Sunrise and sunset heaven: Cirrus and maybe Altocumulus on the way

Yep, a cute tiny little upper air low with just a dollop of high clouds is going to be spit out of the eastern Pacific off Baja Cal today and tomorrow and toward AZ, and along with that will come some Cirrus and probably Altocumulus floccus and castellanus clouds, maybe with virga. The first Cirrus cloud is likely to get here by late afternoon or evening today, and the sky should be full of high, icy Cirrus clouds tomorrow morning. So charge your camera batteries now for some of the “everyday-but stupendous” AZ color at sunset today and at sunrise tomorrow. You’ve been warned.

Below a map of the air flow and pressure patterns at 300 mb, or about 30,000 feet, the domain where cirriform clouds like to reside, valid at 5 AM LST this morning.

The Twelve…rain drops in Catalina, that is

Well, maybe there were about 27, but anyway….not very many; still, those drops were to be treasured after not seeing a single “hydrometeor” display in SE AZ in so–ooooo LONG A TIME!

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PG-13 advisory; DRIZZLE is discussed

I have to warn you at this point. That rain event yesterday WAS NOT DRIZZLE!!!!!!!!!!!!!!!!!!!!!!!!!!! I will be ROYALLY PO-ed if I hear someone in my social network or a TEEVEE weather presenter say that it “drizzled” yesterday!

Why make a BIG THING out of the correct type of precipitation?

I have to tell you a true story (well, I don’t have to, but I am going to anyway) about the importance of drizzle (i. e., fine, close together drops that appear to FLOAT in the air). This event happened during my cloud seeding “vigilante” adventures (see Publications for samples). A well-known professor of cloud seeding in a foreign country asked me to leave his office and never come back after I told him it had been “drizzling” outside, “10s per liter” in the air.

Drizzle is a profound indicator of cloud structure overhead, and the presence of drizzle falling from the clouds in that professor’s region’s meant his numerous reports of how clouds were, ripe for cloud seeding, were in substantial error. So you can understand why a report of true “drizzle” would naturally be upsetting to that professor. Man, am I digressing here! Yikes. My apologies. (BTW, those reports WERE in error, confirmed by aircraft years later! (Spiking football now, with a proper amount of decorum, of course!)

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OK, back on task….

With the sky full of low (“boundary layer”) clouds by mid-day (f you’ve forgotten, that was yesterday, May 10th, 2011) and with RW— in the air (“triple minus”, extremely light rain showers) by 1:30 PM, with gusty winds, temperatures in the mid-60s, it turned out to be quite a “storm.” It just as well could have been but a mostly sunny day with just a scattered Cumulus clouds here and there the way some models were “telling it.”

Here’s a pictorial on how it went, from a Catalina, AZ, perspective:

1) 09:29 AM, itty bitty Cumulus (Cumulus “fractus”) starting to appear,

2) 12:03 PM, larger Cumulus growing up into Cumulus “mediocris” beyond Tortolita Mountains on the horizon,

3) 12:29 PM, virga and rain visible to the NW horizon! Now I am getting apoplectic since the best models in the world did not have this precipitation over thataway! But there it is, bigger than watermelons. The models have to be really red-faced about this! Not everything in the world is predetermined by numerical models; you can say things that might be right and those models are WRONG! Just like in the 1970s when a lot people thought global cooling was underway and that’s where we were headed! But they were WRONG! Who were those clowns anyway?! (hahaha, sort of).

4) 1:25 PM. Now where was I before all that excitement? Oh, yeah. Here’s some ice for you. See the frizzy top parts of this cloud in the center of this photo above the dead tree that the birds like to sit in? Well, them’s ice crystals, and likely snowflakes that have formed in that medium-sized Cumulus cloud (above the dead tree) and its in the upwind direction. Behind that is more ice and precip falling from a wide area of a Cumulus-Stratocumulus complex.

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Mini-diversion

Quiz. How cold does the top of THAT cloud have to be to look like that (have that much ice in it, probably a few per liter to maybe 10 or so, not a tremendous amount but significant)? Well, with bases as cold as they were, near freezing by this time of day at around 7, 000 feet above the ground or 10, 000 feet above sea level, around -15 C (or about 5 F). Amaze your friends with cloud trivia like this! Well, maybe not.

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5) 1:25 PM. Here it is, a band of precipitating clouds overhead. Now the ONLY question remaining, as you gaze upwind at Twin Peaks clearly visible through the precip and virga is, how much will there be? None? Or as much as a “trace”? Measurable is out of the question, looking at this scene below the clouds. Most of the visibility degradation is due to dusty air, not precip. Darn. (Amaze your friends with skills like this! Well, maybe not.)

6) 3:03 PM. The End is Near

7) 7:06 PM. Nice sunset with traces of Cirrus and Ac len on the horizon, driblets from a storm striking the Pac NW. Isn’t there always a storm striking the Pac NW? I digress again.

Man, I could go on about the weather maps of yesterday, but will quit here.

The end.

If you REALLY want to see how it went, take a look at the U of A time lapse video here.

“Oh so pretty….”

You know the rest of the words to this song, the punch line, “…pretty ugly.” Yes, who can forget Johnny Rotten….?

Gorgeous clouds yesterday, but no rain is going to follow them (the “ugly” part)! I had really hoped for a splotch of glaciating Stratocumulus clouds this morning after the great display of….the tongue twister, Altocumulus (Ac) perlucidus undulatus, a mid-level cloud with a honey-comb of elements (“perlucidus”), and those elements also aligned in rows (“undulatus”). If you looked off toward Twin Peaks, you saw that the the back edge to these clouds was very smooth looking and did not advance toward us. That was an Ac lenticularis cloud that started the whole shebang. That lenticular cloud, as often happens, devolved into little cloudlets and rows; its smooth lenticular form devolving into cloudlets that trailed downwind over us here in Catalina. See pretty pictures below. One has the crescent moon in it.

Now it looks “pretty ugly” here for rain since there are no clouds this AM! “Dang”, as a friend would say.

Why get excited about the chance of a sprinkle, or at least some pretty virga this morning because of the two layers of clouds yesterday afternoon? No model indicated any rain. First, it doesn’t happen often, but to HELL with models, they can be WRONG. Don’t bet against them too often, though. You will lose everything.

So, if you were just eye-balling the movement of those two cloud layers later yesterday afternoon and using the crescent moon as your fix, you saw that those mid-level Ac clouds were jetting along at a tremendous speed as they passed it.

How fast?

The NWS balloon sounding indicated that at the height of those pretty Ac clouds, about 20,000 feet above ground level, they were blowing along at no less than 80-90 mph (70-75 knots)! This is a really strong jet for May! And it indicated that the jet stream must be right over us, or darn close, and it was blowing from the SW. If you no doubt know, Buys-Ballots Law, in the northern hemisphere means that a low or trough is to the west of you, and in this case; above you, not at ground level since you’re looking at higher clouds.

Also, the small Cumulus were beginning to cluster into Stratocumulus over the Catalina Mountains. Getting pumped because there movement was showing more southerly now; the wind was more southerly at that level than it had been in the morning, also suggesting the influence of the trough to the west. Here they are. If you really want to relive yesterday’s clouds, particular in the afternoon and evening, our friends at the U of Arizona Wildcat Department of Atmospheric Meteorology have captured them

here. For the really sharpies who DO go here, you’ll see that these cloudlets were further devolving in this time lapse to “ghosts” of their former droplet selves in the form of barely visible, icy little veils as they exit the area. So, can you guess the temperature of those clouds? Piece a cake: probably -20 C or less (-4 F or less). Sounding indicates -20 C, BTW.

Perhaps, I mused yesterday afternoon in a bout of wishful thinking, that in the core of that trough heading for us, there’ll be a smidgeon of Pacific moisture left within its interior, enough for some thicker lower clouds than now, and those clouds will be cold enough, too, so that they will form ice inside them and we’ll see some virga (trails of snow fall out of them) or get a sprinkle (in spite of what the models were saying)! Many of you will remember that according to Willis and Rangno (1971–Final Report to the Bureau of Reclamation by EG&G, Inc) that rain can only fall in the wintertime here when you are in the interior of a trough. I’m sure many of you have this report, and can look it up jf you don’t remember.

Well, we should still see a few isolated Cumulus around, small ones, maybe as big as “mediocris” stage (1 km thick or so, 3300 feet). And, with the coldest air over us this afternoon and evening, I am going to stick with an expectation of some ice in those clouds! And you will here about it tomorrow if there is one crystal up there!

Finally, for cloud technicians, how cold will it have to get at cloud top to have ice in those small clouds around here in Arizona today? Well, between about -10 and -15 C (14 to 5 F)–this is somewhat higher than for those mid-level clouds. So we will check that out tomorrow, too!

“The end”, unless I think of something else later.

Footnote: It now appears that last night’s model run of the “Beowulf Cluster” at the U of A has some precip on the Catalinas, between 3-4 PM LST today. Interesting that after I had this thought based on a crude conceptual model, that the “Cluster” would now have that thought as well…. Hmmmm.

A short rant about another “hide the decline” incident in the climate domain with a short rebuttal

Advisory

If you are queasy, don’t like reading about what the author perceives as “broken science”, hit the back button now.

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Background:

1) The “Hide the decline” phrase alluded to in the title above came out of the “climategate” e-mails. Specifically, “hiding the decline” was about climate scientists deliberately hiding a recent divergence between tree ring widths, ones that they were using as temperature proxies for a record of the past climate over many hundreds of years, and measured temperatures over the past 50 years or so. Those miscreant scientists wanted to hide a divergence in those two parameters; namely, the tree ring widths were not responding in the same way in modern times as those scientists had assumed they did over in their past temperature reconstruction. This divergence, or as they called it, a “decline” in the quality of the relationship between those two parameters was embarassing because if it was pointed out, it would have raised the need for tricky discussions about the use of tree rings to reconstruct the past several hundred years of temperature. (Please read The Hockey Stick Illusion by A. W. Montford and Climategate–The Crutape Letters by Steven Mosher and Thomas W. Fuller, for the awful details about what these climate scientists were doing.)

2) Point of view of the writer: Still on the GW bandwagon, if grudgingly, due to the erosion of ideals of science in that domain. What are those ideals? Go to the NAS and their pub, “On Being a Scientist“, a primer for those considering a science career. There are some senior scientists in the climate domain who need to go back and read this.

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Complaint Department

Another apparent “hide the decline” chapter in addition to the one described above has just been encountered by the author when a friend sent a link to the University of Alaska’s website on climate change.

What “decline” was hidden you ask? The temperature one since the 1920s and 1930s in AK.

http://www.atmos.washington.edu/marka/tmean.alaska.annual.1925-1976.gif

Now the plot for the period of supposed fast runnup of temperatures due to CO2, the “blade” of the infamous “Hockey Stick” for AK after 1976:

http://www.atmos.washington.edu/marka/tmean.alaska.annual.1977-2010.gif

See anything going on there with the temperature? Where’s the “blade”, the sharp runnup in temperatures at these sites?

Nope, you don’t see anything going on except for three very warm years in the early 2000s followed by cooler years up to the present.

So why would the University of Alaska edit their temperature record on the web to show only a rise in temperature that begins with the cold-in-the-Arctic spell of the late 1940s and 1950s, and omit the earlier warm spell in Alaska? Perhaps they want the public to think that no one had a thermometer before 1950 in Alaska. It would seem like it.

But, in reality, of course, just as the “hide the decline” climate scientists tried to avoid tricky discussions about tree rings and temperatures, ones that would inevitably lead to unsatisfactory conclusions, the folks at the U of AK apparently decided that they did not want the public who visit their web site to know that it was quite warm in Alaska prior to the late 1940s, indeed warmth that rivals the warmth of the 1990s into the early 2000s.

How would they explain that warmth? Not very easily because then natural variations in temperature, ones that are not explicable today, would have to be addressed head on. This would raise havoc with their “straw man” simple rise in temperature graph that begins in the 1950s in an apparent attempt to demonstrate the monolithic effect of global warming in Alaska.

To reprise a comment I left weeks ago on Judy Curry’s Climate Etc web site, this except from the Federal Trade Commission on deception in the consumer realm. It should be applied to science reporting, and I am fervently hoping that the American Meteorological Society will adopt this in the Code of Ethics (aka, “Guidelines for Professiosnal Conduct”). The FTC statement below, re-written for science, is being considered by the AMS for inclusion in their Guidelines:

“Certain elements undergird all deception cases. First, there must be a representation, omission or practice that is likely to mislead the consumer.”

When I see a graph like the one shown on the U of AK climate website it makes me think that today we are better protected as consumers of goods than we are as “consumers” of science.

The U of AK temperature graph is clearly meant to “mislead” those ignorant of the AK climate prior to 1949. Good, conscientious science MANDATES that all of the data be shown on an educational site like that at the U of AK. After that, they can show any graph they want, including the edited temperature graph that begins in 1949. Then, if they can, explain why the edited one is so much better than showing ALL OF THE TEMPERATURE DATA THEY HAVE. No one would have a problem with that.

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Acknowledgements: The graphs of Arctic temperatures that are contrasted with that shown on the U of AK website are due to Mark Albright who has unceasingly worked to “clarify” so many dubious/exaggerated climate claims out there. Mark is something of a hero to me for this work. As are other scrutinizers of climate claims and data like McIntrye, Montford, Watts, Michaels, Ballinger, Judy Curry, Lindzen, Pielke, Sr., Jr. and so many more for their courage in taking on dubious “fire in the theatre” climate science claims in the first place. We are all the better off for it, even those of us like me who still think that we have a gradually “global warming” future ahead with natural meanderings along the way.

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Comment received at Word Press by someone not selling me something about this “rant”. This expert says that I went too far re U of AK and GW. Must be posted since it makes some astute observations that I missed in my “heat”, so here it is.

“if you read the text on the university of Alaska’s web-site on “temperature change in Alaska” you’ll see that they emphasize the step-like change in the late 1970s and the PDO — and contrast this with what you might expect as a consequence of increasing trends in CO2 concentrations:

“Considering just a linear trend can mask some important variability characteristics in the time series. The figure at right shows clearly that this trend is non-linear: a linear trend might have been expected from the fairly steady observed increase of CO₂ during this time period. The figure shows the temperature departure from the long-term mean (1949-2009) for all stations. It can be seen that there are large variations from year to year and the 5-year moving average demonstrates large increase in 1976. The period 1949 to 1975 was substantially colder than the period from 1977 to 2009, however since 1977 little additional warming has occurred in Alaska with the exception of Barrow and a few other locations. The stepwise shift appearing in the temperature data in 1976 corresponds to a phase shift of the Pacific Decadal Oscillation from a negative phase to a positive phase. Synoptic conditions with the positive phase tend to consist of increased southerly flow and warm air advection into Alaska during the winter, resulting in positive temperature anomalies.“

Doesn’t sound like they are trying to sell the idea of anthropogenic climate change to me, but maybe that’s just me.

There are some locations with Alaska station data that begin prior to the 1940s, you can access some of these from the Alaska Climate Research Center’s web-site at:

http://climate.gi.alaska.edu/

with a table of station links to time series plots at

http://climate.gi.alaska.edu/Climate/Location/TimeSeries/index.html“

Climate change: what they were saying, 1974

An early anticipation of a possible climate castastrophy

One of the great books of our time on weather modification and climate change came out in 1974: Weather and Climate Modification by Wiley-Interscience Press. It was edited by Wilmot N. Hess, Director of the Environmental Research Labs under NOAA. Hess oversaw 11 ERL programs. The contributors to this book read like a who’s who of those fields back then. The discussion of climate and climate change in this volume involves Joseph Smagorinsky on Global Atmospheric Modeling and the Numerical Simulation of Climate, Les Machta and K. Telegadas on Inadvertent Large Scale Weather Modification, and Helmut Landsberg on Inadvertent Atmospheric Modification through Urbanization–the heat island phenomena. The book was reviewed by numerous equally outstanding scientists of that era, some of whom are still active today. In re-reading this volume, meant to bring a sophisticated lay audience up to date on progress in these fields in 1974, I came across this introduction to Section F on global climate, likely written by Hess, p631-632. Please pay particular attention to the phrase below, “..the majority of participants…” at the end of the first paragraph.

I only point this out because there has been a bit of an attempt to “re-write history” regarding what our best scientists were thinking in those days when the earth’s temperature was in decline, one that began around 1940 or so, a decline that continued into the 1970s with no explanation and counter to increases in CO2 concentrations of those days. Much WAS published concerning CO2 and about its global warming affect, but it wasn’t being observed. Mostly, it was just EASY to perturb the atmosphere in the crude models with something like CO2 with its well-known radiative attributes, hence, maybe get a publication. However, not much else was known about what perturbed the exceedingly complex global climate system and caused the modest temperature meanderings, such as those shown in the third insert.

Yes, its true. Back then (late 60s into the 70s) we were starting to think about global cooling in a visceral way based on obs.

When I say, “we”, I am not referring to myself; I was merely a forecaster-meteorologist with in a large randomized cloud seeding experiment in those days in Durango, Colorado. Weather and Climate Modification was important to me in the years after 1974 because of the sections on cloud seeding, not because of the climate change discussion here which I have re-discovered. (Please excuse the highlighting, done decades ago.)

Below (third insert) is the northern and southern hemisphere’s mean temperature record as deduced by NOAA’s J. Murray Mitchell in those days; these charts appear on p719 of this volume, and were well known at the time. Its easy to see from these graphs why there was so much concern about global cooling in those days when you look at the decline in both hemispheric temperatures after 1940.

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Another bit of interest today is the essay by Machta and Telegadas (Chapter 19, p687) in this book. Their essay concludes with a summary by H. H. Lamb (a well-known East Anglia University climate researcher) that contains predictions of NATURAL (emphasized by the present writer) climatic changes and a brief evaluation of those predictions.

What was particularly remarkable was the evaluation, apparently by Lamb, in the section, “Actual Forecasts“. In this section, seven attempts to forecast the future climate from periodicities deduced in past data are briefly evaluated. In today’s lingo, some of these efforts might be called early detections of pressure “oscillations”, that is, shifts in modes of circulation patterns, where high and low pressures like to reside (footnote). These “actual forecasts”, ones that appeared in the journal literature, were based on such parameters as changes in circulation patterns deduced over decades, patterns in oxygen and hydrogen isotope ratios in ice cores that were then subject to Fourier analysis, climate forecasts based on projected sunspot activity, another on particle radiation from expected solar flares, patterns of “meridionality” or, north and south components in the wind, and “local” circulation patterns over Europe, and that latter in a paper published in 1939! And, of course, the old standby, tree ring patterns, again looking for harmonics or cycles in those data. Most of this kind work, deducing cycles in past data in the way that it was done in these papers would be taken with a grain of salt, or not taken seriously at all.

SO, WHY even mention these studies?

Lamb finds most of the predictions were CORRECT in anticipating the colder weather ahead over coming decades after these studies were published! Its really stupefying to read this section today and see an assessment of “correct” assigned to these forecasts based on no real underlying physical mechanism, such as why did the wind, the pressure pattern change, or on sunspots? (It was interesting to note that the sunspot based forecast was deemed “correct” for weather, but totally wrong on sunspot activity!)

Well, it does make one wonder how these forecasts could have been correct. Were a few researchers on to something that we have missed, or have also “re-discovered”, framing our findings today in more sophisticated terms such as “oscillations” instead of “cycles”?

Or were these forecasts “correct” because they were the only ones of hundreds of such forecasts (in which it would be expected that a few would be “correct” just by chance)? The authors of this Chapter 19 do not divulge how many forecasts were examined.

However, those early forecasts based on circulation pattern changes over decades, should grab the attention of today’s “oscillators” if they haven’t already.

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Footnote: It sometimes seems as though almost every climate researcher today has his own personal “oscillation”, from the Pacific Decadal Oscillation, North Atlantic Oscillation, Arctic Oscillation, Southern Oscillation, on and on. More will be reported. (Maybe I should have one!) ((Actually, I do have my own climate oscillation, but its not been published, probably never will be.))

Yet another nice sunset

This shot, yesterday just after 7 PM. Light snow (virga) is falling from relatively thick Altocumulus (opacus) clouds. Just above the horizon you can see some little turrets poking up from a row of cloud bases making those clouds Altocumulus castellanus.

Bases of these clouds, according to the balloon data obtained from Tucson Int AP indicated that the bases of these clouds were at about 13,000 feet above us here in Catalina, and the temperature was about 15 degrees F (about -10 C). The tops of the clouds were about 18,000 feet above us, or at a chilly -5 F (-20 C), hence the thin, red-orange curtains of light snow illuminated by the setting sun below these clouds.

The clearing on the horizon marked the last of this “mid-level” moisture that streamed over us here in Catalina yesterday as an upper level bend in the winds, called a “trough” was passing by.

Below is a weather map of the winds (blowing along the green lines) at around 30,000 feet (300 “millibars” of pressure) and the clouds as shown on the satellite imagery. If you look closely where the TUS data is, you can see a little fluff of cloud that made our sunset. A loop of the whole sequence can be found here from our friends at the University of Washington Huskies’ Department of Atmospheric Sciences.

Speaking of the Huskies, here’s what it was like today in Seattle, my former home.

The end.

“Pretty in Pink”

Well, “tending” toward pink, anyway… But who remembers the Psychedelic Furs and what their song title alluded anyway? Of course, no one. But I liked its dark sound. Oh, well.

But here it is, that “pretty in pink” sky (2 shots) from yesterday evening in case you missed it. Again these are Cirrus and Altostratus ice clouds with an isolated exception of Altocumulus lenticularis (just above horizon in the second shot), which is composed of droplets. The second photo is a zoomed shot of the stack (several pancakes on top of one another) of a lenticular cloud off to the NW of Catalina.

Those lenticular clouds should always bring some excitement that things are changing, maybe heading toward a rain situation. Rain did fall in the northern third of AZ when these Ac len clouds were present yesterday evening.

Why the excitement?

While these clouds don’t rain themselves, they are usually precursors of rain situations in the region because they illustrate that the winds aloft are relatively strong, the air in the “mid-levels” (roughly 10 to 20 thousand feet above the ground) has some moisture, and they indicate the kind of “stable” conditions in the mid-levels in their flatness, “pancaked-ness”, that precedes fronts. Of course, we also had those moderate SW winds yesterday that also indicates that “something is going on”.

And something was going on as a cold front traversed the Great Basin yesterday. Even this morning there is still precip in NW New Mexico as of 6:30 AM LST this morning.

And how do we know a new air mass came by?

The temperature change over the last 24 hours, from yesterday at this time to today at this time is one of the best ways of keeping track of fronts and changes in air masses. Here is a plot of that 24 h change. As you can see, the drop in temperature, while it has occurred at my gravel driveway (-5 F) is not quite here in Catalina (though it really is) according to the venerable The Weather Channel’s data which does not have my data (or pressure trace which has the usual sharp rise following a cold front–that heavier, denser, cold air is pushing down on all of us this morning and on my aneroid (not a body part, but a name for a barometer, BTW.)

The last shot here is what the clouds looked like before sunset. Lots of gray indicating they are quite thick and fall into the Altostratus category even though they are very high. Cirrus, by definition, cannot have this much grayness. But, when you see this kind of late afternoon sky, you can almost always count on a great evening scene, that sky especially “pretty in pink.”

Don’t see too many misspelled words, bad sentence structure and other grammatical lapses so will post this now…

In case you missed it…yesterday morning’s sunrise

A belated post, to be sure

Yesterday morning’s sounding when the Altocumulus clouds were overhead. Bases about -18 C, tops -27 C. Lots of ice visible along with widespread virga. Whenever you see this much ice in small Altocumulus clouds like these, you should automatically assume that the temperature at the top is less than -20 C.

Usefulness of this information in everyday conversation, a module I call, “Conversational Meteorology.”

The scene: you’re walking/hiking with a friend on a warm morning when sunrise occurs. You see these clouds. The conversation has died off since you’ve been walking for several hours. You’re looking for something to say to re-energize the conversation. Suddenly, you look up and see this scene below and blurt out, “Man, those clouds are cold!” The volume of your blurtation has surprised even you, and startles your friend who was thinking about that tortoise on the trail ahead of you. You rattle on about how cold the clouds with a followup, “Man, they must be at least colder than -20 C!” Your friend seems puzzled at your excitement, but listens politely’ after all he is your friend. You quickly add, “Almost every cloud has some snow coming out of it, no matter how small it is! Wow!” Your friend, now saturated with your exuberances, asks if you saw the last episode of NCIS last night?

The end.

Altocumulus overhead; sunrise photo op coming

An upper level disturbance is going to pass over us today (see map with bend in the winds at 30,000 feet coming toward us here), but the only thing we’ll notice is some nice Altocumulus clouds floating over followed by a clearing later on today. Those clouds are overhead now in the pre-dawn hours, we’ll likely have another one of those gaudy, too-colorful-to-be-believed-like-one-of-those-velvet-art-pieces-sold-on-street-corners-sunrises that we are known for here in AZ. Might even have a little virga with them. Lucky us! So you should have your camera battery charged up in case this one’s really good! You’ll want to add to your collection of 78,000 or so fabulous sunrises and sunsets in Catalina, AZ…like I will.

Note, too, that in this depiction of winds (the wind is flowing along the lines) that where the wind has a “U” shape, there are clouds to the east of those bends for the most part, that is, ahead of where that “U” shape in the winds is headed, and not much to its rearward, or in most cases, immediately to the west of the “U” bends in the winds. We will see the “ahead” portion of a “U” in the winds above us, and the clearing that comes afterward, all today!

The end (for now).

How Cirrus clouds grow up to be “uncinus” ones

What a glorious day yesterday was, if about 20 degrees F below normal! So much new snow on the Catalinas down to such low elevations for almost mid-April. Some sites in the Catalina Mountains reported over an inch of water content in that snow! Yay! Here in Catalina we had a bountiful 0.69 inches, more just to the north and west. Choose April 9th, and “Tucson” in drop down menu on this U of AZCats rain page to see the amounts around here. Truly a remarkable storm for April.

About those Cirrus “uncinus” clouds

How many saw those fabulous Cirrus clouds in the morning? Once in awhile, during the passage of Cirrus clouds you get to see how those long, delicate strands you often see by themselves, get that way, from their initial appearance to the end point; the long strands. Usually you can’t because Cirrus clouds are traveling so rapidly up there at 30,000 feet or so that they have gone over the horizon before much happens. Yesterday, an example of that “life cycle” passed overhead, moving from the W to the E at about 70-80 mph or so. In all of the photos below, the subject Cirrus cloud is in the upper right part of the photo.

Here then is most of the life cycle of a Cirrus cloud as it happened over Catalina. The starting point is that whitist cluster of little cloudlets, upper right. Those strands of Cirrus below that and that appear in rows to the lower left, are old dying cirrus clouds at the end of their life cycle. That top cluster in 1) has just appeared, probably only about 10 min old, and now the larger ice crystals are JUST beginning to leave the origin zone, much like a hiker reeling out rope to a friend stuck on a rock below. Those strands are like that rope having been let go of, then caught by the wind on its way down and stretched to full length while falling through the air. The remaining photos 3)-overhead view and 4)–leaving the scene, show that process continuing as the top cluster fades with longer and longer filaments of ice. In 4), you can see one strand in a side view as it speeds away revealing the lack of wind shear (changes in wind direction and speed) in the layer in which the cloudlets first formed. How do I and you know that? That one tiny filament that is straight up and down pretty much reveals that

You can now see how and why these delicate strands are there. Each long “rope” of ice represents one of the initial tufts that appeared within the cluster; each one has a contribution to make, a “rope” of ice to send downward. Almost always, except in deep storms, the strand of ice encounters drier and drier air and the crystals fall at lower and lower speeds until its negligible. The bottom, or lowest part of these strands then, have the tiniest of ice crystals, and the tail of the strand at this lowest point may appear almost horizontal if you could be up there.

The end.