpit.

The End, again.

——————-

¹I prefer this spelling today; more “o’s” than “l’s” in that word make you think more of a thing full of air; maybe a few more “o’s” would help even more, too, like “baloooon”…

2That size is considered “large” for a cloud droplet, and lab studies have shown that they splinter when they hit something, like soft hail, also called “graupel.” Splintering is thought to lead to all those extra ice crystals at temperatures between -3 and -8 C.

Thunder and virga

Clouds got more enthusiastic than expected here yesterday, reaching sizes big enough to produce light rainshowers to the NE of Catalina, and THUNDER just after 6 PM up toward Oracle town! Nice. Looks like a small Cumulus, postcard day today in Catalina. Cloud tops marginal for ice, holding around -10 C, capped by subsiding, dry air. (Except for the light showers this morning between 7 and 9 AM; this note added at 7:32 AM when I saw a shower developing to the west over Oro Valley!) This, from the U of AZ model. Since the air is colder aloft to the N today, ice will likely be seen in some clouds up thataway.

7:26 AM, looking toward Samaniego Ridge. Water still flows down from the upper reaches of Samaniego Ridge from the winter rains. You’ll have to click on the image to really see this water.

2:25 PM. While Cumulus occasionally filled in, they weren’t getting any deeper. No ice visible at this time.

4:11 PM. There was plenty of ice around at this time, but most of it, as shown here above and to the left of the right most light standard, ejected out the downstream end of the clouds. This meant that the ice crystals had no chance to grow inside a cloud, but were thrown out into dry air and evaporated. Wider and taller clouds were needed for even decent virga to happen.

5:38 PM. Those deeper and wider clouds began to develop. Here a sprinkle or light rain shower reaches the ground toward the town of Oracle. Fifteen minutes later, thunder was even heard coming from this complex.

6:45 PM. The thunderstorm that occurred near or over the town of Oracle weakens and recedes. For a time it appeared building Cu overhead of Catalina might produce a sprinkle, but no.

The End.

Smoky “hello” from Asia

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. Smoke vellum covers sky. Best seen toward the sun. Looks dark on edge when the sun is shinning on it, like to the southwest. — 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. — 6:46 PM. “Ugh” sunset. Smoky haze layer now really evident. More waviness, betraying its high altitude.

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.

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.

13753_trj001 — 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…

The End

“Jumbotrons” again appear in model output

More possibly illusory water on a hot Arizona desert highway in the 12-14 day range. Massive events are predicted, really; thought you like to see these mid to late April blows, even though they’re likely as phony as a two dollar bill¹.

1. Major April rainstorm exits Cal, brings generous rains to AZ. From IPS MeteoStar, these:

2015040800_WST_GFS_500_HGT_WINDS_336 — Valid (or invalid, probably) for 5 PM AST, April 21st.

2. Second in sequence, shown off Orygon, moves in position for a followup Cal blast.

2015040800_WST_GFS_500_HGT_WINDS_360 — For April 22nd, 5 PM AST.

3. “Jumbotron 2” marches toward the Cal coast. For mid-April, southern California and Arizona folks would be wondering about “climate change” should this happen, which it probably won’t, but we can dream. Truly, a map like this is really exceptional for the 20th of April due to how strong and deep that low is off ‘Frisco, and the strength of the jet stream at the latitude of Baja below.

2015040800_WST_GFS_500_HGT_WINDS_384 — For April 23rd, at 5 PM AST. A storm in this configuration, being out of the main jet stream, would take a long time to go by. Might rain for two or three days, so it COULD be a real drought denter. In any event, spaghetti is strongly suggesting “troughiness” in our area over the next couple of weeks, and that will lead to some real rain chances. However, April marks the real beginning of our dry season, averaging only about half an inch here in Catalinaland, compared with over an inch and three quarters in March.

Below, some morning spaghetti for you:

For April 20th, 5 PM AST. Looks very promising for storms then, as you would know. BTW, we still have some of the Dry Fittm Tees of "I Heart Spaghetti" available for $12 plus $62 shipping. — For April 20th, 5 PM AST. Looks very promising for storms during the second decade and beyond in April, as you would know, of course. BTW, we still have some of the Dry Fit^tm Tees of “I Heart Spaghetti” available for $12 plus $62 shipping.

To help you further understand a perspective on the “gigantism” of the predicted late April storms that came out in yesterday’s 5 PM AST global data crunch, as they are seen in the eyes of meteorologists, let us compare dinosaurs of the Mesozoic as a metaphor:

Valid 250 million years ago. — Valid 65 to 250 million years ago. Humans back then had to be especially careful; death by trampling was quite common.

Speaking of the Mesozoic, I think you would like to hear some birdsongs of the Mesozoic. Its quite good.

About clouds

Been having some fairly nice ones lately. Miscellaneous array from yesterday below:

The End

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¹Recall spaghetti has been keeping a trough, i.e., a dip in the winds to lower latitudes, here and in the eastern Pacific for some time; these maps are likely an exaggeration of the REAL troughs that happen in ten days to two weeks, since in these eyes, this series of two storms shown above would likely break April rainfall records in some southern California locations before reaching Arizona with generous rains. So, the more extreme the weather prediction in the 10-15 day period, the more reason to treat it as a knee-slapper. Still, it COULD happen….

Miscellaneous stuff; also, regime change now in progress!

Haven’t had much weather/clouds to gab about; maybe I’ll help reader with some extra material today, not usually associated with a site about clouds; kind of go outside the lines a little.

Miscellaneous item 1

The Oracle Road report. Thought you’d like to see that.

Yesterday afternoon report. — Yesterday afternoon’s report. Seem to be some people working. That’s good. You can see some curbing going in, too. Kind of reminds me of how high pressure has been “curbing” our storms lately, to introduce a weather theme. Photo not taken while driving, of course.

Miscellaneous item 2

This. Its quite good. You’ll see people really liking it, too. It may raise the question in your mind, “How many other people are “‘question marks'”? Cloud Maven person?

Clouds?

Well, we had some nice Cirrus yesterday, and for the past few days. Lots more to come, too, but that’s about it for awhile.

3:20 PM. If you on Mt. Everest this would quite a little passing snow shower of tiny crystals, quite fun, because it would only last a minute or so. Well maybe since the wind would be 100 mph, maybe it wouldn’t be THAT fun because the little crystals, likely bullet rosettes, as you would know, would sting your face if it wasn’t protected.

There’ll be a lot of Cirrus over the next two weeks, we hope with some rain underneath, with the best chance being

For yesterday afternoon, 5 PM AST. The green areas represent moist conditions at Cirrus levels, here for about 300 mb or 30,000 feet. Streamers of Cirrus are coming at us for awhile from the sub-tropics. You can see a lot more green in this two week forecast from IPS MeteoStar.

Regime change?

Yep, mostly for Cal, though, as far as rain and snow go. Folks in Cal are quite excited about the drought they’re having, but this April will put a damper on that excitement as the storms roar in from the Pac like they should have all winter. It won’t end the drought, but it won’t be quite as dire, either. You can read about direness here from the LA Times. You’ll read that Governor Brown¹ has declared a water emergency in California. Of course, most of the water use is in sometimes inappropriate agricultural practices, like growing rice around Bakersfield in the San Joaquin desert, that kind of thing, not by home owners.

California can be very wet in April. For example, in 1926, and in 1965, Los Angeles got over seven inches, and five inches, respectively. So, “It ain’t over til its over”, the Cal rain season that is, as they say. It will be interest to look back as May arrives, and see how much the drought was alleviated.

You can see all the storm set to pound Cal here, plus our own chance around April 12-13th from this rendering of last evening’s global data.

How does Cloud Maven know for sure there is a regime change taking place that will help Cal? From a helping of spaghetti. Lets look at spaghetti two weeks out, way more longer than weather models can be considered reliable. Cloud Maven person was VERY excited when he saw this, as you will be as well!

Valid on April 17th, 5 PM AST. Note how the red lines (contour number 576 dm) are squished in the Great SW, drooping southward into Mexico! This is tremendous, since it virtually guarantees a trough in the SW. The other plots are similar. You just don;’t see this much in squished contours very often this far out in the model run in our area. Usually these contours are like the ones off Africa. I hope you know where Africa is…. Those blue lines (number 552 dm contours) are in the heart of the jet stream, really on the poleward side, and notice how some of them dip into the SW. This is good, too. Now, for California, olden studies have shown that its the contour BETWEEN these (564 decameters) that delineates where rain falls when a trough hits the Cal coast. That contour is between the red and blue lines, and so there would be plenty of rain falling in Cal during these first two weeks, with no sign of let up here at the end of the model run. SO, in conlcusion, that’s why CMP is sticking his neck out about a wet, drought-denting April in Cal.

What will our Catalina weather be like in April?

Under this new regime, whether it rains or not, you can expect windier conditions than normal during the month since storms exiting Cal will be close enough to excite not only meteorologists, but a “Tonopah Low” in the lee of the Sierras, something that helps generate wind here as they progress into the Great Basin after forming.

Wow, this is really too much detail for an entire month to come²! Oh, well. Remember our motto here at C-M:

“Right or wrong; you heard it here first!”

The End.

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¹Remember how we used to call him, “Governor Moonbeam” when he was governor of Cal the first time around in the 1970s due to his quirky, ascetic lifestyle? That was fun. Lots of quirky people in the Haight-Asbury district then, too. How many question marks were among those folks…and where are they now?

²We’ll be looking back at April come the beginning of May, by which time you will have forgotten anything that was written here, and I could almost anything.